1 //===--- MacroArgs.h - Formal argument info for Macros ----------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // This file defines the MacroArgs interface.
11 //===----------------------------------------------------------------------===//
13 #ifndef LLVM_CLANG_LEX_MACROARGS_H
14 #define LLVM_CLANG_LEX_MACROARGS_H
16 #include "clang/Basic/LLVM.h"
17 #include "clang/Lex/Token.h"
18 #include "llvm/ADT/ArrayRef.h"
19 #include "llvm/Support/TrailingObjects.h"
27 /// MacroArgs - An instance of this class captures information about
28 /// the formal arguments specified to a function-like macro invocation.
30 : private llvm::TrailingObjects<MacroArgs, Token> {
32 friend TrailingObjects;
33 /// NumUnexpArgTokens - The number of raw, unexpanded tokens for the
34 /// arguments. All of the actual argument tokens are allocated immediately
35 /// after the MacroArgs object in memory. This is all of the arguments
36 /// concatenated together, with 'EOF' markers at the end of each argument.
37 unsigned NumUnexpArgTokens;
39 /// VarargsElided - True if this is a C99 style varargs macro invocation and
40 /// there was no argument specified for the "..." argument. If the argument
41 /// was specified (even empty) or this isn't a C99 style varargs function, or
42 /// if in strict mode and the C99 varargs macro had only a ... argument, this
46 /// PreExpArgTokens - Pre-expanded tokens for arguments that need them. Empty
47 /// if not yet computed. This includes the EOF marker at the end of the
49 std::vector<std::vector<Token> > PreExpArgTokens;
51 /// StringifiedArgs - This contains arguments in 'stringified' form. If the
52 /// stringified form of an argument has not yet been computed, this is empty.
53 std::vector<Token> StringifiedArgs;
55 /// ArgCache - This is a linked list of MacroArgs objects that the
56 /// Preprocessor owns which we use to avoid thrashing malloc/free.
59 /// MacroArgs - The number of arguments the invoked macro expects.
60 unsigned NumMacroArgs;
62 MacroArgs(unsigned NumToks, bool varargsElided, unsigned MacroArgs)
63 : NumUnexpArgTokens(NumToks), VarargsElided(varargsElided),
64 ArgCache(nullptr), NumMacroArgs(MacroArgs) {}
65 ~MacroArgs() = default;
68 /// MacroArgs ctor function - Create a new MacroArgs object with the specified
69 /// macro and argument info.
70 static MacroArgs *create(const MacroInfo *MI,
71 ArrayRef<Token> UnexpArgTokens,
72 bool VarargsElided, Preprocessor &PP);
74 /// destroy - Destroy and deallocate the memory for this object.
76 void destroy(Preprocessor &PP);
78 /// ArgNeedsPreexpansion - If we can prove that the argument won't be affected
79 /// by pre-expansion, return false. Otherwise, conservatively return true.
80 bool ArgNeedsPreexpansion(const Token *ArgTok, Preprocessor &PP) const;
82 /// getUnexpArgument - Return a pointer to the first token of the unexpanded
83 /// token list for the specified formal.
85 const Token *getUnexpArgument(unsigned Arg) const;
87 /// getArgLength - Given a pointer to an expanded or unexpanded argument,
88 /// return the number of tokens, not counting the EOF, that make up the
90 static unsigned getArgLength(const Token *ArgPtr);
92 /// getPreExpArgument - Return the pre-expanded form of the specified
94 const std::vector<Token> &
95 getPreExpArgument(unsigned Arg, Preprocessor &PP);
97 /// getStringifiedArgument - Compute, cache, and return the specified argument
98 /// that has been 'stringified' as required by the # operator.
99 const Token &getStringifiedArgument(unsigned ArgNo, Preprocessor &PP,
100 SourceLocation ExpansionLocStart,
101 SourceLocation ExpansionLocEnd);
103 /// getNumMacroArguments - Return the number of arguments the invoked macro
105 unsigned getNumMacroArguments() const { return NumMacroArgs; }
107 /// isVarargsElidedUse - Return true if this is a C99 style varargs macro
108 /// invocation and there was no argument specified for the "..." argument. If
109 /// the argument was specified (even empty) or this isn't a C99 style varargs
110 /// function, or if in strict mode and the C99 varargs macro had only a ...
111 /// argument, this returns false.
112 bool isVarargsElidedUse() const { return VarargsElided; }
114 /// Returns true if the macro was defined with a variadic (ellipsis) parameter
115 /// AND was invoked with at least one token supplied as a variadic argument
116 /// (after pre-expansion).
120 /// #define V(a, ...) __VA_OPT__(a)
121 /// F() <-- returns false on this invocation.
122 /// V(,a) <-- returns true on this invocation.
123 /// V(,) <-- returns false on this invocation.
124 /// V(,F()) <-- returns false on this invocation.
127 bool invokedWithVariadicArgument(const MacroInfo *const MI, Preprocessor &PP);
129 /// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of
130 /// tokens into the literal string token that should be produced by the C #
131 /// preprocessor operator. If Charify is true, then it should be turned into
132 /// a character literal for the Microsoft charize (#@) extension.
134 static Token StringifyArgument(const Token *ArgToks,
135 Preprocessor &PP, bool Charify,
136 SourceLocation ExpansionLocStart,
137 SourceLocation ExpansionLocEnd);
140 /// deallocate - This should only be called by the Preprocessor when managing
142 MacroArgs *deallocate();
145 } // end namespace clang