LTO support for -fsave-optimization-record on Darwin

[anemet]

Summary

I guess this would have to be added for each linker.

[mehdi_amini]

LGTM.

[mehdi_amini]

Well, maybe not entirely, what do you expect for output with ThinLTO?

[anemet]

In D26833#599382, @mehdi_amini wrote:

Well, maybe not entirely, what do you expect for output with ThinLTO?

For now, I'd like to just ignore it. So I need to somehow restrict this to LTO-only...

[mehdi_amini]

I'm not incline to agree with this, unless you have very strong arguments.

[anemet]

Nothing strong, just trying to go step-by-step. I haven't thought about it how this should map to ThinLTO. We can discuss it tomorrow.

[anemet]

Mehdi offered to help out making this work for ThinLTO on the LLVM side. For now this option will be ignored by ThinLTO.

lib/Driver/Tools.cpp

if (Args.hasArg(options::OPT_ccc_arcmt_check,
     C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, None));
     return;
   }
 
   // I'm not sure why this particular decomposition exists in gcc, but
   // we follow suite for ease of comparison.
   AddLinkArgs(C, Args, CmdArgs, Inputs);
 
+  // For LTO, pass the name of the optimization record file.
+  if (Args.hasFlag(options::OPT_fsave_optimization_record,
+                   options::OPT_fno_save_optimization_record, false)) {
+    CmdArgs.push_back("-mllvm");
+    CmdArgs.push_back("-pass-remarks-output");
+    CmdArgs.push_back("-mllvm");
+
+    SmallString<128> F;
+    F = Output.getFilename();
+    F += ".opt.yaml";
+    CmdArgs.push_back(Args.MakeArgString(F));
+  }
+
   // It seems that the 'e' option is completely ignored for dynamic executables
   // (the default), and with static executables, the last one wins, as expected.
   Args.AddAllArgs(CmdArgs, {options::OPT_d_Flag, options::OPT_s, options::OPT_t,
                             options::OPT_Z_Flag, options::OPT_u_Group,
                             options::OPT_e, options::OPT_r});
 
   // Forward -ObjC when either -ObjC or -ObjC++ is used, to force loading
   // members of static archive libraries which implement Objective-C classes or

test/Driver/darwin-ld.c

 // RUN: FileCheck -check-prefix=LINK_VERSION_DIGITS %s < %t.log
 // LINK_VERSION_DIGITS-NOT: invalid version number in '-mlinker-version=133.3'
 // LINK_VERSION_DIGITS-NOT: invalid version number in '-mlinker-version=133.3.0'
 // LINK_VERSION_DIGITS-NOT: invalid version number in '-mlinker-version=133.3.0.1'
 // LINK_VERSION_DIGITS-NOT: invalid version number in '-mlinker-version=133.3.0.1.2'
 // LINK_VERSION_DIGITS: invalid version number in '-mlinker-version=133.3.0.1.2.6'
 // LINK_VERSION_DIGITS: invalid version number in '-mlinker-version=133.3.0.1.a'
 // LINK_VERSION_DIGITS: invalid version number in '-mlinker-version=133.3.0.1a'
+
+// Check that we're passing -pass-remarks-output for LTO
+// RUN: %clang -target x86_64-apple-darwin12 %t.o -fsave-optimization-record -### -o foo/bar.out 2> %t.log
+// RUN: FileCheck -check-prefix=PASS_REMARKS_OUTPUT %s < %t.log
+// PASS_REMARKS_OUTPUT: "-mllvm" "-pass-remarks-output" "-mllvm" "foo/bar.out.opt.yaml"
+
+// RUN: %clang -target x86_64-apple-darwin12 %t.o -fsave-optimization-record -### 2> %t.log
+// RUN: FileCheck -check-prefix=PASS_REMARKS_OUTPUT_NO_O %s < %t.log
+// PASS_REMARKS_OUTPUT_NO_O: "-mllvm" "-pass-remarks-output" "-mllvm" "a.out.opt.yaml"