[clang] Updating to include gcc-toolsets 13 and 14

[roadswitcher]

Updating clang/lib/Driver to detect the newer gcc-toolchain versions.

( submitted to llvm-commits mailing list )

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[llvmbot]

@llvm/pr-subscribers-clang-driver

@llvm/pr-subscribers-clang

Author: Bill Blum (roadswitcher)

Changes

Updating clang/lib/Driver to detect the newer gcc-toolchain versions.

( submitted to llvm-commits mailing list )

---

Full diff: https://github.com/llvm/llvm-project/pull/128438.diff

1 Files Affected:

• (modified) clang/lib/Driver/ToolChains/Gnu.cpp (+2)

diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
index f56eeda3cb5f6..b95fb379f9b0e 100644
--- a/clang/lib/Driver/ToolChains/Gnu.cpp
+++ b/clang/lib/Driver/ToolChains/Gnu.cpp
@@ -2381,6 +2381,8 @@ void Generic_GCC::GCCInstallationDetector::AddDefaultGCCPrefixes(
       D.getVFS().exists("/opt/rh")) {
     // TODO: We may want to remove this, since the functionality
     //   can be achieved using config files.
+    Prefixes.push_back("/opt/rh/gcc-toolset-14/root/usr");
+    Prefixes.push_back("/opt/rh/gcc-toolset-13/root/usr");
     Prefixes.push_back("/opt/rh/gcc-toolset-12/root/usr");
     Prefixes.push_back("/opt/rh/gcc-toolset-11/root/usr");
     Prefixes.push_back("/opt/rh/gcc-toolset-10/root/usr");

[MaskRay]

I think redhat gcc-toolset support should move to Clang configuration files https://reviews.llvm.org/D136435 @tbaederr

[nikic]

@MaskRay We already do that, with the following content in the config file:

%if %{defined gts_version}
%global cfg_file_content %{cfg_file_content} --gcc-install-dir=/opt/rh/gcc-toolset-%{gts_version}/root/%{_exec_prefix}/lib/gcc/%{_target_cpu}-redhat-linux/%{gts_version}
%endif

I suspect that this change may be about people building their own clang (not the one RHEL ships) and wanting to use GCC toolset. Would be good to clarify what exactly the motivation is.

Edit: This is in upcoming versions of RHEL. The current releases use -DGCC_INSTALL_PREFIX=/opt/rh/gcc-toolset-%{gts_version}/root/usr instead. I believe that means they also don't depend on the code changed here.

[roadswitcher]

I suspect that this change may be about people building their own clang (not the one RHEL ships) and wanting to use GCC toolset.

Sorry, I should have been more specific in my original comment.
Yes, we are building LLVM 19 from source along with a number of other tools/libraries and are trying to standardize on using the most recent gcc-toolset available to us in the process.

I didn't see anything obvious in the CMake configuration variables page here ( https://llvm.org/docs/CMake.html ), or any notes under "Compiler Platform Specific Topics" ( https://llvm.org/docs/CMake.html#compiler-platform-specific-topics ).

If there's a preferred way going forwards to specify the GCC toolchain used for the build that's documented in someone's mailing list traffic, I'm happy to pivot this PR into turning mailing list traffic into something for the docs.