Added macro name to redifine and undef macro as a part of the issue#88882

[saideepaksana]

For the issue #88882,
files changed clang/include/clang/Basic/DiagnosticLexKinds.td, clang/lib/Lex/PPDirectives.cpp. I tried adding %0 place holder in the .td file, so by passing the identifier info of the redefined builtin macro, so now it says clearly which macro affected, before it was warning: redefining builtin macro and now it is warning: redefining builtin macro '__FILE__'.

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[llvmbot]

@llvm/pr-subscribers-clang

Author: Sai Deepak Sana (saideepaksana)

Changes

For the issue #88882,
files changed clang/include/clang/Basic/DiagnosticLexKinds.td, clang/lib/Lex/PPDirectives.cpp. I tried adding %0 place holder in the .td file, so by passing the identifier info of the redefined builtin macro, so now it says clearly which macro affected, before it was warning: redefining builtin macro and now it is warning: redefining builtin macro '__FILE__'.

---

Full diff: https://github.com/llvm/llvm-project/pull/167299.diff

2 Files Affected:

• (modified) clang/include/clang/Basic/DiagnosticLexKinds.td (+1-1)
• (modified) clang/lib/Lex/PPDirectives.cpp (+2-2)

diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td b/clang/include/clang/Basic/DiagnosticLexKinds.td
index 417187222e448..e9339f473c67a 100644
--- a/clang/include/clang/Basic/DiagnosticLexKinds.td
+++ b/clang/include/clang/Basic/DiagnosticLexKinds.td
@@ -396,7 +396,7 @@ def pp_out_of_date_dependency : Warning<
   "current file is older than dependency %0">;
 def ext_pp_undef_builtin_macro : ExtWarn<"undefining builtin macro">,
   InGroup<BuiltinMacroRedefined>;
-def ext_pp_redef_builtin_macro : ExtWarn<"redefining builtin macro">,
+def ext_pp_redef_builtin_macro : ExtWarn<"redefining builtin macro '%0'">,
   InGroup<BuiltinMacroRedefined>;
 def pp_disabled_macro_expansion : Warning<
   "disabled expansion of recursive macro">, DefaultIgnore,
diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 891c8ab7f3155..38780f4fc9a89 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -3289,7 +3289,7 @@ void Preprocessor::HandleDefineDirective(
       // Warn if defining "__LINE__" and other builtins, per C99 6.10.8/4 and
       // C++ [cpp.predefined]p4, but allow it as an extension.
       if (isLanguageDefinedBuiltin(SourceMgr, OtherMI, II->getName()))
-        Diag(MacroNameTok, diag::ext_pp_redef_builtin_macro);
+        Diag(MacroNameTok, diag::ext_pp_redef_builtin_macro) << MacroNameTok.getIdentifierInfo(); // inserting this diagonstic message into stream.
       // Macros must be identical.  This means all tokens and whitespace
       // separation must be the same.  C99 6.10.3p2.
       else if (!OtherMI->isAllowRedefinitionsWithoutWarning() &&
@@ -3354,7 +3354,7 @@ void Preprocessor::HandleUndefDirective() {
     // Warn if undefining "__LINE__" and other builtins, per C99 6.10.8/4 and
     // C++ [cpp.predefined]p4, but allow it as an extension.
     if (isLanguageDefinedBuiltin(SourceMgr, MI, II->getName()))
-      Diag(MacroNameTok, diag::ext_pp_undef_builtin_macro);
+      Diag(MacroNameTok, diag::ext_pp_undef_builtin_macro) << MacroNameTok.getIdentifierInfo(); // inserting this diagnostic message into it
 
     if (MI->isWarnIfUnused())
       WarnUnusedMacroLocs.erase(MI->getDefinitionLoc());

[zwuis]

Thank you for your patch!

Did you run regression tests locally to ensure that this patch doesn't break anything?

[github-actions]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff origin/main HEAD --extensions cpp -- clang/lib/Lex/PPDirectives.cpp --diff_from_common_commit

⚠️
The reproduction instructions above might return results for more than one PR
in a stack if you are using a stacked PR workflow. You can limit the results by
changing origin/main to the base branch/commit you want to compare against.
⚠️

View the diff from clang-format here.

diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 38780f4fc..88448f9b3 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -3289,7 +3289,9 @@ void Preprocessor::HandleDefineDirective(
       // Warn if defining "__LINE__" and other builtins, per C99 6.10.8/4 and
       // C++ [cpp.predefined]p4, but allow it as an extension.
       if (isLanguageDefinedBuiltin(SourceMgr, OtherMI, II->getName()))
-        Diag(MacroNameTok, diag::ext_pp_redef_builtin_macro) << MacroNameTok.getIdentifierInfo(); // inserting this diagonstic message into stream.
+        Diag(MacroNameTok, diag::ext_pp_redef_builtin_macro)
+            << MacroNameTok.getIdentifierInfo(); // inserting this diagonstic
+                                                 // message into stream.
       // Macros must be identical.  This means all tokens and whitespace
       // separation must be the same.  C99 6.10.3p2.
       else if (!OtherMI->isAllowRedefinitionsWithoutWarning() &&
@@ -3354,7 +3356,9 @@ void Preprocessor::HandleUndefDirective() {
     // Warn if undefining "__LINE__" and other builtins, per C99 6.10.8/4 and
     // C++ [cpp.predefined]p4, but allow it as an extension.
     if (isLanguageDefinedBuiltin(SourceMgr, MI, II->getName()))
-      Diag(MacroNameTok, diag::ext_pp_undef_builtin_macro) << MacroNameTok.getIdentifierInfo(); // inserting this diagnostic message into it
+      Diag(MacroNameTok, diag::ext_pp_undef_builtin_macro)
+          << MacroNameTok.getIdentifierInfo(); // inserting this diagnostic
+                                               // message into it
 
     if (MI->isWarnIfUnused())
       WarnUnusedMacroLocs.erase(MI->getDefinitionLoc());

[zwuis]

Please use this syntax to reference the issue fixed by this patch.

Please update tests in "clang/test/" to verify that macros appear in diagnostic messages.

Please add a release note entry to "clang/docs/ReleaseNotes.rst".

[zwuis]

Unnecessary comment. Ditto below.