[clangd] Add support for static fields in rename

[kbobyrev]

Summary

Follow-up on D91952 and D71880.

Fixes: https://github.com/clangd/clangd/issues/604

[kbobyrev]

Add comments and a check to ensure proper behavior.

[hokein]

clang-tools-extra/clangd/unittests/RenameTests.cpp

630

hmm, looks like these two tests are already working at head (without the patch).

[kbobyrev]

Need to check this patch again.

[kbobyrev]

clang-tools-extra/clangd/unittests/RenameTests.cpp

630

You're right, thanks for spotting it 😆 I'm quite confused, though, I was pretty sure it didn't work before. Maybe I did something wrong, I don't know.

[kbobyrev]

Yeah this does indeed already work.

clang-tools-extra/clangd/refactor/Rename.cpp

 #include "ParsedAST.h"
 #include "Selection.h"
 #include "SourceCode.h"
 #include "index/SymbolCollector.h"
 #include "support/Logger.h"
 #include "support/Trace.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclTemplate.h"
+#include "clang/Basic/LLVM.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Tooling/Syntax/Tokens.h"
 #include "llvm/ADT/None.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/FormatVariadic.h"
 #include <algorithm>
if (const auto *Field = dyn_cast<FieldDecl>(D)) {
     // Field is not instantiation.
     if (!FieldParent || Field->getParent() == FieldParent)
       return Field->getCanonicalDecl();
     for (const FieldDecl *Candidate : FieldParent->fields())
       if (Field->getDeclName() == Candidate->getDeclName())
         return Candidate->getCanonicalDecl();
     elog("FieldParent should have field with the same name as Field.");
   }
+  // This handles static fields - it's similar to FieldDecl handling above but
+  // the AST looks different for static fields (starting with the node type
+  // being VarDecl).
   if (const auto *VD = dyn_cast<VarDecl>(D)) {
     if (const VarDecl *OriginalVD = VD->getInstantiatedFromStaticDataMember())
       VD = OriginalVD;
-    return VD->getCanonicalDecl();
+    VD = VD->getCanonicalDecl();
+    const auto *Context = VD->getDeclContext()->getParent();
+    // VarDecl is not instantiation of static field.
+    if (!dyn_cast_or_null<ClassTemplateSpecializationDecl>(
+            VD->getDeclContext()) ||
+        !Context || Context->getDeclKind() != Decl::Kind::CXXRecord)
+      return VD;
+    const auto LookupResult = Context->lookup(D->getDeclName());
+    if (LookupResult.size() != 1)
+      return VD;
+    if (const auto *Result = dyn_cast<VarDecl>(LookupResult.front()))
+      return Result->getCanonicalDecl();
+    return VD;
   }
   return dyn_cast<NamedDecl>(D->getCanonicalDecl());
 }
 
 llvm::DenseSet<const NamedDecl *> locateDeclAt(ParsedAST &AST,
                                                SourceLocation TokenStartLoc) {
   unsigned Offset =
       AST.getSourceManager().getDecomposedSpellingLoc(TokenStartLoc).second;

clang-tools-extra/clangd/unittests/RenameTests.cpp

llvm::StringRef Tests[] = {
         template <>
         bool Foo<bool>::[[Var^iable]] = true;
 
         void foo() {
           int LocalInt = Foo<int>::[[Var^iable]];
           bool LocalBool = Foo<bool>::[[Var^iable]];
         }
       )cpp",
+      R"cpp(
+        template <typename T, typename U> struct Foo { static T Variable; };
+
+        template <typename T> struct Foo<T, bool> {
+          static T [[Var^iable]];
+        };
+
+        void test() {
+          Foo<int, bool>::[[Var^iable]] = 5;
+        }
+      )cpp",
+      R"cpp(
+        template <typename T, typename U> struct Foo {
+          static T [[Var^iable]];
+        };
+
+        template <typename T> struct Foo<T, bool> {
+          static T Variable;
+        };
+
+        void test() {
+          Foo<int, int>::[[Var^iable]] = 5;
+        }
+      )cpp",
 
       // Template parameters.
       R"cpp(
         template <typename [[^T]]>
         class Foo {
           [[T^]] foo([[T^]] arg, [[T^]]& ref, [[^T]]* ptr) {
             [[T]] value;
             int number = 42;