[clang-tidy] Add portability-avoid-platform-specific-fundamental-types

clang-tools-extra/clang-tidy/portability/AvoidPlatformSpecificFundamentalTypesCheck.cpp

@@ -0,0 +1,260 @@
+//===--- AvoidPlatformSpecificFundamentalTypesCheck.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 "AvoidPlatformSpecificFundamentalTypesCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Basic/TargetInfo.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::portability {
+
+AvoidPlatformSpecificFundamentalTypesCheck::
+ AvoidPlatformSpecificFundamentalTypesCheck(StringRef Name,
+ ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context),
+ WarnOnFloats(Options.get("WarnOnFloats", true)),
+ WarnOnInts(Options.get("WarnOnInts", true)),
+ WarnOnChars(Options.get("WarnOnChars", true)),
+ IncludeInserter(Options.getLocalOrGlobal("IncludeStyle",
+ utils::IncludeSorter::IS_LLVM),
+ areDiagsSelfContained()) {}
+
+void AvoidPlatformSpecificFundamentalTypesCheck::registerPPCallbacks(
+ const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
+ IncludeInserter.registerPreprocessor(PP);
+}
+
+void AvoidPlatformSpecificFundamentalTypesCheck::storeOptions(
+ ClangTidyOptions::OptionMap &Opts) {
+ Options.store(Opts, "WarnOnFloats", WarnOnFloats);
+ Options.store(Opts, "WarnOnInts", WarnOnInts);
+ Options.store(Opts, "WarnOnChars", WarnOnChars);
+ Options.store(Opts, "IncludeStyle", IncludeInserter.getStyle());
+}
+
+std::string AvoidPlatformSpecificFundamentalTypesCheck::getFloatReplacement(
+ const BuiltinType *BT, ASTContext &Context) const {
+ const TargetInfo &Target = Context.getTargetInfo();
+
+ auto GetReplacementType = [](unsigned Width) {
+ switch (Width) {
+ // This is ambiguous by default since it could be bfloat16 or float16
+ case 16U:
+ return "";
+ case 32U:
+ return "float32_t";
+ case 64U:
+ return "float64_t";
+ case 128U:
+ return "float128_t";
+ default:
+ return "";
+ }
+ };
+
+ switch (BT->getKind()) {
+ // Not an ambiguous type
+ case BuiltinType::BFloat16:
+ return "bfloat16_t";
+ case BuiltinType::Half:
+ return GetReplacementType(Target.getHalfWidth());
+ case BuiltinType::Float:
+ return GetReplacementType(Target.getFloatWidth());
+ case BuiltinType::Double:
+ return GetReplacementType(Target.getDoubleWidth());
+ default:
+ return "";
+ }
+}
+
+void AvoidPlatformSpecificFundamentalTypesCheck::registerMatchers(
+ MatchFinder *Finder) {
+ // Build the list of type strings to match
+ std::vector<std::string> TypeStrings;
+
+ // Add integer types if the option is enabled
+ if (WarnOnInts) {
+ TypeStrings.insert(TypeStrings.end(), {"short",
+ "short int",
+ "signed short",
+ "signed short int",
+ "unsigned short",
+ "unsigned short int",
+ "int",
+ "signed",
+ "signed int",
+ "unsigned",
+ "unsigned int",
+ "long",
+ "long int",
+ "signed long",
+ "signed long int",
+ "unsigned long",
+ "unsigned long int",
+ "long long",
+ "long long int",
+ "signed long long",
+ "signed long long int",
+ "unsigned long long",
+ "unsigned long long int"});
+ }
+
+ // Add float types if the option is enabled
+ if (WarnOnFloats) {
+ TypeStrings.insert(TypeStrings.end(),
+ {"half", "__bf16", "float", "double", "long double"});
+ }
+
+ // Add char types if the option is enabled
+ if (WarnOnChars) {
+ TypeStrings.insert(TypeStrings.end(),
+ {"char", "signed char", "unsigned char"});
+ }
+
+ // If no types are enabled, return early
+ if (TypeStrings.empty()) {
+ return;
+ }
+
+ // Create the matcher dynamically
+ auto TypeMatcher = asString(TypeStrings.front());
+ for (const auto &TypeString : TypeStrings) {
+ TypeMatcher = anyOf(TypeMatcher, asString(TypeString));
+ }
+
+ auto PlatformSpecificFundamentalType = qualType(allOf(
+ // Must be a builtin type directly (not through typedef)
+ builtinType(),
+ // Match the specific fundamental types we care about
+ TypeMatcher));
+
+ // Match variable declarations with platform-specific fundamental types
+ Finder->addMatcher(
+ varDecl(hasType(PlatformSpecificFundamentalType)).bind("var_decl"), this);
+
+ // Match function declarations with platform-specific fundamental return types
+ Finder->addMatcher(
+ functionDecl(returns(PlatformSpecificFundamentalType)).bind("func_decl"),
+ this);
+
+ // Match function parameters with platform-specific fundamental types
+ Finder->addMatcher(
+ parmVarDecl(hasType(PlatformSpecificFundamentalType)).bind("param_decl"),
+ this);
+
+ // Match field declarations with platform-specific fundamental types
+ Finder->addMatcher(
+ fieldDecl(hasType(PlatformSpecificFundamentalType)).bind("field_decl"),
+ this);
+
+ // Match typedef declarations with platform-specific fundamental underlying
+ // types
+ Finder->addMatcher(
+ typedefDecl(hasUnderlyingType(PlatformSpecificFundamentalType))
+ .bind("typedef_decl"),
+ this);
+
+ // Match type alias declarations with platform-specific fundamental underlying
+ // types
+ Finder->addMatcher(typeAliasDecl(hasType(PlatformSpecificFundamentalType))
+ .bind("alias_decl"),
+ this);
+}
+
+void AvoidPlatformSpecificFundamentalTypesCheck::check(
+ const MatchFinder::MatchResult &Result) {
+ SourceLocation Loc;
+ QualType QT;
+ SourceRange TypeRange;
+
+ auto SetTypeRange = [&TypeRange](auto Decl) {
+ if (Decl->getTypeSourceInfo()) {
+ TypeRange = Decl->getTypeSourceInfo()->getTypeLoc().getSourceRange();
+ }
+ };
+
+ if (const auto *VD = Result.Nodes.getNodeAs<VarDecl>("var_decl")) {
+ Loc = VD->getLocation();
+ QT = VD->getType();
+ SetTypeRange(VD);
+ } else if (const auto *FD =
+ Result.Nodes.getNodeAs<FunctionDecl>("func_decl")) {
+ Loc = FD->getLocation();
+ QT = FD->getReturnType();
+ SetTypeRange(FD);
+ } else if (const auto *PD =
+ Result.Nodes.getNodeAs<ParmVarDecl>("param_decl")) {
+ Loc = PD->getLocation();
+ QT = PD->getType();
+ SetTypeRange(PD);
+ } else if (const auto *FD = Result.Nodes.getNodeAs<FieldDecl>("field_decl")) {
+ Loc = FD->getLocation();
+ QT = FD->getType();
+ SetTypeRange(FD);
+ } else if (const auto *TD =
+ Result.Nodes.getNodeAs<TypedefDecl>("typedef_decl")) {
+ Loc = TD->getLocation();
+ QT = TD->getUnderlyingType();
+ SetTypeRange(TD);
+ } else if (const auto *AD =
+ Result.Nodes.getNodeAs<TypeAliasDecl>("alias_decl")) {
+ Loc = AD->getLocation();
+ QT = AD->getUnderlyingType();
+ SetTypeRange(AD);
+ } else {
+ return;
+ }
+
+ // Get the type name for the diagnostic
+ const std::string TypeName = QT.getAsString();
+
+ // Check the type category
+ const auto *BT = QT->getAs<BuiltinType>();
+
+ if (BT->isFloatingPoint()) {
+ // Handle floating point types
+ const std::string Replacement = getFloatReplacement(BT, *Result.Context);
+ if (!Replacement.empty()) {
+ auto Diag =
+ diag(Loc, "avoid using platform-dependent floating point type '%0'; "
+ "consider using '%1' instead")
+ << TypeName << Replacement;
+
+ if (TypeRange.isValid()) {
+ Diag << FixItHint::CreateReplacement(TypeRange, Replacement);
+ }
+
+ if (auto IncludeFixit = IncludeInserter.createIncludeInsertion(
+ Result.SourceManager->getFileID(Loc), "<stdfloat>")) {
+ Diag << *IncludeFixit;
+ }
+ } else {
+ diag(Loc, "avoid using platform-dependent floating point type '%0'; "
+ "consider using a typedef or fixed-width type instead")
+ << TypeName;
+ }
+ } else if (BT->getKind() == BuiltinType::Char_S ||
+ BT->getKind() == BuiltinType::Char_U ||
+ BT->getKind() == BuiltinType::SChar ||
+ BT->getKind() == BuiltinType::UChar) {
+ // Handle char types
+ diag(Loc, "avoid using platform-dependent character type '%0'; "
+ "consider using char8_t for text or std::byte for bytes")
+ << TypeName;
+ } else {
+ // Handle integer types
+ diag(Loc, "avoid using platform-dependent fundamental integer type '%0'; "
+ "consider using a typedef or fixed-width type instead")
+ << TypeName;
+ }
+}
+
+} // namespace clang::tidy::portability

clang-tools-extra/clang-tidy/portability/AvoidPlatformSpecificFundamentalTypesCheck.h

@@ -0,0 +1,52 @@
+//==-- AvoidPlatformSpecificFundamentalTypesCheck.h - clang-tidy -*- 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
+//
+//==------------------------------------------------------------------------==//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PORTABILITY_AVOIDPLATFORMSPECIFICFUNDAMENTALTYPESCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PORTABILITY_AVOIDPLATFORMSPECIFICFUNDAMENTALTYPESCHECK_H
+
+#include "../ClangTidyCheck.h"
+#include "../utils/IncludeInserter.h"
+
+namespace clang::tidy::portability {
+
+/// Find fundamental platform-dependent types and recommend using typedefs or
+/// fixed-width types.
+///
+/// Detects fundamental types (int, short, long, long long, char, float, etc)
+/// and warns against their use due to platform-dependent behavior.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/portability/avoid-platform-specific-fundamental-types.html
+class AvoidPlatformSpecificFundamentalTypesCheck : public ClangTidyCheck {
+public:
+ AvoidPlatformSpecificFundamentalTypesCheck(StringRef Name,
+ ClangTidyContext *Context);
+ void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
+ Preprocessor *ModuleExpanderPP) override;
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+ void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+ bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
+ return LangOpts.CPlusPlus11;
+ }
+ std::optional<TraversalKind> getCheckTraversalKind() const override {
+ return TK_IgnoreUnlessSpelledInSource;
+ }
+
+private:
+ const bool WarnOnFloats;
+ const bool WarnOnInts;
+ const bool WarnOnChars;
+ utils::IncludeInserter IncludeInserter;
+ std::string getFloatReplacement(const BuiltinType *BT,
+ ASTContext &Context) const;
+};
+
+} // namespace clang::tidy::portability
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PORTABILITY_AVOIDPLATFORMSPECIFICFUNDAMENTALTYPESCHECK_H

clang-tools-extra/clang-tidy/portability/CMakeLists.txt

@@ -5,6 +5,7 @@ set(LLVM_LINK_COMPONENTS
  )
 
 add_clang_library(clangTidyPortabilityModule STATIC
+ AvoidPlatformSpecificFundamentalTypesCheck.cpp
  AvoidPragmaOnceCheck.cpp
  PortabilityTidyModule.cpp
  RestrictSystemIncludesCheck.cpp

clang-tools-extra/clang-tidy/portability/PortabilityTidyModule.cpp

@@ -9,6 +9,7 @@
 #include "../ClangTidy.h"
 #include "../ClangTidyModule.h"
 #include "../ClangTidyModuleRegistry.h"
+#include "AvoidPlatformSpecificFundamentalTypesCheck.h"
 #include "AvoidPragmaOnceCheck.h"
 #include "RestrictSystemIncludesCheck.h"
 #include "SIMDIntrinsicsCheck.h"
@@ -21,6 +22,8 @@ namespace portability {
 class PortabilityModule : public ClangTidyModule {
 public:
  void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
+ CheckFactories.registerCheck<AvoidPlatformSpecificFundamentalTypesCheck>(
+ "portability-avoid-platform-specific-fundamental-types");
  CheckFactories.registerCheck<AvoidPragmaOnceCheck>(
  "portability-avoid-pragma-once");
  CheckFactories.registerCheck<RestrictSystemIncludesCheck>(

clang-tools-extra/docs/ReleaseNotes.rst

@@ -148,6 +148,13 @@ New checks
  Finds uses of ``std::lock_guard`` and suggests replacing them with C++17's
  alternative ``std::scoped_lock``.
 
+- New :doc:`portability-avoid-platform-specific-fundamental-types
+ <clang-tidy/checks/portability/avoid-platform-specific-fundamental-types>` 
+ check.
+
+ Finds fundamental types (e.g. `int`, `float`) and recommends using typedefs 
+ or fixed-width types instead to improve portability across different platforms.
+
 - New :doc:`portability-avoid-pragma-once
  <clang-tidy/checks/portability/avoid-pragma-once>` check.
 

clang-tools-extra/docs/clang-tidy/checks/list.rst

@@ -353,6 +353,7 @@ Clang-Tidy Checks
  :doc:`performance-type-promotion-in-math-fn <performance/type-promotion-in-math-fn>`, "Yes"
  :doc:`performance-unnecessary-copy-initialization <performance/unnecessary-copy-initialization>`, "Yes"
  :doc:`performance-unnecessary-value-param <performance/unnecessary-value-param>`, "Yes"
+ :doc:`portability-avoid-platform-specific-fundamental-types <portability/avoid-platform-specific-fundamental-types>`,
  :doc:`portability-avoid-pragma-once <portability/avoid-pragma-once>`,
  :doc:`portability-restrict-system-includes <portability/restrict-system-includes>`, "Yes"
  :doc:`portability-simd-intrinsics <portability/simd-intrinsics>`,