[Index] Expose USR generation for types

[ilya-biryukov]

Summary

Used in clangd.

include/clang/Index/USRGeneration.h

 //===- USRGeneration.h - Routines for USR generation ------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_INDEX_USRGENERATION_H
 #define LLVM_CLANG_INDEX_USRGENERATION_H
 
 #include "clang/Basic/LLVM.h"
 #include "llvm/ADT/StringRef.h"
 
 namespace clang {
+class ASTContext;
 class Decl;
 class MacroDefinitionRecord;
 class Module;
 class SourceLocation;
 class SourceManager;
+class QualType;
 
 namespace index {
 
 static inline StringRef getUSRSpacePrefix() {
   return "c:";
 }
 
 /// Generate a USR for a Decl, including the USR prefix.

 /// Generate a USR for a macro, including the USR prefix.
 ///
 /// \returns true on error, false on success.
 bool generateUSRForMacro(const MacroDefinitionRecord *MD,
                          const SourceManager &SM, SmallVectorImpl<char> &Buf);
 bool generateUSRForMacro(StringRef MacroName, SourceLocation Loc,
                          const SourceManager &SM, SmallVectorImpl<char> &Buf);
 
+/// Generates a USR for a type.
+///
+/// \return true on error, false on success.
+bool generateUSRForType(QualType T, ASTContext &Ctx, SmallVectorImpl<char> &Buf);
+
 /// Generate a USR for a module, including the USR prefix.
 /// \returns true on error, false on success.
 bool generateFullUSRForModule(const Module *Mod, raw_ostream &OS);
 
 /// Generate a USR for a top-level module name, including the USR prefix.
 /// \returns true on error, false on success.
 bool generateFullUSRForTopLevelModuleName(StringRef ModName, raw_ostream &OS);
 
 /// Generate a USR fragment for a module.
 /// \returns true on error, false on success.
 bool generateUSRFragmentForModule(const Module *Mod, raw_ostream &OS);
 
 /// Generate a USR fragment for a module name.
 /// \returns true on error, false on success.
 bool generateUSRFragmentForModuleName(StringRef ModName, raw_ostream &OS);
 
+
 } // namespace index
 } // namespace clang
 
 #endif // LLVM_CLANG_INDEX_USRGENERATION_H
 

lib/Index/USRGeneration.cpp

bool clang::index::generateUSRForMacro(StringRef MacroName, SourceLocation Loc,
   Out << getUSRSpacePrefix();
   if (ShouldGenerateLocation)
     printLoc(Out, Loc, SM, /*IncludeOffset=*/true);
   Out << "@macro@";
   Out << MacroName;
   return false;
 }
 
+bool clang::index::generateUSRForType(QualType T, ASTContext &Ctx,
+                                      SmallVectorImpl<char> &Buf) {
+  if (T.isNull())
+    return true;
+  T = T.getCanonicalType();
+
+  USRGenerator UG(&Ctx, Buf);
+  UG.VisitType(T);
+  return UG.ignoreResults();
+}
+
 bool clang::index::generateFullUSRForModule(const Module *Mod,
                                             raw_ostream &OS) {
   if (!Mod->Parent)
     return generateFullUSRForTopLevelModuleName(Mod->Name, OS);
   if (generateFullUSRForModule(Mod->Parent, OS))
     return true;
   return generateUSRFragmentForModule(Mod, OS);
 }