CGExprConstant.cpp source code [clang_source_code/lib/CodeGen/CGExprConstant.cpp]

1	//===--- CGExprConstant.cpp - Emit LLVM Code from Constant Expressions ----===//
2	//
3	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4	// See https://llvm.org/LICENSE.txt for license information.
5	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6	//
7	//===----------------------------------------------------------------------===//
8	//
9	// This contains code to emit Constant Expr nodes as LLVM code.
10	//
11	//===----------------------------------------------------------------------===//
12
13	#include "CodeGenFunction.h"
14	#include "CGCXXABI.h"
15	#include "CGObjCRuntime.h"
16	#include "CGRecordLayout.h"
17	#include "CodeGenModule.h"
18	#include "ConstantEmitter.h"
19	#include "TargetInfo.h"
20	#include "clang/AST/APValue.h"
21	#include "clang/AST/ASTContext.h"
22	#include "clang/AST/RecordLayout.h"
23	#include "clang/AST/StmtVisitor.h"
24	#include "clang/Basic/Builtins.h"
25	#include "llvm/IR/Constants.h"
26	#include "llvm/IR/DataLayout.h"
27	#include "llvm/IR/Function.h"
28	#include "llvm/IR/GlobalVariable.h"
29	using namespace clang;
30	using namespace CodeGen;
31
32	//===----------------------------------------------------------------------===//
33	// ConstStructBuilder
34	//===----------------------------------------------------------------------===//
35
36	namespace {
37	class ConstExprEmitter;
38	class ConstStructBuilder {
39	CodeGenModule &CGM;
40	ConstantEmitter &Emitter;
41
42	bool Packed;
43	CharUnits NextFieldOffsetInChars;
44	CharUnits LLVMStructAlignment;
45	SmallVector<llvm::Constant *, 32> Elements;
46	public:
47	static llvm::Constant *BuildStruct(ConstantEmitter &Emitter,
48	ConstExprEmitter *ExprEmitter,
49	llvm::Constant *Base,
50	InitListExpr *Updater,
51	QualType ValTy);
52	static llvm::Constant *BuildStruct(ConstantEmitter &Emitter,
53	InitListExpr *ILE, QualType StructTy);
54	static llvm::Constant *BuildStruct(ConstantEmitter &Emitter,
55	const APValue &Value, QualType ValTy);
56
57	private:
58	ConstStructBuilder(ConstantEmitter &emitter)
59	: CGM(emitter.CGM), Emitter(emitter), Packed(false),
60	NextFieldOffsetInChars(CharUnits::Zero()),
61	LLVMStructAlignment(CharUnits::One()) { }
62
63	void AppendField(const FieldDecl *Field, uint64_t FieldOffset,
64	llvm::Constant *InitExpr);
65
66	void AppendBytes(CharUnits FieldOffsetInChars, llvm::Constant *InitCst);
67
68	void AppendBitField(const FieldDecl *Field, uint64_t FieldOffset,
69	llvm::ConstantInt *InitExpr);
70
71	void AppendPadding(CharUnits PadSize);
72
73	void AppendTailPadding(CharUnits RecordSize);
74
75	void ConvertStructToPacked();
76
77	bool Build(InitListExpr *ILE);
78	bool Build(ConstExprEmitter Emitter, llvm::Constant Base,
79	InitListExpr *Updater);
80	bool Build(const APValue &Val, const RecordDecl *RD, bool IsPrimaryBase,
81	const CXXRecordDecl *VTableClass, CharUnits BaseOffset);
82	llvm::Constant *Finalize(QualType Ty);
83
84	CharUnits getAlignment(const llvm::Constant *C) const {
85	if (Packed) return CharUnits::One();
86	return CharUnits::fromQuantity(
87	CGM.getDataLayout().getABITypeAlignment(C->getType()));
88	}
89
90	CharUnits getSizeInChars(const llvm::Constant *C) const {
91	return CharUnits::fromQuantity(
92	CGM.getDataLayout().getTypeAllocSize(C->getType()));
93	}
94	};
95
96	void ConstStructBuilder::
97	AppendField(const FieldDecl *Field, uint64_t FieldOffset,
98	llvm::Constant *InitCst) {
99	const ASTContext &Context = CGM.getContext();
100
101	CharUnits FieldOffsetInChars = Context.toCharUnitsFromBits(FieldOffset);
102
103	AppendBytes(FieldOffsetInChars, InitCst);
104	}
105
106	void ConstStructBuilder::
107	AppendBytes(CharUnits FieldOffsetInChars, llvm::Constant *InitCst) {
108
109	(0) . __assert_fail ("NextFieldOffsetInChars <= FieldOffsetInChars && \"Field offset mismatch!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 110, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(NextFieldOffsetInChars <= FieldOffsetInChars
110	(0) . __assert_fail ("NextFieldOffsetInChars <= FieldOffsetInChars && \"Field offset mismatch!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 110, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> && "Field offset mismatch!");
111
112	CharUnits FieldAlignment = getAlignment(InitCst);
113
114	// Round up the field offset to the alignment of the field type.
115	CharUnits AlignedNextFieldOffsetInChars =
116	NextFieldOffsetInChars.alignTo(FieldAlignment);
117
118	if (AlignedNextFieldOffsetInChars < FieldOffsetInChars) {
119	// We need to append padding.
120	AppendPadding(FieldOffsetInChars - NextFieldOffsetInChars);
121
122	(0) . __assert_fail ("NextFieldOffsetInChars == FieldOffsetInChars && \"Did not add enough padding!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 123, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(NextFieldOffsetInChars == FieldOffsetInChars &&
123	(0) . __assert_fail ("NextFieldOffsetInChars == FieldOffsetInChars && \"Did not add enough padding!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 123, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Did not add enough padding!");
124
125	AlignedNextFieldOffsetInChars =
126	NextFieldOffsetInChars.alignTo(FieldAlignment);
127	}
128
129	if (AlignedNextFieldOffsetInChars > FieldOffsetInChars) {
130	(0) . __assert_fail ("!Packed && \"Alignment is wrong even with a packed struct!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 130, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(!Packed && "Alignment is wrong even with a packed struct!");
131
132	// Convert the struct to a packed struct.
133	ConvertStructToPacked();
134
135	// After we pack the struct, we may need to insert padding.
136	if (NextFieldOffsetInChars < FieldOffsetInChars) {
137	// We need to append padding.
138	AppendPadding(FieldOffsetInChars - NextFieldOffsetInChars);
139
140	(0) . __assert_fail ("NextFieldOffsetInChars == FieldOffsetInChars && \"Did not add enough padding!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 141, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(NextFieldOffsetInChars == FieldOffsetInChars &&
141	(0) . __assert_fail ("NextFieldOffsetInChars == FieldOffsetInChars && \"Did not add enough padding!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 141, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Did not add enough padding!");
142	}
143	AlignedNextFieldOffsetInChars = NextFieldOffsetInChars;
144	}
145
146	// Add the field.
147	Elements.push_back(InitCst);
148	NextFieldOffsetInChars = AlignedNextFieldOffsetInChars +
149	getSizeInChars(InitCst);
150
151	if (Packed)
152	(0) . __assert_fail ("LLVMStructAlignment == CharUnits..One() && \"Packed struct not byte-aligned!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 153, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(LLVMStructAlignment == CharUnits::One() &&
153	(0) . __assert_fail ("LLVMStructAlignment == CharUnits..One() && \"Packed struct not byte-aligned!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 153, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Packed struct not byte-aligned!");
154	else
155	LLVMStructAlignment = std::max(LLVMStructAlignment, FieldAlignment);
156	}
157
158	void ConstStructBuilder::AppendBitField(const FieldDecl *Field,
159	uint64_t FieldOffset,
160	llvm::ConstantInt *CI) {
161	const ASTContext &Context = CGM.getContext();
162	const uint64_t CharWidth = Context.getCharWidth();
163	uint64_t NextFieldOffsetInBits = Context.toBits(NextFieldOffsetInChars);
164	if (FieldOffset > NextFieldOffsetInBits) {
165	// We need to add padding.
166	CharUnits PadSize = Context.toCharUnitsFromBits(
167	llvm::alignTo(FieldOffset - NextFieldOffsetInBits,
168	Context.getTargetInfo().getCharAlign()));
169
170	AppendPadding(PadSize);
171	}
172
173	uint64_t FieldSize = Field->getBitWidthValue(Context);
174
175	llvm::APInt FieldValue = CI->getValue();
176
177	// Promote the size of FieldValue if necessary
178	// FIXME: This should never occur, but currently it can because initializer
179	// constants are cast to bool, and because clang is not enforcing bitfield
180	// width limits.
181	if (FieldSize > FieldValue.getBitWidth())
182	FieldValue = FieldValue.zext(FieldSize);
183
184	// Truncate the size of FieldValue to the bit field size.
185	if (FieldSize < FieldValue.getBitWidth())
186	FieldValue = FieldValue.trunc(FieldSize);
187
188	NextFieldOffsetInBits = Context.toBits(NextFieldOffsetInChars);
189	if (FieldOffset < NextFieldOffsetInBits) {
190	// Either part of the field or the entire field can go into the previous
191	// byte.
192	(0) . __assert_fail ("!Elements.empty() && \"Elements can't be empty!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 192, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(!Elements.empty() && "Elements can't be empty!");
193
194	unsigned BitsInPreviousByte = NextFieldOffsetInBits - FieldOffset;
195
196	bool FitsCompletelyInPreviousByte =
197	BitsInPreviousByte >= FieldValue.getBitWidth();
198
199	llvm::APInt Tmp = FieldValue;
200
201	if (!FitsCompletelyInPreviousByte) {
202	unsigned NewFieldWidth = FieldSize - BitsInPreviousByte;
203
204	if (CGM.getDataLayout().isBigEndian()) {
205	Tmp.lshrInPlace(NewFieldWidth);
206	Tmp = Tmp.trunc(BitsInPreviousByte);
207
208	// We want the remaining high bits.
209	FieldValue = FieldValue.trunc(NewFieldWidth);
210	} else {
211	Tmp = Tmp.trunc(BitsInPreviousByte);
212
213	// We want the remaining low bits.
214	FieldValue.lshrInPlace(BitsInPreviousByte);
215	FieldValue = FieldValue.trunc(NewFieldWidth);
216	}
217	}
218
219	Tmp = Tmp.zext(CharWidth);
220	if (CGM.getDataLayout().isBigEndian()) {
221	if (FitsCompletelyInPreviousByte)
222	Tmp = Tmp.shl(BitsInPreviousByte - FieldValue.getBitWidth());
223	} else {
224	Tmp = Tmp.shl(CharWidth - BitsInPreviousByte);
225	}
226
227	// 'or' in the bits that go into the previous byte.
228	llvm::Value *LastElt = Elements.back();
229	if (llvm::ConstantInt *Val = dyn_cast<llvm::ConstantInt>(LastElt))
230	Tmp \|= Val->getValue();
231	else {
232	(LastElt)", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 232, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(isa<llvm::UndefValue>(LastElt));
233	// If there is an undef field that we're adding to, it can either be a
234	// scalar undef (in which case, we just replace it with our field) or it
235	// is an array. If it is an array, we have to pull one byte off the
236	// array so that the other undef bytes stay around.
237	if (!isa<llvm::IntegerType>(LastElt->getType())) {
238	// The undef padding will be a multibyte array, create a new smaller
239	// padding and then an hole for our i8 to get plopped into.
240	(0) . __assert_fail ("isa(LastElt->getType()) && \"Expected array padding of undefs\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 241, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(isa<llvm::ArrayType>(LastElt->getType()) &&
241	(0) . __assert_fail ("isa(LastElt->getType()) && \"Expected array padding of undefs\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 241, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Expected array padding of undefs");
242	llvm::ArrayType *AT = cast<llvm::ArrayType>(LastElt->getType());
243	(0) . __assert_fail ("AT->getElementType()->isIntegerTy(CharWidth) && AT->getNumElements() != 0 && \"Expected non-empty array padding of undefs\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 245, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(AT->getElementType()->isIntegerTy(CharWidth) &&
244	(0) . __assert_fail ("AT->getElementType()->isIntegerTy(CharWidth) && AT->getNumElements() != 0 && \"Expected non-empty array padding of undefs\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 245, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> AT->getNumElements() != 0 &&
245	(0) . __assert_fail ("AT->getElementType()->isIntegerTy(CharWidth) && AT->getNumElements() != 0 && \"Expected non-empty array padding of undefs\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 245, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Expected non-empty array padding of undefs");
246
247	// Remove the padding array.
248	NextFieldOffsetInChars -= CharUnits::fromQuantity(AT->getNumElements());
249	Elements.pop_back();
250
251	// Add the padding back in two chunks.
252	AppendPadding(CharUnits::fromQuantity(AT->getNumElements()-1));
253	AppendPadding(CharUnits::One());
254	(0) . __assert_fail ("isa(Elements.back()) && Elements.back()->getType()->isIntegerTy(CharWidth) && \"Padding addition didn't work right\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 256, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(isa<llvm::UndefValue>(Elements.back()) &&
255	(0) . __assert_fail ("isa(Elements.back()) && Elements.back()->getType()->isIntegerTy(CharWidth) && \"Padding addition didn't work right\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 256, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> Elements.back()->getType()->isIntegerTy(CharWidth) &&
256	(0) . __assert_fail ("isa(Elements.back()) && Elements.back()->getType()->isIntegerTy(CharWidth) && \"Padding addition didn't work right\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 256, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Padding addition didn't work right");
257	}
258	}
259
260	Elements.back() = llvm::ConstantInt::get(CGM.getLLVMContext(), Tmp);
261
262	if (FitsCompletelyInPreviousByte)
263	return;
264	}
265
266	while (FieldValue.getBitWidth() > CharWidth) {
267	llvm::APInt Tmp;
268
269	if (CGM.getDataLayout().isBigEndian()) {
270	// We want the high bits.
271	Tmp =
272	FieldValue.lshr(FieldValue.getBitWidth() - CharWidth).trunc(CharWidth);
273	} else {
274	// We want the low bits.
275	Tmp = FieldValue.trunc(CharWidth);
276
277	FieldValue.lshrInPlace(CharWidth);
278	}
279
280	Elements.push_back(llvm::ConstantInt::get(CGM.getLLVMContext(), Tmp));
281	++NextFieldOffsetInChars;
282
283	FieldValue = FieldValue.trunc(FieldValue.getBitWidth() - CharWidth);
284	}
285
286	(0) . __assert_fail ("FieldValue.getBitWidth() > 0 && \"Should have at least one bit left!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 287, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(FieldValue.getBitWidth() > 0 &&
287	(0) . __assert_fail ("FieldValue.getBitWidth() > 0 && \"Should have at least one bit left!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 287, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Should have at least one bit left!");
288	(0) . __assert_fail ("FieldValue.getBitWidth() <= CharWidth && \"Should not have more than a byte left!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 289, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(FieldValue.getBitWidth() <= CharWidth &&
289	(0) . __assert_fail ("FieldValue.getBitWidth() <= CharWidth && \"Should not have more than a byte left!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 289, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Should not have more than a byte left!");
290
291	if (FieldValue.getBitWidth() < CharWidth) {
292	if (CGM.getDataLayout().isBigEndian()) {
293	unsigned BitWidth = FieldValue.getBitWidth();
294
295	FieldValue = FieldValue.zext(CharWidth) << (CharWidth - BitWidth);
296	} else
297	FieldValue = FieldValue.zext(CharWidth);
298	}
299
300	// Append the last element.
301	Elements.push_back(llvm::ConstantInt::get(CGM.getLLVMContext(),
302	FieldValue));
303	++NextFieldOffsetInChars;
304	}
305
306	void ConstStructBuilder::AppendPadding(CharUnits PadSize) {
307	if (PadSize.isZero())
308	return;
309
310	llvm::Type *Ty = CGM.Int8Ty;
311	if (PadSize > CharUnits::One())
312	Ty = llvm::ArrayType::get(Ty, PadSize.getQuantity());
313
314	llvm::Constant *C = llvm::UndefValue::get(Ty);
315	Elements.push_back(C);
316	(0) . __assert_fail ("getAlignment(C) == CharUnits..One() && \"Padding must have 1 byte alignment!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 317, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(getAlignment(C) == CharUnits::One() &&
317	(0) . __assert_fail ("getAlignment(C) == CharUnits..One() && \"Padding must have 1 byte alignment!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 317, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Padding must have 1 byte alignment!");
318
319	NextFieldOffsetInChars += getSizeInChars(C);
320	}
321
322	void ConstStructBuilder::AppendTailPadding(CharUnits RecordSize) {
323	(0) . __assert_fail ("NextFieldOffsetInChars <= RecordSize && \"Size mismatch!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 324, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(NextFieldOffsetInChars <= RecordSize &&
324	(0) . __assert_fail ("NextFieldOffsetInChars <= RecordSize && \"Size mismatch!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 324, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Size mismatch!");
325
326	AppendPadding(RecordSize - NextFieldOffsetInChars);
327	}
328
329	void ConstStructBuilder::ConvertStructToPacked() {
330	SmallVector<llvm::Constant *, 16> PackedElements;
331	CharUnits ElementOffsetInChars = CharUnits::Zero();
332
333	for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
334	llvm::Constant *C = Elements[i];
335
336	CharUnits ElementAlign = CharUnits::fromQuantity(
337	CGM.getDataLayout().getABITypeAlignment(C->getType()));
338	CharUnits AlignedElementOffsetInChars =
339	ElementOffsetInChars.alignTo(ElementAlign);
340
341	if (AlignedElementOffsetInChars > ElementOffsetInChars) {
342	// We need some padding.
343	CharUnits NumChars =
344	AlignedElementOffsetInChars - ElementOffsetInChars;
345
346	llvm::Type *Ty = CGM.Int8Ty;
347	if (NumChars > CharUnits::One())
348	Ty = llvm::ArrayType::get(Ty, NumChars.getQuantity());
349
350	llvm::Constant *Padding = llvm::UndefValue::get(Ty);
351	PackedElements.push_back(Padding);
352	ElementOffsetInChars += getSizeInChars(Padding);
353	}
354
355	PackedElements.push_back(C);
356	ElementOffsetInChars += getSizeInChars(C);
357	}
358
359	(0) . __assert_fail ("ElementOffsetInChars == NextFieldOffsetInChars && \"Packing the struct changed its size!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 360, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(ElementOffsetInChars == NextFieldOffsetInChars &&
360	(0) . __assert_fail ("ElementOffsetInChars == NextFieldOffsetInChars && \"Packing the struct changed its size!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 360, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Packing the struct changed its size!");
361
362	Elements.swap(PackedElements);
363	LLVMStructAlignment = CharUnits::One();
364	Packed = true;
365	}
366
367	bool ConstStructBuilder::Build(InitListExpr *ILE) {
368	RecordDecl *RD = ILE->getType()->getAs<RecordType>()->getDecl();
369	const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
370
371	unsigned FieldNo = 0;
372	unsigned ElementNo = 0;
373
374	// Bail out if we have base classes. We could support these, but they only
375	// arise in C++1z where we will have already constant folded most interesting
376	// cases. FIXME: There are still a few more cases we can handle this way.
377	if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
378	if (CXXRD->getNumBases())
379	return false;
380
381	for (RecordDecl::field_iterator Field = RD->field_begin(),
382	FieldEnd = RD->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
383	// If this is a union, skip all the fields that aren't being initialized.
384	if (RD->isUnion() && ILE->getInitializedFieldInUnion() != *Field)
385	continue;
386
387	// Don't emit anonymous bitfields, they just affect layout.
388	if (Field->isUnnamedBitfield())
389	continue;
390
391	// Get the initializer. A struct can include fields without initializers,
392	// we just use explicit null values for them.
393	llvm::Constant *EltInit;
394	if (ElementNo < ILE->getNumInits())
395	EltInit = Emitter.tryEmitPrivateForMemory(ILE->getInit(ElementNo++),
396	Field->getType());
397	else
398	EltInit = Emitter.emitNullForMemory(Field->getType());
399
400	if (!EltInit)
401	return false;
402
403	if (!Field->isBitField()) {
404	// Handle non-bitfield members.
405	AppendField(*Field, Layout.getFieldOffset(FieldNo), EltInit);
406	} else {
407	// Otherwise we have a bitfield.
408	if (auto *CI = dyn_cast<llvm::ConstantInt>(EltInit)) {
409	AppendBitField(*Field, Layout.getFieldOffset(FieldNo), CI);
410	} else {
411	// We are trying to initialize a bitfield with a non-trivial constant,
412	// this must require run-time code.
413	return false;
414	}
415	}
416	}
417
418	return true;
419	}
420
421	namespace {
422	struct BaseInfo {
423	BaseInfo(const CXXRecordDecl *Decl, CharUnits Offset, unsigned Index)
424	: Decl(Decl), Offset(Offset), Index(Index) {
425	}
426
427	const CXXRecordDecl *Decl;
428	CharUnits Offset;
429	unsigned Index;
430
431	bool operator<(const BaseInfo &O) const { return Offset < O.Offset; }
432	};
433	}
434
435	bool ConstStructBuilder::Build(const APValue &Val, const RecordDecl *RD,
436	bool IsPrimaryBase,
437	const CXXRecordDecl *VTableClass,
438	CharUnits Offset) {
439	const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
440
441	if (const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD)) {
442	// Add a vtable pointer, if we need one and it hasn't already been added.
443	if (CD->isDynamicClass() && !IsPrimaryBase) {
444	llvm::Constant *VTableAddressPoint =
445	CGM.getCXXABI().getVTableAddressPointForConstExpr(
446	BaseSubobject(CD, Offset), VTableClass);
447	AppendBytes(Offset, VTableAddressPoint);
448	}
449
450	// Accumulate and sort bases, in order to visit them in address order, which
451	// may not be the same as declaration order.
452	SmallVector<BaseInfo, 8> Bases;
453	Bases.reserve(CD->getNumBases());
454	unsigned BaseNo = 0;
455	for (CXXRecordDecl::base_class_const_iterator Base = CD->bases_begin(),
456	BaseEnd = CD->bases_end(); Base != BaseEnd; ++Base, ++BaseNo) {
457	(0) . __assert_fail ("!Base->isVirtual() && \"should not have virtual bases here\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 457, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(!Base->isVirtual() && "should not have virtual bases here");
458	const CXXRecordDecl *BD = Base->getType()->getAsCXXRecordDecl();
459	CharUnits BaseOffset = Layout.getBaseClassOffset(BD);
460	Bases.push_back(BaseInfo(BD, BaseOffset, BaseNo));
461	}
462	std::stable_sort(Bases.begin(), Bases.end());
463
464	for (unsigned I = 0, N = Bases.size(); I != N; ++I) {
465	BaseInfo &Base = Bases[I];
466
467	bool IsPrimaryBase = Layout.getPrimaryBase() == Base.Decl;
468	Build(Val.getStructBase(Base.Index), Base.Decl, IsPrimaryBase,
469	VTableClass, Offset + Base.Offset);
470	}
471	}
472
473	unsigned FieldNo = 0;
474	uint64_t OffsetBits = CGM.getContext().toBits(Offset);
475
476	for (RecordDecl::field_iterator Field = RD->field_begin(),
477	FieldEnd = RD->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
478	// If this is a union, skip all the fields that aren't being initialized.
479	if (RD->isUnion() && Val.getUnionField() != *Field)
480	continue;
481
482	// Don't emit anonymous bitfields, they just affect layout.
483	if (Field->isUnnamedBitfield())
484	continue;
485
486	// Emit the value of the initializer.
487	const APValue &FieldValue =
488	RD->isUnion() ? Val.getUnionValue() : Val.getStructField(FieldNo);
489	llvm::Constant *EltInit =
490	Emitter.tryEmitPrivateForMemory(FieldValue, Field->getType());
491	if (!EltInit)
492	return false;
493
494	if (!Field->isBitField()) {
495	// Handle non-bitfield members.
496	AppendField(*Field, Layout.getFieldOffset(FieldNo) + OffsetBits, EltInit);
497	} else {
498	// Otherwise we have a bitfield.
499	AppendBitField(*Field, Layout.getFieldOffset(FieldNo) + OffsetBits,
500	cast<llvm::ConstantInt>(EltInit));
501	}
502	}
503
504	return true;
505	}
506
507	llvm::Constant *ConstStructBuilder::Finalize(QualType Ty) {
508	RecordDecl *RD = Ty->getAs<RecordType>()->getDecl();
509	const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
510
511	CharUnits LayoutSizeInChars = Layout.getSize();
512
513	if (NextFieldOffsetInChars > LayoutSizeInChars) {
514	// If the struct is bigger than the size of the record type,
515	// we must have a flexible array member at the end.
516	(0) . __assert_fail ("RD->hasFlexibleArrayMember() && \"Must have flexible array member if struct is bigger than type!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 517, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(RD->hasFlexibleArrayMember() &&
517	(0) . __assert_fail ("RD->hasFlexibleArrayMember() && \"Must have flexible array member if struct is bigger than type!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 517, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Must have flexible array member if struct is bigger than type!");
518
519	// No tail padding is necessary.
520	} else {
521	// Append tail padding if necessary.
522	CharUnits LLVMSizeInChars =
523	NextFieldOffsetInChars.alignTo(LLVMStructAlignment);
524
525	if (LLVMSizeInChars != LayoutSizeInChars)
526	AppendTailPadding(LayoutSizeInChars);
527
528	LLVMSizeInChars = NextFieldOffsetInChars.alignTo(LLVMStructAlignment);
529
530	// Check if we need to convert the struct to a packed struct.
531	if (NextFieldOffsetInChars <= LayoutSizeInChars &&
532	LLVMSizeInChars > LayoutSizeInChars) {
533	(0) . __assert_fail ("!Packed && \"Size mismatch!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 533, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(!Packed && "Size mismatch!");
534
535	ConvertStructToPacked();
536	(0) . __assert_fail ("NextFieldOffsetInChars <= LayoutSizeInChars && \"Converting to packed did not help!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 537, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(NextFieldOffsetInChars <= LayoutSizeInChars &&
537	(0) . __assert_fail ("NextFieldOffsetInChars <= LayoutSizeInChars && \"Converting to packed did not help!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 537, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Converting to packed did not help!");
538	}
539
540	LLVMSizeInChars = NextFieldOffsetInChars.alignTo(LLVMStructAlignment);
541
542	(0) . __assert_fail ("LayoutSizeInChars == LLVMSizeInChars && \"Tail padding mismatch!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 543, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(LayoutSizeInChars == LLVMSizeInChars &&
543	(0) . __assert_fail ("LayoutSizeInChars == LLVMSizeInChars && \"Tail padding mismatch!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 543, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Tail padding mismatch!");
544	}
545
546	// Pick the type to use. If the type is layout identical to the ConvertType
547	// type then use it, otherwise use whatever the builder produced for us.
548	llvm::StructType *STy =
549	llvm::ConstantStruct::getTypeForElements(CGM.getLLVMContext(),
550	Elements, Packed);
551	llvm::Type *ValTy = CGM.getTypes().ConvertType(Ty);
552	if (llvm::StructType *ValSTy = dyn_cast<llvm::StructType>(ValTy)) {
553	if (ValSTy->isLayoutIdentical(STy))
554	STy = ValSTy;
555	}
556
557	llvm::Constant *Result = llvm::ConstantStruct::get(STy, Elements);
558
559	(0) . __assert_fail ("NextFieldOffsetInChars.alignTo(getAlignment(Result)) == getSizeInChars(Result) && \"Size mismatch!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 561, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(NextFieldOffsetInChars.alignTo(getAlignment(Result)) ==
560	(0) . __assert_fail ("NextFieldOffsetInChars.alignTo(getAlignment(Result)) == getSizeInChars(Result) && \"Size mismatch!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 561, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> getSizeInChars(Result) &&
561	(0) . __assert_fail ("NextFieldOffsetInChars.alignTo(getAlignment(Result)) == getSizeInChars(Result) && \"Size mismatch!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 561, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Size mismatch!");
562
563	return Result;
564	}
565
566	llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter,
567	ConstExprEmitter *ExprEmitter,
568	llvm::Constant *Base,
569	InitListExpr *Updater,
570	QualType ValTy) {
571	ConstStructBuilder Builder(Emitter);
572	if (!Builder.Build(ExprEmitter, Base, Updater))
573	return nullptr;
574	return Builder.Finalize(ValTy);
575	}
576
577	llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter,
578	InitListExpr *ILE,
579	QualType ValTy) {
580	ConstStructBuilder Builder(Emitter);
581
582	if (!Builder.Build(ILE))
583	return nullptr;
584
585	return Builder.Finalize(ValTy);
586	}
587
588	llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter,
589	const APValue &Val,
590	QualType ValTy) {
591	ConstStructBuilder Builder(Emitter);
592
593	const RecordDecl *RD = ValTy->castAs<RecordType>()->getDecl();
594	const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD);
595	if (!Builder.Build(Val, RD, false, CD, CharUnits::Zero()))
596	return nullptr;
597
598	return Builder.Finalize(ValTy);
599	}
600
601
602	//===----------------------------------------------------------------------===//
603	// ConstExprEmitter
604	//===----------------------------------------------------------------------===//
605
606	static ConstantAddress tryEmitGlobalCompoundLiteral(CodeGenModule &CGM,
607	CodeGenFunction *CGF,
608	const CompoundLiteralExpr *E) {
609	CharUnits Align = CGM.getContext().getTypeAlignInChars(E->getType());
610	if (llvm::GlobalVariable *Addr =
611	CGM.getAddrOfConstantCompoundLiteralIfEmitted(E))
612	return ConstantAddress(Addr, Align);
613
614	LangAS addressSpace = E->getType().getAddressSpace();
615
616	ConstantEmitter emitter(CGM, CGF);
617	llvm::Constant *C = emitter.tryEmitForInitializer(E->getInitializer(),
618	addressSpace, E->getType());
619	if (!C) {
620	(0) . __assert_fail ("!E->isFileScope() && \"file-scope compound literal did not have constant initializer!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 621, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(!E->isFileScope() &&
621	(0) . __assert_fail ("!E->isFileScope() && \"file-scope compound literal did not have constant initializer!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 621, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "file-scope compound literal did not have constant initializer!");
622	return ConstantAddress::invalid();
623	}
624
625	auto GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(),
626	CGM.isTypeConstant(E->getType(), true),
627	llvm::GlobalValue::InternalLinkage,
628	C, ".compoundliteral", nullptr,
629	llvm::GlobalVariable::NotThreadLocal,
630	CGM.getContext().getTargetAddressSpace(addressSpace));
631	emitter.finalize(GV);
632	GV->setAlignment(Align.getQuantity());
633	CGM.setAddrOfConstantCompoundLiteral(E, GV);
634	return ConstantAddress(GV, Align);
635	}
636
637	static llvm::Constant *
638	EmitArrayConstant(CodeGenModule &CGM, const ConstantArrayType *DestType,
639	llvm::Type *CommonElementType, unsigned ArrayBound,
640	SmallVectorImpl<llvm::Constant *> &Elements,
641	llvm::Constant *Filler) {
642	// Figure out how long the initial prefix of non-zero elements is.
643	unsigned NonzeroLength = ArrayBound;
644	if (Elements.size() < NonzeroLength && Filler->isNullValue())
645	NonzeroLength = Elements.size();
646	if (NonzeroLength == Elements.size()) {
647	while (NonzeroLength > 0 && Elements[NonzeroLength - 1]->isNullValue())
648	--NonzeroLength;
649	}
650
651	if (NonzeroLength == 0) {
652	return llvm::ConstantAggregateZero::get(
653	CGM.getTypes().ConvertType(QualType(DestType, 0)));
654	}
655
656	// Add a zeroinitializer array filler if we have lots of trailing zeroes.
657	unsigned TrailingZeroes = ArrayBound - NonzeroLength;
658	if (TrailingZeroes >= 8) {
659	(0) . __assert_fail ("Elements.size() >= NonzeroLength && \"missing initializer for non-zero element\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 660, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(Elements.size() >= NonzeroLength &&
660	(0) . __assert_fail ("Elements.size() >= NonzeroLength && \"missing initializer for non-zero element\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 660, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "missing initializer for non-zero element");
661
662	// If all the elements had the same type up to the trailing zeroes, emit a
663	// struct of two arrays (the nonzero data and the zeroinitializer).
664	if (CommonElementType && NonzeroLength >= 8) {
665	llvm::Constant *Initial = llvm::ConstantArray::get(
666	llvm::ArrayType::get(CommonElementType, NonzeroLength),
667	makeArrayRef(Elements).take_front(NonzeroLength));
668	Elements.resize(2);
669	Elements[0] = Initial;
670	} else {
671	Elements.resize(NonzeroLength + 1);
672	}
673
674	auto *FillerType =
675	CommonElementType
676	? CommonElementType
677	: CGM.getTypes().ConvertType(DestType->getElementType());
678	FillerType = llvm::ArrayType::get(FillerType, TrailingZeroes);
679	Elements.back() = llvm::ConstantAggregateZero::get(FillerType);
680	CommonElementType = nullptr;
681	} else if (Elements.size() != ArrayBound) {
682	// Otherwise pad to the right size with the filler if necessary.
683	Elements.resize(ArrayBound, Filler);
684	if (Filler->getType() != CommonElementType)
685	CommonElementType = nullptr;
686	}
687
688	// If all elements have the same type, just emit an array constant.
689	if (CommonElementType)
690	return llvm::ConstantArray::get(
691	llvm::ArrayType::get(CommonElementType, ArrayBound), Elements);
692
693	// We have mixed types. Use a packed struct.
694	llvm::SmallVector<llvm::Type *, 16> Types;
695	Types.reserve(Elements.size());
696	for (llvm::Constant *Elt : Elements)
697	Types.push_back(Elt->getType());
698	llvm::StructType *SType =
699	llvm::StructType::get(CGM.getLLVMContext(), Types, true);
700	return llvm::ConstantStruct::get(SType, Elements);
701	}
702
703	// This class only needs to handle arrays, structs and unions. Outside C++11
704	// mode, we don't currently constant fold those types. All other types are
705	// handled by constant folding.
706	//
707	// Constant folding is currently missing support for a few features supported
708	// here: CK_ToUnion, CK_ReinterpretMemberPointer, and DesignatedInitUpdateExpr.
709	class ConstExprEmitter :
710	public StmtVisitor<ConstExprEmitter, llvm::Constant*, QualType> {
711	CodeGenModule &CGM;
712	ConstantEmitter &Emitter;
713	llvm::LLVMContext &VMContext;
714	public:
715	ConstExprEmitter(ConstantEmitter &emitter)
716	: CGM(emitter.CGM), Emitter(emitter), VMContext(CGM.getLLVMContext()) {
717	}
718
719	//===--------------------------------------------------------------------===//
720	// Visitor Methods
721	//===--------------------------------------------------------------------===//
722
723	llvm::Constant VisitStmt(Stmt S, QualType T) {
724	return nullptr;
725	}
726
727	llvm::Constant VisitConstantExpr(ConstantExpr CE, QualType T) {
728	return Visit(CE->getSubExpr(), T);
729	}
730
731	llvm::Constant VisitParenExpr(ParenExpr PE, QualType T) {
732	return Visit(PE->getSubExpr(), T);
733	}
734
735	llvm::Constant *
736	VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE,
737	QualType T) {
738	return Visit(PE->getReplacement(), T);
739	}
740
741	llvm::Constant VisitGenericSelectionExpr(GenericSelectionExpr GE,
742	QualType T) {
743	return Visit(GE->getResultExpr(), T);
744	}
745
746	llvm::Constant VisitChooseExpr(ChooseExpr CE, QualType T) {
747	return Visit(CE->getChosenSubExpr(), T);
748	}
749
750	llvm::Constant VisitCompoundLiteralExpr(CompoundLiteralExpr E, QualType T) {
751	return Visit(E->getInitializer(), T);
752	}
753
754	llvm::Constant VisitCastExpr(CastExpr E, QualType destType) {
755	if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
756	CGM.EmitExplicitCastExprType(ECE, Emitter.CGF);
757	Expr *subExpr = E->getSubExpr();
758
759	switch (E->getCastKind()) {
760	case CK_ToUnion: {
761	// GCC cast to union extension
762	(0) . __assert_fail ("E->getType()->isUnionType() && \"Destination type is not union type!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 763, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(E->getType()->isUnionType() &&
763	(0) . __assert_fail ("E->getType()->isUnionType() && \"Destination type is not union type!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 763, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Destination type is not union type!");
764
765	auto field = E->getTargetUnionField();
766
767	auto C = Emitter.tryEmitPrivateForMemory(subExpr, field->getType());
768	if (!C) return nullptr;
769
770	auto destTy = ConvertType(destType);
771	if (C->getType() == destTy) return C;
772
773	// Build a struct with the union sub-element as the first member,
774	// and padded to the appropriate size.
775	SmallVector<llvm::Constant*, 2> Elts;
776	SmallVector<llvm::Type*, 2> Types;
777	Elts.push_back(C);
778	Types.push_back(C->getType());
779	unsigned CurSize = CGM.getDataLayout().getTypeAllocSize(C->getType());
780	unsigned TotalSize = CGM.getDataLayout().getTypeAllocSize(destTy);
781
782	(0) . __assert_fail ("CurSize <= TotalSize && \"Union size mismatch!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 782, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(CurSize <= TotalSize && "Union size mismatch!");
783	if (unsigned NumPadBytes = TotalSize - CurSize) {
784	llvm::Type *Ty = CGM.Int8Ty;
785	if (NumPadBytes > 1)
786	Ty = llvm::ArrayType::get(Ty, NumPadBytes);
787
788	Elts.push_back(llvm::UndefValue::get(Ty));
789	Types.push_back(Ty);
790	}
791
792	llvm::StructType *STy = llvm::StructType::get(VMContext, Types, false);
793	return llvm::ConstantStruct::get(STy, Elts);
794	}
795
796	case CK_AddressSpaceConversion: {
797	auto C = Emitter.tryEmitPrivate(subExpr, subExpr->getType());
798	if (!C) return nullptr;
799	LangAS destAS = E->getType()->getPointeeType().getAddressSpace();
800	LangAS srcAS = subExpr->getType()->getPointeeType().getAddressSpace();
801	llvm::Type *destTy = ConvertType(E->getType());
802	return CGM.getTargetCodeGenInfo().performAddrSpaceCast(CGM, C, srcAS,
803	destAS, destTy);
804	}
805
806	case CK_LValueToRValue:
807	case CK_AtomicToNonAtomic:
808	case CK_NonAtomicToAtomic:
809	case CK_NoOp:
810	case CK_ConstructorConversion:
811	return Visit(subExpr, destType);
812
813	case CK_IntToOCLSampler:
814	llvm_unreachable("global sampler variables are not generated");
815
816	case CK_Dependent: llvm_unreachable("saw dependent cast!");
817
818	case CK_BuiltinFnToFnPtr:
819	llvm_unreachable("builtin functions are handled elsewhere");
820
821	case CK_ReinterpretMemberPointer:
822	case CK_DerivedToBaseMemberPointer:
823	case CK_BaseToDerivedMemberPointer: {
824	auto C = Emitter.tryEmitPrivate(subExpr, subExpr->getType());
825	if (!C) return nullptr;
826	return CGM.getCXXABI().EmitMemberPointerConversion(E, C);
827	}
828
829	// These will never be supported.
830	case CK_ObjCObjectLValueCast:
831	case CK_ARCProduceObject:
832	case CK_ARCConsumeObject:
833	case CK_ARCReclaimReturnedObject:
834	case CK_ARCExtendBlockObject:
835	case CK_CopyAndAutoreleaseBlockObject:
836	return nullptr;
837
838	// These don't need to be handled here because Evaluate knows how to
839	// evaluate them in the cases where they can be folded.
840	case CK_BitCast:
841	case CK_ToVoid:
842	case CK_Dynamic:
843	case CK_LValueBitCast:
844	case CK_NullToMemberPointer:
845	case CK_UserDefinedConversion:
846	case CK_CPointerToObjCPointerCast:
847	case CK_BlockPointerToObjCPointerCast:
848	case CK_AnyPointerToBlockPointerCast:
849	case CK_ArrayToPointerDecay:
850	case CK_FunctionToPointerDecay:
851	case CK_BaseToDerived:
852	case CK_DerivedToBase:
853	case CK_UncheckedDerivedToBase:
854	case CK_MemberPointerToBoolean:
855	case CK_VectorSplat:
856	case CK_FloatingRealToComplex:
857	case CK_FloatingComplexToReal:
858	case CK_FloatingComplexToBoolean:
859	case CK_FloatingComplexCast:
860	case CK_FloatingComplexToIntegralComplex:
861	case CK_IntegralRealToComplex:
862	case CK_IntegralComplexToReal:
863	case CK_IntegralComplexToBoolean:
864	case CK_IntegralComplexCast:
865	case CK_IntegralComplexToFloatingComplex:
866	case CK_PointerToIntegral:
867	case CK_PointerToBoolean:
868	case CK_NullToPointer:
869	case CK_IntegralCast:
870	case CK_BooleanToSignedIntegral:
871	case CK_IntegralToPointer:
872	case CK_IntegralToBoolean:
873	case CK_IntegralToFloating:
874	case CK_FloatingToIntegral:
875	case CK_FloatingToBoolean:
876	case CK_FloatingCast:
877	case CK_FixedPointCast:
878	case CK_FixedPointToBoolean:
879	case CK_FixedPointToIntegral:
880	case CK_IntegralToFixedPoint:
881	case CK_ZeroToOCLOpaqueType:
882	return nullptr;
883	}
884	llvm_unreachable("Invalid CastKind");
885	}
886
887	llvm::Constant VisitCXXDefaultArgExpr(CXXDefaultArgExpr DAE, QualType T) {
888	return Visit(DAE->getExpr(), T);
889	}
890
891	llvm::Constant VisitCXXDefaultInitExpr(CXXDefaultInitExpr DIE, QualType T) {
892	// No need for a DefaultInitExprScope: we don't handle 'this' in a
893	// constant expression.
894	return Visit(DIE->getExpr(), T);
895	}
896
897	llvm::Constant VisitExprWithCleanups(ExprWithCleanups E, QualType T) {
898	if (!E->cleanupsHaveSideEffects())
899	return Visit(E->getSubExpr(), T);
900	return nullptr;
901	}
902
903	llvm::Constant VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr E,
904	QualType T) {
905	return Visit(E->GetTemporaryExpr(), T);
906	}
907
908	llvm::Constant EmitArrayInitialization(InitListExpr ILE, QualType T) {
909	auto *CAT = CGM.getContext().getAsConstantArrayType(ILE->getType());
910	(0) . __assert_fail ("CAT && \"can't emit array init for non-constant-bound array\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 910, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(CAT && "can't emit array init for non-constant-bound array");
911	unsigned NumInitElements = ILE->getNumInits();
912	unsigned NumElements = CAT->getSize().getZExtValue();
913
914	// Initialising an array requires us to automatically
915	// initialise any elements that have not been initialised explicitly
916	unsigned NumInitableElts = std::min(NumInitElements, NumElements);
917
918	QualType EltType = CAT->getElementType();
919
920	// Initialize remaining array elements.
921	llvm::Constant *fillC = nullptr;
922	if (Expr *filler = ILE->getArrayFiller()) {
923	fillC = Emitter.tryEmitAbstractForMemory(filler, EltType);
924	if (!fillC)
925	return nullptr;
926	}
927
928	// Copy initializer elements.
929	SmallVector<llvm::Constant*, 16> Elts;
930	if (fillC && fillC->isNullValue())
931	Elts.reserve(NumInitableElts + 1);
932	else
933	Elts.reserve(NumElements);
934
935	llvm::Type *CommonElementType = nullptr;
936	for (unsigned i = 0; i < NumInitableElts; ++i) {
937	Expr *Init = ILE->getInit(i);
938	llvm::Constant *C = Emitter.tryEmitPrivateForMemory(Init, EltType);
939	if (!C)
940	return nullptr;
941	if (i == 0)
942	CommonElementType = C->getType();
943	else if (C->getType() != CommonElementType)
944	CommonElementType = nullptr;
945	Elts.push_back(C);
946	}
947
948	return EmitArrayConstant(CGM, CAT, CommonElementType, NumElements, Elts,
949	fillC);
950	}
951
952	llvm::Constant EmitRecordInitialization(InitListExpr ILE, QualType T) {
953	return ConstStructBuilder::BuildStruct(Emitter, ILE, T);
954	}
955
956	llvm::Constant VisitImplicitValueInitExpr(ImplicitValueInitExpr E,
957	QualType T) {
958	return CGM.EmitNullConstant(T);
959	}
960
961	llvm::Constant VisitInitListExpr(InitListExpr ILE, QualType T) {
962	if (ILE->isTransparent())
963	return Visit(ILE->getInit(0), T);
964
965	if (ILE->getType()->isArrayType())
966	return EmitArrayInitialization(ILE, T);
967
968	if (ILE->getType()->isRecordType())
969	return EmitRecordInitialization(ILE, T);
970
971	return nullptr;
972	}
973
974	llvm::Constant EmitDesignatedInitUpdater(llvm::Constant Base,
975	InitListExpr *Updater,
976	QualType destType) {
977	if (auto destAT = CGM.getContext().getAsArrayType(destType)) {
978	llvm::ArrayType *AType = cast<llvm::ArrayType>(ConvertType(destType));
979	llvm::Type *ElemType = AType->getElementType();
980
981	unsigned NumInitElements = Updater->getNumInits();
982	unsigned NumElements = AType->getNumElements();
983
984	std::vector<llvm::Constant *> Elts;
985	Elts.reserve(NumElements);
986
987	QualType destElemType = destAT->getElementType();
988
989	if (auto DataArray = dyn_cast<llvm::ConstantDataArray>(Base))
990	for (unsigned i = 0; i != NumElements; ++i)
991	Elts.push_back(DataArray->getElementAsConstant(i));
992	else if (auto Array = dyn_cast<llvm::ConstantArray>(Base))
993	for (unsigned i = 0; i != NumElements; ++i)
994	Elts.push_back(Array->getOperand(i));
995	else
996	return nullptr; // FIXME: other array types not implemented
997
998	llvm::Constant *fillC = nullptr;
999	if (Expr *filler = Updater->getArrayFiller())
1000	if (!isa<NoInitExpr>(filler))
1001	fillC = Emitter.tryEmitAbstractForMemory(filler, destElemType);
1002	bool RewriteType = (fillC && fillC->getType() != ElemType);
1003
1004	for (unsigned i = 0; i != NumElements; ++i) {
1005	Expr *Init = nullptr;
1006	if (i < NumInitElements)
1007	Init = Updater->getInit(i);
1008
1009	if (!Init && fillC)
1010	Elts[i] = fillC;
1011	else if (!Init \|\| isa<NoInitExpr>(Init))
1012	; // Do nothing.
1013	else if (InitListExpr *ChildILE = dyn_cast<InitListExpr>(Init))
1014	Elts[i] = EmitDesignatedInitUpdater(Elts[i], ChildILE, destElemType);
1015	else
1016	Elts[i] = Emitter.tryEmitPrivateForMemory(Init, destElemType);
1017
1018	if (!Elts[i])
1019	return nullptr;
1020	RewriteType \|= (Elts[i]->getType() != ElemType);
1021	}
1022
1023	if (RewriteType) {
1024	std::vector<llvm::Type *> Types;
1025	Types.reserve(NumElements);
1026	for (unsigned i = 0; i != NumElements; ++i)
1027	Types.push_back(Elts[i]->getType());
1028	llvm::StructType *SType = llvm::StructType::get(AType->getContext(),
1029	Types, true);
1030	return llvm::ConstantStruct::get(SType, Elts);
1031	}
1032
1033	return llvm::ConstantArray::get(AType, Elts);
1034	}
1035
1036	if (destType->isRecordType())
1037	return ConstStructBuilder::BuildStruct(Emitter, this, Base, Updater,
1038	destType);
1039
1040	return nullptr;
1041	}
1042
1043	llvm::Constant VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr E,
1044	QualType destType) {
1045	auto C = Visit(E->getBase(), destType);
1046	if (!C) return nullptr;
1047	return EmitDesignatedInitUpdater(C, E->getUpdater(), destType);
1048	}
1049
1050	llvm::Constant VisitCXXConstructExpr(CXXConstructExpr E, QualType Ty) {
1051	if (!E->getConstructor()->isTrivial())
1052	return nullptr;
1053
1054	// FIXME: We should not have to call getBaseElementType here.
1055	const RecordType *RT =
1056	CGM.getContext().getBaseElementType(Ty)->getAs<RecordType>();
1057	const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1058
1059	// If the class doesn't have a trivial destructor, we can't emit it as a
1060	// constant expr.
1061	if (!RD->hasTrivialDestructor())
1062	return nullptr;
1063
1064	// Only copy and default constructors can be trivial.
1065
1066
1067	if (E->getNumArgs()) {
1068	1 argument") ? static_cast (0) . __assert_fail ("E->getNumArgs() == 1 && \"trivial ctor with > 1 argument\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1068, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(E->getNumArgs() == 1 && "trivial ctor with > 1 argument");
1069	(0) . __assert_fail ("E->getConstructor()->isCopyOrMoveConstructor() && \"trivial ctor has argument but isn't a copy/move ctor\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1070, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(E->getConstructor()->isCopyOrMoveConstructor() &&
1070	(0) . __assert_fail ("E->getConstructor()->isCopyOrMoveConstructor() && \"trivial ctor has argument but isn't a copy/move ctor\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1070, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "trivial ctor has argument but isn't a copy/move ctor");
1071
1072	Expr *Arg = E->getArg(0);
1073	(0) . __assert_fail ("CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) && \"argument to copy ctor is of wrong type\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1074, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) &&
1074	(0) . __assert_fail ("CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) && \"argument to copy ctor is of wrong type\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1074, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "argument to copy ctor is of wrong type");
1075
1076	return Visit(Arg, Ty);
1077	}
1078
1079	return CGM.EmitNullConstant(Ty);
1080	}
1081
1082	llvm::Constant VisitStringLiteral(StringLiteral E, QualType T) {
1083	// This is a string literal initializing an array in an initializer.
1084	return CGM.GetConstantArrayFromStringLiteral(E);
1085	}
1086
1087	llvm::Constant VisitObjCEncodeExpr(ObjCEncodeExpr E, QualType T) {
1088	// This must be an @encode initializing an array in a static initializer.
1089	// Don't emit it as the address of the string, emit the string data itself
1090	// as an inline array.
1091	std::string Str;
1092	CGM.getContext().getObjCEncodingForType(E->getEncodedType(), Str);
1093	const ConstantArrayType *CAT = CGM.getContext().getAsConstantArrayType(T);
1094
1095	// Resize the string to the right size, adding zeros at the end, or
1096	// truncating as needed.
1097	Str.resize(CAT->getSize().getZExtValue(), '\0');
1098	return llvm::ConstantDataArray::getString(VMContext, Str, false);
1099	}
1100
1101	llvm::Constant VisitUnaryExtension(const UnaryOperator E, QualType T) {
1102	return Visit(E->getSubExpr(), T);
1103	}
1104
1105	// Utility methods
1106	llvm::Type *ConvertType(QualType T) {
1107	return CGM.getTypes().ConvertType(T);
1108	}
1109	};
1110
1111	} // end anonymous namespace.
1112
1113	bool ConstStructBuilder::Build(ConstExprEmitter *ExprEmitter,
1114	llvm::Constant *Base,
1115	InitListExpr *Updater) {
1116	(0) . __assert_fail ("Base && \"base expression should not be empty\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1116, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(Base && "base expression should not be empty");
1117
1118	QualType ExprType = Updater->getType();
1119	RecordDecl *RD = ExprType->getAs<RecordType>()->getDecl();
1120	const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
1121	const llvm::StructLayout *BaseLayout = CGM.getDataLayout().getStructLayout(
1122	cast<llvm::StructType>(Base->getType()));
1123	unsigned FieldNo = -1;
1124	unsigned ElementNo = 0;
1125
1126	// Bail out if we have base classes. We could support these, but they only
1127	// arise in C++1z where we will have already constant folded most interesting
1128	// cases. FIXME: There are still a few more cases we can handle this way.
1129	if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
1130	if (CXXRD->getNumBases())
1131	return false;
1132
1133	for (FieldDecl *Field : RD->fields()) {
1134	++FieldNo;
1135
1136	if (RD->isUnion() && Updater->getInitializedFieldInUnion() != Field)
1137	continue;
1138
1139	// Skip anonymous bitfields.
1140	if (Field->isUnnamedBitfield())
1141	continue;
1142
1143	llvm::Constant *EltInit = Base->getAggregateElement(ElementNo);
1144
1145	// Bail out if the type of the ConstantStruct does not have the same layout
1146	// as the type of the InitListExpr.
1147	if (CGM.getTypes().ConvertType(Field->getType()) != EltInit->getType() \|\|
1148	Layout.getFieldOffset(ElementNo) !=
1149	BaseLayout->getElementOffsetInBits(ElementNo))
1150	return false;
1151
1152	// Get the initializer. If we encounter an empty field or a NoInitExpr,
1153	// we use values from the base expression.
1154	Expr *Init = nullptr;
1155	if (ElementNo < Updater->getNumInits())
1156	Init = Updater->getInit(ElementNo);
1157
1158	if (!Init \|\| isa<NoInitExpr>(Init))
1159	; // Do nothing.
1160	else if (InitListExpr *ChildILE = dyn_cast<InitListExpr>(Init))
1161	EltInit = ExprEmitter->EmitDesignatedInitUpdater(EltInit, ChildILE,
1162	Field->getType());
1163	else
1164	EltInit = Emitter.tryEmitPrivateForMemory(Init, Field->getType());
1165
1166	++ElementNo;
1167
1168	if (!EltInit)
1169	return false;
1170
1171	if (!Field->isBitField())
1172	AppendField(Field, Layout.getFieldOffset(FieldNo), EltInit);
1173	else if (llvm::ConstantInt *CI = dyn_cast<llvm::ConstantInt>(EltInit))
1174	AppendBitField(Field, Layout.getFieldOffset(FieldNo), CI);
1175	else
1176	// Initializing a bitfield with a non-trivial constant?
1177	return false;
1178	}
1179
1180	return true;
1181	}
1182
1183	llvm::Constant ConstantEmitter::validateAndPopAbstract(llvm::Constant C,
1184	AbstractState saved) {
1185	Abstract = saved.OldValue;
1186
1187	(0) . __assert_fail ("saved.OldPlaceholdersSize == PlaceholderAddresses.size() && \"created a placeholder while doing an abstract emission?\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1188, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(saved.OldPlaceholdersSize == PlaceholderAddresses.size() &&
1188	(0) . __assert_fail ("saved.OldPlaceholdersSize == PlaceholderAddresses.size() && \"created a placeholder while doing an abstract emission?\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1188, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "created a placeholder while doing an abstract emission?");
1189
1190	// No validation necessary for now.
1191	// No cleanup to do for now.
1192	return C;
1193	}
1194
1195	llvm::Constant *
1196	ConstantEmitter::tryEmitAbstractForInitializer(const VarDecl &D) {
1197	auto state = pushAbstract();
1198	auto C = tryEmitPrivateForVarInit(D);
1199	return validateAndPopAbstract(C, state);
1200	}
1201
1202	llvm::Constant *
1203	ConstantEmitter::tryEmitAbstract(const Expr *E, QualType destType) {
1204	auto state = pushAbstract();
1205	auto C = tryEmitPrivate(E, destType);
1206	return validateAndPopAbstract(C, state);
1207	}
1208
1209	llvm::Constant *
1210	ConstantEmitter::tryEmitAbstract(const APValue &value, QualType destType) {
1211	auto state = pushAbstract();
1212	auto C = tryEmitPrivate(value, destType);
1213	return validateAndPopAbstract(C, state);
1214	}
1215
1216	llvm::Constant *
1217	ConstantEmitter::emitAbstract(const Expr *E, QualType destType) {
1218	auto state = pushAbstract();
1219	auto C = tryEmitPrivate(E, destType);
1220	C = validateAndPopAbstract(C, state);
1221	if (!C) {
1222	CGM.Error(E->getExprLoc(),
1223	"internal error: could not emit constant value \"abstractly\"");
1224	C = CGM.EmitNullConstant(destType);
1225	}
1226	return C;
1227	}
1228
1229	llvm::Constant *
1230	ConstantEmitter::emitAbstract(SourceLocation loc, const APValue &value,
1231	QualType destType) {
1232	auto state = pushAbstract();
1233	auto C = tryEmitPrivate(value, destType);
1234	C = validateAndPopAbstract(C, state);
1235	if (!C) {
1236	CGM.Error(loc,
1237	"internal error: could not emit constant value \"abstractly\"");
1238	C = CGM.EmitNullConstant(destType);
1239	}
1240	return C;
1241	}
1242
1243	llvm::Constant *ConstantEmitter::tryEmitForInitializer(const VarDecl &D) {
1244	initializeNonAbstract(D.getType().getAddressSpace());
1245	return markIfFailed(tryEmitPrivateForVarInit(D));
1246	}
1247
1248	llvm::Constant ConstantEmitter::tryEmitForInitializer(const Expr E,
1249	LangAS destAddrSpace,
1250	QualType destType) {
1251	initializeNonAbstract(destAddrSpace);
1252	return markIfFailed(tryEmitPrivateForMemory(E, destType));
1253	}
1254
1255	llvm::Constant *ConstantEmitter::emitForInitializer(const APValue &value,
1256	LangAS destAddrSpace,
1257	QualType destType) {
1258	initializeNonAbstract(destAddrSpace);
1259	auto C = tryEmitPrivateForMemory(value, destType);
1260	(0) . __assert_fail ("C && \"couldn't emit constant value non-abstractly?\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1260, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(C && "couldn't emit constant value non-abstractly?");
1261	return C;
1262	}
1263
1264	llvm::GlobalValue *ConstantEmitter::getCurrentAddrPrivate() {
1265	(0) . __assert_fail ("!Abstract && \"cannot get current address for abstract constant\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1265, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(!Abstract && "cannot get current address for abstract constant");
1266
1267
1268
1269	// Make an obviously ill-formed global that should blow up compilation
1270	// if it survives.
1271	auto global = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty, true,
1272	llvm::GlobalValue::PrivateLinkage,
1273	/init/ nullptr,
1274	/name/ "",
1275	/before/ nullptr,
1276	llvm::GlobalVariable::NotThreadLocal,
1277	CGM.getContext().getTargetAddressSpace(DestAddressSpace));
1278
1279	PlaceholderAddresses.push_back(std::make_pair(nullptr, global));
1280
1281	return global;
1282	}
1283
1284	void ConstantEmitter::registerCurrentAddrPrivate(llvm::Constant *signal,
1285	llvm::GlobalValue *placeholder) {
1286	assert(!PlaceholderAddresses.empty());
1287	assert(PlaceholderAddresses.back().first == nullptr);
1288	assert(PlaceholderAddresses.back().second == placeholder);
1289	PlaceholderAddresses.back().first = signal;
1290	}
1291
1292	namespace {
1293	struct ReplacePlaceholders {
1294	CodeGenModule &CGM;
1295
1296	/// The base address of the global.
1297	llvm::Constant *Base;
1298	llvm::Type *BaseValueTy = nullptr;
1299
1300	/// The placeholder addresses that were registered during emission.
1301	llvm::DenseMap<llvm::Constant, llvm::GlobalVariable> PlaceholderAddresses;
1302
1303	/// The locations of the placeholder signals.
1304	llvm::DenseMap<llvm::GlobalVariable, llvm::Constant> Locations;
1305
1306	/// The current index stack. We use a simple unsigned stack because
1307	/// we assume that placeholders will be relatively sparse in the
1308	/// initializer, but we cache the index values we find just in case.
1309	llvm::SmallVector<unsigned, 8> Indices;
1310	llvm::SmallVector<llvm::Constant*, 8> IndexValues;
1311
1312	ReplacePlaceholders(CodeGenModule &CGM, llvm::Constant *base,
1313	ArrayRef<std::pair<llvm::Constant*,
1314	llvm::GlobalVariable*>> addresses)
1315	: CGM(CGM), Base(base),
1316	PlaceholderAddresses(addresses.begin(), addresses.end()) {
1317	}
1318
1319	void replaceInInitializer(llvm::Constant *init) {
1320	// Remember the type of the top-most initializer.
1321	BaseValueTy = init->getType();
1322
1323	// Initialize the stack.
1324	Indices.push_back(0);
1325	IndexValues.push_back(nullptr);
1326
1327	// Recurse into the initializer.
1328	findLocations(init);
1329
1330	// Check invariants.
1331	(0) . __assert_fail ("IndexValues.size() == Indices.size() && \"mismatch\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1331, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(IndexValues.size() == Indices.size() && "mismatch");
1332	(0) . __assert_fail ("Indices.size() == 1 && \"didn't pop all indices\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1332, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(Indices.size() == 1 && "didn't pop all indices");
1333
1334	// Do the replacement; this basically invalidates 'init'.
1335	(0) . __assert_fail ("Locations.size() == PlaceholderAddresses.size() && \"missed a placeholder?\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1336, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(Locations.size() == PlaceholderAddresses.size() &&
1336	(0) . __assert_fail ("Locations.size() == PlaceholderAddresses.size() && \"missed a placeholder?\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1336, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "missed a placeholder?");
1337
1338	// We're iterating over a hashtable, so this would be a source of
1339	// non-determinism in compiler output except that we're just
1340	// messing around with llvm::Constant structures, which never itself
1341	// does anything that should be visible in compiler output.
1342	for (auto &entry : Locations) {
1343	(0) . __assert_fail ("entry.first->getParent() == nullptr && \"not a placeholder!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1343, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(entry.first->getParent() == nullptr && "not a placeholder!");
1344	entry.first->replaceAllUsesWith(entry.second);
1345	entry.first->eraseFromParent();
1346	}
1347	}
1348
1349	private:
1350	void findLocations(llvm::Constant *init) {
1351	// Recurse into aggregates.
1352	if (auto agg = dyn_cast<llvm::ConstantAggregate>(init)) {
1353	for (unsigned i = 0, e = agg->getNumOperands(); i != e; ++i) {
1354	Indices.push_back(i);
1355	IndexValues.push_back(nullptr);
1356
1357	findLocations(agg->getOperand(i));
1358
1359	IndexValues.pop_back();
1360	Indices.pop_back();
1361	}
1362	return;
1363	}
1364
1365	// Otherwise, check for registered constants.
1366	while (true) {
1367	auto it = PlaceholderAddresses.find(init);
1368	if (it != PlaceholderAddresses.end()) {
1369	setLocation(it->second);
1370	break;
1371	}
1372
1373	// Look through bitcasts or other expressions.
1374	if (auto expr = dyn_cast<llvm::ConstantExpr>(init)) {
1375	init = expr->getOperand(0);
1376	} else {
1377	break;
1378	}
1379	}
1380	}
1381
1382	void setLocation(llvm::GlobalVariable *placeholder) {
1383	(0) . __assert_fail ("Locations.find(placeholder) == Locations.end() && \"already found location for placeholder!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1384, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(Locations.find(placeholder) == Locations.end() &&
1384	(0) . __assert_fail ("Locations.find(placeholder) == Locations.end() && \"already found location for placeholder!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1384, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "already found location for placeholder!");
1385
1386	// Lazily fill in IndexValues with the values from Indices.
1387	// We do this in reverse because we should always have a strict
1388	// prefix of indices from the start.
1389	assert(Indices.size() == IndexValues.size());
1390	for (size_t i = Indices.size() - 1; i != size_t(-1); --i) {
1391	if (IndexValues[i]) {
1392	#ifndef NDEBUG
1393	for (size_t j = 0; j != i + 1; ++j) {
1394	(IndexValues[j]) && cast(IndexValues[j])->getZExtValue() == Indices[j]", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1397, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(IndexValues[j] &&
1395	(IndexValues[j]) && cast(IndexValues[j])->getZExtValue() == Indices[j]", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1397, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> isa<llvm::ConstantInt>(IndexValues[j]) &&
1396	(IndexValues[j]) && cast(IndexValues[j])->getZExtValue() == Indices[j]", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1397, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue()
1397	(IndexValues[j]) && cast(IndexValues[j])->getZExtValue() == Indices[j]", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1397, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> == Indices[j]);
1398	}
1399	#endif
1400	break;
1401	}
1402
1403	IndexValues[i] = llvm::ConstantInt::get(CGM.Int32Ty, Indices[i]);
1404	}
1405
1406	// Form a GEP and then bitcast to the placeholder type so that the
1407	// replacement will succeed.
1408	llvm::Constant *location =
1409	llvm::ConstantExpr::getInBoundsGetElementPtr(BaseValueTy,
1410	Base, IndexValues);
1411	location = llvm::ConstantExpr::getBitCast(location,
1412	placeholder->getType());
1413
1414	Locations.insert({placeholder, location});
1415	}
1416	};
1417	}
1418
1419	void ConstantEmitter::finalize(llvm::GlobalVariable *global) {
1420	(0) . __assert_fail ("InitializedNonAbstract && \"finalizing emitter that was used for abstract emission?\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1421, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(InitializedNonAbstract &&
1421	(0) . __assert_fail ("InitializedNonAbstract && \"finalizing emitter that was used for abstract emission?\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1421, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "finalizing emitter that was used for abstract emission?");
1422	(0) . __assert_fail ("!Finalized && \"finalizing emitter multiple times\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1422, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(!Finalized && "finalizing emitter multiple times");
1423	getInitializer()", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1423, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(global->getInitializer());
1424
1425	// Note that we might also be Failed.
1426	Finalized = true;
1427
1428	if (!PlaceholderAddresses.empty()) {
1429	ReplacePlaceholders(CGM, global, PlaceholderAddresses)
1430	.replaceInInitializer(global->getInitializer());
1431	PlaceholderAddresses.clear(); // satisfy
1432	}
1433	}
1434
1435	ConstantEmitter::~ConstantEmitter() {
1436	(0) . __assert_fail ("(!InitializedNonAbstract \|\| Finalized \|\| Failed) && \"not finalized after being initialized for non-abstract emission\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1437, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert((!InitializedNonAbstract \|\| Finalized \|\| Failed) &&
1437	(0) . __assert_fail ("(!InitializedNonAbstract \|\| Finalized \|\| Failed) && \"not finalized after being initialized for non-abstract emission\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1437, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "not finalized after being initialized for non-abstract emission");
1438	(0) . __assert_fail ("PlaceholderAddresses.empty() && \"unhandled placeholders\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1438, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(PlaceholderAddresses.empty() && "unhandled placeholders");
1439	}
1440
1441	static QualType getNonMemoryType(CodeGenModule &CGM, QualType type) {
1442	if (auto AT = type->getAs<AtomicType>()) {
1443	return CGM.getContext().getQualifiedType(AT->getValueType(),
1444	type.getQualifiers());
1445	}
1446	return type;
1447	}
1448
1449	llvm::Constant *ConstantEmitter::tryEmitPrivateForVarInit(const VarDecl &D) {
1450	// Make a quick check if variable can be default NULL initialized
1451	// and avoid going through rest of code which may do, for c++11,
1452	// initialization of memory to all NULLs.
1453	if (!D.hasLocalStorage()) {
1454	QualType Ty = CGM.getContext().getBaseElementType(D.getType());
1455	if (Ty->isRecordType())
1456	if (const CXXConstructExpr *E =
1457	dyn_cast_or_null<CXXConstructExpr>(D.getInit())) {
1458	const CXXConstructorDecl *CD = E->getConstructor();
1459	if (CD->isTrivial() && CD->isDefaultConstructor())
1460	return CGM.EmitNullConstant(D.getType());
1461	}
1462	InConstantContext = true;
1463	}
1464
1465	QualType destType = D.getType();
1466
1467	// Try to emit the initializer. Note that this can allow some things that
1468	// are not allowed by tryEmitPrivateForMemory alone.
1469	if (auto value = D.evaluateValue()) {
1470	return tryEmitPrivateForMemory(*value, destType);
1471	}
1472
1473	// FIXME: Implement C++11 [basic.start.init]p2: if the initializer of a
1474	// reference is a constant expression, and the reference binds to a temporary,
1475	// then constant initialization is performed. ConstExprEmitter will
1476	// incorrectly emit a prvalue constant in this case, and the calling code
1477	// interprets that as the (pointer) value of the reference, rather than the
1478	// desired value of the referee.
1479	if (destType->isReferenceType())
1480	return nullptr;
1481
1482	const Expr *E = D.getInit();
1483	(0) . __assert_fail ("E && \"No initializer to emit\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1483, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(E && "No initializer to emit");
1484
1485	auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1486	auto C =
1487	ConstExprEmitter(this).Visit(const_cast<Expr>(E), nonMemoryDestType);
1488	return (C ? emitForMemory(C, destType) : nullptr);
1489	}
1490
1491	llvm::Constant *
1492	ConstantEmitter::tryEmitAbstractForMemory(const Expr *E, QualType destType) {
1493	auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1494	auto C = tryEmitAbstract(E, nonMemoryDestType);
1495	return (C ? emitForMemory(C, destType) : nullptr);
1496	}
1497
1498	llvm::Constant *
1499	ConstantEmitter::tryEmitAbstractForMemory(const APValue &value,
1500	QualType destType) {
1501	auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1502	auto C = tryEmitAbstract(value, nonMemoryDestType);
1503	return (C ? emitForMemory(C, destType) : nullptr);
1504	}
1505
1506	llvm::Constant ConstantEmitter::tryEmitPrivateForMemory(const Expr E,
1507	QualType destType) {
1508	auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1509	llvm::Constant *C = tryEmitPrivate(E, nonMemoryDestType);
1510	return (C ? emitForMemory(C, destType) : nullptr);
1511	}
1512
1513	llvm::Constant *ConstantEmitter::tryEmitPrivateForMemory(const APValue &value,
1514	QualType destType) {
1515	auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1516	auto C = tryEmitPrivate(value, nonMemoryDestType);
1517	return (C ? emitForMemory(C, destType) : nullptr);
1518	}
1519
1520	llvm::Constant *ConstantEmitter::emitForMemory(CodeGenModule &CGM,
1521	llvm::Constant *C,
1522	QualType destType) {
1523	// For an _Atomic-qualified constant, we may need to add tail padding.
1524	if (auto AT = destType->getAs<AtomicType>()) {
1525	QualType destValueType = AT->getValueType();
1526	C = emitForMemory(CGM, C, destValueType);
1527
1528	uint64_t innerSize = CGM.getContext().getTypeSize(destValueType);
1529	uint64_t outerSize = CGM.getContext().getTypeSize(destType);
1530	if (innerSize == outerSize)
1531	return C;
1532
1533	(0) . __assert_fail ("innerSize < outerSize && \"emitted over-large constant for atomic\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1533, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(innerSize < outerSize && "emitted over-large constant for atomic");
1534	llvm::Constant *elts[] = {
1535	C,
1536	llvm::ConstantAggregateZero::get(
1537	llvm::ArrayType::get(CGM.Int8Ty, (outerSize - innerSize) / 8))
1538	};
1539	return llvm::ConstantStruct::getAnon(elts);
1540	}
1541
1542	// Zero-extend bool.
1543	if (C->getType()->isIntegerTy(1)) {
1544	llvm::Type *boolTy = CGM.getTypes().ConvertTypeForMem(destType);
1545	return llvm::ConstantExpr::getZExt(C, boolTy);
1546	}
1547
1548	return C;
1549	}
1550
1551	llvm::Constant ConstantEmitter::tryEmitPrivate(const Expr E,
1552	QualType destType) {
1553	Expr::EvalResult Result;
1554
1555	bool Success = false;
1556
1557	if (destType->isReferenceType())
1558	Success = E->EvaluateAsLValue(Result, CGM.getContext());
1559	else
1560	Success = E->EvaluateAsRValue(Result, CGM.getContext(), InConstantContext);
1561
1562	llvm::Constant *C;
1563	if (Success && !Result.HasSideEffects)
1564	C = tryEmitPrivate(Result.Val, destType);
1565	else
1566	C = ConstExprEmitter(this).Visit(const_cast<Expr>(E), destType);
1567
1568	return C;
1569	}
1570
1571	llvm::Constant CodeGenModule::getNullPointer(llvm::PointerType T, QualType QT) {
1572	return getTargetCodeGenInfo().getNullPointer(*this, T, QT);
1573	}
1574
1575	namespace {
1576	/// A struct which can be used to peephole certain kinds of finalization
1577	/// that normally happen during l-value emission.
1578	struct ConstantLValue {
1579	llvm::Constant *Value;
1580	bool HasOffsetApplied;
1581
1582	/implicit/ ConstantLValue(llvm::Constant *value,
1583	bool hasOffsetApplied = false)
1584	: Value(value), HasOffsetApplied(false) {}
1585
1586	/implicit/ ConstantLValue(ConstantAddress address)
1587	: ConstantLValue(address.getPointer()) {}
1588	};
1589
1590	/// A helper class for emitting constant l-values.
1591	class ConstantLValueEmitter : public ConstStmtVisitor<ConstantLValueEmitter,
1592	ConstantLValue> {
1593	CodeGenModule &CGM;
1594	ConstantEmitter &Emitter;
1595	const APValue &Value;
1596	QualType DestType;
1597
1598	// Befriend StmtVisitorBase so that we don't have to expose Visit*.
1599	friend StmtVisitorBase;
1600
1601	public:
1602	ConstantLValueEmitter(ConstantEmitter &emitter, const APValue &value,
1603	QualType destType)
1604	: CGM(emitter.CGM), Emitter(emitter), Value(value), DestType(destType) {}
1605
1606	llvm::Constant *tryEmit();
1607
1608	private:
1609	llvm::Constant tryEmitAbsolute(llvm::Type destTy);
1610	ConstantLValue tryEmitBase(const APValue::LValueBase &base);
1611
1612	ConstantLValue VisitStmt(const Stmt *S) { return nullptr; }
1613	ConstantLValue VisitConstantExpr(const ConstantExpr *E);
1614	ConstantLValue VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
1615	ConstantLValue VisitStringLiteral(const StringLiteral *E);
1616	ConstantLValue VisitObjCBoxedExpr(const ObjCBoxedExpr *E);
1617	ConstantLValue VisitObjCEncodeExpr(const ObjCEncodeExpr *E);
1618	ConstantLValue VisitObjCStringLiteral(const ObjCStringLiteral *E);
1619	ConstantLValue VisitPredefinedExpr(const PredefinedExpr *E);
1620	ConstantLValue VisitAddrLabelExpr(const AddrLabelExpr *E);
1621	ConstantLValue VisitCallExpr(const CallExpr *E);
1622	ConstantLValue VisitBlockExpr(const BlockExpr *E);
1623	ConstantLValue VisitCXXTypeidExpr(const CXXTypeidExpr *E);
1624	ConstantLValue VisitCXXUuidofExpr(const CXXUuidofExpr *E);
1625	ConstantLValue VisitMaterializeTemporaryExpr(
1626	const MaterializeTemporaryExpr *E);
1627
1628	bool hasNonZeroOffset() const {
1629	return !Value.getLValueOffset().isZero();
1630	}
1631
1632	/// Return the value offset.
1633	llvm::Constant *getOffset() {
1634	return llvm::ConstantInt::get(CGM.Int64Ty,
1635	Value.getLValueOffset().getQuantity());
1636	}
1637
1638	/// Apply the value offset to the given constant.
1639	llvm::Constant applyOffset(llvm::Constant C) {
1640	if (!hasNonZeroOffset())
1641	return C;
1642
1643	llvm::Type *origPtrTy = C->getType();
1644	unsigned AS = origPtrTy->getPointerAddressSpace();
1645	llvm::Type *charPtrTy = CGM.Int8Ty->getPointerTo(AS);
1646	C = llvm::ConstantExpr::getBitCast(C, charPtrTy);
1647	C = llvm::ConstantExpr::getGetElementPtr(CGM.Int8Ty, C, getOffset());
1648	C = llvm::ConstantExpr::getPointerCast(C, origPtrTy);
1649	return C;
1650	}
1651	};
1652
1653	}
1654
1655	llvm::Constant *ConstantLValueEmitter::tryEmit() {
1656	const APValue::LValueBase &base = Value.getLValueBase();
1657
1658	// The destination type should be a pointer or reference
1659	// type, but it might also be a cast thereof.
1660	//
1661	// FIXME: the chain of casts required should be reflected in the APValue.
1662	// We need this in order to correctly handle things like a ptrtoint of a
1663	// non-zero null pointer and addrspace casts that aren't trivially
1664	// represented in LLVM IR.
1665	auto destTy = CGM.getTypes().ConvertTypeForMem(DestType);
1666	(destTy) \|\| isa(destTy)", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1666, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(isa<llvm::IntegerType>(destTy) \|\| isa<llvm::PointerType>(destTy));
1667
1668	// If there's no base at all, this is a null or absolute pointer,
1669	// possibly cast back to an integer type.
1670	if (!base) {
1671	return tryEmitAbsolute(destTy);
1672	}
1673
1674	// Otherwise, try to emit the base.
1675	ConstantLValue result = tryEmitBase(base);
1676
1677	// If that failed, we're done.
1678	llvm::Constant *value = result.Value;
1679	if (!value) return nullptr;
1680
1681	// Apply the offset if necessary and not already done.
1682	if (!result.HasOffsetApplied) {
1683	value = applyOffset(value);
1684	}
1685
1686	// Convert to the appropriate type; this could be an lvalue for
1687	// an integer. FIXME: performAddrSpaceCast
1688	if (isa<llvm::PointerType>(destTy))
1689	return llvm::ConstantExpr::getPointerCast(value, destTy);
1690
1691	return llvm::ConstantExpr::getPtrToInt(value, destTy);
1692	}
1693
1694	/// Try to emit an absolute l-value, such as a null pointer or an integer
1695	/// bitcast to pointer type.
1696	llvm::Constant *
1697	ConstantLValueEmitter::tryEmitAbsolute(llvm::Type *destTy) {
1698	auto offset = getOffset();
1699
1700	// If we're producing a pointer, this is easy.
1701	auto destPtrTy = cast<llvm::PointerType>(destTy);
1702	if (Value.isNullPointer()) {
1703	// FIXME: integer offsets from non-zero null pointers.
1704	return CGM.getNullPointer(destPtrTy, DestType);
1705	}
1706
1707	// Convert the integer to a pointer-sized integer before converting it
1708	// to a pointer.
1709	// FIXME: signedness depends on the original integer type.
1710	auto intptrTy = CGM.getDataLayout().getIntPtrType(destPtrTy);
1711	llvm::Constant *C = offset;
1712	C = llvm::ConstantExpr::getIntegerCast(getOffset(), intptrTy,
1713	/isSigned/ false);
1714	C = llvm::ConstantExpr::getIntToPtr(C, destPtrTy);
1715	return C;
1716	}
1717
1718	ConstantLValue
1719	ConstantLValueEmitter::tryEmitBase(const APValue::LValueBase &base) {
1720	// Handle values.
1721	if (const ValueDecl D = base.dyn_cast<const ValueDecl>()) {
1722	if (D->hasAttr<WeakRefAttr>())
1723	return CGM.GetWeakRefReference(D).getPointer();
1724
1725	if (auto FD = dyn_cast<FunctionDecl>(D))
1726	return CGM.GetAddrOfFunction(FD);
1727
1728	if (auto VD = dyn_cast<VarDecl>(D)) {
1729	// We can never refer to a variable with local storage.
1730	if (!VD->hasLocalStorage()) {
1731	if (VD->isFileVarDecl() \|\| VD->hasExternalStorage())
1732	return CGM.GetAddrOfGlobalVar(VD);
1733
1734	if (VD->isLocalVarDecl()) {
1735	return CGM.getOrCreateStaticVarDecl(
1736	VD, CGM.getLLVMLinkageVarDefinition(VD, /isConstant=*/false));
1737	}
1738	}
1739	}
1740
1741	return nullptr;
1742	}
1743
1744	// Otherwise, it must be an expression.
1745	return Visit(base.get<const Expr*>());
1746	}
1747
1748	ConstantLValue
1749	ConstantLValueEmitter::VisitConstantExpr(const ConstantExpr *E) {
1750	return Visit(E->getSubExpr());
1751	}
1752
1753	ConstantLValue
1754	ConstantLValueEmitter::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
1755	return tryEmitGlobalCompoundLiteral(CGM, Emitter.CGF, E);
1756	}
1757
1758	ConstantLValue
1759	ConstantLValueEmitter::VisitStringLiteral(const StringLiteral *E) {
1760	return CGM.GetAddrOfConstantStringFromLiteral(E);
1761	}
1762
1763	ConstantLValue
1764	ConstantLValueEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) {
1765	return CGM.GetAddrOfConstantStringFromObjCEncode(E);
1766	}
1767
1768	static ConstantLValue emitConstantObjCStringLiteral(const StringLiteral *S,
1769	QualType T,
1770	CodeGenModule &CGM) {
1771	auto C = CGM.getObjCRuntime().GenerateConstantString(S);
1772	return C.getElementBitCast(CGM.getTypes().ConvertTypeForMem(T));
1773	}
1774
1775	ConstantLValue
1776	ConstantLValueEmitter::VisitObjCStringLiteral(const ObjCStringLiteral *E) {
1777	return emitConstantObjCStringLiteral(E->getString(), E->getType(), CGM);
1778	}
1779
1780	ConstantLValue
1781	ConstantLValueEmitter::VisitObjCBoxedExpr(const ObjCBoxedExpr *E) {
1782	(0) . __assert_fail ("E->isExpressibleAsConstantInitializer() && \"this boxed expression can't be emitted as a compile-time constant\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1783, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(E->isExpressibleAsConstantInitializer() &&
1783	(0) . __assert_fail ("E->isExpressibleAsConstantInitializer() && \"this boxed expression can't be emitted as a compile-time constant\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1783, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "this boxed expression can't be emitted as a compile-time constant");
1784	auto *SL = cast<StringLiteral>(E->getSubExpr()->IgnoreParenCasts());
1785	return emitConstantObjCStringLiteral(SL, E->getType(), CGM);
1786	}
1787
1788	ConstantLValue
1789	ConstantLValueEmitter::VisitPredefinedExpr(const PredefinedExpr *E) {
1790	return CGM.GetAddrOfConstantStringFromLiteral(E->getFunctionName());
1791	}
1792
1793	ConstantLValue
1794	ConstantLValueEmitter::VisitAddrLabelExpr(const AddrLabelExpr *E) {
1795	(0) . __assert_fail ("Emitter.CGF && \"Invalid address of label expression outside function\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1795, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(Emitter.CGF && "Invalid address of label expression outside function");
1796	llvm::Constant *Ptr = Emitter.CGF->GetAddrOfLabel(E->getLabel());
1797	Ptr = llvm::ConstantExpr::getBitCast(Ptr,
1798	CGM.getTypes().ConvertType(E->getType()));
1799	return Ptr;
1800	}
1801
1802	ConstantLValue
1803	ConstantLValueEmitter::VisitCallExpr(const CallExpr *E) {
1804	unsigned builtin = E->getBuiltinCallee();
1805	if (builtin != Builtin::BI__builtin___CFStringMakeConstantString &&
1806	builtin != Builtin::BI__builtin___NSStringMakeConstantString)
1807	return nullptr;
1808
1809	auto literal = cast<StringLiteral>(E->getArg(0)->IgnoreParenCasts());
1810	if (builtin == Builtin::BI__builtin___NSStringMakeConstantString) {
1811	return CGM.getObjCRuntime().GenerateConstantString(literal);
1812	} else {
1813	// FIXME: need to deal with UCN conversion issues.
1814	return CGM.GetAddrOfConstantCFString(literal);
1815	}
1816	}
1817
1818	ConstantLValue
1819	ConstantLValueEmitter::VisitBlockExpr(const BlockExpr *E) {
1820	StringRef functionName;
1821	if (auto CGF = Emitter.CGF)
1822	functionName = CGF->CurFn->getName();
1823	else
1824	functionName = "global";
1825
1826	return CGM.GetAddrOfGlobalBlock(E, functionName);
1827	}
1828
1829	ConstantLValue
1830	ConstantLValueEmitter::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
1831	QualType T;
1832	if (E->isTypeOperand())
1833	T = E->getTypeOperand(CGM.getContext());
1834	else
1835	T = E->getExprOperand()->getType();
1836	return CGM.GetAddrOfRTTIDescriptor(T);
1837	}
1838
1839	ConstantLValue
1840	ConstantLValueEmitter::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {
1841	return CGM.GetAddrOfUuidDescriptor(E);
1842	}
1843
1844	ConstantLValue
1845	ConstantLValueEmitter::VisitMaterializeTemporaryExpr(
1846	const MaterializeTemporaryExpr *E) {
1847	getStorageDuration() == SD_Static", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 1847, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(E->getStorageDuration() == SD_Static);
1848	SmallVector<const Expr *, 2> CommaLHSs;
1849	SmallVector<SubobjectAdjustment, 2> Adjustments;
1850	const Expr *Inner = E->GetTemporaryExpr()
1851	->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
1852	return CGM.GetAddrOfGlobalTemporary(E, Inner);
1853	}
1854
1855	llvm::Constant *ConstantEmitter::tryEmitPrivate(const APValue &Value,
1856	QualType DestType) {
1857	switch (Value.getKind()) {
1858	case APValue::Uninitialized:
1859	llvm_unreachable("Constant expressions should be initialized.");
1860	case APValue::LValue:
1861	return ConstantLValueEmitter(*this, Value, DestType).tryEmit();
1862	case APValue::Int:
1863	return llvm::ConstantInt::get(CGM.getLLVMContext(), Value.getInt());
1864	case APValue::FixedPoint:
1865	return llvm::ConstantInt::get(CGM.getLLVMContext(),
1866	Value.getFixedPoint().getValue());
1867	case APValue::ComplexInt: {
1868	llvm::Constant *Complex[2];
1869
1870	Complex[0] = llvm::ConstantInt::get(CGM.getLLVMContext(),
1871	Value.getComplexIntReal());
1872	Complex[1] = llvm::ConstantInt::get(CGM.getLLVMContext(),
1873	Value.getComplexIntImag());
1874
1875	// FIXME: the target may want to specify that this is packed.
1876	llvm::StructType *STy =
1877	llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
1878	return llvm::ConstantStruct::get(STy, Complex);
1879	}
1880	case APValue::Float: {
1881	const llvm::APFloat &Init = Value.getFloat();
1882	if (&Init.getSemantics() == &llvm::APFloat::IEEEhalf() &&
1883	!CGM.getContext().getLangOpts().NativeHalfType &&
1884	CGM.getContext().getTargetInfo().useFP16ConversionIntrinsics())
1885	return llvm::ConstantInt::get(CGM.getLLVMContext(),
1886	Init.bitcastToAPInt());
1887	else
1888	return llvm::ConstantFP::get(CGM.getLLVMContext(), Init);
1889	}
1890	case APValue::ComplexFloat: {
1891	llvm::Constant *Complex[2];
1892
1893	Complex[0] = llvm::ConstantFP::get(CGM.getLLVMContext(),
1894	Value.getComplexFloatReal());
1895	Complex[1] = llvm::ConstantFP::get(CGM.getLLVMContext(),
1896	Value.getComplexFloatImag());
1897
1898	// FIXME: the target may want to specify that this is packed.
1899	llvm::StructType *STy =
1900	llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
1901	return llvm::ConstantStruct::get(STy, Complex);
1902	}
1903	case APValue::Vector: {
1904	unsigned NumElts = Value.getVectorLength();
1905	SmallVector<llvm::Constant *, 4> Inits(NumElts);
1906
1907	for (unsigned I = 0; I != NumElts; ++I) {
1908	const APValue &Elt = Value.getVectorElt(I);
1909	if (Elt.isInt())
1910	Inits[I] = llvm::ConstantInt::get(CGM.getLLVMContext(), Elt.getInt());
1911	else if (Elt.isFloat())
1912	Inits[I] = llvm::ConstantFP::get(CGM.getLLVMContext(), Elt.getFloat());
1913	else
1914	llvm_unreachable("unsupported vector element type");
1915	}
1916	return llvm::ConstantVector::get(Inits);
1917	}
1918	case APValue::AddrLabelDiff: {
1919	const AddrLabelExpr *LHSExpr = Value.getAddrLabelDiffLHS();
1920	const AddrLabelExpr *RHSExpr = Value.getAddrLabelDiffRHS();
1921	llvm::Constant *LHS = tryEmitPrivate(LHSExpr, LHSExpr->getType());
1922	llvm::Constant *RHS = tryEmitPrivate(RHSExpr, RHSExpr->getType());
1923	if (!LHS \|\| !RHS) return nullptr;
1924
1925	// Compute difference
1926	llvm::Type *ResultType = CGM.getTypes().ConvertType(DestType);
1927	LHS = llvm::ConstantExpr::getPtrToInt(LHS, CGM.IntPtrTy);
1928	RHS = llvm::ConstantExpr::getPtrToInt(RHS, CGM.IntPtrTy);
1929	llvm::Constant *AddrLabelDiff = llvm::ConstantExpr::getSub(LHS, RHS);
1930
1931	// LLVM is a bit sensitive about the exact format of the
1932	// address-of-label difference; make sure to truncate after
1933	// the subtraction.
1934	return llvm::ConstantExpr::getTruncOrBitCast(AddrLabelDiff, ResultType);
1935	}
1936	case APValue::Struct:
1937	case APValue::Union:
1938	return ConstStructBuilder::BuildStruct(*this, Value, DestType);
1939	case APValue::Array: {
1940	const ConstantArrayType *CAT =
1941	CGM.getContext().getAsConstantArrayType(DestType);
1942	unsigned NumElements = Value.getArraySize();
1943	unsigned NumInitElts = Value.getArrayInitializedElts();
1944
1945	// Emit array filler, if there is one.
1946	llvm::Constant *Filler = nullptr;
1947	if (Value.hasArrayFiller()) {
1948	Filler = tryEmitAbstractForMemory(Value.getArrayFiller(),
1949	CAT->getElementType());
1950	if (!Filler)
1951	return nullptr;
1952	}
1953
1954	// Emit initializer elements.
1955	SmallVector<llvm::Constant*, 16> Elts;
1956	if (Filler && Filler->isNullValue())
1957	Elts.reserve(NumInitElts + 1);
1958	else
1959	Elts.reserve(NumElements);
1960
1961	llvm::Type *CommonElementType = nullptr;
1962	for (unsigned I = 0; I < NumInitElts; ++I) {
1963	llvm::Constant *C = tryEmitPrivateForMemory(
1964	Value.getArrayInitializedElt(I), CAT->getElementType());
1965	if (!C) return nullptr;
1966
1967	if (I == 0)
1968	CommonElementType = C->getType();
1969	else if (C->getType() != CommonElementType)
1970	CommonElementType = nullptr;
1971	Elts.push_back(C);
1972	}
1973
1974	// This means that the array type is probably "IncompleteType" or some
1975	// type that is not ConstantArray.
1976	if (CAT == nullptr && CommonElementType == nullptr && !NumInitElts) {
1977	const ArrayType *AT = CGM.getContext().getAsArrayType(DestType);
1978	CommonElementType = CGM.getTypes().ConvertType(AT->getElementType());
1979	llvm::ArrayType *AType = llvm::ArrayType::get(CommonElementType,
1980	NumElements);
1981	return llvm::ConstantAggregateZero::get(AType);
1982	}
1983
1984	return EmitArrayConstant(CGM, CAT, CommonElementType, NumElements, Elts,
1985	Filler);
1986	}
1987	case APValue::MemberPointer:
1988	return CGM.getCXXABI().EmitMemberPointer(Value, DestType);
1989	}
1990	llvm_unreachable("Unknown APValue kind");
1991	}
1992
1993	llvm::GlobalVariable *CodeGenModule::getAddrOfConstantCompoundLiteralIfEmitted(
1994	const CompoundLiteralExpr *E) {
1995	return EmittedCompoundLiterals.lookup(E);
1996	}
1997
1998	void CodeGenModule::setAddrOfConstantCompoundLiteral(
1999	const CompoundLiteralExpr CLE, llvm::GlobalVariable GV) {
2000	bool Ok = EmittedCompoundLiterals.insert(std::make_pair(CLE, GV)).second;
2001	(void)Ok;
2002	(0) . __assert_fail ("Ok && \"CLE has already been emitted!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 2002, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(Ok && "CLE has already been emitted!");
2003	}
2004
2005	ConstantAddress
2006	CodeGenModule::GetAddrOfConstantCompoundLiteral(const CompoundLiteralExpr *E) {
2007	(0) . __assert_fail ("E->isFileScope() && \"not a file-scope compound literal expr\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 2007, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(E->isFileScope() && "not a file-scope compound literal expr");
2008	return tryEmitGlobalCompoundLiteral(*this, nullptr, E);
2009	}
2010
2011	llvm::Constant *
2012	CodeGenModule::getMemberPointerConstant(const UnaryOperator *uo) {
2013	// Member pointer constants always have a very particular form.
2014	const MemberPointerType *type = cast<MemberPointerType>(uo->getType());
2015	const ValueDecl *decl = cast<DeclRefExpr>(uo->getSubExpr())->getDecl();
2016
2017	// A member function pointer.
2018	if (const CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(decl))
2019	return getCXXABI().EmitMemberFunctionPointer(method);
2020
2021	// Otherwise, a member data pointer.
2022	uint64_t fieldOffset = getContext().getFieldOffset(decl);
2023	CharUnits chars = getContext().toCharUnitsFromBits((int64_t) fieldOffset);
2024	return getCXXABI().EmitMemberDataPointer(type, chars);
2025	}
2026
2027	static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
2028	llvm::Type *baseType,
2029	const CXXRecordDecl *base);
2030
2031	static llvm::Constant *EmitNullConstant(CodeGenModule &CGM,
2032	const RecordDecl *record,
2033	bool asCompleteObject) {
2034	const CGRecordLayout &layout = CGM.getTypes().getCGRecordLayout(record);
2035	llvm::StructType *structure =
2036	(asCompleteObject ? layout.getLLVMType()
2037	: layout.getBaseSubobjectLLVMType());
2038
2039	unsigned numElements = structure->getNumElements();
2040	std::vector<llvm::Constant *> elements(numElements);
2041
2042	auto CXXR = dyn_cast<CXXRecordDecl>(record);
2043	// Fill in all the bases.
2044	if (CXXR) {
2045	for (const auto &I : CXXR->bases()) {
2046	if (I.isVirtual()) {
2047	// Ignore virtual bases; if we're laying out for a complete
2048	// object, we'll lay these out later.
2049	continue;
2050	}
2051
2052	const CXXRecordDecl *base =
2053	cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
2054
2055	// Ignore empty bases.
2056	if (base->isEmpty() \|\|
2057	CGM.getContext().getASTRecordLayout(base).getNonVirtualSize()
2058	.isZero())
2059	continue;
2060
2061	unsigned fieldIndex = layout.getNonVirtualBaseLLVMFieldNo(base);
2062	llvm::Type *baseType = structure->getElementType(fieldIndex);
2063	elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
2064	}
2065	}
2066
2067	// Fill in all the fields.
2068	for (const auto *Field : record->fields()) {
2069	// Fill in non-bitfields. (Bitfields always use a zero pattern, which we
2070	// will fill in later.)
2071	if (!Field->isBitField()) {
2072	unsigned fieldIndex = layout.getLLVMFieldNo(Field);
2073	elements[fieldIndex] = CGM.EmitNullConstant(Field->getType());
2074	}
2075
2076	// For unions, stop after the first named field.
2077	if (record->isUnion()) {
2078	if (Field->getIdentifier())
2079	break;
2080	if (const auto *FieldRD = Field->getType()->getAsRecordDecl())
2081	if (FieldRD->findFirstNamedDataMember())
2082	break;
2083	}
2084	}
2085
2086	// Fill in the virtual bases, if we're working with the complete object.
2087	if (CXXR && asCompleteObject) {
2088	for (const auto &I : CXXR->vbases()) {
2089	const CXXRecordDecl *base =
2090	cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
2091
2092	// Ignore empty bases.
2093	if (base->isEmpty())
2094	continue;
2095
2096	unsigned fieldIndex = layout.getVirtualBaseIndex(base);
2097
2098	// We might have already laid this field out.
2099	if (elements[fieldIndex]) continue;
2100
2101	llvm::Type *baseType = structure->getElementType(fieldIndex);
2102	elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
2103	}
2104	}
2105
2106	// Now go through all other fields and zero them out.
2107	for (unsigned i = 0; i != numElements; ++i) {
2108	if (!elements[i])
2109	elements[i] = llvm::Constant::getNullValue(structure->getElementType(i));
2110	}
2111
2112	return llvm::ConstantStruct::get(structure, elements);
2113	}
2114
2115	/// Emit the null constant for a base subobject.
2116	static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
2117	llvm::Type *baseType,
2118	const CXXRecordDecl *base) {
2119	const CGRecordLayout &baseLayout = CGM.getTypes().getCGRecordLayout(base);
2120
2121	// Just zero out bases that don't have any pointer to data members.
2122	if (baseLayout.isZeroInitializableAsBase())
2123	return llvm::Constant::getNullValue(baseType);
2124
2125	// Otherwise, we can just use its null constant.
2126	return EmitNullConstant(CGM, base, /asCompleteObject=/false);
2127	}
2128
2129	llvm::Constant *ConstantEmitter::emitNullForMemory(CodeGenModule &CGM,
2130	QualType T) {
2131	return emitForMemory(CGM, CGM.EmitNullConstant(T), T);
2132	}
2133
2134	llvm::Constant *CodeGenModule::EmitNullConstant(QualType T) {
2135	if (T->getAs<PointerType>())
2136	return getNullPointer(
2137	cast<llvm::PointerType>(getTypes().ConvertTypeForMem(T)), T);
2138
2139	if (getTypes().isZeroInitializable(T))
2140	return llvm::Constant::getNullValue(getTypes().ConvertTypeForMem(T));
2141
2142	if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(T)) {
2143	llvm::ArrayType *ATy =
2144	cast<llvm::ArrayType>(getTypes().ConvertTypeForMem(T));
2145
2146	QualType ElementTy = CAT->getElementType();
2147
2148	llvm::Constant *Element =
2149	ConstantEmitter::emitNullForMemory(*this, ElementTy);
2150	unsigned NumElements = CAT->getSize().getZExtValue();
2151	SmallVector<llvm::Constant *, 8> Array(NumElements, Element);
2152	return llvm::ConstantArray::get(ATy, Array);
2153	}
2154
2155	if (const RecordType *RT = T->getAs<RecordType>())
2156	return ::EmitNullConstant(this, RT->getDecl(), /complete object*/ true);
2157
2158	(0) . __assert_fail ("T->isMemberDataPointerType() && \"Should only see pointers to data members here!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 2159, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(T->isMemberDataPointerType() &&
2159	(0) . __assert_fail ("T->isMemberDataPointerType() && \"Should only see pointers to data members here!\"", "/home/seafit/code_projects/clang_source/clang/lib/CodeGen/CGExprConstant.cpp", 2159, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true"> "Should only see pointers to data members here!");
2160
2161	return getCXXABI().EmitNullMemberPointer(T->castAs<MemberPointerType>());
2162	}
2163
2164	llvm::Constant *
2165	CodeGenModule::EmitNullConstantForBase(const CXXRecordDecl *Record) {
2166	return ::EmitNullConstant(*this, Record, false);
2167	}
2168