[NFC][Clang][FMV] Refactor sema checking of target_version/clones attributes. (#149067)

Sema currently has checkTargetVersionAttr and
checkTargetClonesAttrString to diagnose the said attributes. However the
code tries to handle all of AArch64, RISC-V and X86 targets at once
which is hard to maintain, therefore I am splitting these functions.
Unfortunately I could not use polymorphism because all of Sema, SemaARM,
SemaRISCV and SemaX86 inherit from SemaBase. The Sema instance itself
contains instances of every other target specific Sema.

Author: labrinea

clang/include/clang/Sema/Sema.h

@@ -834,6 +834,13 @@ enum class CCEKind {
                            ///< message.
 };
 
+/// Enums for the diagnostics of target, target_version and target_clones.
+namespace DiagAttrParams {
+enum DiagType { Unsupported, Duplicate, Unknown };
+enum Specifier { None, CPU, Tune };
+enum AttrName { Target, TargetClones, TargetVersion };
+} // end namespace DiagAttrParams
+
 void inferNoReturnAttr(Sema &S, const Decl *D);
 
 /// Sema - This implements semantic analysis and AST building for C.
@@ -4922,13 +4929,6 @@ class Sema final : public SemaBase {
   // handled later in the process, once we know how many exist.
   bool checkTargetAttr(SourceLocation LiteralLoc, StringRef Str);
 
-  /// Check Target Version attrs
-  bool checkTargetVersionAttr(SourceLocation Loc, Decl *D, StringRef Str);
-  bool checkTargetClonesAttrString(
-      SourceLocation LiteralLoc, StringRef Str, const StringLiteral *Literal,
-      Decl *D, bool &HasDefault, bool &HasCommas, bool &HasNotDefault,
-      SmallVectorImpl<SmallString<64>> &StringsBuffer);
-
   ErrorAttr *mergeErrorAttr(Decl *D, const AttributeCommonInfo &CI,
                             StringRef NewUserDiagnostic);
   FormatAttr *mergeFormatAttr(Decl *D, const AttributeCommonInfo &CI,

clang/include/clang/Sema/SemaARM.h

@@ -91,6 +91,11 @@ class SemaARM : public SemaBase {
   /// Return true if the given vector types are lax-compatible SVE vector types,
   /// false otherwise.
   bool areLaxCompatibleSveTypes(QualType FirstType, QualType SecondType);
+
+  bool checkTargetVersionAttr(const StringRef Str, const SourceLocation Loc);
+  bool checkTargetClonesAttr(SmallVectorImpl<StringRef> &Params,
+                             SmallVectorImpl<SourceLocation> &Locs,
+                             SmallVectorImpl<SmallString<64>> &NewParams);
 };
 
 SemaARM::ArmStreamingType getArmStreamingFnType(const FunctionDecl *FD);

clang/include/clang/Sema/SemaRISCV.h

@@ -55,6 +55,11 @@ class SemaRISCV : public SemaBase {
   bool DeclareAndesVectorBuiltins = false;
 
   std::unique_ptr<sema::RISCVIntrinsicManager> IntrinsicManager;
+
+  bool checkTargetVersionAttr(const StringRef Param, const SourceLocation Loc);
+  bool checkTargetClonesAttr(SmallVectorImpl<StringRef> &Params,
+                             SmallVectorImpl<SourceLocation> &Locs,
+                             SmallVectorImpl<SmallString<64>> &NewParams);
 };
 
 std::unique_ptr<sema::RISCVIntrinsicManager>

clang/include/clang/Sema/SemaX86.h

@@ -37,6 +37,10 @@ class SemaX86 : public SemaBase {
 
   void handleAnyInterruptAttr(Decl *D, const ParsedAttr &AL);
   void handleForceAlignArgPointerAttr(Decl *D, const ParsedAttr &AL);
+
+  bool checkTargetClonesAttr(SmallVectorImpl<StringRef> &Params,
+                             SmallVectorImpl<SourceLocation> &Locs,
+                             SmallVectorImpl<SmallString<64>> &NewParams);
 };
 } // namespace clang
 

clang/lib/Sema/SemaARM.cpp

@@ -1535,4 +1535,95 @@ bool SemaARM::areLaxCompatibleSveTypes(QualType FirstType,
          IsLaxCompatible(SecondType, FirstType);
 }
 
+bool SemaARM::checkTargetVersionAttr(const StringRef Param,
+                                     const SourceLocation Loc) {
+  using namespace DiagAttrParams;
+
+  llvm::SmallVector<StringRef, 8> Features;
+  Param.split(Features, '+');
+  for (StringRef Feat : Features) {
+    Feat = Feat.trim();
+    if (Feat == "default")
+      continue;
+    if (!getASTContext().getTargetInfo().validateCpuSupports(Feat))
+      return Diag(Loc, diag::warn_unsupported_target_attribute)
+             << Unsupported << None << Feat << TargetVersion;
+  }
+  return false;
+}
+
+bool SemaARM::checkTargetClonesAttr(
+    SmallVectorImpl<StringRef> &Params, SmallVectorImpl<SourceLocation> &Locs,
+    SmallVectorImpl<SmallString<64>> &NewParams) {
+  using namespace DiagAttrParams;
+
+  if (!getASTContext().getTargetInfo().hasFeature("fmv"))
+    return true;
+
+  assert(Params.size() == Locs.size() &&
+         "Mismatch between number of string parameters and locations");
+
+  bool HasDefault = false;
+  bool HasNonDefault = false;
+  for (unsigned I = 0, E = Params.size(); I < E; ++I) {
+    const StringRef Param = Params[I].trim();
+    const SourceLocation &Loc = Locs[I];
+
+    if (Param.empty())
+      return Diag(Loc, diag::warn_unsupported_target_attribute)
+             << Unsupported << None << "" << TargetClones;
+
+    if (Param == "default") {
+      if (HasDefault)
+        Diag(Loc, diag::warn_target_clone_duplicate_options);
+      else {
+        NewParams.push_back(Param);
+        HasDefault = true;
+      }
+      continue;
+    }
+
+    bool HasCodeGenImpact = false;
+    llvm::SmallVector<StringRef, 8> Features;
+    llvm::SmallVector<StringRef, 8> ValidFeatures;
+    Param.split(Features, '+');
+    for (StringRef Feat : Features) {
+      Feat = Feat.trim();
+      if (!getASTContext().getTargetInfo().validateCpuSupports(Feat)) {
+        Diag(Loc, diag::warn_unsupported_target_attribute)
+            << Unsupported << None << Feat << TargetClones;
+        continue;
+      }
+      if (getASTContext().getTargetInfo().doesFeatureAffectCodeGen(Feat))
+        HasCodeGenImpact = true;
+      ValidFeatures.push_back(Feat);
+    }
+
+    // Ignore features that don't impact code generation.
+    if (!HasCodeGenImpact) {
+      Diag(Loc, diag::warn_target_clone_no_impact_options);
+      continue;
+    }
+
+    if (ValidFeatures.empty())
+      continue;
+
+    // Canonicalize attribute parameter.
+    llvm::sort(ValidFeatures);
+    SmallString<64> NewParam(llvm::join(ValidFeatures, "+"));
+    if (llvm::is_contained(NewParams, NewParam)) {
+      Diag(Loc, diag::warn_target_clone_duplicate_options);
+      continue;
+    }
+
+    // Valid non-default argument.
+    NewParams.push_back(NewParam);
+    HasNonDefault = true;
+  }
+  if (!HasNonDefault)
+    return true;
+
+  return false;
+}
+
 } // namespace clang