Also check /Fo when deciding on the .gcna / .gcda filename (PR44208)

[hans]

Summary

See bug.

[rnk]

lgtm

clang/lib/Driver/ToolChains/Clang.cpp

911

The FIXME acknowledges the possibility of this bug. :)

clang/lib/Driver/ToolChains/Clang.cpp

static void addPGOAndCoverageFlags(const ToolChain &TC, Compilation &C,
   // targeted way to suppress the warning.
   Arg *FProfileDir = nullptr;
   if (Args.hasArg(options::OPT_fprofile_arcs) ||
       Args.hasArg(options::OPT_coverage))
     FProfileDir = Args.getLastArg(options::OPT_fprofile_dir);
 
   // Put the .gcno and .gcda files (if needed) next to the object file or
   // bitcode file in the case of LTO.
   // FIXME: There should be a simpler way to find the object file for this
   // input, and this code probably does the wrong thing for commands that
   // compile and link all at once.
   if ((Args.hasArg(options::OPT_c) || Args.hasArg(options::OPT_S)) &&
       (EmitCovNotes || EmitCovData) && Output.isFilename()) {
     SmallString<128> OutputFilename;
-    if (Arg *FinalOutput = C.getArgs().getLastArg(options::OPT_o))
+    if (Arg *FinalOutput = C.getArgs().getLastArg(options::OPT__SLASH_Fo))
+      OutputFilename = FinalOutput->getValue();
+    else if (Arg *FinalOutput = C.getArgs().getLastArg(options::OPT_o))
       OutputFilename = FinalOutput->getValue();
     else
       OutputFilename = llvm::sys::path::filename(Output.getBaseInput());
     SmallString<128> CoverageFilename = OutputFilename;
     if (llvm::sys::path::is_relative(CoverageFilename))
       (void)D.getVFS().makeAbsolute(CoverageFilename);
     llvm::sys::path::replace_extension(CoverageFilename, "gcno");
 

clang/test/Driver/clang_f_opts.c

 // RUN: %clang -### -S -fprofile-arcs -fprofile-dir=abc %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-DIR %s
 // RUN: %clang -### -S --coverage -fprofile-dir=abc %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-DIR %s
 // RUN: %clang -### -S -fprofile-arcs -fno-profile-arcs -fprofile-dir=abc %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-DIR-NEITHER %s
 // CHECK-PROFILE-DIR: "-coverage-data-file" "abc
 // CHECK-PROFILE-DIR-UNUSED: argument unused
 // CHECK-PROFILE-DIR-UNUSED-NOT: "-coverage-data-file" "abc
 // CHECK-PROFILE-DIR-NEITHER-NOT: argument unused
 
+// RUN: %clang_cl -### /c --coverage /Fo/foo/bar.obj -- %s 2>&1 | FileCheck -check-prefix=CHECK-GCNO-LOCATION %s
+// CHECK-GCNO-LOCATION: "-coverage-notes-file" "{{.*}}/foo/bar.gcno"
+
 // RUN: %clang -### -fprofile-arcs -ftest-coverage %s 2>&1 | FileCheck -check-prefix=CHECK-u %s
 // RUN: %clang -### --coverage %s 2>&1 | FileCheck -check-prefix=CHECK-u %s
 // CHECK-u-NOT: "-u{{.*}}"
 
 // RUN: %clang -### -S -fprofile-generate %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-GENERATE-LLVM %s
 // RUN: %clang -### -S -fprofile-instr-generate %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-GENERATE %s
 // RUN: %clang -### -S -fprofile-generate=/some/dir %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-GENERATE-DIR %s
 // RUN: %clang -### -S -fprofile-instr-generate=/tmp/somefile.profraw %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-GENERATE-FILE %s