[clang] fix comment lexing of special command names

[mdenson]

Comment lexer fails to parse non-alphanumeric names. I'm not sure how common this is, but it appears to be allowed by doxygen. However, I didn't see any references to exactly what was allowed. I expect breaking on whitespace will break things like \param[in]. Doxygen's alias could add complexity.

This is simple, seems reasonable, but not the only option.

1. Leave as it was, document the behavior
2. Update the rules, defining expected behavior
3. Something else entirely

fixes #33296

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[llvmbot]

@llvm/pr-subscribers-clang

Author: None (mdenson)

Changes

Comment lexer fails to parse non-alphanumeric names. I'm not sure how common this is, but it appears to be allowed by doxygen. However, I didn't see any references to exactly what was allowed. I expect breaking on whitespace will break things like \param[in]. Doxygen's alias could add complexity.

This is simple, seems reasonable, but not the only option.

1. Leave as it was, document the behavior
2. Update the rules, defining expected behavior
3. Something else entirely

fixes #33296

---

Full diff: https://github.com/llvm/llvm-project/pull/152943.diff

2 Files Affected:

• (modified) clang/lib/AST/CommentLexer.cpp (+1-1)
• (modified) clang/test/AST/ast-dump-comment.cpp (+6)

diff --git a/clang/lib/AST/CommentLexer.cpp b/clang/lib/AST/CommentLexer.cpp
index e19c2327aebdc..a0903d0903dd8 100644
--- a/clang/lib/AST/CommentLexer.cpp
+++ b/clang/lib/AST/CommentLexer.cpp
@@ -214,7 +214,7 @@ bool isCommandNameStartCharacter(char C) {
 }
 
 bool isCommandNameCharacter(char C) {
-  return isAlphanumeric(C);
+  return isAsciiIdentifierContinue(C, false);
 }
 
 const char *skipCommandName(const char *BufferPtr, const char *BufferEnd) {
diff --git a/clang/test/AST/ast-dump-comment.cpp b/clang/test/AST/ast-dump-comment.cpp
index 40c3edb62821b..2b4ec63765f41 100644
--- a/clang/test/AST/ast-dump-comment.cpp
+++ b/clang/test/AST/ast-dump-comment.cpp
@@ -131,3 +131,9 @@ void Test_TemplatedFunctionVariadic(int arg, ...);
 // CHECK:        ParamCommandComment{{.*}} [in] implicitly Param="..."
 // CHECK-NEXT:     ParagraphComment
 // CHECK-NEXT:       TextComment{{.*}} Text=" More arguments"
+
+/// \thread_safe test for underscore in special command
+int Test_UnderscoreInSpecialCommand;
+// CHECK:      VarDecl{{.*}}Test_UnderscoreInSpecialCommand 'int'
+// CHECK:        InlineCommandComment{{.*}} Name="thread_safe" RenderNormal
+// CHECK-NEXT:     TextComment{{.*}} Text=" test for underscore in special command"
\ No newline at end of file

[evelez7]

This file needs an empty line at the end of it.

[cor3ntin]

This change needs a release note.
Please add an entry to clang/docs/ReleaseNotes.rst in the section the most adapted to the change, and referencing any Github issue this change fixes. Thanks!

[AaronBallman]

This change needs a release note. Please add an entry to clang/docs/ReleaseNotes.rst in the section the most adapted to the change, and referencing any Github issue this change fixes. Thanks!

+1, but otherwise LGTM

[cor3ntin]

LGTM. Do you need us to merge that for you?

[mdenson]

perhaps. sorry, i'm new here. looks like it failed a doc test in tools/clang/docs/OpenMPSupport.rst:89:Malformed table.

[evelez7]

Do you want the tests to run again? Don't think you have perms for that, I can rerun them for you.

[cor3ntin]

The tests look fine to me, I'll merge!

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