[clang-tools-extra] [clang-tidy] Add portability-avoid-platform-specific-fundamental-types (PR #146970)

[Baranov Victor via cfe-commits]

================
@@ -0,0 +1,254 @@
+//===--- 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/AST/Type.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Basic/TargetInfo.h"
+
+using namespace clang::ast_matchers;
+
+namespace {
+
+static bool isCharType(const clang::BuiltinType *BT) {
+  using clang::BuiltinType;
+  switch (BT->getKind()) {
+  case BuiltinType::Char_S:
+  case BuiltinType::Char_U:
+  case BuiltinType::SChar:
+  case BuiltinType::UChar:
+    return true;
+  default:
+    return false;
+  }
+}
+
+AST_MATCHER(clang::QualType, isBuiltinInt) {
+  const auto *BT = Node->getAs<clang::BuiltinType>();
+  if (!BT)
+    return false;
+
+  switch (BT->getKind()) {
+  case clang::BuiltinType::Short:
+  case clang::BuiltinType::UShort:
+  case clang::BuiltinType::Int:
+  case clang::BuiltinType::UInt:
+  case clang::BuiltinType::Long:
+  case clang::BuiltinType::ULong:
+  case clang::BuiltinType::LongLong:
+  case clang::BuiltinType::ULongLong:
+    return true;
+  default:
+    return false;
+  }
+}
+
+AST_MATCHER(clang::QualType, isBuiltinFloat) {
+  const auto *BT = Node->getAs<clang::BuiltinType>();
+  if (!BT)
+    return false;
+
+  switch (BT->getKind()) {
+  case clang::BuiltinType::Half:
+  case clang::BuiltinType::BFloat16:
+  case clang::BuiltinType::Float:
+  case clang::BuiltinType::Double:
+  case clang::BuiltinType::LongDouble:
+    return true;
+  default:
+    return false;
+  }
+}
+
+AST_MATCHER(clang::QualType, isBuiltinChar) {
+  const auto *BT = Node->getAs<clang::BuiltinType>();
+  if (!BT)
+    return false;
+
+  return isCharType(BT);
+}
+} // namespace
+
+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());
+}
+
+static std::string getFloatReplacement(const BuiltinType *BT,
+                                       ASTContext &Context) {
+  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) {
+  auto PlatformSpecificFundamentalType = qualType(
+      allOf(builtinType(),
+            anyOf(WarnOnInts ? isBuiltinInt() : unless(anything()),
+                  WarnOnFloats ? isBuiltinFloat() : unless(anything()),
+                  WarnOnChars ? isBuiltinChar() : unless(anything()))));
+
+  if (!WarnOnInts && !WarnOnFloats && !WarnOnChars)
+    return;
+
+  Finder->addMatcher(
+      varDecl(hasType(PlatformSpecificFundamentalType)).bind("var_decl"), this);
+
+  Finder->addMatcher(
+      functionDecl(returns(PlatformSpecificFundamentalType)).bind("func_decl"),
+      this);
+
+  Finder->addMatcher(
+      parmVarDecl(hasType(PlatformSpecificFundamentalType)).bind("param_decl"),
+      this);
+
+  Finder->addMatcher(
+      fieldDecl(hasType(PlatformSpecificFundamentalType)).bind("field_decl"),
+      this);
----------------
vbvictor wrote:

You could simplify these 4 matchers into one. The only bind you need is bad fundamental type.
You could use something like:
```cpp
Finder->addMatcher(typeLoc(loc(hasType(PlatformSpecificFundamentalType))).bind("type"));
```
See how it is done in `ReplaceAutoPtrCheck.cpp`.

https://github.com/llvm/llvm-project/pull/146970