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Ah well removing TAKES_PATH probably broke the WIN32 path conversion, it was indeed suspicious from the start. Maybe adding a new compopt flag would be necessary, I'll have a look. |
jrosdahl
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Dec 21, 2025
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Clang uses the .pch extension by default, but the tests were written to use the .gch extension. None of the suite was running with clang due to this issue
Author
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I've noticed that the pch tests actually did not run at all with clang due to some default extension mix-up (maybe it was updated in a more recent clang version). Additionally, the 2 parts of the change: do not rewrite -isysroot and cache it as relative with --relocatable-pch; have also been split. |
Even with BASEDIR, compilers should not be given a relative -isysroot directory as argument. Clang for example just ignores it in this case.
Clang recommends using -isysroot with relocatable-pch but it needs to be passed as an absolute path. However, we can use the relative path as a cache key in this case to actually make a use of the relocatable pch feature.
jrosdahl
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Jan 19, 2026
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| if (compopt_takes_path_abs(arg)) { | ||
| // some paths should not be made relative (eg -isysroot) |
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I'm not confident that we can ignore rewriting -isysroot unconditionally like this.
Consider this test script:
#!/bin/sh
set -eu
compiler=gcc
rm -rf pr-1661-test
mkdir pr-1661-test
cd pr-1661-test
mkdir -p example/arch1/sysroot/usr/include
touch example/arch1/sysroot/usr/include/h.h
cp -a example/arch1 example/arch2
cat <<EOF >example/arch1/c.c
#include <h.h>
EOF
cp example/arch1/c.c example/arch2
dir=$PWD
export CCACHE_BASEDIR=$dir
export CCACHE_DIR=$dir/ccache
export CCACHE_DEBUG=1
cd example/arch1
ccache $compiler -isysroot $dir/example/arch1/sysroot -c c.c
grep Executing c.o.*ccache-log || true
grep Result: c.o.*ccache-log || true
echo
cd ../..
cd example/arch2
ccache $compiler -isysroot $dir/example/arch2/sysroot -c c.c
grep Executing c.o.*ccache-log || true
grep Result: c.o.*ccache-log || trueWithout this PR the second compilation is a cache hit:
[2026-01-19T20:28:11.063512 3688461] Executing /usr/bin/gcc -isysroot sysroot -E -o /run/user/1000/ccache-tmp/cpp_stdout.tmp.oxOKwJ.i c.c
[2026-01-19T20:28:11.067772 3688461] Executing /usr/bin/gcc -isysroot sysroot -fdiagnostics-color -c -o c.o c.c
[2026-01-19T20:28:11.073773 3688461] Result: cache_miss
[2026-01-19T20:28:11.073774 3688461] Result: direct_cache_miss
[2026-01-19T20:28:11.073775 3688461] Result: local_storage_miss
[2026-01-19T20:28:11.073775 3688461] Result: local_storage_read_miss
[2026-01-19T20:28:11.073776 3688461] Result: local_storage_read_miss
[2026-01-19T20:28:11.073776 3688461] Result: local_storage_write
[2026-01-19T20:28:11.073777 3688461] Result: local_storage_write
[2026-01-19T20:28:11.073777 3688461] Result: preprocessed_cache_miss
[2026-01-19T20:28:11.078599 3688469] Result: direct_cache_hit
[2026-01-19T20:28:11.078600 3688469] Result: local_storage_hit
[2026-01-19T20:28:11.078600 3688469] Result: local_storage_read_hit
[2026-01-19T20:28:11.078601 3688469] Result: local_storage_read_hit
But with this PR it's a miss:
[2026-01-19T20:28:18.669134 3688663] Executing /usr/bin/gcc -isysroot /home/joel/[...]/pr-1661-test/example/arch1/sysroot -E -o /run/user/1000/ccache-tmp/cpp_stdout.tmp.8xlFDp.i c.c
[2026-01-19T20:28:18.672752 3688663] Executing /usr/bin/gcc -isysroot /home/joel/[...]/pr-1661-test/example/arch1/sysroot -fdiagnostics-color -c -o c.o c.c
[2026-01-19T20:28:18.679678 3688663] Result: cache_miss
[2026-01-19T20:28:18.679680 3688663] Result: direct_cache_miss
[2026-01-19T20:28:18.679682 3688663] Result: local_storage_miss
[2026-01-19T20:28:18.679683 3688663] Result: local_storage_read_miss
[2026-01-19T20:28:18.679685 3688663] Result: local_storage_read_miss
[2026-01-19T20:28:18.679686 3688663] Result: local_storage_write
[2026-01-19T20:28:18.679687 3688663] Result: local_storage_write
[2026-01-19T20:28:18.679688 3688663] Result: preprocessed_cache_miss
[2026-01-19T20:28:18.684241 3688671] Executing /usr/bin/gcc -isysroot /home/joel/[...]/pr-1661-test/example/arch2/sysroot -E -o /run/user/1000/ccache-tmp/cpp_stdout.tmp.m4Dned.i c.c
[2026-01-19T20:28:18.688607 3688671] Executing /usr/bin/gcc -isysroot /home/joel/[...]/pr-1661-test/example/arch2/sysroot -fdiagnostics-color -c -o c.o c.c
[2026-01-19T20:28:18.702156 3688671] Result: cache_miss
[2026-01-19T20:28:18.702163 3688671] Result: direct_cache_miss
[2026-01-19T20:28:18.702167 3688671] Result: local_storage_miss
[2026-01-19T20:28:18.702170 3688671] Result: local_storage_read_miss
[2026-01-19T20:28:18.702174 3688671] Result: local_storage_read_miss
[2026-01-19T20:28:18.702177 3688671] Result: local_storage_write
[2026-01-19T20:28:18.702180 3688671] Result: local_storage_write
[2026-01-19T20:28:18.702183 3688671] Result: preprocessed_cache_miss
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Here is an attempt to solve #1322 with one of the proposed approaches from the thread.
To reduce risk, I thought about restricting this behavior to invocations with
--relocatable-pchbut it would probably lead to bigger changes ashash_argumentis collecting everything in one pass.Fixes #1322