[PATCH] D116833: [clang][Sema] Disable -Wc++20-designator in system macros

[Carlos Galvez via Phabricator via cfe-commits]

carlosgalvezp created this revision.
carlosgalvezp requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

To be consistent with GCC.

Fixes #52944.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D116833

Files:
  clang/lib/Sema/SemaExpr.cpp
  clang/test/SemaCXX/warn-sysheader-macro.cpp


Index: clang/test/SemaCXX/warn-sysheader-macro.cpp
===================================================================
--- clang/test/SemaCXX/warn-sysheader-macro.cpp
+++ clang/test/SemaCXX/warn-sysheader-macro.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -verify -fsyntax-only -Wshadow -Wold-style-cast %s
+// RUN: %clang_cc1 -verify -fsyntax-only -Wshadow -Wold-style-cast -Wc++20-designator %s
 
 // Test that macro expansions from system headers don't trigger 'syntactic'
 // warnings that are not actionable.
@@ -12,6 +12,11 @@
 
 #define OLD_STYLE_CAST(a) ((int) (a))
 
+struct Foo {
+  int x;
+};
+#define DESIGNATED_INITIALIZERS (Foo{.x = 123})
+
 #else
 
 #define IS_SYSHEADER
@@ -32,4 +37,9 @@
   int i = OLD_STYLE_CAST(0);
 }
 
+void PR52944() {
+  // no -Wc++20-designator in system macro expansion
+  auto i = DESIGNATED_INITIALIZERS;
+}
+
 #endif
Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -7157,7 +7157,8 @@
     // Only diagnose designated initiaization as a C++20 extension if we didn't
     // already diagnose use of (non-C++20) C99 designator syntax.
     if (getLangOpts().CPlusPlus && !DiagnosedArrayDesignator &&
-        !DiagnosedNestedDesignator && !DiagnosedMixedDesignator) {
+        !DiagnosedNestedDesignator && !DiagnosedMixedDesignator &&
+        !getSourceManager().isInSystemMacro(FirstDesignator)) {
       Diag(FirstDesignator, getLangOpts().CPlusPlus20
                                 ? diag::warn_cxx17_compat_designated_init
                                 : diag::ext_cxx_designated_init);


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