[llvm-branch-commits] [compiler-rt] 4e858e4 - Merging r372038:

[Tom Stellard via llvm-branch-commits]

Author: Jian Cai
Date: 2019-11-08T12:33:21-08:00
New Revision: 4e858e4ac00b59f064da4e1f7e276916e7d296aa

URL: https://github.com/llvm/llvm-project/commit/4e858e4ac00b59f064da4e1f7e276916e7d296aa
DIFF: https://github.com/llvm/llvm-project/commit/4e858e4ac00b59f064da4e1f7e276916e7d296aa.diff

LOG: Merging r372038:

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r372038 | jcai19 | 2019-09-16 14:47:47 -0700 (Mon, 16 Sep 2019) | 15 lines

[compiler-rt][crt]  make test case nontrivial in check_cxx_section_exists

Summary:
.init_array gets optimized away when building with -O2 and as a result,
check_cxx_section_exists failed to pass -DCOMPILER_RT_HAS_INITFINI_ARRAY
when building crtbegin.o and crtend.o, which causes binaries linked with
them encounter segmentation fault. See https://crbug.com/855759 for
details. This change prevents .init_array section to be optimized away
even with -O2 or higher optimization level.

Subscribers: dberris, mgorny, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D67628
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Added: 
    

Modified: 
    compiler-rt/lib/crt/CMakeLists.txt

Removed: 
    


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diff  --git a/compiler-rt/lib/crt/CMakeLists.txt b/compiler-rt/lib/crt/CMakeLists.txt
index 03a07f475d7e..03e7b663ec40 100644
--- a/compiler-rt/lib/crt/CMakeLists.txt
+++ b/compiler-rt/lib/crt/CMakeLists.txt
@@ -69,7 +69,7 @@ function(check_cxx_section_exists section output)
 endfunction()
 
 check_cxx_section_exists(".init_array" COMPILER_RT_HAS_INITFINI_ARRAY
-  SOURCE "__attribute__((constructor)) void f() {}\nint main() { return 0; }\n")
+  SOURCE "volatile int x;\n__attribute__((constructor)) void f() {x = 0;}\nint main() { return 0; }\n")
 
 append_list_if(COMPILER_RT_HAS_STD_C11_FLAG -std=c11 CRT_CFLAGS)
 append_list_if(COMPILER_RT_HAS_INITFINI_ARRAY -DCRT_HAS_INITFINI_ARRAY CRT_CFLAGS)