3 Commits

Author SHA1 Message Date
Arthur Eubanks
578a4716f5 Reland [clang] Canonicalize system headers in dependency file when -canonical-prefixes
Clang was writing paths to the dependency file that don't exist when using a sysroot with symlinks, causing everything to get rebuilt every time. This is reproducible on Linux by creating a symlink to '/', using that as the sysroot, and trying to build something with ninja that includes the C++ stdlib (e.g. a typical build of LLVM).

This fixes https://github.com/ninja-build/ninja/issues/1330 and somewhat matches gcc.

gcc canonicalizes system headers in dependency files under a -f[no-]canonical-system-headers, but it makes more sense to look at -canonical-prefixes.

D37954 was a previous attempt at this.

Fixed use of %T instead of %t in test, causing bots to fail the test on the initial commit.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D149187
2023-05-01 12:44:52 -07:00
Arthur Eubanks
f9fbda7102 Revert "[clang] Canonicalize system headers in dependency file when -canonical-prefixes"
This reverts commit 8f0dd4ef3ed2137d1e2554204127434fc46ee190.

Causes bot failures: https://lab.llvm.org/buildbot/#builders/139/builds/39964
2023-05-01 10:55:53 -07:00
Arthur Eubanks
8f0dd4ef3e [clang] Canonicalize system headers in dependency file when -canonical-prefixes
Clang was writing paths to the dependency file that don't exist when using a sysroot with symlinks, causing everything to get rebuilt every time. This is reproducible on Linux by creating a symlink to '/', using that as the sysroot, and trying to build something with ninja that includes the C++ stdlib (e.g. a typical build of LLVM).

This fixes https://github.com/ninja-build/ninja/issues/1330 and somewhat matches gcc.

gcc canonicalizes system headers in dependency files under a -f[no-]canonical-system-headers, but it makes more sense to look at -canonical-prefixes.

D37954 was a previous attempt at this.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D149187
2023-05-01 10:40:18 -07:00