1 CMake Caches 2 ============ 3 4 This directory contains CMake cache scripts that pre-populate the CMakeCache in 5 a build directory with commonly used settings. 6 7 You can use the caches files with the following CMake invocation: 8 9 cmake -G <build system> 10 -C <path to cache file> 11 [additional CMake options (i.e. -DCMAKE_INSTALL_PREFIX=<install path>)] 12 <path to llvm> 13 14 Options specified on the command line will override options in the cache files. 15 16 The following cache files exist. 17 18 Apple-stage1 19 ------------ 20 21 The Apple stage1 cache configures a two stage build similar to how Apple builds 22 the clang shipped with Xcode. The build files generated from this invocation has 23 a target named "stage2" which performs an LTO build of clang. 24 25 The Apple-stage2 cache can be used directly to match the build settings Apple 26 uses in shipping builds without doing a full bootstrap build. 27 28 PGO 29 --- 30 31 The PGO CMake cache can be used to generate a multi-stage instrumented compiler. 32 You can configure your build directory with the following invocation of CMake: 33 34 cmake -G <generator> -C <path_to_clang>/cmake/caches/PGO.cmake <source dir> 35 36 After configuration the following additional targets will be generated: 37 38 stage2-instrumented: 39 Builds a stage1 x86 compiler, runtime, and required tools (llvm-config, 40 llvm-profdata) then uses that compiler to build an instrumented stage2 compiler. 41 42 stage2-instrumented-generate-profdata: 43 Depends on "stage2-instrumented" and will use the instrumented compiler to 44 generate profdata based on the training files in <clang>/utils/perf-training 45 46 stage2: 47 Depends on "stage2-instrumented-generate-profdata" and will use the stage1 48 compiler with the stage2 profdata to build a PGO-optimized compiler. 49 50 stage2-check-llvm: 51 Depends on stage2 and runs check-llvm using the stage3 compiler. 52 53 stage2-check-clang: 54 Depends on stage2 and runs check-clang using the stage3 compiler. 55 56 stage2-check-all: 57 Depends on stage2 and runs check-all using the stage3 compiler. 58 59 stage2-test-suite: 60 Depends on stage2 and runs the test-suite using the stage3 compiler (requires 61 in-tree test-suite). 62 63 3-stage 64 ------- 65 66 This cache file can be used to generate a 3-stage clang build. You can configure 67 using the following CMake command: 68 69 cmake -C <path to clang>/cmake/caches/3-stage.cmake -G Ninja <path to llvm> 70 71 You can then run "ninja stage3-clang" to build stage1, stage2 and stage3 clangs. 72 73 This is useful for finding non-determinism the compiler by verifying that stage2 74 and stage3 are identical. 75
