Julian Schmidt 028ea71fdd
[clang-tidy] fix insertion location for function pointers in cppcoreguidelines-init-variables (#112091)
Previously, the insertion location for the `= nullptr` fix would be
after the variable name. However, if the variable is of type function
pointer that is not an alias, then the insertion would happen inside the
type specification: `void (*a1)(void*);` -> `void (*a1 =
nullptr)(void*);`.
With this change, the insertion location will be at the next
'terminator'. That is, at the next `,` or `;`, as that will finish the
current declaration: `void (a1)(void*) = nullptr;`.

Fixes #112089
2024-11-10 18:26:42 +01:00

122 lines
4.3 KiB
C++

//===--- InitVariablesCheck.cpp - clang-tidy ------------------------------===//
//
// 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 "InitVariablesCheck.h"
#include "../utils/LexerUtils.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Type.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Preprocessor.h"
#include <optional>
using namespace clang::ast_matchers;
namespace clang::tidy::cppcoreguidelines {
namespace {
AST_MATCHER(VarDecl, isLocalVarDecl) { return Node.isLocalVarDecl(); }
} // namespace
InitVariablesCheck::InitVariablesCheck(StringRef Name,
ClangTidyContext *Context)
: ClangTidyCheck(Name, Context),
IncludeInserter(Options.getLocalOrGlobal("IncludeStyle",
utils::IncludeSorter::IS_LLVM),
areDiagsSelfContained()),
MathHeader(Options.get("MathHeader", "<math.h>")) {}
void InitVariablesCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
Options.store(Opts, "IncludeStyle", IncludeInserter.getStyle());
Options.store(Opts, "MathHeader", MathHeader);
}
void InitVariablesCheck::registerMatchers(MatchFinder *Finder) {
std::string BadDecl = "badDecl";
Finder->addMatcher(
varDecl(unless(hasInitializer(anything())), unless(isInstantiated()),
isLocalVarDecl(), unless(isStaticLocal()), isDefinition(),
unless(hasParent(cxxCatchStmt())),
optionally(hasParent(declStmt(hasParent(
cxxForRangeStmt(hasLoopVariable(varDecl().bind(BadDecl))))))),
unless(equalsBoundNode(BadDecl)))
.bind("vardecl"),
this);
}
void InitVariablesCheck::registerPPCallbacks(const SourceManager &SM,
Preprocessor *PP,
Preprocessor *ModuleExpanderPP) {
IncludeInserter.registerPreprocessor(PP);
}
void InitVariablesCheck::check(const MatchFinder::MatchResult &Result) {
const auto *MatchedDecl = Result.Nodes.getNodeAs<VarDecl>("vardecl");
const ASTContext &Context = *Result.Context;
const SourceManager &Source = Context.getSourceManager();
// Clang diagnostic error may cause the variable to be an invalid int vardecl
if (MatchedDecl->isInvalidDecl())
return;
// We want to warn about cases where the type name
// comes from a macro like this:
//
// TYPENAME_FROM_MACRO var;
//
// but not if the entire declaration comes from
// one:
//
// DEFINE_SOME_VARIABLE();
//
// or if the definition comes from a macro like SWAP
// that uses an internal temporary variable.
//
// Thus check that the variable name does
// not come from a macro expansion.
if (MatchedDecl->getEndLoc().isMacroID())
return;
QualType TypePtr = MatchedDecl->getType();
std::optional<const char *> InitializationString;
bool AddMathInclude = false;
if (TypePtr->isEnumeralType())
InitializationString = nullptr;
else if (TypePtr->isBooleanType())
InitializationString = " = false";
else if (TypePtr->isIntegerType())
InitializationString = " = 0";
else if (TypePtr->isFloatingType()) {
InitializationString = " = NAN";
AddMathInclude = true;
} else if (TypePtr->isAnyPointerType()) {
if (getLangOpts().CPlusPlus11)
InitializationString = " = nullptr";
else
InitializationString = " = NULL";
}
if (InitializationString) {
auto Diagnostic =
diag(MatchedDecl->getLocation(), "variable %0 is not initialized")
<< MatchedDecl;
if (*InitializationString != nullptr)
Diagnostic << FixItHint::CreateInsertion(
utils::lexer::findNextTerminator(MatchedDecl->getLocation(),
*Result.SourceManager,
Result.Context->getLangOpts()),
*InitializationString);
if (AddMathInclude) {
Diagnostic << IncludeInserter.createIncludeInsertion(
Source.getFileID(MatchedDecl->getBeginLoc()), MathHeader);
}
}
}
} // namespace clang::tidy::cppcoreguidelines