[clang-rename] add support for template parameter renaming

[omtcyfz]

Summary

Few simple tweaks allow template parameters to be renamed. See TemplateTypenameFindBy{TemplateParam|TypeInside}.cpp for example how it works.

[omtcyfz]

Ping. Change is quite trivial.

[omtcyfz]

git rebase; git resolve conflicts

[alexfh]

clang-rename/USRFinder.cpp

80

It's not common to use braces around single-line if bodies in LLVM/Clang code.

clang-rename/USRLocFinder.cpp

107

nit: const auto *

test/clang-rename/TemplateTypenameFindByTemplateParam.cpp

4–5

As noted elsewhere, this way of testing is wrong.

test/clang-rename/TemplateTypenameFindByTypeInside.cpp

4–5

ditto

[omtcyfz]

clang-rename/USRFinder.cpp

80

I do that literally everywhere :D LLVM Code Style isn't against it and I thinks it is good in terms of readability.

[omtcyfz]

Addressed comments; updated to the latest revision.

[omtcyfz]

Apply clang-format to fit 80 cols limit.

[alexfh]

LG

clang-rename/USRFinder.cpp

80

I'm not saying it's prohibited by the LLVM coding guidelines, I'm saying that the other convention seems to be substantially more popular across the LLVM project. The difference in how readable the two styles are is not large, however, mixing the styles may actually hurt readability.

It looks like the use of braces for single-line if/for/... bodies is more common in the files being changed in this patch, so being locally consistent wrt. brace usage here is probably more valuable than pursuing consistency with LLVM code in general.

However, please be careful when changing code that prevalently uses the other style (no braces for single-line if/... bodies). Introducing inconsistencies is not good in terms of readability.

[chapuni]

Seems a couple of tests would be incompatible to -fdelayed-template-parsing. Appeased in r277452.

[alexfh]

In D22853#503303, @chapuni wrote:

Seems a couple of tests would be incompatible to -fdelayed-template-parsing. Appeased in r277452.

Thank you! And sorry for the inconvenience.

clang-rename/USRFinder.cpp

public:
   }
 
   // Other visitors:
 
   bool VisitTypeLoc(const TypeLoc Loc) {
     const auto TypeBeginLoc = Loc.getBeginLoc();
     const auto TypeEndLoc = Lexer::getLocForEndOfToken(
         TypeBeginLoc, 0, Context.getSourceManager(), Context.getLangOpts());
+    if (const auto *TemplateTypeParm =
+            dyn_cast<TemplateTypeParmType>(Loc.getType())) {
+      return setResult(TemplateTypeParm->getDecl(), TypeBeginLoc, TypeEndLoc);
+    }
     return setResult(Loc.getType()->getAsCXXRecordDecl(), TypeBeginLoc,
                      TypeEndLoc);
   }
 
   // Other:
 
   const NamedDecl *getNamedDecl() { return Result; }
 

clang-rename/USRLocFinder.cpp

public:
 
   // Other visitors:
 
   bool VisitTypeLoc(const TypeLoc Loc) {
     if (USRSet.find(getUSRForDecl(Loc.getType()->getAsCXXRecordDecl())) !=
         USRSet.end()) {
       checkAndAddLocation(Loc.getBeginLoc());
     }
+    if (const auto *TemplateTypeParm =
+            dyn_cast<TemplateTypeParmType>(Loc.getType())) {
+      if (USRSet.find(getUSRForDecl(TemplateTypeParm->getDecl())) != USRSet.end()) {
+        checkAndAddLocation(Loc.getBeginLoc());
+      }
+    }
     return true;
   }
 
   // Non-visitors:
 
   // \brief Returns a list of unique locations. Duplicate or overlapping
   // locations are erroneous and should be reported!
   const std::vector<clang::SourceLocation> &getLocationsFound() const {

test/clang-rename/TemplateTypenameFindByTemplateParam.cpp

 // RUN: cat %s > %t.cpp
-// RUN: clang-rename -offset=270 -new-name=U %t.cpp -i --
+// RUN: clang-rename -offset=147 -new-name=U %t.cpp -i --
 // RUN: sed 's,//.*,,' %t.cpp | FileCheck %s
 
-// Currently unsupported test.
-// FIXME: clang-rename should be able to rename template parameters correctly.
-// XFAIL: *
-
 template <typename T>             // CHECK: template <typename U>
 class Foo {
 T foo(T arg, T& ref, T* ptr) {    // CHECK: U foo(U arg, U& ref, U* ptr) {
   T value;                        // CHECK: U value;
   int number = 42;
   value = (T)number;              // CHECK: value = (U)number;
   value = static_cast<T>(number); // CHECK: value = static_cast<U>(number);
   return value;
 }
 
 static void foo(T value) {}       // CHECK: static void foo(U value) {}
 
 T member;                         // CHECK: U member;
 };

test/clang-rename/TemplateTypenameFindByTypeInside.cpp

 // RUN: cat %s > %t.cpp
-// RUN: clang-rename -offset=350 -new-name=U %t.cpp -i --
+// RUN: clang-rename -offset=227 -new-name=U %t.cpp -i --
 // RUN: sed 's,//.*,,' %t.cpp | FileCheck %s
 
-// Currently unsupported test.
-// FIXME: clang-rename should be able to rename template parameters correctly.
-// XFAIL: *
-
 template <typename T>             // CHECK: template <typename U>
 class Foo {
 T foo(T arg, T& ref, T* ptr) {    // CHECK: U foo(U arg, U& ref, U* ptr) {
   T value;                        // CHECK: U value;
   int number = 42;
   value = (T)number;              // CHECK: value = (U)number;
   value = static_cast<T>(number); // CHECK: value = static_cast<U>(number);
   return value;
 }
 
 static void foo(T value) {}       // CHECK: static void foo(U value) {}
 
 T member;                         // CHECK: U member;
 };