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

[Max Winkler via cfe-commits]

https://github.com/MaxEW707 updated https://github.com/llvm/llvm-project/pull/98105

>From f9def27dcbfe6ce1a55fd5c41d15d55b05d9a056 Mon Sep 17 00:00:00 2001
From: MaxEW707 <max.enrico.winkler at gmail.com>
Date: Mon, 8 Jul 2024 19:14:11 -0700
Subject: [PATCH 1/3] Fix erroneous `-Wmissing-prototypes` for Win32 entry
 points

---
 clang/lib/Sema/SemaDecl.cpp                 |  3 +++
 clang/test/Sema/no-warn-missing-prototype.c | 27 +++++++++++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index b3bfdacb01790..b4d8d653616b1 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -15214,6 +15214,9 @@ 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..577718c928e59 100644
--- a/clang/test/Sema/no-warn-missing-prototype.c
+++ b/clang/test/Sema/no-warn-missing-prototype.c
@@ -1,10 +1,33 @@
 // 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 -x c++ -ffreestanding -triple=x86_64-pc-win32 -verify -DMS %s
 // expected-no-diagnostics
 int main() {
-  return 0;
+    return 0;
 }
 
 int efi_main() {
-  return 0;
+    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
\ No newline at end of file

>From 1143a06a4b4b7f435c19325bd3b2253cde02372c Mon Sep 17 00:00:00 2001
From: MaxEW707 <max.enrico.winkler at gmail.com>
Date: Mon, 8 Jul 2024 19:19:07 -0700
Subject: [PATCH 2/3] formatting

---
 clang/test/Sema/no-warn-missing-prototype.c | 26 +++++++++------------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/clang/test/Sema/no-warn-missing-prototype.c b/clang/test/Sema/no-warn-missing-prototype.c
index 577718c928e59..1b6e8f059fc45 100644
--- a/clang/test/Sema/no-warn-missing-prototype.c
+++ b/clang/test/Sema/no-warn-missing-prototype.c
@@ -3,31 +3,27 @@
 // RUN: %clang_cc1 -fms-compatibility -fsyntax-only -x c++ -ffreestanding -triple=x86_64-pc-win32 -verify -DMS %s
 // expected-no-diagnostics
 int main() {
-    return 0;
+  return 0;
 }
 
 int efi_main() {
-    return 0;
+  return 0;
 }
 
 #ifdef MS
-int wmain(int, wchar_t *[], wchar_t *[])
-{
-    return 0;
+int wmain(int, wchar_t *[], wchar_t *[]) {
+  return 0;
 }
 
-int wWinMain(void*, void*, wchar_t*, int)
-{
-    return 0;
+int wWinMain(void*, void*, wchar_t*, int) {
+  return 0;
 }
 
-int WinMain(void*, void*, char*, int)
-{
-    return 0;
+int WinMain(void*, void*, char*, int) {
+  return 0;
 }
 
-bool DllMain(void*, unsigned, void*)
-{
-    return true;
+bool DllMain(void*, unsigned, void* {
+  return true;
 }
-#endif
\ No newline at end of file
+#endif

>From bc40af777e31df856de3c68fe749311c8011f21f Mon Sep 17 00:00:00 2001
From: MaxEW707 <max.enrico.winkler at gmail.com>
Date: Mon, 8 Jul 2024 19:26:29 -0700
Subject: [PATCH 3/3] fix unit test

---
 clang/test/Sema/no-warn-missing-prototype.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/clang/test/Sema/no-warn-missing-prototype.c b/clang/test/Sema/no-warn-missing-prototype.c
index 1b6e8f059fc45..17d69ac8913fa 100644
--- a/clang/test/Sema/no-warn-missing-prototype.c
+++ b/clang/test/Sema/no-warn-missing-prototype.c
@@ -1,6 +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 -x c++ -ffreestanding -triple=x86_64-pc-win32 -verify -DMS %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;
@@ -23,7 +23,7 @@ int WinMain(void*, void*, char*, int) {
   return 0;
 }
 
-bool DllMain(void*, unsigned, void* {
+bool DllMain(void*, unsigned, void*) {
   return true;
 }
 #endif