//===--- MacroArgs.h - Formal argument info for Macros ----------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the MacroArgs interface.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_LEX_MACROARGS_H
#define LLVM_CLANG_LEX_MACROARGS_H
#include "clang/Basic/LLVM.h"
#include "clang/Lex/Token.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/Support/TrailingObjects.h"
#include <vector>
namespace clang {
class MacroInfo;
class Preprocessor;
class SourceLocation;
/// MacroArgs - An instance of this class captures information about
/// the formal arguments specified to a function-like macro invocation.
class MacroArgs final
: private llvm::TrailingObjects<MacroArgs, Token> {
friend TrailingObjects;
/// NumUnexpArgTokens - The number of raw, unexpanded tokens for the
/// arguments. All of the actual argument tokens are allocated immediately
/// after the MacroArgs object in memory. This is all of the arguments
/// concatenated together, with 'EOF' markers at the end of each argument.
unsigned NumUnexpArgTokens;
/// VarargsElided - True if this is a C99 style varargs macro invocation and
/// there was no argument specified for the "..." argument. If the argument
/// was specified (even empty) or this isn't a C99 style varargs function, or
/// if in strict mode and the C99 varargs macro had only a ... argument, this
/// is false.
bool VarargsElided;
/// PreExpArgTokens - Pre-expanded tokens for arguments that need them. Empty
/// if not yet computed. This includes the EOF marker at the end of the
/// stream.
std::vector<std::vector<Token> > PreExpArgTokens;
/// ArgCache - This is a linked list of MacroArgs objects that the
/// Preprocessor owns which we use to avoid thrashing malloc/free.
MacroArgs *ArgCache;
/// MacroArgs - The number of arguments the invoked macro expects.
unsigned NumMacroArgs;
MacroArgs(unsigned NumToks, bool varargsElided, unsigned MacroArgs)
: NumUnexpArgTokens(NumToks), VarargsElided(varargsElided),
ArgCache(nullptr), NumMacroArgs(MacroArgs) {}
~MacroArgs() = default;
public:
/// MacroArgs ctor function - Create a new MacroArgs object with the specified
/// macro and argument info.
static MacroArgs *create(const MacroInfo *MI,
ArrayRef<Token> UnexpArgTokens,
bool VarargsElided, Preprocessor &PP);
/// destroy - Destroy and deallocate the memory for this object.
///
void destroy(Preprocessor &PP);
/// ArgNeedsPreexpansion - If we can prove that the argument won't be affected
/// by pre-expansion, return false. Otherwise, conservatively return true.
bool ArgNeedsPreexpansion(const Token *ArgTok, Preprocessor &PP) const;
/// getUnexpArgument - Return a pointer to the first token of the unexpanded
/// token list for the specified formal.
///
const Token *getUnexpArgument(unsigned Arg) const;
/// getArgLength - Given a pointer to an expanded or unexpanded argument,
/// return the number of tokens, not counting the EOF, that make up the
/// argument.
static unsigned getArgLength(const Token *ArgPtr);
/// getPreExpArgument - Return the pre-expanded form of the specified
/// argument.
const std::vector<Token> &
getPreExpArgument(unsigned Arg, Preprocessor &PP);
/// getNumMacroArguments - Return the number of arguments the invoked macro
/// expects.
unsigned getNumMacroArguments() const { return NumMacroArgs; }
/// isVarargsElidedUse - Return true if this is a C99 style varargs macro
/// invocation and there was no argument specified for the "..." argument. If
/// the argument was specified (even empty) or this isn't a C99 style varargs
/// function, or if in strict mode and the C99 varargs macro had only a ...
/// argument, this returns false.
bool isVarargsElidedUse() const { return VarargsElided; }
/// Returns true if the macro was defined with a variadic (ellipsis) parameter
/// AND was invoked with at least one token supplied as a variadic argument
/// (after pre-expansion).
///
/// \code
/// #define F(a) a
/// #define V(a, ...) __VA_OPT__(a)
/// F() <-- returns false on this invocation.
/// V(,a) <-- returns true on this invocation.
/// V(,) <-- returns false on this invocation.
/// V(,F()) <-- returns false on this invocation.
/// \endcode
///
bool invokedWithVariadicArgument(const MacroInfo *const MI, Preprocessor &PP);
/// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of
/// tokens into the literal string token that should be produced by the C #
/// preprocessor operator. If Charify is true, then it should be turned into
/// a character literal for the Microsoft charize (#@) extension.
///
static Token StringifyArgument(const Token *ArgToks,
Preprocessor &PP, bool Charify,
SourceLocation ExpansionLocStart,
SourceLocation ExpansionLocEnd);
/// deallocate - This should only be called by the Preprocessor when managing
/// its freelist.
MacroArgs *deallocate();
};
} // end namespace clang
#endif