VariadicMacroSupport.h source code [clang_source_code/include/clang/Lex/VariadicMacroSupport.h]

1	//===- VariadicMacroSupport.h - state machines and scope guards -- C++ --===//
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 file defines support types to help with preprocessing variadic macro
10	// (i.e. macros that use: ellipses __VA_ARGS__ ) definitions and
11	// expansions.
12	//
13	//===----------------------------------------------------------------------===//
14
15	#ifndef LLVM_CLANG_LEX_VARIADICMACROSUPPORT_H
16	#define LLVM_CLANG_LEX_VARIADICMACROSUPPORT_H
17
18	#include "clang/Lex/Preprocessor.h"
19	#include "llvm/ADT/SmallVector.h"
20
21	namespace clang {
22	class Preprocessor;
23
24	/// An RAII class that tracks when the Preprocessor starts and stops lexing
25	/// the definition of a (ISO C/C++) variadic macro. As an example, this is
26	/// useful for unpoisoning and repoisoning certain identifiers (such as
27	/// __VA_ARGS__) that are only allowed in this context. Also, being a friend
28	/// of the Preprocessor class allows it to access PP's cached identifiers
29	/// directly (as opposed to performing a lookup each time).
30	class VariadicMacroScopeGuard {
31	const Preprocessor &PP;
32	IdentifierInfo *const Ident__VA_ARGS__;
33	IdentifierInfo *const Ident__VA_OPT__;
34
35	public:
36	VariadicMacroScopeGuard(const Preprocessor &P)
37	: PP(P), Ident__VA_ARGS__(PP.Ident__VA_ARGS__),
38	Ident__VA_OPT__(PP.Ident__VA_OPT__) {
39	(0) . __assert_fail ("Ident__VA_ARGS__->isPoisoned() && \"__VA_ARGS__ should be poisoned \" \"outside an ISO C/C++ variadic \" \"macro definition!\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 41, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(Ident__VA_ARGS__->isPoisoned() && "__VA_ARGS__ should be poisoned "
40	(0) . __assert_fail ("Ident__VA_ARGS__->isPoisoned() && \"__VA_ARGS__ should be poisoned \" \"outside an ISO C/C++ variadic \" \"macro definition!\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 41, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "outside an ISO C/C++ variadic "
41	(0) . __assert_fail ("Ident__VA_ARGS__->isPoisoned() && \"__VA_ARGS__ should be poisoned \" \"outside an ISO C/C++ variadic \" \"macro definition!\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 41, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "macro definition!");
42	(0) . __assert_fail ("!Ident__VA_OPT__ \|\| (Ident__VA_OPT__->isPoisoned() && \"__VA_OPT__ should be poisoned!\")", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 44, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(
43	(0) . __assert_fail ("!Ident__VA_OPT__ \|\| (Ident__VA_OPT__->isPoisoned() && \"__VA_OPT__ should be poisoned!\")", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 44, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> !Ident__VA_OPT__ \|\|
44	(0) . __assert_fail ("!Ident__VA_OPT__ \|\| (Ident__VA_OPT__->isPoisoned() && \"__VA_OPT__ should be poisoned!\")", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 44, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> (Ident__VA_OPT__->isPoisoned() && "__VA_OPT__ should be poisoned!"));
45	}
46
47	/// Client code should call this function just before the Preprocessor is
48	/// about to Lex tokens from the definition of a variadic (ISO C/C++) macro.
49	void enterScope() {
50	Ident__VA_ARGS__->setIsPoisoned(false);
51	if (Ident__VA_OPT__)
52	Ident__VA_OPT__->setIsPoisoned(false);
53	}
54
55	/// Client code should call this function as soon as the Preprocessor has
56	/// either completed lexing the macro's definition tokens, or an error
57	/// occurred and the context is being exited. This function is idempotent
58	/// (might be explicitly called, and then reinvoked via the destructor).
59	void exitScope() {
60	Ident__VA_ARGS__->setIsPoisoned(true);
61	if (Ident__VA_OPT__)
62	Ident__VA_OPT__->setIsPoisoned(true);
63	}
64
65	~VariadicMacroScopeGuard() { exitScope(); }
66	};
67
68	/// A class for tracking whether we're inside a VA_OPT during a
69	/// traversal of the tokens of a variadic macro definition.
70	class VAOptDefinitionContext {
71	/// Contains all the locations of so far unmatched lparens.
72	SmallVector<SourceLocation, 8> UnmatchedOpeningParens;
73
74	const IdentifierInfo *const Ident__VA_OPT__;
75
76
77	public:
78	VAOptDefinitionContext(Preprocessor &PP)
79	: Ident__VA_OPT__(PP.Ident__VA_OPT__) {}
80
81	bool isVAOptToken(const Token &T) const {
82	return Ident__VA_OPT__ && T.getIdentifierInfo() == Ident__VA_OPT__;
83	}
84
85	/// Returns true if we have seen the __VA_OPT__ and '(' but before having
86	/// seen the matching ')'.
87	bool isInVAOpt() const { return UnmatchedOpeningParens.size(); }
88
89	/// Call this function as soon as you see __VA_OPT__ and '('.
90	void sawVAOptFollowedByOpeningParens(const SourceLocation LParenLoc) {
91	(0) . __assert_fail ("!isInVAOpt() && \"Must NOT be within VAOPT context to call this\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 91, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!isInVAOpt() && "Must NOT be within VAOPT context to call this");
92	UnmatchedOpeningParens.push_back(LParenLoc);
93
94	}
95
96	SourceLocation getUnmatchedOpeningParenLoc() const {
97	(0) . __assert_fail ("isInVAOpt() && \"Must be within VAOPT context to call this\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 97, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(isInVAOpt() && "Must be within VAOPT context to call this");
98	return UnmatchedOpeningParens.back();
99	}
100
101	/// Call this function each time an rparen is seen. It returns true only if
102	/// the rparen that was just seen was the eventual (non-nested) closing
103	/// paren for VAOPT, and ejects us out of the VAOPT context.
104	bool sawClosingParen() {
105	(0) . __assert_fail ("isInVAOpt() && \"Must be within VAOPT context to call this\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 105, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(isInVAOpt() && "Must be within VAOPT context to call this");
106	UnmatchedOpeningParens.pop_back();
107	return !UnmatchedOpeningParens.size();
108	}
109
110	/// Call this function each time an lparen is seen.
111	void sawOpeningParen(SourceLocation LParenLoc) {
112	(0) . __assert_fail ("isInVAOpt() && \"Must be within VAOPT context to call this\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 112, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(isInVAOpt() && "Must be within VAOPT context to call this");
113	UnmatchedOpeningParens.push_back(LParenLoc);
114	}
115
116	};
117
118	/// A class for tracking whether we're inside a VA_OPT during a
119	/// traversal of the tokens of a macro during macro expansion.
120	class VAOptExpansionContext : VAOptDefinitionContext {
121
122	Token SyntheticEOFToken;
123
124	// The (spelling) location of the current __VA_OPT__ in the replacement list
125	// of the function-like macro being expanded.
126	SourceLocation VAOptLoc;
127
128	// NumOfTokensPriorToVAOpt : when != -1, contains the index of the first
129	// token of the current VAOPT contents (so we know where to start eager
130	// token-pasting and stringification) within the substituted tokens of
131	// the function-like macro's new replacement list.
132	int NumOfTokensPriorToVAOpt = -1;
133
134	unsigned LeadingSpaceForStringifiedToken : 1;
135
136	unsigned StringifyBefore : 1;
137	unsigned CharifyBefore : 1;
138
139
140	bool hasStringifyBefore() const {
141	(0) . __assert_fail ("!isReset() && \"Must only be called if the state has not been reset\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 142, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!isReset() &&
142	(0) . __assert_fail ("!isReset() && \"Must only be called if the state has not been reset\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 142, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "Must only be called if the state has not been reset");
143	return StringifyBefore;
144	}
145
146	bool isReset() const {
147	return NumOfTokensPriorToVAOpt == -1 \|\|
148	VAOptLoc.isInvalid();
149	}
150
151	public:
152	VAOptExpansionContext(Preprocessor &PP)
153	: VAOptDefinitionContext(PP), LeadingSpaceForStringifiedToken(false),
154	StringifyBefore(false), CharifyBefore(false) {
155	SyntheticEOFToken.startToken();
156	SyntheticEOFToken.setKind(tok::eof);
157	}
158
159	void reset() {
160	VAOptLoc = SourceLocation();
161	NumOfTokensPriorToVAOpt = -1;
162	LeadingSpaceForStringifiedToken = false;
163	StringifyBefore = false;
164	CharifyBefore = false;
165	}
166
167	const Token &getEOFTok() const { return SyntheticEOFToken; }
168
169	void sawHashOrHashAtBefore(const bool HasLeadingSpace,
170	const bool IsHashAt) {
171
172	StringifyBefore = !IsHashAt;
173	CharifyBefore = IsHashAt;
174	LeadingSpaceForStringifiedToken = HasLeadingSpace;
175	}
176
177
178
179	bool hasCharifyBefore() const {
180	(0) . __assert_fail ("!isReset() && \"Must only be called if the state has not been reset\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 181, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!isReset() &&
181	(0) . __assert_fail ("!isReset() && \"Must only be called if the state has not been reset\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 181, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "Must only be called if the state has not been reset");
182	return CharifyBefore;
183	}
184	bool hasStringifyOrCharifyBefore() const {
185	return hasStringifyBefore() \|\| hasCharifyBefore();
186	}
187
188	unsigned int getNumberOfTokensPriorToVAOpt() const {
189	(0) . __assert_fail ("!isReset() && \"Must only be called if the state has not been reset\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 190, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!isReset() &&
190	(0) . __assert_fail ("!isReset() && \"Must only be called if the state has not been reset\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 190, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "Must only be called if the state has not been reset");
191	return NumOfTokensPriorToVAOpt;
192	}
193
194	bool getLeadingSpaceForStringifiedToken() const {
195	(0) . __assert_fail ("hasStringifyBefore() && \"Must only be called if this has been marked for stringification\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 196, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(hasStringifyBefore() &&
196	(0) . __assert_fail ("hasStringifyBefore() && \"Must only be called if this has been marked for stringification\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 196, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "Must only be called if this has been marked for stringification");
197	return LeadingSpaceForStringifiedToken;
198	}
199
200	void sawVAOptFollowedByOpeningParens(const SourceLocation VAOptLoc,
201	const unsigned int NumPriorTokens) {
202	(0) . __assert_fail ("VAOptLoc.isFileID() && \"Must not come from a macro expansion\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 202, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(VAOptLoc.isFileID() && "Must not come from a macro expansion");
203	(0) . __assert_fail ("isReset() && \"Must only be called if the state has been reset\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 203, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(isReset() && "Must only be called if the state has been reset");
204	VAOptDefinitionContext::sawVAOptFollowedByOpeningParens(SourceLocation());
205	this->VAOptLoc = VAOptLoc;
206	NumOfTokensPriorToVAOpt = NumPriorTokens;
207	(0) . __assert_fail ("NumOfTokensPriorToVAOpt > -1 && \"Too many prior tokens\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 208, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(NumOfTokensPriorToVAOpt > -1 &&
208	(0) . __assert_fail ("NumOfTokensPriorToVAOpt > -1 && \"Too many prior tokens\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 208, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "Too many prior tokens");
209	}
210
211	SourceLocation getVAOptLoc() const {
212	(0) . __assert_fail ("!isReset() && \"Must only be called if the state has not been reset\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 213, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!isReset() &&
213	(0) . __assert_fail ("!isReset() && \"Must only be called if the state has not been reset\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 213, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "Must only be called if the state has not been reset");
214	(0) . __assert_fail ("VAOptLoc.isValid() && \"__VA_OPT__ location must be valid\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/VariadicMacroSupport.h", 214, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(VAOptLoc.isValid() && "__VA_OPT__ location must be valid");
215	return VAOptLoc;
216	}
217	using VAOptDefinitionContext::isVAOptToken;
218	using VAOptDefinitionContext::isInVAOpt;
219	using VAOptDefinitionContext::sawClosingParen;
220	using VAOptDefinitionContext::sawOpeningParen;
221
222	};
223	} // end namespace clang
224
225	#endif
226