//===--- MacroArgs.cpp - Formal argument info for Macros ------------------===// // // 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 implements the MacroArgs interface. // //===----------------------------------------------------------------------===// #include "clang/Lex/MacroArgs.h" #include "clang/Lex/LexDiagnostic.h" #include "clang/Lex/MacroInfo.h" #include "clang/Lex/Preprocessor.h" #include "llvm/ADT/SmallString.h" #include "llvm/Support/SaveAndRestore.h" #include using namespace clang; /// MacroArgs ctor function - This destroys the vector passed in. MacroArgs *MacroArgs::create(const MacroInfo *MI, ArrayRef UnexpArgTokens, bool VarargsElided, Preprocessor &PP) { assert(MI->isFunctionLike() && "Can't have args for an object-like macro!"); MacroArgs **ResultEnt = nullptr; unsigned ClosestMatch = ~0U; // See if we have an entry with a big enough argument list to reuse on the // free list. If so, reuse it. for (MacroArgs **Entry = &PP.MacroArgCache; *Entry; Entry = &(*Entry)->ArgCache) { if ((*Entry)->NumUnexpArgTokens >= UnexpArgTokens.size() && (*Entry)->NumUnexpArgTokens < ClosestMatch) { ResultEnt = Entry; // If we have an exact match, use it. if ((*Entry)->NumUnexpArgTokens == UnexpArgTokens.size()) break; // Otherwise, use the best fit. ClosestMatch = (*Entry)->NumUnexpArgTokens; } } MacroArgs *Result; if (!ResultEnt) { // Allocate memory for a MacroArgs object with the lexer tokens at the end, // and construct the MacroArgs object. Result = new ( llvm::safe_malloc(totalSizeToAlloc(UnexpArgTokens.size()))) MacroArgs(UnexpArgTokens.size(), VarargsElided, MI->getNumParams()); } else { Result = *ResultEnt; // Unlink this node from the preprocessors singly linked list. *ResultEnt = Result->ArgCache; Result->NumUnexpArgTokens = UnexpArgTokens.size(); Result->VarargsElided = VarargsElided; Result->NumMacroArgs = MI->getNumParams(); } // Copy the actual unexpanded tokens to immediately after the result ptr. if (!UnexpArgTokens.empty()) { static_assert(std::is_trivial::value, "assume trivial copyability if copying into the " "uninitialized array (as opposed to reusing a cached " "MacroArgs)"); std::copy(UnexpArgTokens.begin(), UnexpArgTokens.end(), Result->getTrailingObjects()); } return Result; } /// destroy - Destroy and deallocate the memory for this object. /// void MacroArgs::destroy(Preprocessor &PP) { // Don't clear PreExpArgTokens, just clear the entries. Clearing the entries // would deallocate the element vectors. for (unsigned i = 0, e = PreExpArgTokens.size(); i != e; ++i) PreExpArgTokens[i].clear(); // Add this to the preprocessor's free list. ArgCache = PP.MacroArgCache; PP.MacroArgCache = this; } /// deallocate - This should only be called by the Preprocessor when managing /// its freelist. MacroArgs *MacroArgs::deallocate() { MacroArgs *Next = ArgCache; // Run the dtor to deallocate the vectors. this->~MacroArgs(); // Release the memory for the object. static_assert(std::is_trivially_destructible::value, "assume trivially destructible and forego destructors"); free(this); return Next; } /// getArgLength - Given a pointer to an expanded or unexpanded argument, /// return the number of tokens, not counting the EOF, that make up the /// argument. unsigned MacroArgs::getArgLength(const Token *ArgPtr) { unsigned NumArgTokens = 0; for (; ArgPtr->isNot(tok::eof); ++ArgPtr) ++NumArgTokens; return NumArgTokens; } /// getUnexpArgument - Return the unexpanded tokens for the specified formal. /// const Token *MacroArgs::getUnexpArgument(unsigned Arg) const { assert(Arg < getNumMacroArguments() && "Invalid arg #"); // The unexpanded argument tokens start immediately after the MacroArgs object // in memory. const Token *Start = getTrailingObjects(); const Token *Result = Start; // Scan to find Arg. for (; Arg; ++Result) { assert(Result < Start+NumUnexpArgTokens && "Invalid arg #"); if (Result->is(tok::eof)) --Arg; } assert(Result < Start+NumUnexpArgTokens && "Invalid arg #"); return Result; } bool MacroArgs::invokedWithVariadicArgument(const MacroInfo *const MI, Preprocessor &PP) { if (!MI->isVariadic()) return false; const int VariadicArgIndex = getNumMacroArguments() - 1; return getPreExpArgument(VariadicArgIndex, PP).front().isNot(tok::eof); } /// ArgNeedsPreexpansion - If we can prove that the argument won't be affected /// by pre-expansion, return false. Otherwise, conservatively return true. bool MacroArgs::ArgNeedsPreexpansion(const Token *ArgTok, Preprocessor &PP) const { // If there are no identifiers in the argument list, or if the identifiers are // known to not be macros, pre-expansion won't modify it. for (; ArgTok->isNot(tok::eof); ++ArgTok) if (IdentifierInfo *II = ArgTok->getIdentifierInfo()) if (II->hasMacroDefinition()) // Return true even though the macro could be a function-like macro // without a following '(' token, or could be disabled, or not visible. return true; return false; } /// getPreExpArgument - Return the pre-expanded form of the specified /// argument. const std::vector &MacroArgs::getPreExpArgument(unsigned Arg, Preprocessor &PP) { assert(Arg < getNumMacroArguments() && "Invalid argument number!"); // If we have already computed this, return it. if (PreExpArgTokens.size() < getNumMacroArguments()) PreExpArgTokens.resize(getNumMacroArguments()); std::vector &Result = PreExpArgTokens[Arg]; if (!Result.empty()) return Result; SaveAndRestore PreExpandingMacroArgs(PP.InMacroArgPreExpansion, true); const Token *AT = getUnexpArgument(Arg); unsigned NumToks = getArgLength(AT)+1; // Include the EOF. // Otherwise, we have to pre-expand this argument, populating Result. To do // this, we set up a fake TokenLexer to lex from the unexpanded argument // list. With this installed, we lex expanded tokens until we hit the EOF // token at the end of the unexp list. PP.EnterTokenStream(AT, NumToks, false /*disable expand*/, false /*owns tokens*/, false /*is reinject*/); // Lex all of the macro-expanded tokens into Result. do { Result.push_back(Token()); Token &Tok = Result.back(); PP.Lex(Tok); } while (Result.back().isNot(tok::eof)); // Pop the token stream off the top of the stack. We know that the internal // pointer inside of it is to the "end" of the token stream, but the stack // will not otherwise be popped until the next token is lexed. The problem is // that the token may be lexed sometime after the vector of tokens itself is // destroyed, which would be badness. if (PP.InCachingLexMode()) PP.ExitCachingLexMode(); PP.RemoveTopOfLexerStack(); return Result; } /// 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. /// Token MacroArgs::StringifyArgument(const Token *ArgToks, Preprocessor &PP, bool Charify, SourceLocation ExpansionLocStart, SourceLocation ExpansionLocEnd) { Token Tok; Tok.startToken(); Tok.setKind(Charify ? tok::char_constant : tok::string_literal); const Token *ArgTokStart = ArgToks; // Stringify all the tokens. SmallString<128> Result; Result += "\""; bool isFirst = true; for (; ArgToks->isNot(tok::eof); ++ArgToks) { const Token &Tok = *ArgToks; if (!isFirst && (Tok.hasLeadingSpace() || Tok.isAtStartOfLine())) Result += ' '; isFirst = false; // If this is a string or character constant, escape the token as specified // by 6.10.3.2p2. if (tok::isStringLiteral(Tok.getKind()) || // "foo", u8R"x(foo)x"_bar, etc. Tok.is(tok::char_constant) || // 'x' Tok.is(tok::wide_char_constant) || // L'x'. Tok.is(tok::utf8_char_constant) || // u8'x'. Tok.is(tok::utf16_char_constant) || // u'x'. Tok.is(tok::utf32_char_constant)) { // U'x'. bool Invalid = false; std::string TokStr = PP.getSpelling(Tok, &Invalid); if (!Invalid) { std::string Str = Lexer::Stringify(TokStr); Result.append(Str.begin(), Str.end()); } } else if (Tok.is(tok::code_completion)) { PP.CodeCompleteNaturalLanguage(); } else { // Otherwise, just append the token. Do some gymnastics to get the token // in place and avoid copies where possible. unsigned CurStrLen = Result.size(); Result.resize(CurStrLen+Tok.getLength()); const char *BufPtr = Result.data() + CurStrLen; bool Invalid = false; unsigned ActualTokLen = PP.getSpelling(Tok, BufPtr, &Invalid); if (!Invalid) { // If getSpelling returned a pointer to an already uniqued version of // the string instead of filling in BufPtr, memcpy it onto our string. if (ActualTokLen && BufPtr != &Result[CurStrLen]) memcpy(&Result[CurStrLen], BufPtr, ActualTokLen); // If the token was dirty, the spelling may be shorter than the token. if (ActualTokLen != Tok.getLength()) Result.resize(CurStrLen+ActualTokLen); } } } // If the last character of the string is a \, and if it isn't escaped, this // is an invalid string literal, diagnose it as specified in C99. if (Result.back() == '\\') { // Count the number of consecutive \ characters. If even, then they are // just escaped backslashes, otherwise it's an error. unsigned FirstNonSlash = Result.size()-2; // Guaranteed to find the starting " if nothing else. while (Result[FirstNonSlash] == '\\') --FirstNonSlash; if ((Result.size()-1-FirstNonSlash) & 1) { // Diagnose errors for things like: #define F(X) #X / F(\) PP.Diag(ArgToks[-1], diag::pp_invalid_string_literal); Result.pop_back(); // remove one of the \'s. } } Result += '"'; // If this is the charify operation and the result is not a legal character // constant, diagnose it. if (Charify) { // First step, turn double quotes into single quotes: Result[0] = '\''; Result[Result.size()-1] = '\''; // Check for bogus character. bool isBad = false; if (Result.size() == 3) isBad = Result[1] == '\''; // ''' is not legal. '\' already fixed above. else isBad = (Result.size() != 4 || Result[1] != '\\'); // Not '\x' if (isBad) { PP.Diag(ArgTokStart[0], diag::err_invalid_character_to_charify); Result = "' '"; // Use something arbitrary, but legal. } } PP.CreateString(Result, Tok, ExpansionLocStart, ExpansionLocEnd); return Tok; }