================ @@ -0,0 +1,189 @@ +//===----------------------------------------------------------------------===// +// +// 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 +// +//===----------------------------------------------------------------------===// + +#include "FormatvStringCheck.h" +#include "../utils/OptionsUtils.h" +#include "clang/AST/DeclTemplate.h" +#include "clang/AST/Expr.h" +#include "clang/ASTMatchers/ASTMatchers.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SmallBitVector.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/Support/Error.h" +#include <iterator> +#include <vector> + +using namespace clang::ast_matchers; + +namespace clang::tidy::llvm_check { + +namespace { + +struct ParseResult { + SmallVector<unsigned, 4> Indices; + unsigned MaxIndex = 0; +}; + +} // namespace + +static Expected<ParseResult> parseFormatvString(StringRef Fmt) { + ParseResult Result; + unsigned NextAutoIndex = 0; + bool HasAutomatic = false; + bool HasExplicit = false; + + while (!Fmt.empty()) { + const size_t OpenBrace = Fmt.find('{'); + if (OpenBrace == StringRef::npos) + break; + + Fmt = Fmt.drop_front(OpenBrace); + + // Handle escaped braces '{{'. + if (Fmt.size() > 1 && Fmt[1] == '{') { + Fmt = Fmt.drop_front(2); + continue; + } + + // Find the closing '}'. + const size_t CloseBrace = Fmt.find('}'); + if (CloseBrace == StringRef::npos) + return llvm::createStringError("unterminated brace in format string"); + + // Extract the content between braces. + const StringRef Content = Fmt.substr(1, CloseBrace - 1); + Fmt = Fmt.drop_front(CloseBrace + 1); + + // Parse the replacement field: [index] ["," layout] [":" format] + StringRef IndexStr = Content; + + // Strip layout and format parts for index parsing. + const size_t CommaPos = Content.find(','); + const size_t ColonPos = Content.find(':'); + if (CommaPos != StringRef::npos) + IndexStr = Content.substr(0, CommaPos); + else if (ColonPos != StringRef::npos) + IndexStr = Content.substr(0, ColonPos); + + IndexStr = IndexStr.trim(); + + unsigned Index = 0; + if (IndexStr.empty()) { + Index = NextAutoIndex++; + HasAutomatic = true; + } else { + if (IndexStr.getAsInteger(10, Index)) + return llvm::createStringError( + "invalid replacement index in format string"); + HasExplicit = true; + } + + Result.Indices.push_back(Index); + Result.MaxIndex = std::max(Result.MaxIndex, Index); + } + + if (HasAutomatic && HasExplicit) + return llvm::createStringError( + "format string mixes automatic and explicit indices"); + + return Result; +} + +FormatvStringCheck::FormatvStringCheck(StringRef Name, + ClangTidyContext *Context) + : ClangTidyCheck(Name, Context), + AdditionalFunctions(Options.get("AdditionalFunctions", "")) { + Functions = {"llvm::formatv", "llvm::createStringErrorV"}; + + std::vector<StringRef> CustomFunctions = + utils::options::parseStringList(AdditionalFunctions); + copy(CustomFunctions, std::back_inserter(Functions)); +} + +void FormatvStringCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) { + Options.store(Opts, "AdditionalFunctions", AdditionalFunctions); +} + +void FormatvStringCheck::registerMatchers(MatchFinder *Finder) { + // Build a matcher for all configured function names. + Finder->addMatcher( + callExpr(callee(functionDecl(hasAnyName(Functions), + ast_matchers::isTemplateInstantiation())), + argumentCountAtLeast(1)) + .bind("call"), + this); +} + +void FormatvStringCheck::check(const MatchFinder::MatchResult &Result) { + const auto *Call = Result.Nodes.getNodeAs<CallExpr>("call"); + assert(Call && Call->getNumArgs() > 0); + + const auto *FD = Call->getDirectCallee(); + assert(FD); + + // Find the format string index from the template signature: it's the + // parameter immediately before the trailing parameter pack. + const FunctionDecl *TemplateDecl = FD; + if (const FunctionTemplateDecl *Primary = FD->getPrimaryTemplate()) + TemplateDecl = Primary->getTemplatedDecl(); + + const unsigned NumDeclParams = TemplateDecl->getNumParams(); + if (NumDeclParams < 2) + return; + + const unsigned PackParamIndex = NumDeclParams - 1; + if (!TemplateDecl->getParamDecl(PackParamIndex)->isParameterPack()) + return; + + const unsigned FmtStringIndex = PackParamIndex - 1; + + if (Call->getNumArgs() <= FmtStringIndex) + return; + + // Extract the format string literal. + const Expr *FmtArg = Call->getArg(FmtStringIndex)->IgnoreParenImpCasts(); + const auto *FmtLiteral = dyn_cast<StringLiteral>(FmtArg); + if (!FmtLiteral) + return; + + const StringRef FmtString = FmtLiteral->getString(); + const int NumFmtArgs = Call->getNumArgs() - PackParamIndex; + + auto ParsedOrErr = parseFormatvString(FmtString); + if (!ParsedOrErr) { + diag(FmtLiteral->getBeginLoc(), toString(ParsedOrErr.takeError())); + return; + } + + const ParseResult &Parsed = *ParsedOrErr; + const int NumRequiredArgs = Parsed.Indices.empty() ? 0 : Parsed.MaxIndex + 1; + + if (NumRequiredArgs != NumFmtArgs) { + diag(FmtLiteral->getBeginLoc(), + "format string requires %0 argument%s0, but %1 argument%s1 " + "%plural{1:was|:were}1 provided") + << NumRequiredArgs << NumFmtArgs; + return; + } + + // Check for unused arguments. + if (!Parsed.Indices.empty()) { ---------------- localspook wrote:
I think this outermost `if` can be removed; everything inside it already handles the `n == 0` case correctly. https://github.com/llvm/llvm-project/pull/195974 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
