[PATCH] D126796: [clang][driver] adds `-print-diagnostics`

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman accepted this revision.
aaron.ballman added a comment.
This revision is now accepted and ready to land.

LGTM!



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Comment at: clang/lib/Basic/DiagnosticIDs.cpp:656
 std::vector<std::string> DiagnosticIDs::getDiagnosticFlags() {
-  std::vector<std::string> Res;
+  std::vector<std::string> Res{"-W", "-Wno-"};
   for (size_t I = 1; DiagGroupNames[I] != '\0';) {
----------------
cjdb wrote:
> aaron.ballman wrote:
> > I presume this change doesn't have any negative effects in `Driver::HandleAutocompletions()`? (That's currently the only consumer of this API.)
> All tests pass, so I hope not?
Sure, we can go with that. I also spot-checked and I don't think this should have a negative impact there.


================
Comment at: clang/lib/Driver/Driver.cpp:2010
+  if (C.getArgs().hasArg(options::OPT_print_diagnostic_options)) {
+    std::vector<std::string> Flags = DiagnosticIDs::getDiagnosticFlags();
+    for (std::size_t I = 0; I != Flags.size(); I += 2)
----------------
cjdb wrote:
> aaron.ballman wrote:
> > Declare the type as a const reference?
> > 
> > (Btw, when uploading patches, you should give them plenty of patch context -- that's what allows reviewers to suggest changes directly in Phab, but it also gives more information to reviewers so they don't have to leave the review to go to a code editor. FWIW, I usually use `-U999` to add context.)
> > Declare the type as a const reference?
> 
> I'm not seeing the advantage of doing this here. Happy to make it const, but the reference doesn't add a benefit and potentially introduces confusion.
> 
> > (Btw, when uploading patches, you should give them plenty of patch context -- that's what allows reviewers to suggest changes directly in Phab, but it also gives more information to reviewers so they don't have to leave the review to go to a code editor. FWIW, I usually use -U999 to add context.)
> 
> Sorry about that. I usually use `arc diff` to upload patches, but have been having problems with it recently and did a rushed manual upload instead.
> I'm not seeing the advantage of doing this here. Happy to make it const, but the reference doesn't add a benefit and potentially introduces confusion.

I still reflexively assume that some older compilers aren't as good at move operations as they should be, and this would be inducing a copy of a pretty large vector. Using a const reference means the result of the call is lifetime extended and there's no chance of a big copy. However, I don't insist as I think we should be able to rely on move operations these days?

> Sorry about that. I usually use arc diff to upload patches, but have been having problems with it recently and did a rushed manual upload instead.

Ah, no worries! I just mentioned it in case you weren't aware. :-)


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D126796/new/

https://reviews.llvm.org/D126796