[clang] Make handling of unnamed template params similar to function params

Summary:
Clang uses the location identifier should be inserted for declarator
decls when a decl is unnamed. But for type template and template template
paramaters it uses the location of "typename/class" keyword, which makes it hard
for tooling to insert/change parameter names.

This change tries to unify these two cases by making template parameter
parsing and sourcerange operations similar to function params/declarator decls.

Reviewers: ilya-biryukov

Subscribers: arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68143

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@373340 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AST/DeclTemplate.cpp

@@ -510,8 +510,12 @@ SourceRange TemplateTypeParmDecl::getSourceRange() const {
   if (hasDefaultArgument() && !defaultArgumentWasInherited())
     return SourceRange(getBeginLoc(),
                        getDefaultArgumentInfo()->getTypeLoc().getEndLoc());
-  else
-    return TypeDecl::getSourceRange();
+  // TypeDecl::getSourceRange returns a range containing name location, which is
+  // wrong for unnamed template parameters. e.g:
+  // it will return <[[typename>]] instead of <[[typename]]>
+  else if (getDeclName().isEmpty())
+    return SourceRange(getBeginLoc());
+  return TypeDecl::getSourceRange();
 }
 
 unsigned TemplateTypeParmDecl::getDepth() const {

lib/Parse/ParseTemplate.cpp

@@ -630,11 +630,11 @@ NamedDecl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) {
   }
 
   // Grab the template parameter name (if given)
-  SourceLocation NameLoc;
+  SourceLocation NameLoc = Tok.getLocation();
   IdentifierInfo *ParamName = nullptr;
   if (Tok.is(tok::identifier)) {
     ParamName = Tok.getIdentifierInfo();
-    NameLoc = ConsumeToken();
+    ConsumeToken();
   } else if (Tok.isOneOf(tok::equal, tok::comma, tok::greater,
                          tok::greatergreater)) {
     // Unnamed template parameter. Don't have to do anything here, just
@@ -727,11 +727,11 @@ Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
            : diag::ext_variadic_templates);
 
   // Get the identifier, if given.
-  SourceLocation NameLoc;
+  SourceLocation NameLoc = Tok.getLocation();
   IdentifierInfo *ParamName = nullptr;
   if (Tok.is(tok::identifier)) {
     ParamName = Tok.getIdentifierInfo();
-    NameLoc = ConsumeToken();
+    ConsumeToken();
   } else if (Tok.isOneOf(tok::equal, tok::comma, tok::greater,
                          tok::greatergreater)) {
     // Unnamed template parameter. Don't have to do anything here, just

lib/Sema/SemaTemplate.cpp

@@ -1005,15 +1005,10 @@ NamedDecl *Sema::ActOnTypeParameter(Scope *S, bool Typename,
   assert(S->isTemplateParamScope() &&
          "Template type parameter not in template parameter scope!");
 
-  SourceLocation Loc = ParamNameLoc;
-  if (!ParamName)
-    Loc = KeyLoc;
-
   bool IsParameterPack = EllipsisLoc.isValid();
-  TemplateTypeParmDecl *Param
-    = TemplateTypeParmDecl::Create(Context, Context.getTranslationUnitDecl(),
-                                   KeyLoc, Loc, Depth, Position, ParamName,
-                                   Typename, IsParameterPack);
+  TemplateTypeParmDecl *Param = TemplateTypeParmDecl::Create(
+      Context, Context.getTranslationUnitDecl(), KeyLoc, ParamNameLoc, Depth,
+      Position, ParamName, Typename, IsParameterPack);
   Param->setAccess(AS_public);
 
   if (Param->isParameterPack())
@@ -1044,7 +1039,7 @@ NamedDecl *Sema::ActOnTypeParameter(Scope *S, bool Typename,
     assert(DefaultTInfo && "expected source information for type");
 
     // Check for unexpanded parameter packs.
-    if (DiagnoseUnexpandedParameterPack(Loc, DefaultTInfo,
+    if (DiagnoseUnexpandedParameterPack(ParamNameLoc, DefaultTInfo,
                                         UPPC_DefaultArgument))
       return Param;
 

test/AST/ast-dump-decl.cpp

@@ -413,13 +413,13 @@ namespace testClassTemplateDecl {
 
 // CHECK:       ClassTemplateDecl 0x{{.+}} <{{.+}}:275:3, col:68> col:68 TestTemplateTemplateDefaultType
 // CHECK-NEXT:  |-TemplateTemplateParmDecl 0x{{.+}} <col:12, col:42> col:37 depth 0 index 0 TT
-// CHECK-NEXT:  | |-TemplateTypeParmDecl 0x{{.+}} <col:21> col:21 typename depth 1 index 0
+// CHECK-NEXT:  | |-TemplateTypeParmDecl 0x{{.+}} <col:21> col:29 typename depth 1 index 0
 // CHECK-NEXT:  | `-TemplateArgument <col:42> template TestClassTemplate
 // CHECK-NEXT:  `-CXXRecordDecl 0x{{.+}} <col:61, col:68> col:68 struct TestTemplateTemplateDefaultType
 
 // CHECK:       ClassTemplateDecl 0x{{.+}} prev 0x{{.+}} <{{.+}}:276:3, col:82> col:48 TestTemplateTemplateDefaultType
 // CHECK-NEXT:  |-TemplateTemplateParmDecl 0x{{.+}} <col:12, col:37> col:37 depth 0 index 0 TT
-// CHECK-NEXT:  | |-TemplateTypeParmDecl 0x{{.+}} <col:21> col:21 typename depth 1 index 0
+// CHECK-NEXT:  | |-TemplateTypeParmDecl 0x{{.+}} <col:21> col:29 typename depth 1 index 0
 // CHECK-NEXT:  | `-TemplateArgument <line:275:42> template TestClassTemplate
 // CHECK-NEXT:  |   `-inherited from TemplateTemplateParm 0x{{.+}} 'TT'
 // CHECK-NEXT:  `-CXXRecordDecl 0x{{.+}} prev 0x{{.+}} <line:276:41, col:82> col:48 struct TestTemplateTemplateDefaultType definition

test/AST/ast-dump-record-definition-data-json.cpp

@@ -395,14 +395,8 @@ struct DoesNotAllowConstDefaultInit {
 // CHECK-NEXT:       "tokLen": 4
 // CHECK-NEXT:      },
 // CHECK-NEXT:      "range": {
-// CHECK-NEXT:       "begin": {
-// CHECK-NEXT:        "col": 29,
-// CHECK-NEXT:        "tokLen": 4
-// CHECK-NEXT:       },
-// CHECK-NEXT:       "end": {
-// CHECK-NEXT:        "col": 29,
-// CHECK-NEXT:        "tokLen": 4
-// CHECK-NEXT:       }
+// CHECK-NEXT:       "begin": {},
+// CHECK-NEXT:       "end": {}
 // CHECK-NEXT:      },
 // CHECK-NEXT:      "isImplicit": true,
 // CHECK-NEXT:      "tagUsed": "class",
@@ -497,14 +491,8 @@ struct DoesNotAllowConstDefaultInit {
 // CHECK-NEXT:       "tokLen": 4
 // CHECK-NEXT:      },
 // CHECK-NEXT:      "range": {
-// CHECK-NEXT:       "begin": {
-// CHECK-NEXT:        "col": 29,
-// CHECK-NEXT:        "tokLen": 4
-// CHECK-NEXT:       },
-// CHECK-NEXT:       "end": {
-// CHECK-NEXT:        "col": 29,
-// CHECK-NEXT:        "tokLen": 4
-// CHECK-NEXT:       }
+// CHECK-NEXT:       "begin": {},
+// CHECK-NEXT:       "end": {}
 // CHECK-NEXT:      },
 // CHECK-NEXT:      "isImplicit": true,
 // CHECK-NEXT:      "tagUsed": "class",
@@ -563,14 +551,8 @@ struct DoesNotAllowConstDefaultInit {
 // CHECK-NEXT:       "tokLen": 4
 // CHECK-NEXT:      },
 // CHECK-NEXT:      "range": {
-// CHECK-NEXT:       "begin": {
-// CHECK-NEXT:        "col": 29,
-// CHECK-NEXT:        "tokLen": 4
-// CHECK-NEXT:       },
-// CHECK-NEXT:       "end": {
-// CHECK-NEXT:        "col": 29,
-// CHECK-NEXT:        "tokLen": 4
-// CHECK-NEXT:       }
+// CHECK-NEXT:       "begin": {},
+// CHECK-NEXT:       "end": {}
 // CHECK-NEXT:      },
 // CHECK-NEXT:      "isImplicit": true,
 // CHECK-NEXT:      "tagUsed": "class",

test/AST/ast-dump-template-decls-json.cpp

@@ -656,8 +656,8 @@ void V<Ty>::f() {}
 // CHECK-NEXT:        "id": "0x{{.*}}",
 // CHECK-NEXT:        "kind": "TemplateTypeParmDecl",
 // CHECK-NEXT:        "loc": {
-// CHECK-NEXT:         "col": 33,
-// CHECK-NEXT:         "tokLen": 8
+// CHECK-NEXT:         "col": 41,
+// CHECK-NEXT:         "tokLen": 1
 // CHECK-NEXT:        },
 // CHECK-NEXT:        "range": {
 // CHECK-NEXT:         "begin": {
@@ -1099,8 +1099,8 @@ void V<Ty>::f() {}
 // CHECK-NEXT:      "kind": "TemplateTypeParmDecl",
 // CHECK-NEXT:      "loc": {
 // CHECK-NEXT:       "line": 27,
-// CHECK-NEXT:       "col": 11,
-// CHECK-NEXT:       "tokLen": 8
+// CHECK-NEXT:       "col": 20,
+// CHECK-NEXT:       "tokLen": 1
 // CHECK-NEXT:      },
 // CHECK-NEXT:      "range": {
 // CHECK-NEXT:       "begin": {

test/AST/ast-dump-template-decls.cpp

@@ -26,7 +26,7 @@ template <typename Ty, template<typename> typename Uy>
 // CHECK: FunctionTemplateDecl 0x{{[^ ]*}} <line:[[@LINE-1]]:1, line:[[@LINE+4]]:18> col:6 d
 // CHECK-NEXT: TemplateTypeParmDecl 0x{{[^ ]*}} <line:[[@LINE-2]]:11, col:20> col:20 referenced typename depth 0 index 0 Ty
 // CHECK-NEXT: TemplateTemplateParmDecl 0x{{[^ ]*}} <col:24, col:52> col:52 depth 0 index 1 Uy
-// CHECK-NEXT: TemplateTypeParmDecl 0x{{[^ ]*}} <col:33> col:33 typename depth 1 index 0
+// CHECK-NEXT: TemplateTypeParmDecl 0x{{[^ ]*}} <col:33> col:41 typename depth 1 index 0
 void d(Ty, Uy<Ty>);
 
 template <class Ty>
@@ -47,7 +47,7 @@ void g(Ty);
 
 template <typename = void>
 // CHECK: FunctionTemplateDecl 0x{{[^ ]*}} <line:[[@LINE-1]]:1, line:[[@LINE+3]]:8> col:6 h
-// CHECK-NEXT: TemplateTypeParmDecl 0x{{[^ ]*}} <line:[[@LINE-2]]:11, col:22> col:11 typename depth 0 index 0
+// CHECK-NEXT: TemplateTypeParmDecl 0x{{[^ ]*}} <line:[[@LINE-2]]:11, col:22> col:20 typename depth 0 index 0
 // CHECK-NEXT: TemplateArgument type 'void'
 void h();
 

test/ASTMerge/class-template/test.cpp

@@ -9,13 +9,13 @@ static_assert(sizeof(X0<int>().getValue(1)) == sizeof(int));
 // CHECK: class-template2.cpp:9:15: note: declared here with type 'long'
 
 // CHECK: class-template1.cpp:12:14: warning: template parameter has different kinds in different translation units
-// CHECK: class-template2.cpp:12:10: note: template parameter declared here
+// CHECK: class-template2.cpp:12:18: note: template parameter declared here
 
 // CHECK: class-template1.cpp:18:23: warning: non-type template parameter declared with incompatible types in different translation units ('long' vs. 'int')
 // CHECK: class-template2.cpp:18:23: note: declared here with type 'int'
 
-// CHECK: class-template1.cpp:21:10: warning: template parameter has different kinds in different translation units
-// CHECK: class-template2.cpp:21:10: note: template parameter declared here
+// CHECK: class-template1.cpp:21:18: warning: template parameter has different kinds in different translation units
+// CHECK: class-template2.cpp:21:31: note: template parameter declared here
 
 // CHECK: class-template2.cpp:27:20: warning: external variable 'x0r' declared with incompatible types in different translation units ('X0<double> *' vs. 'X0<float> *')
 // CHECK: class-template1.cpp:26:19: note: declared here with type 'X0<float> *'

test/Index/index-templates.cpp

@@ -155,7 +155,7 @@ using alias = T;
 // CHECK-LOAD: index-templates.cpp:36:44: DeclRefExpr=OneDimension:35:16 Extent=[36:44 - 36:56]
 // CHECK-LOAD: index-templates.cpp:40:8: ClassTemplate=storage:40:8 (Definition) Extent=[39:1 - 40:19]
 // CHECK-LOAD: index-templates.cpp:39:45: TemplateTemplateParameter=DataStructure:39:45 (Definition) Extent=[39:10 - 39:66]
-// CHECK-LOAD: index-templates.cpp:39:19: TemplateTypeParameter=:39:19 (Definition) Extent=[39:19 - 39:27]
+// CHECK-LOAD: index-templates.cpp:39:27: TemplateTypeParameter=:39:27 (Definition) Extent=[39:19 - 39:27]
 // CHECK-LOAD: index-templates.cpp:39:37: NonTypeTemplateParameter=:39:37 (Definition) Extent=[39:29 - 39:37]
 // CHECK-LOAD: index-templates.cpp:39:61: TemplateRef=array:37:8 Extent=[39:61 - 39:66]
 // CHECK-LOAD: index-templates.cpp:42:18: TypedefDecl=Unsigned:42:18 (Definition) Extent=[42:1 - 42:26]