[clang] b0b96fb - Fix erroneous `-Wmissing-prototypes` for Win32 entry points (#98105)

[via cfe-commits]

Author: Max Winkler
Date: 2024-07-09T18:38:32-07:00
New Revision: b0b96fbff47c74940a62073c579372f3c47df9c8

URL: https://github.com/llvm/llvm-project/commit/b0b96fbff47c74940a62073c579372f3c47df9c8
DIFF: https://github.com/llvm/llvm-project/commit/b0b96fbff47c74940a62073c579372f3c47df9c8.diff

LOG: Fix erroneous `-Wmissing-prototypes` for Win32 entry points (#98105)

Fixes https://github.com/llvm/llvm-project/issues/94366.

Added: 
    

Modified: 
    clang/docs/ReleaseNotes.rst
    clang/lib/Sema/SemaDecl.cpp
    clang/test/Sema/no-warn-missing-prototype.c

Removed: 
    


################################################################################
diff  --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index fac4c8e69dc15..3b105d91958cc 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -686,6 +686,9 @@ Improvements to Clang's diagnostics
 
 - Clang now shows implicit deduction guides when diagnosing overload resolution failure. #GH92393.
 
+- Clang no longer emits a "no previous prototype" warning for Win32 entry points under ``-Wmissing-prototypes``.
+  Fixes #GH94366.
+
 Improvements to Clang's time-trace
 ----------------------------------
 

diff  --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index aa44608035538..97e1f7e05e44e 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -15222,6 +15222,9 @@ ShouldWarnAboutMissingPrototype(const FunctionDecl *FD,
       if (II->isStr("main") || II->isStr("efi_main"))
         return false;
 
+  if (FD->isMSVCRTEntryPoint())
+    return false;
+
   // Don't warn about inline functions.
   if (FD->isInlined())
     return false;

diff  --git a/clang/test/Sema/no-warn-missing-prototype.c b/clang/test/Sema/no-warn-missing-prototype.c
index 6059b6aa0f146..17d69ac8913fa 100644
--- a/clang/test/Sema/no-warn-missing-prototype.c
+++ b/clang/test/Sema/no-warn-missing-prototype.c
@@ -1,5 +1,6 @@
 // RUN: %clang_cc1 -fsyntax-only -Wmissing-prototypes -x c -ffreestanding -verify %s
 // RUN: %clang_cc1 -fsyntax-only -Wmissing-prototypes -x c++ -ffreestanding -verify %s
+// RUN: %clang_cc1 -fms-compatibility -fsyntax-only -Wmissing-prototypes -x c++ -ffreestanding -triple=x86_64-pc-win32 -verify -DMS %s
 // expected-no-diagnostics
 int main() {
   return 0;
@@ -8,3 +9,21 @@ int main() {
 int efi_main() {
   return 0;
 }
+
+#ifdef MS
+int wmain(int, wchar_t *[], wchar_t *[]) {
+  return 0;
+}
+
+int wWinMain(void*, void*, wchar_t*, int) {
+  return 0;
+}
+
+int WinMain(void*, void*, char*, int) {
+  return 0;
+}
+
+bool DllMain(void*, unsigned, void*) {
+  return true;
+}
+#endif