[clang] Add missing LinkageSpec case to getCursorKindForDecl (llvm#72401)

The LinkageSpec case was omitted, and there is a declared CXCursor_Kind
for it. Adapt the testsuite drivers to print mangled names for
declarations with extern linkage. Also update the test baseline for the
recursive-cxx-member-calls.cpp test.

Co-authored-by: Matthieu Eyraud <[email protected]>

Author: sebastianpoeplau

clang/docs/ReleaseNotes.rst

@@ -938,6 +938,8 @@ libclang
 --------
 
 - Exposed arguments of ``clang::annotate``.
+- ``clang::getCursorKindForDecl`` now recognizes linkage specifications such as
+  ``extern "C"`` and reports them as ``CXCursor_LinkageSpec``.
 
 Static Analyzer
 ---------------

clang/lib/Sema/SemaCodeComplete.cpp

@@ -4165,6 +4165,9 @@ CXCursorKind clang::getCursorKindForDecl(const Decl *D) {
   case Decl::Concept:
     return CXCursor_ConceptDecl;
 
+  case Decl::LinkageSpec:
+    return CXCursor_LinkageSpec;
+
   default:
     if (const auto *TD = dyn_cast<TagDecl>(D)) {
       switch (TD->getTagKind()) {

clang/test/Index/recursive-cxx-member-calls.cpp

@@ -216,9 +216,9 @@ AttributeList::Kind AttributeList::getKind(const IdentifierInfo * Name) {
 // CHECK-tokens: Punctuation: "}" [4:63 - 4:64] ClassTemplate=pair:4:44 (Definition)
 // CHECK-tokens: Punctuation: ";" [4:64 - 4:65] Namespace=std:3:11 (Definition)
 // CHECK-tokens: Punctuation: "}" [5:1 - 5:2] Namespace=std:3:11 (Definition)
-// CHECK-tokens: Keyword: "extern" [6:1 - 6:7]
-// CHECK-tokens: Literal: ""C"" [6:8 - 6:11] UnexposedDecl=:6:8 (Definition)
-// CHECK-tokens: Punctuation: "{" [6:12 - 6:13] UnexposedDecl=:6:8 (Definition)
+// CHECK-tokens: Keyword: "extern" [6:1 - 6:7] LinkageSpec=:6:8 (Definition)
+// CHECK-tokens: Literal: ""C"" [6:8 - 6:11] LinkageSpec=:6:8 (Definition)
+// CHECK-tokens: Punctuation: "{" [6:12 - 6:13] LinkageSpec=:6:8 (Definition)
 // CHECK-tokens: Keyword: "int" [7:3 - 7:6] FunctionDecl=memcmp:7:7
 // CHECK-tokens: Identifier: "memcmp" [7:7 - 7:13] FunctionDecl=memcmp:7:7
 // CHECK-tokens: Punctuation: "(" [7:13 - 7:14] FunctionDecl=memcmp:7:7
@@ -232,7 +232,7 @@ AttributeList::Kind AttributeList::getKind(const IdentifierInfo * Name) {
 // CHECK-tokens: Punctuation: "," [7:40 - 7:41] FunctionDecl=memcmp:7:7
 // CHECK-tokens: Identifier: "size_t" [7:42 - 7:48] TypeRef=size_t:2:25
 // CHECK-tokens: Punctuation: ")" [7:48 - 7:49] FunctionDecl=memcmp:7:7
-// CHECK-tokens: Punctuation: ";" [7:49 - 7:50] UnexposedDecl=:6:8 (Definition)
+// CHECK-tokens: Punctuation: ";" [7:49 - 7:50] LinkageSpec=:6:8 (Definition)
 // CHECK-tokens: Identifier: "size_t" [8:3 - 8:9] TypeRef=size_t:2:25
 // CHECK-tokens: Identifier: "strlen" [8:10 - 8:16] FunctionDecl=strlen:8:10
 // CHECK-tokens: Punctuation: "(" [8:16 - 8:17] FunctionDecl=strlen:8:10
@@ -1532,7 +1532,7 @@ AttributeList::Kind AttributeList::getKind(const IdentifierInfo * Name) {
 // CHECK: 4:20: TemplateTypeParameter=_T1:4:20 (Definition) Extent=[4:14 - 4:23]
 // CHECK: 4:31: TemplateTypeParameter=_T2:4:31 (Definition) Extent=[4:25 - 4:34]
 // CHECK: 4:55: FieldDecl=second:4:55 (Definition) Extent=[4:51 - 4:61]
-// CHECK: 6:8: UnexposedDecl=:6:8 (Definition) Extent=[6:1 - 9:2]
+// CHECK: 6:8: LinkageSpec=:6:8 (Definition) Extent=[6:1 - 9:2]
 // CHECK: 7:7: FunctionDecl=memcmp:7:7 Extent=[7:3 - 7:49]
 // CHECK: 7:26: ParmDecl=:7:26 (Definition) Extent=[7:14 - 7:26]
 // CHECK: 7:40: ParmDecl=:7:40 (Definition) Extent=[7:28 - 7:40]

clang/tools/c-index-test/c-index-test.c

@@ -1838,6 +1838,8 @@ static enum CXChildVisitResult PrintMangledName(CXCursor cursor, CXCursor p,
   CXString MangledName;
   if (clang_isUnexposed(clang_getCursorKind(cursor)))
     return CXChildVisit_Recurse;
+  if (clang_getCursorKind(cursor) == CXCursor_LinkageSpec)
+    return CXChildVisit_Recurse;
   PrintCursor(cursor, NULL);
   MangledName = clang_Cursor_getMangling(cursor);
   printf(" [mangled=%s]\n", clang_getCString(MangledName));
@@ -1853,6 +1855,8 @@ static enum CXChildVisitResult PrintManglings(CXCursor cursor, CXCursor p,
     return CXChildVisit_Recurse;
   if (!clang_isDeclaration(clang_getCursorKind(cursor)))
     return CXChildVisit_Recurse;
+  if (clang_getCursorKind(cursor) == CXCursor_LinkageSpec)
+    return CXChildVisit_Recurse;
   if (clang_getCursorKind(cursor) == CXCursor_ParmDecl)
     return CXChildVisit_Continue;
   PrintCursor(cursor, NULL);