ben.boeckel added a comment. In D137534#4024249 <https://reviews.llvm.org/D137534#4024249>, @jansvoboda11 wrote:
> I'm getting confused by the semantics of `--p1689-targeted-output=`. In > D137527 <https://reviews.llvm.org/D137527>, it's used to populate > `CompilerCommand::Output` which is supposed to be the main compiler output > (`.o` file). Is that correct? If that's not the case and this flag is > supposed to only control where to put the JSON file with the dependency > information, it might as well have more generic name, like `-o` or `--output` > and apply to the rest of `clang-scan-deps`, no? So the scanner has a few jobs: - given this command line for this object file (we do not think in terms of source files because object files are unique; source files can be reused with different flags), please write out a P1689 <https://reviews.llvm.org/P1689> file describing the module requirements and any module(s) provided (plural because Fortran supports multiple modules in a single source file and unity builds can also do this though I have no idea how likely unity module builds is ever going to be) - the format supports doing this for a set of object files (but given the way it tangles the dep graph, is unlikely to be a perf win for incremental/developer builds; CI may prefer it, but that can be future work) - because it is a rule that can itself read extra files that affect the scanning; this is the `-MF`-style output so that make/ninja can know "oh, frabnitz.h changed, it can affect the scan results in glom.ddi, so I will rescan") Note that multi-arch builds are an open question (just like multi-arch `.pcm` files are I believe); the format could support it as two reports on provides/reqs, but the merged object file complicates things. The object can be obtained from the `-o` on the command line, but the rest is "lying" if it is extracted from the clang command line and not given to `clang-scan-deps` directly. This paper may be useful for the overall strategy being used here: https://mathstuf.fedorapeople.org/fortran-modules/fortran-modules.html CHANGES SINCE LAST ACTION https://reviews.llvm.org/D137534/new/ https://reviews.llvm.org/D137534 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
