The clang invocation was assembled inline across four regions of Build,
interleaved with the dependency-graph walk, so nothing else could ask "what
flags does this Configuration compile with". The linter's AST layer needs
exactly that, and it cannot approximate it: a precompiled module is rejected
outright by a translation unit whose target features differ from the one that
wrote it. Dropping just -march=native produces hundreds of "compiled with the
target feature '+avx512bw' but the current translation unit is not" errors and
no usable parse, so reconstructed flags fail hard rather than degrade.
GetCompileCommand is the config-pure part: target, arch, standard,
configuration defines, module search paths, includes, user compileFlags,
optimisation and LTO. Build appends only what depends on work having happened
— dependency public flags and external dependency flags. The sub-strings it
also needs on their own (includes, defines, user flags, LTO) come back as
struct members, so the .c compile path is unchanged.
Verified by probing `command` at the equivalent point before and after and
diffing: byte-identical across all 23 configurations exercised by a full build
plus the test suite.
Two incidental simplifications fell out. pcmDir was recomputing what
Configuration::PcmDir() already returns, and cmakeBuildType is now a
one-liner. GetCompileCommand is also most of what a compile_commands.json
would need, which this repo lacks.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Jorijn van der Graaf
7bb0a19ed0