[PATCH] D70222: [clangd] Add support for .rsp files in compile_commands.json

[liu hui via Phabricator via cfe-commits]

lh123 marked an inline comment as done.
lh123 added inline comments.


================
Comment at: clang/lib/Tooling/ExpandResponseFilesCompilationDatabase.cpp:167
+    for (auto &Cmd : Cmds) {
+      expandResponseFiles(Cmd, Tokenizer);
+    }
----------------
lh123 wrote:
> kadircet wrote:
> > so it looks like we already have `ExpandResponseFiles` exposed in `llvm/include/llvm/Support/CommandLine.h` could you make use of it in here instead of re-implementing it again?
> > 
> > I see that it has a different signature, but we can do the conversion back and forth in here, going from `std::string` to `char*` is cheap anyways, coming back is expensive though, and we can limit that to iff we have seen an argument starting with an `@`. So this would be something like:
> > 
> > ```
> > llvm::SmallVector<const char*, 20> Argvs;
> > Argvs.reserve(Cmd.CommandLine.size());
> > bool SeenRSPFile = false;
> > for(auto &Argv : Cmd.CommandLine) {
> >   Argvs.push_back(Argv.c_str());
> >   SeenRSPFile |= Argv.front() == '@';
> > }
> > if(!SeenRSPFile)
> >   continue;
> > 
> > // call ExpandResponseFiles with Argvs, convert back to vector<std::string> and assign to Cmd.CommandLine
> > ```
> I think it's not easy to reuse `ExpandResponseFiles` without changing code because it uses llvm::sys::fs::current_path to resolve relative paths.
> 
> In fact, most of the code here is copied from `CommandLine`
But we can reuse `static bool ExpandResponseFile(StringRef FName, StringSaver &Saver, TokenizerCallback Tokenizer, SmallVectorImpl<const char *> &NewArgv, bool MarkEOLs, bool RelativeNames)` if we expose it in `CommandLine.h`


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  https://reviews.llvm.org/D70222/new/

https://reviews.llvm.org/D70222