[PATCH] D15829: [PGO] Clang Option that enables IR level PGO instrumentation

[Chad Rosier via cfe-commits]

mcrosier added a subscriber: mcrosier.
mcrosier added a comment.

Would it make sense to include an additional test (in test/Driver) that shows the -fprofile-ir-instr option being passed from the driver to the frontend? Such a test case would land in clang_f_opt.c, which has many examples.


================
Comment at: lib/Driver/Tools.cpp:3279
@@ -3278,1 +3278,3 @@
+
+  Args.AddAllArgs(CmdArgs, options::OPT_fprofile_ir_instr);
 }
----------------
I don't think AddAllArgs is what you really want.  What if the user specifies the option twice?  Do we really want to pass the flag from the driver to the front-end twice?  Also, should we warn if the option is passed twice?

I also think some of the logic in CompilerInvocation should land here...  see comments below.

================
Comment at: lib/Frontend/CompilerInvocation.cpp:482
@@ +481,3 @@
+  Opts.ProfileIRInstr = Args.hasArg(OPT_fprofile_ir_instr) &&
+                        (Args.hasArg(OPT_fprofile_instr_generate) ||
+                         Args.hasArg(OPT_fprofile_instr_generate_EQ) ||
----------------
IIRC, the general practice is to put this type of logic in the driver.  Specifically, in Driver.cpp include something like

if (Args.hasArg(OPT_fprofile_ir_instr) &&
    (Args.hasArg(OPT_fprofile_instr_generate) ||
     Args.hasArg(OPT_fprofile_instr_generate_EQ) ||
     Args.hasArg(OPT_fprofile_instr_use_EQ)))
  // Add -fprofile_ir_instr flag....




http://reviews.llvm.org/D15829