[clang][IFS] Allow 2 output files when using -o and -c with clang IFS stubs.

This patch allows for -o to be used with -c when compiling with clang
interface stubs enabled. This is because the second file will be an
intermediate ifs stubs file that is the text stub analog of the .o file.
Both get produces in this case, so two files.

Why are we doing this? Because we want to support the case where
interface stubs are used bu first invoking clang like so:

clang -c <other flags> -emit-interface-stubs foo.c -o foo.o
...
clang -emit-interface-stubs <.o files> -o libfoo.so

This should generate N .ifs files, and one .ifso file. Prior to this
patch, using -o with the -c invocation was not possible. Currently the
clang driver supports generating a a.out/.so file at the same time as a
merged ifs file / ifso file, but this is done by checking that the final
job is the IfsMerge job. When -c is used, the final job is a Compile job
so what this patch does is check to figure out of the job type is
TY_IFS_CPP.

Differential Revision: https://reviews.llvm.org/D70763

1 files changed, 19 insertions, 0 deletions

diff --git a/clang/test/InterfaceStubs/driver-test3.c b/clang/test/InterfaceStubs/driver-test3.c
new file mode 100644
index 00000000000..bccd1c9bccd
--- /dev/null
+++ b/clang/test/InterfaceStubs/driver-test3.c
@@ -0,0 +1,19 @@
+// REQUIRES: x86-registered-target
+// REQUIRES: shell
+
+// RUN: mkdir -p %t; cd %t
+// RUN: %clang -target x86_64-unknown-linux-gnu -c -emit-interface-stubs %s -o %t/driver-test3.o
+// RUN: llvm-nm %t/driver-test3.o | FileCheck --check-prefix=CHECK-OBJ %s
+// RUN: cat %t/driver-test3.ifs | FileCheck --check-prefix=CHECK-IFS %s
+
+// CHECK-OBJ: bar
+
+// CHECK-IFS: --- !experimental-ifs-v1
+// CHECK-IFS-NEXT: IfsVersion:
+// CHECK-IFS-NEXT: Triple:
+// CHECK-IFS-NEXT: ObjectFileFormat:
+// CHECK-IFS-NEXT: Symbols:
+// CHECK-IFS-NEXT:   "bar" : { Type: Func }
+// CHECK-IFS-NEXT: ...
+
+int bar(int a) { return a; }