[compiler-rt] Propagate sysroot from CMake to msan tests

[zeroomega]

Some msan tests requires rpc/xdr.h, which is no longer available in some newer glibc. In build systems with hermetic sysroot set through CMake, this issue can be solved by setting the sysroot to CMAKE_SYSROOT for these tests. This patch implements it.

[llvmbot]

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Haowei (zeroomega)

Changes

Some msan tests requires rpc/xdr.h, which is no longer available in some newer glibc. In build systems with hermetic sysroot set through CMake, this issue can be solved by setting the sysroot to CMAKE_SYSROOT for these tests. This patch implements it.

---

Full diff: https://github.com/llvm/llvm-project/pull/132299.diff

2 Files Affected:

• (modified) compiler-rt/test/msan/lit.cfg.py (+4)
• (modified) compiler-rt/test/msan/lit.site.cfg.py.in (+1)

diff --git a/compiler-rt/test/msan/lit.cfg.py b/compiler-rt/test/msan/lit.cfg.py
index 361be79e2557e..7282d29340201 100644
--- a/compiler-rt/test/msan/lit.cfg.py
+++ b/compiler-rt/test/msan/lit.cfg.py
@@ -17,6 +17,10 @@
         "-fno-optimize-sibling-calls",
     ]
     + [config.target_cflags]
+    + [
+        "--sysroot",
+        config.cmake_sysroot
+    ] if config.cmake_sysroot and config.host_os == "Linux" else []
     + config.debug_info_flags
 )
 # Some Msan tests leverage backtrace() which requires libexecinfo on FreeBSD.
diff --git a/compiler-rt/test/msan/lit.site.cfg.py.in b/compiler-rt/test/msan/lit.site.cfg.py.in
index 47264d0986946..41231359692ed 100644
--- a/compiler-rt/test/msan/lit.site.cfg.py.in
+++ b/compiler-rt/test/msan/lit.site.cfg.py.in
@@ -6,6 +6,7 @@ config.target_cflags = "@MSAN_TEST_TARGET_CFLAGS@"
 config.target_arch = "@MSAN_TEST_TARGET_ARCH@"
 config.use_lld = @MSAN_TEST_USE_LLD@
 config.use_thinlto = @MSAN_TEST_USE_THINLTO@
+config.cmake_sysroot = "@CMAKE_SYSROOT@"
 
 # Load common config for all compiler-rt lit tests.
 lit_config.load_config(config, "@COMPILER_RT_BINARY_DIR@/test/lit.common.configured")

[github-actions]

✅ With the latest revision this PR passed the Python code formatter.

[vitalybuka]

should we do that for entire compiler-rt?
https://github.com/llvm/llvm-project/blob/main/compiler-rt/test/lit.common.configured.in

[zeroomega]

I tried but ran into some further issues as some rtsan unit tests are not compatible with older glibc as memfd_create was not defined in glibc 2.19, it still can be invoked through syscall wrappers but that probably needs a separate patch. Therefore, I current limit the change to msan on Linux only to avoid other unwanted breakages.

[vitalybuka]

It's seems like incremental which which does not lead us to desired direction.
Could you try to figure out rtsan issue instead?

[petrhosek]

This needs to be included in MSAN_UNITTEST_COMMON_CFLAGS as well.

[petrhosek]

This is just a nit, but I'd suggest calling it just sysroot, the fact that it comes from CMake isn't relevant.

Suggested change

	config.cmake_sysroot = "@CMAKE_SYSROOT@"
	config.sysroot = "@CMAKE_SYSROOT@"

[vitalybuka]

if it's good enough @petrhosek, then it's good enough for me. LGTM