[clang][IFS] Driver pipeline: generate interface stubs after standard pipeline.

Up until now, clang interface stubs has replaced the standard
PP -> C -> BE -> ASM -> LNK pipeline. With this change, it will happen in
conjunction with it. So what when you build your code you will get an
a.out or lib.so as well as an interface stub file.

Example:

clang -shared -o libfoo.so -emit-interface-stubs ...

will generate both a libfoo.so and a libfoo.ifso. The .so file will
contain the code from the standard compilation pipeline and the .ifso
file will contain the ELF stub library.

Differential Revision: https://reviews.llvm.org/D70274

3 files changed, 24 insertions, 7 deletions

diff --git a/clang/test/InterfaceStubs/driver-test.c b/clang/test/InterfaceStubs/driver-test.c
index d4e50295411..bb2868f6df0 100644
--- a/clang/test/InterfaceStubs/driver-test.c
+++ b/clang/test/InterfaceStubs/driver-test.c
@@ -1,11 +1,13 @@
 // REQUIRES: x86-registered-target
 
-// RUN: %clang -target x86_64-unknown-linux-gnu -x c -o %t1.so -emit-interface-stubs %s %S/object.c %S/weak.cpp && \
-// RUN: llvm-nm %t1.so 2>&1 | FileCheck --check-prefix=CHECK-IFS %s
+// RUN: %clang -target x86_64-unknown-linux-gnu -x c -o %t1 -emit-interface-stubs %s %S/object.c %S/weak.cpp
+// RUN: llvm-nm %t1 2>&1 | FileCheck %s
+// RUN: llvm-nm %t1.ifso 2>&1 | FileCheck %s
 
-// CHECK-IFS-DAG: data
-// CHECK-IFS-DAG: foo
-// CHECK-IFS-DAG: strongFunc
-// CHECK-IFS-DAG: weakFunc
+// CHECK-DAG: data
+// CHECK-DAG: foo
+// CHECK-DAG: strongFunc
+// CHECK-DAG: weakFunc
 
 int foo(int bar) { return 42 + 1844; }
+int main() { return foo(23); }
diff --git a/clang/test/InterfaceStubs/driver-test2.c b/clang/test/InterfaceStubs/driver-test2.c
new file mode 100644
index 00000000000..f0f889a799d
--- /dev/null
+++ b/clang/test/InterfaceStubs/driver-test2.c
@@ -0,0 +1,14 @@
+// REQUIRES: x86-registered-target
+
+// RUN: %clang -target x86_64-unknown-linux-gnu -c -emit-interface-stubs \
+// RUN:   %s %S/object.c %S/weak.cpp
+// RUN: %clang -emit-interface-stubs -emit-merged-ifs \
+// RUN:   driver-test2.o object.o weak.o -S -o - | FileCheck %s
+
+// CHECK-DAG: data
+// CHECK-DAG: bar
+// CHECK-DAG: strongFunc
+// CHECK-DAG: weakFunc
+
+int bar(int a) { return a; }
+int main() { return 0; }
diff --git a/clang/test/InterfaceStubs/windows.cpp b/clang/test/InterfaceStubs/windows.cpp
index 9ccb771a2f3..c81c702861e 100644
--- a/clang/test/InterfaceStubs/windows.cpp
+++ b/clang/test/InterfaceStubs/windows.cpp
@@ -1,6 +1,7 @@
 // REQUIRES: x86-registered-target
 // RUN: %clang_cc1 -triple x86_64-windows-msvc -o - %s -emit-interface-stubs | FileCheck -check-prefix=CHECK-CC1 %s
-// RUN: %clang -target x86_64-windows-msvc -o - %s -emit-interface-stubs -emit-merged-ifs | FileCheck -check-prefix=CHECK-IFS %s
+// RUN: %clang -target x86_64-windows-msvc -o - %s -emit-interface-stubs -emit-merged-ifs -S | FileCheck -check-prefix=CHECK-IFS %s
+// note: -S is added here to prevent clang from invoking link.exe
 
 // CHECK-CC1: Symbols:
 // CHECK-CC1-NEXT: ?helloWindowsMsvc@@YAHXZ