Order File Instrumentation: add clang support for -forder-file-instrumentation

[manmanren]

Summary

When -forder-file-instrumentation is on, we pass llvm flag to enable the order file instrumentation pass.

[modocache]

Looks good, thanks for adding a driver option for this!

include/clang/Driver/Options.td

774

Would it make sense to add documentation to the Clang User's Manual for this option? Some other profiling options are mentioned there, but not all.

[smeenai]

lib/Driver/ToolChains/Clang.cpp

5312

What about full LTO?

test/Driver/clang_f_opts.c

137

Can you add a test for not passing this for the ThinLTO case?

[manmanren]

include/clang/Driver/Options.td

774

Will do this in a followup!

[manmanren]

r355333

[ychen]

In D58751#1417467, @manmanren wrote:

r355333

Hello, thanks for this nice feature. Are there any docs on how to use it?

include/clang/Driver/Options.td

 def fno_profile_use : Flag<["-"], "fno-profile-use">,
     Alias<fno_profile_instr_use>;
 def fprofile_filter_files_EQ : Joined<["-"], "fprofile-filter-files=">,
     Group<f_Group>, Flags<[CC1Option, CoreOption]>,
     HelpText<"Instrument only functions from files where names match any regex separated by a semi-colon">;
 def fprofile_exclude_files_EQ : Joined<["-"], "fprofile-exclude-files=">,
     Group<f_Group>, Flags<[CC1Option, CoreOption]>,
     HelpText<"Instrument only functions from files where names don't match all the regexes separated by a semi-colon">;
+def forder_file_instrumentation : Flag<["-"], "forder-file-instrumentation">,
+    Group<f_Group>, Flags<[CoreOption]>,
+    HelpText<"Generate instrumented code to collect order file into default.profraw file (overridden by '=' form of option or LLVM_PROFILE_FILE env var)">;
 
 def faddrsig : Flag<["-"], "faddrsig">, Group<f_Group>, Flags<[CoreOption, CC1Option]>,
   HelpText<"Emit an address-significance table">;
 def fno_addrsig : Flag<["-"], "fno-addrsig">, Group<f_Group>, Flags<[CoreOption]>,
   HelpText<"Don't emit an address-significance table">;
 def fblocks : Flag<["-"], "fblocks">, Group<f_Group>, Flags<[CoreOption, CC1Option]>,
   HelpText<"Enable the 'blocks' language feature">;
 def fbootclasspath_EQ : Joined<["-"], "fbootclasspath=">, Group<f_Group>;

lib/Driver/ToolChain.cpp

 }
 
 bool ToolChain::needsProfileRT(const ArgList &Args) {
   if (needsGCovInstrumentation(Args) ||
       Args.hasArg(options::OPT_fprofile_generate) ||
       Args.hasArg(options::OPT_fprofile_generate_EQ) ||
       Args.hasArg(options::OPT_fprofile_instr_generate) ||
       Args.hasArg(options::OPT_fprofile_instr_generate_EQ) ||
-      Args.hasArg(options::OPT_fcreate_profile))
+      Args.hasArg(options::OPT_fcreate_profile) ||
+      Args.hasArg(options::OPT_forder_file_instrumentation)) 
     return true;
 
   return false;
 }
 
 bool ToolChain::needsGCovInstrumentation(const llvm::opt::ArgList &Args) {
   return Args.hasFlag(options::OPT_fprofile_arcs, options::OPT_fno_profile_arcs,
                       false) ||

lib/Driver/ToolChains/Clang.cpp

if (A->getOption().matches(options::OPT_fexperimental_isel)) {
         else
           D.Diag(diag::warn_drv_experimental_isel_incomplete_opt);
       }
     } else {
       CmdArgs.push_back("-global-isel=0");
     }
   }
 
+  if (Args.hasArg(options::OPT_forder_file_instrumentation)) {
+     CmdArgs.push_back("-forder-file-instrumentation");
+     // Enable order file instrumentation when ThinLTO is not on. When ThinLTO is
+     // on, we need to pass these flags as linker flags and that will be handled
+     // outside of the compiler.
+     if (D.getLTOMode() != LTOK_Thin) {
+       CmdArgs.push_back("-mllvm");
+       CmdArgs.push_back("-enable-order-file-instrumentation");
+     }
+  }
+
   if (Arg *A = Args.getLastArg(options::OPT_fforce_enable_int128,
                                options::OPT_fno_force_enable_int128)) {
     if (A->getOption().matches(options::OPT_fforce_enable_int128))
       CmdArgs.push_back("-fforce-enable-int128");
   }
 
   if (Args.hasFlag(options::OPT_fcomplete_member_pointers,
                    options::OPT_fno_complete_member_pointers, false))

test/Driver/clang_f_opts.c

 // RUN: %clang -### -S -fprofile-instr-use=file -fno-profile-instr-use %s 2>&1 | FileCheck -check-prefix=CHECK-DISABLE-USE %s
 // RUN: %clang -### -S -fprofile-instr-use=file -fno-profile-use %s 2>&1 | FileCheck -check-prefix=CHECK-DISABLE-USE %s
 // RUN: %clang -### -S -fprofile-use=file -fno-profile-use %s 2>&1 | FileCheck -check-prefix=CHECK-DISABLE-USE %s
 // RUN: %clang -### -S -fprofile-use=file -fno-profile-instr-use %s 2>&1 | FileCheck -check-prefix=CHECK-DISABLE-USE %s
 // RUN: %clang -### -S -fcoverage-mapping %s 2>&1 | FileCheck -check-prefix=CHECK-COVERAGE-AND-GEN %s
 // RUN: %clang -### -S -fcoverage-mapping -fno-coverage-mapping %s 2>&1 | FileCheck -check-prefix=CHECK-DISABLE-COVERAGE %s
 // RUN: %clang -### -S -fprofile-instr-generate -fcoverage-mapping -fno-coverage-mapping %s 2>&1 | FileCheck -check-prefix=CHECK-DISABLE-COVERAGE %s
 // RUN: %clang -### -S -fprofile-remapping-file foo/bar.txt %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-REMAP %s
+// RUN: %clang -### -S -forder-file-instrumentation %s 2>&1 | FileCheck -check-prefix=CHECK-ORDERFILE-INSTR %s
 // CHECK-PROFILE-GENERATE: "-fprofile-instrument=clang"
 // CHECK-PROFILE-GENERATE-LLVM: "-fprofile-instrument=llvm"
 // CHECK-PROFILE-GENERATE-DIR: "-fprofile-instrument-path=/some/dir{{/|\\\\}}{{.*}}"
 // CHECK-PROFILE-GENERATE-FILE: "-fprofile-instrument-path=/tmp/somefile.profraw"
 // CHECK-NO-MIX-GEN-USE: '{{[a-z=-]*}}' not allowed with '{{[a-z=-]*}}'
 // CHECK-NO-MIX-GENERATE: '{{[a-z=-]*}}' not allowed with '{{[a-z=-]*}}'
 // CHECK-DISABLE-GEN-NOT: "-fprofile-instrument=clang"
 // CHECK-DISABLE-USE-NOT: "-fprofile-instr-use"
 // CHECK-COVERAGE-AND-GEN: '-fcoverage-mapping' only allowed with '-fprofile-instr-generate'
 // CHECK-DISABLE-COVERAGE-NOT: "-fcoverage-mapping"
 // CHECK-PROFILE-REMAP: "-fprofile-remapping-file=foo/bar.txt"
+// CHECK-ORDERFILE-INSTR: "-forder-file-instrumentation"
+// CHECK-ORDERFILE-INSTR: "-enable-order-file-instrumentation"
 
 // RUN: %clang -### -S -fprofile-use %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-USE %s
 // RUN: %clang -### -S -fprofile-instr-use %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-USE %s
 // RUN: mkdir -p %t.d/some/dir
 // RUN: %clang -### -S -fprofile-use=%t.d/some/dir %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-USE-DIR %s
 // RUN: %clang -### -S -fprofile-instr-use=/tmp/somefile.prof %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-USE-FILE %s
 // CHECK-PROFILE-USE: "-fprofile-instrument-use-path=default.profdata"
 // CHECK-PROFILE-USE-DIR: "-fprofile-instrument-use-path={{.*}}.d/some/dir{{/|\\\\}}default.profdata"