[Clang] add fix-it hints for unknown attributes

Author: a-tarasyuk

clang/docs/ReleaseNotes.rst

@@ -601,6 +601,8 @@ Improvements to Clang's diagnostics
   trigger a ``'Blue' is deprecated`` warning, which can be turned off with
   ``-Wno-deprecated-declarations-switch-case``.
 
+- Clang now suggests fixit hints for unknown attributes.
+
 Improvements to Clang's time-trace
 ----------------------------------
 

clang/include/clang/Basic/AttributeCommonInfo.h

@@ -14,6 +14,7 @@
 #ifndef LLVM_CLANG_BASIC_ATTRIBUTECOMMONINFO_H
 #define LLVM_CLANG_BASIC_ATTRIBUTECOMMONINFO_H
 
+#include "clang/Basic/AttributeScopeInfo.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/TokenKinds.h"
 
@@ -61,6 +62,7 @@ class AttributeCommonInfo {
     /// implicitly.
     AS_Implicit
   };
+
   enum Kind {
 #define PARSED_ATTR(NAME) AT_##NAME,
 #include "clang/Basic/AttrParsedAttrList.inc"
@@ -78,9 +80,9 @@ class AttributeCommonInfo {
 
 private:
   const IdentifierInfo *AttrName = nullptr;
-  const IdentifierInfo *ScopeName = nullptr;
+  AttributeScopeInfo AttrScope;
   SourceRange AttrRange;
-  const SourceLocation ScopeLoc;
+
   // Corresponds to the Kind enum.
   LLVM_PREFERRED_TYPE(Kind)
   unsigned AttrKind : 16;
@@ -146,33 +148,31 @@ class AttributeCommonInfo {
   };
 
   AttributeCommonInfo(const IdentifierInfo *AttrName,
-                      const IdentifierInfo *ScopeName, SourceRange AttrRange,
-                      SourceLocation ScopeLoc, Kind AttrKind, Form FormUsed)
-      : AttrName(AttrName), ScopeName(ScopeName), AttrRange(AttrRange),
-        ScopeLoc(ScopeLoc), AttrKind(AttrKind),
-        SyntaxUsed(FormUsed.getSyntax()),
+                      AttributeScopeInfo AttrScope, SourceRange AttrRange,
+                      Kind AttrKind, Form FormUsed)
+      : AttrName(AttrName), AttrScope(AttrScope), AttrRange(AttrRange),
+        AttrKind(AttrKind), SyntaxUsed(FormUsed.getSyntax()),
         SpellingIndex(FormUsed.getSpellingIndex()),
         IsAlignas(FormUsed.isAlignas()),
         IsRegularKeywordAttribute(FormUsed.isRegularKeywordAttribute()) {
     assert(SyntaxUsed >= AS_GNU && SyntaxUsed <= AS_Implicit &&
            "Invalid syntax!");
   }
 
-  AttributeCommonInfo(const IdentifierInfo *AttrName,
-                      const IdentifierInfo *ScopeName, SourceRange AttrRange,
-                      SourceLocation ScopeLoc, Form FormUsed)
+  AttributeCommonInfo(const IdentifierInfo *AttrName, AttributeScopeInfo Scope,
+                      SourceRange AttrRange, Form FormUsed)
       : AttributeCommonInfo(
-            AttrName, ScopeName, AttrRange, ScopeLoc,
-            getParsedKind(AttrName, ScopeName, FormUsed.getSyntax()),
+            AttrName, Scope, AttrRange,
+            getParsedKind(AttrName, Scope.getName(), FormUsed.getSyntax()),
             FormUsed) {}
 
   AttributeCommonInfo(const IdentifierInfo *AttrName, SourceRange AttrRange,
                       Form FormUsed)
-      : AttributeCommonInfo(AttrName, nullptr, AttrRange, SourceLocation(),
+      : AttributeCommonInfo(AttrName, AttributeScopeInfo(), AttrRange,
                             FormUsed) {}
 
   AttributeCommonInfo(SourceRange AttrRange, Kind K, Form FormUsed)
-      : AttributeCommonInfo(nullptr, nullptr, AttrRange, SourceLocation(), K,
+      : AttributeCommonInfo(nullptr, AttributeScopeInfo(), AttrRange, K,
                             FormUsed) {}
 
   AttributeCommonInfo(AttributeCommonInfo &&) = default;
@@ -190,17 +190,27 @@ class AttributeCommonInfo {
   SourceRange getRange() const { return AttrRange; }
   void setRange(SourceRange R) { AttrRange = R; }
 
-  bool hasScope() const { return ScopeName; }
-  const IdentifierInfo *getScopeName() const { return ScopeName; }
-  SourceLocation getScopeLoc() const { return ScopeLoc; }
+  bool hasScope() const { return AttrScope.isValid(); }
+  bool isExplicitScope() const { return AttrScope.IsExplicit(); }
+
+  const IdentifierInfo *getScopeName() const { return AttrScope.getName(); }
+  SourceLocation getScopeLoc() const { return AttrScope.getNameLoc(); }
 
   /// Gets the normalized full name, which consists of both scope and name and
   /// with surrounding underscores removed as appropriate (e.g.
   /// __gnu__::__attr__ will be normalized to gnu::attr).
   std::string getNormalizedFullName() const;
-  std::optional<std::string>
-  getCorrectedFullName(const TargetInfo &Target,
-                       const LangOptions &LangOpts) const;
+  std::string getNormalizedFullName(StringRef ScopeName,
+                                    StringRef AttrName) const;
+  StringRef getNormalizedScopeName() const;
+  StringRef getNormalizedAttrName(StringRef ScopeName) const;
+
+  std::optional<StringRef> tryGetCorrectedScopeName(StringRef ScopeName) const;
+  std::optional<StringRef>
+  tryGetCorrectedAttrName(StringRef ScopeName, StringRef AttrName,
+                          const TargetInfo &Target,
+                          const LangOptions &LangOpts) const;
+
   SourceRange getNormalizedRange() const;
 
   bool isDeclspecAttribute() const { return SyntaxUsed == AS_Declspec; }

clang/include/clang/Basic/AttributeScopeInfo.h

@@ -0,0 +1,35 @@
+#ifndef LLVM_CLANG_BASIC_ATTRIBUTESCOPEINFO_H
+#define LLVM_CLANG_BASIC_ATTRIBUTESCOPEINFO_H
+
+#include "clang/Basic/SourceLocation.h"
+
+namespace clang {
+
+class IdentifierInfo;
+
+class AttributeScopeInfo {
+public:
+  AttributeScopeInfo() = default;
+
+  AttributeScopeInfo(const IdentifierInfo *Name, SourceLocation NameLoc)
+      : Name(Name), NameLoc(NameLoc) {}
+
+  AttributeScopeInfo(const IdentifierInfo *Name, SourceLocation NameLoc,
+                     SourceLocation UsingPrefixLoc)
+      : Name(Name), NameLoc(NameLoc), UsingPrefixLoc(UsingPrefixLoc) {}
+
+  const IdentifierInfo *getName() const { return Name; }
+  SourceLocation getNameLoc() const { return NameLoc; }
+
+  bool isValid() const { return Name != nullptr; }
+  bool IsExplicit() const { return UsingPrefixLoc.isInvalid(); }
+
+private:
+  const IdentifierInfo *Name = nullptr;
+  SourceLocation NameLoc;
+  SourceLocation UsingPrefixLoc;
+};
+
+} // namespace clang
+
+#endif // LLVM_CLANG_BASIC_ATTRIBUTESCOPEINFO_H