[libcxx-commits] [libcxx] 250c39c - [libcxx] Add cast to avoid pointer casting warning on Windows (#92738)

[via libcxx-commits]

Author: Martin Storsjö
Date: 2024-05-20T23:30:51+03:00
New Revision: 250c39cd7aae8d4a6a76e2f04cfe5ce657f8260c

URL: https://github.com/llvm/llvm-project/commit/250c39cd7aae8d4a6a76e2f04cfe5ce657f8260c
DIFF: https://github.com/llvm/llvm-project/commit/250c39cd7aae8d4a6a76e2f04cfe5ce657f8260c.diff

LOG: [libcxx] Add cast to avoid pointer casting warning on Windows (#92738)

This avoids the following build time warning, when building with the
latest nightly Clang:

warning: cast from 'FARPROC' (aka 'int (*)() __attribute__((stdcall))')
to
'GetSystemTimeAsFileTimePtr' (aka 'void (*)(_FILETIME *)
__attribute__((stdcall))')
converts to incompatible function type [-Wcast-function-type-mismatch]

This warning seems to have appeared since Clang commit
999d4f840777bf8de26d45947192aa0728edc0fb, which restructured.

The GetProcAddress function returns a `FARPROC` type, which is `int
(WINAPI *)()`. Directly casting this to another function pointer type
triggers this warning, but casting to a `void*` inbetween avoids this
issue. (On Unix-like platforms, dlsym returns a `void*`, which doesn't
exhibit this casting problem.)

Added: 
    

Modified: 
    libcxx/src/chrono.cpp

Removed: 
    


################################################################################
diff  --git a/libcxx/src/chrono.cpp b/libcxx/src/chrono.cpp
index e7d6dfbc22924..83e8a64504ae0 100644
--- a/libcxx/src/chrono.cpp
+++ b/libcxx/src/chrono.cpp
@@ -77,8 +77,8 @@ typedef void(WINAPI* GetSystemTimeAsFileTimePtr)(LPFILETIME);
 class GetSystemTimeInit {
 public:
   GetSystemTimeInit() {
-    fp =
-        (GetSystemTimeAsFileTimePtr)GetProcAddress(GetModuleHandleW(L"kernel32.dll"), "GetSystemTimePreciseAsFileTime");
+    fp = (GetSystemTimeAsFileTimePtr)(void*)GetProcAddress(
+        GetModuleHandleW(L"kernel32.dll"), "GetSystemTimePreciseAsFileTime");
     if (fp == nullptr)
       fp = GetSystemTimeAsFileTime;
   }