[Clang] Fix how ReadMacroParameterList handles comments in macro parameter-list when in -CC mode

Currently when in -CC mode when processing a function like macro
ReadMacroParameterList(...) does not handle the case where there is a comment
embedded in the parameter-list.

Instead of using LexUnexpandedToken(...) I switched to using
LexUnexpandedNonComment(...) which eats comments while lexing.

Fixes: llvm#60887

Differential Revision: https://reviews.llvm.org/D144511

Author: shafik

clang/docs/ReleaseNotes.rst

@@ -254,6 +254,9 @@ Bug Fixes in This Version
   requires on lambdas when not allowed, which we previously missed.
   (`#61748 <https://github.com/llvm/llvm-project/issues/61748>`_)
 - Fix confusing diagnostic for incorrect use of qualified concepts names.
+- Fix handling of comments in function like macros so they are ignored in -CC
+  mode.
+  (`#60887 <https://github.com/llvm/llvm-project/issues/60887>`_)
 
 
 Bug Fixes to Compiler Builtins

clang/lib/Lex/PPDirectives.cpp

@@ -2643,7 +2643,7 @@ bool Preprocessor::ReadMacroParameterList(MacroInfo *MI, Token &Tok) {
   SmallVector<IdentifierInfo*, 32> Parameters;
 
   while (true) {
-    LexUnexpandedToken(Tok);
+    LexUnexpandedNonComment(Tok);
     switch (Tok.getKind()) {
     case tok::r_paren:
       // Found the end of the parameter list.
@@ -2664,7 +2664,7 @@ bool Preprocessor::ReadMacroParameterList(MacroInfo *MI, Token &Tok) {
       }
 
       // Lex the token after the identifier.
-      LexUnexpandedToken(Tok);
+      LexUnexpandedNonComment(Tok);
       if (Tok.isNot(tok::r_paren)) {
         Diag(Tok, diag::err_pp_missing_rparen_in_macro_def);
         return true;
@@ -2698,7 +2698,7 @@ bool Preprocessor::ReadMacroParameterList(MacroInfo *MI, Token &Tok) {
       Parameters.push_back(II);
 
       // Lex the token after the identifier.
-      LexUnexpandedToken(Tok);
+      LexUnexpandedNonComment(Tok);
 
       switch (Tok.getKind()) {
       default:          // #define X(A B
@@ -2714,7 +2714,7 @@ bool Preprocessor::ReadMacroParameterList(MacroInfo *MI, Token &Tok) {
         Diag(Tok, diag::ext_named_variadic_macro);
 
         // Lex the token after the identifier.
-        LexUnexpandedToken(Tok);
+        LexUnexpandedNonComment(Tok);
         if (Tok.isNot(tok::r_paren)) {
           Diag(Tok, diag::err_pp_missing_rparen_in_macro_def);
           return true;

clang/test/Preprocessor/comment_save_macro.c

@@ -1,13 +1,28 @@
 // RUN: %clang_cc1 -E -C %s | FileCheck -check-prefix=CHECK-C -strict-whitespace %s
 // CHECK-C: boo bork bar // zot
+// CHECK-C: ( 0 );
+// CHECK-C: ( 0,1,2 );
+// CHECK-C: ( 0,1,2 );
 
 // RUN: %clang_cc1 -E -CC %s | FileCheck -check-prefix=CHECK-CC -strict-whitespace %s
 // CHECK-CC: boo bork /* blah*/ bar // zot
+// CHECK-CC: (/**/0/**/);
+// CHECK-CC: (/**/0,1,2/**/);
+// CHECK-CC: (/**/0,1,2/**/);
 
 // RUN: %clang_cc1 -E %s | FileCheck -strict-whitespace %s
 // CHECK: boo bork bar
+// CHECK: ( 0 );
+// CHECK: ( 0,1,2 );
+// CHECK: ( 0,1,2 );
 
 
 #define FOO bork // blah
 boo FOO bar // zot
+#define M(/**/x/**/) (/**/x/**/)
+M(0);
+#define M2(/**/.../**/) (/**/__VA_ARGS__/**/)
+M2(0,1,2);
+#define M3(/**/x.../**/) (/**/x/**/)
+M3(0,1,2);