llvm-project/clang/test/Driver/cc1-spawnprocess.c

// RUN: env CLANG_SPAWN_CC1= %clang -c %s -o /dev/null
// RUN: env CLANG_SPAWN_CC1=0 %clang -c %s -o /dev/null
// RUN: env CLANG_SPAWN_CC1=1 %clang -c %s -o /dev/null
// RUN: env CLANG_SPAWN_CC1=test not %clang -c %s -o /dev/null
Fix NetBSD bot after b4a99a061f517e60985667e39519f60186cbb469 ([Clang][Driver] Re-use the calling process instead of creating a new process for the cc1 invocation) 2020-01-15 03:14:07 +08:00			`// RUN: env CLANG_SPAWN_CC1= %clang -c %s -o /dev/null`
[Clang][Driver] Re-use the calling process instead of creating a new process for the cc1 invocation 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 2020-01-13 23:40:04 +08:00			`// RUN: env CLANG_SPAWN_CC1=0 %clang -c %s -o /dev/null`
			`// RUN: env CLANG_SPAWN_CC1=1 %clang -c %s -o /dev/null`
			`// RUN: env CLANG_SPAWN_CC1=test not %clang -c %s -o /dev/null`