[sanitizer_common] Provide dummy ThreadDescriptorSize on Solaris

[rorth]

Since 2c69a09, the Solaris build is broken like

Undefined			first referenced
 symbol  			    in file
_ZN11__sanitizer20ThreadDescriptorSizeEv projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.i386.dir/sanitizer_linux_libcdep.cpp.o

The ThreadDescriptorSize reference is from sanitizer_linux_libcdep.cpp (GetTls), l.590. This isn't actually needed on non-glibc targets AFAICS, so this patch provides a dummy to restore the build.

Tested on sparcv9-sun-solaris2.11, amd64-pc-solaris2.11, and x86_64-pc-linux-gnu.

[llvmbot]

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

Author: Rainer Orth (rorth)

Changes

Since 2c69a09, the Solaris build is broken like

Undefined			first referenced
 symbol  			    in file
_ZN11__sanitizer20ThreadDescriptorSizeEv projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.i386.dir/sanitizer_linux_libcdep.cpp.o

The ThreadDescriptorSize reference is from sanitizer_linux_libcdep.cpp (GetTls), l.590. This isn't actually needed on non-glibc targets AFAICS, so this patch provides a dummy to restore the build.

Tested on sparcv9-sun-solaris2.11, amd64-pc-solaris2.11, and x86_64-pc-linux-gnu.

---

Full diff: https://github.com/llvm/llvm-project/pull/109285.diff

1 Files Affected:

• (modified) compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp (+2-1)

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp
index aa156acd7b657a..4fc99197aae3d5 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp
@@ -226,7 +226,7 @@ static void GetGLibcVersion(int *major, int *minor, int *patch) {
 // sizeof(struct pthread) from glibc.
 static uptr thread_descriptor_size;
 
-// FIXME: Implementation is very GLIBC specific, but it's used by FREEBSD.
+// FIXME: Implementation is very GLIBC specific, but it's used by FreeBSD.
 static uptr ThreadDescriptorSizeFallback() {
 #    if defined(__x86_64__) || defined(__i386__) || defined(__arm__) || \
         SANITIZER_RISCV64
@@ -364,6 +364,7 @@ static uptr TlsPreTcbSize() {
 #    endif
 #  else   // (SANITIZER_FREEBSD || SANITIZER_GLIBC) && !SANITIZER_GO
 void InitTlsSize() {}
+uptr ThreadDescriptorSize() { return 0; }
 #  endif  // (SANITIZER_FREEBSD || SANITIZER_GLIBC) && !SANITIZER_GO
 
 #  if (SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_SOLARIS) && \

[rorth]

This (and the previous) Solaris build breakage are a consequence of thecompiler-rt source organisation, I belive: quite a number of source files with linux in their name are either not Linux-specific at all or contain just a few lines of non-Linux content, which is both very confusing. It's extremely difficult to find one's way through the resulting maze of #ifdefs, not breaking non-Linux targets while working on the Linux code.

[rorth]

The Solaris builds have been broken for 3 days now, and I got no reaction whatsoever.

Given the trivial nature of the patch and the testing done, I'll commit the patch now to unbreak the builds.

[vitalybuka]

The Solaris builds have been broken for 3 days now, and I got no reaction whatsoever.

Given the trivial nature of the patch and the testing done, I'll commit the patch now to unbreak the builds.

Thanks for fixing!
Sorry, I didn't notice the email on time.
Don't hesitate to revert or fix such trivial matters without a review.

[vitalybuka]

Oh, I was confused how Solaris references to the function are possible, I looked through the code before landing 2c69a09.

But the reason is that some references to the function are guarded with if (SANITIZER_GLIBC) instead of #ifdef SANITIZER_GLIBC.