| //===--- 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 <algorithm> |
| |
| using namespace clang; |
| |
| /// MacroArgs ctor function - This destroys the vector passed in. |
| MacroArgs *MacroArgs::create(const MacroInfo *MI, |
| ArrayRef<Token> 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<Token>(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<Token>::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<Token>()); |
| } |
| |
| 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<Token>::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<Token>(); |
| 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<Token> &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<Token> &Result = PreExpArgTokens[Arg]; |
| if (!Result.empty()) return Result; |
| |
| SaveAndRestore<bool> 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; |
| } |