With this patch, the clang tool will now call the -cc1 invocation directly inside the same process. Previously, the -cc1 invocation was creating, and waiting for, a new process.
This patch therefore reduces the number of created processes during a build, thus it reduces build times on platforms where process creation can be costly (Windows) and/or impacted by a antivirus.
It also makes debugging a bit easier, as there's no need to attach to the secondary -cc1 process anymore, breakpoints will be hit inside the same process.
Crashes or signaling inside the -cc1 invocation will have the same side-effect as before, and will be reported through the same means.
This behavior can be controlled at compile-time through the CLANG_SPAWN_CC1 cmake flag, which defaults to OFF. Setting it to ON will revert to the previous behavior, where any -cc1 invocation will create/fork a secondary process.
At run-time, it is also possible to tweak the CLANG_SPAWN_CC1 environment variable. Setting it and will override the compile-time setting. A value of 0 calls -cc1 inside the calling process; a value of 1 will create a secondary process, as before.
Differential Revision: https://reviews.llvm.org/D69825
If the linker is gcc (the default for Generic_ELF toolchains), we end up
passing most of the arguments to the linker.
Some tests were failing to account for this in their usage of *-NOT: lines
and would fail if compiled with
-DLLVM_DEFAULT_TARGET_TRIPLE=x86_64-unknown-unknown
llvm-svn: 228902
- Split pedantic driver flag test into separate test file, and XFAIL on cygwin,mingw32
- Fix bug in tablegen logic where a missing '{' caused errors to be included in -Wpedantic.
llvm-svn: 159892
Alexandre Ganea