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