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| author | Ben Boeckel <ben.boeckel@kitware.com> | 2023-11-20 14:15:46 (GMT) |
|---|---|---|
| committer | Brad King <brad.king@kitware.com> | 2023-11-21 14:41:59 (GMT) |
| commit | 77a7edb73fcfee88c4998bd8e4d72aaddc5524e5 (patch) | |
| tree | 7685988f591208d9249a36386ceb091cdf4420b4 /Modules/Compiler | |
| parent | 079bf537fd869e5dc098f15dacfc999790ff6a13 (diff) | |
| download | CMake-77a7edb73fcfee88c4998bd8e4d72aaddc5524e5.zip CMake-77a7edb73fcfee88c4998bd8e4d72aaddc5524e5.tar.gz CMake-77a7edb73fcfee88c4998bd8e4d72aaddc5524e5.tar.bz2 | |
Clang-CXX: copy into the dyndep output on success
When `clang-scan-deps` fails to scan (e.g., bad source syntax, junk
flags, etc.), the redirection unconditionally updates the file. If this
fails, the `.ddi` file timestamp is updated. If the state is then
reverted (e.g., the command line returns to the state of the last
successful build), the updated file is not useful, but `ninja` does not
rerun because:
- the command hash matches the last successful run
- the output file is newer than its inputs
However, since the `.ddi` file has been updated with bogus contents from
a failed scan, collation fails as the `rules` array is empty (or
incomplete from a batch scan).
If `clang-scan-deps` were properly aware of its output file, it could
use this to not write the file if any inner scan fails. Requested in
https://github.com/llvm/llvm-project/issues/72875.
See: https://github.com/llvm/llvm-project/issues/72875
Fixes: #25429
Diffstat (limited to 'Modules/Compiler')
| -rw-r--r-- | Modules/Compiler/Clang-CXX.cmake | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/Modules/Compiler/Clang-CXX.cmake b/Modules/Compiler/Clang-CXX.cmake index c0d2356..a1ce6a1 100644 --- a/Modules/Compiler/Clang-CXX.cmake +++ b/Modules/Compiler/Clang-CXX.cmake @@ -32,6 +32,13 @@ endif() if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 16.0) if("x${CMAKE_CXX_COMPILER_FRONTEND_VARIANT}" STREQUAL "xGNU") + if (CMAKE_HOST_WIN32) + # `rename` doesn't overwrite and doesn't retry in case of "target file is + # busy". + set(_clang_scan_deps_mv "\"${CMAKE_COMMAND}\" -E rename") + else () + set(_clang_scan_deps_mv "mv") + endif () string(CONCAT CMAKE_CXX_SCANDEP_SOURCE "\"${CMAKE_CXX_COMPILER_CLANG_SCAN_DEPS}\"" " -format=p1689" @@ -40,7 +47,15 @@ if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 16.0) " -x c++ <SOURCE> -c -o <OBJECT>" " -MT <DYNDEP_FILE>" " -MD -MF <DEP_FILE>" - " > <DYNDEP_FILE>") + # Write to a temporary file. If the scan fails, we do not want to update + # the actual output file as `ninja` (at least) assumes that failed + # commands either delete or leave output files alone. See Issue#25419. + " > <DYNDEP_FILE>.tmp" + # We cannot use `copy_if_different` as the rule does not have a feature + # analogous to `ninja`'s `restat = 1`. It would also leave behind the + # `.tmp` file. + " && ${_clang_scan_deps_mv} <DYNDEP_FILE>.tmp <DYNDEP_FILE>") + unset(_clang_scan_deps_mv) set(CMAKE_CXX_MODULE_MAP_FORMAT "clang") set(CMAKE_CXX_MODULE_MAP_FLAG "@<MODULE_MAP_FILE>") set(CMAKE_CXX_MODULE_BMI_ONLY_FLAG "--precompile") |