Description
A 2-stage build with flang included is currently broken on Linux/sparc64 with tons of errors like
error: current translation unit is compiled with the target feature '+vis' but the AST file 'tools/flang/lib/Parser/CMakeFiles/FortranParser.dir/cmake_pch.hxx.pch' was not
I could trace this to the fact that the object file creating is run with clang-21 -cc1 -triple sparc64-unknown-linux-gnu -emit-obj -target-feature +vis while the pch generation uses clang-21 -cc1 -triple sparc64-unknown-linux-gnu -emit-pch without the -target-feature +vis, thus the inconsistency.
Even without flang, there are three testsuite regressions showing the same error:
Clang :: ClangScanDeps/modules-symlink.c
Clang :: ClangScanDeps/prebuilt-modules-in-stable-dirs.c
Clang :: SemaCXX/warn-unused-local-typedef-serialize.cpp
While I managed to get further along with the attached preliminary patch, which adds the missing option for -emit-pch and -emit-llvm (which fixes the flang build), this introduces tons of new regressions instead:
Clang :: ClangScanDeps/module-format.c
Clang :: ClangScanDeps/modules-pch-common-submodule.c
Clang :: ClangScanDeps/modules-pch-common-via-submodule.c
Clang :: ClangScanDeps/modules-pch-dangling.c
Clang :: ClangScanDeps/modules-pch-imports.c
Clang :: ClangScanDeps/modules-pch.c
Clang :: ClangScanDeps/optimize-vfs-pch.m
Clang :: Index/pch-with-errors.c
Clang :: PCH/different-diagnostic-level.c
Clang :: PCH/gch-probe.c
Clang :: PCH/pch-dir.c
Clang :: Tooling/pch.cpp
Now the .pch files are correctly built with -target-feature +vis, but the TUs are claimed to be not and I have no idea what's going on.
Fortunately, Solaris/sparcv9 isn't affected because for unknown reasons commit 3853116, which introduced -target-feature +vis, doesn't pass that option on Solaris.
It seems other targets are less affected because unlike the sparcv9 case they only enable -target-feature with special flags and not in general.