[libc] set -Wno-frame-address for thread.cpp (#77140)

nickdesaulniers · web-flow · commit 12101ca8e322 · 2024-01-08T08:51:44.000-08:00
The aarch64 code is using __builtin_return_address with a non-zero parameter, which generates the following warning: llvm-project/libc/src/__support/threads/linux/thread.cpp:171:38: error: calling '__builtin_frame_address' with a nonzero argument is unsafe [-Werror,-Wframe-address] 171 | return reinterpret_cast<uintptr_t>(__builtin_frame_address(1)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~ Disable this diagnostic just for this file so that we can enable -Werror. Fixes: #77007
diff --git a/libc/src/__support/threads/linux/CMakeLists.txt b/libc/src/__support/threads/linux/CMakeLists.txt
@@ -39,6 +39,8 @@ add_object_library(
     -O3
     -fno-omit-frame-pointer # This allows us to sniff out the thread args from
                             # the new thread's stack reliably.
+    -Wno-frame-address      # Yes, calling __builtin_return_address with a
+                            # value other than 0 is dangerous. We know.
 )
 
 add_object_library(

Original file line number	Diff line number	Diff line change
`@@ -39,6 +39,8 @@ add_object_library(`
`39`	`39`	`-O3`
`40`	`40`	`-fno-omit-frame-pointer # This allows us to sniff out the thread args from`
`41`	`41`	`# the new thread's stack reliably.`
	`42`	`+ -Wno-frame-address # Yes, calling __builtin_return_address with a`
	`43`	`+ # value other than 0 is dangerous. We know.`
`42`	`44`	`)`
`43`	`45`
`44`	`46`	`add_object_library(`