[PATCH] D144190: [AIX][clang] Storage Locations for Constant Pointers

[Hubert Tong via Phabricator via cfe-commits]

hubert.reinterpretcast added inline comments.


================
Comment at: clang/lib/Driver/ToolChains/Clang.cpp:5250
 
+  if (Args.hasArg(options::OPT_mroptr) || Args.hasArg(options::OPT_mno_roptr)) {
+    bool HasRoptr =
----------------
This only checks for `-m[no-]roptr` when the front-end is invoked. When the driver is used just for linking, we get no diagnostic at all for using these options on other platforms.

@MaskRay:

As Clang code owner for the Driver, are you concerned if platform-specific options are sometimes silently ignored on other platforms? Is there a better place for the diagnostic?

For info, in this case, the option would have effects on AIX at both compile-from-C/C++ time and at link time. 

Also, should `-Wunused-command-line-argument` warnings be generated for cases where the option has no effect (e.g., `-emit-llvm` or `-fsyntax-only`)? I think `-flto` is a bit of an exception because it may be unfriendly to expect users to change other aspects of their compile invocations when adding `-flto`. At the same time, it can be argued instead that generating a `-Wunused-command-line-argument` warning for "back-end" options on `-flto` compiles helps the user realize that they need to provide the option on their link step.



Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D144190/new/

https://reviews.llvm.org/D144190