[clang][driver][AIX] Add OpenMP runtime if -fopenmp specified

[xingxue]

Summary

This patch adds OpenMP runtime to the linker command line if -fopenmp is specifed.

[daltenty]

Needs a test, I think we should add a couple of -fopenmp=foo run lines to clang/test/Driver/aix-ld.c to verify that the correct linker options are produced for each.

[xingxue]

Addressed comments.

• added test scenarios for option fopenmp in clang/test/Driver/aix-ld.c

[daltenty]

Some minor nits about how we can shorten the test, but otherwise LGTM

clang/test/Driver/aix-ld.c

1027

nit: since the output for these tests are really the same, apart from one line with the library name, we could use two prefixes, a common one and a specific one to avoid repetition:

// RUN:   | FileCheck --check-prefixes=CHECK-FOPENMP,CHECK-FOPENMP-OMP %s

and then the CHECK block can go something like this:

...
// CHECK-FOPENMP-NOT: "-lm"
// CHECK-FOPENMP-OMP:     "-lomp"
// CHECK-FOPENMP-IOMP5:  "-liomp5"
// CHECK-FOPENMP-GOMP:   "-lgomp
// CHECK-FOPENMP:     "-lc"
...

[xingxue]

clang/test/Driver/aix-ld.c

1027

Good suggestion, thanks!

clang/lib/Driver/ToolChains/AIX.cpp

void aix::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   ToolChain.addProfileRTLibs(Args, CmdArgs);
 
   if (getToolChain().ShouldLinkCXXStdlib(Args))
     getToolChain().AddCXXStdlibLibArgs(Args, CmdArgs);
 
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
     AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
 
+    // Add OpenMP runtime if -fopenmp is specified.
+    if (Args.hasFlag(options::OPT_fopenmp, options::OPT_fopenmp_EQ,
+                     options::OPT_fno_openmp, false)) {
+      switch (ToolChain.getDriver().getOpenMPRuntime(Args)) {
+      case Driver::OMPRT_OMP:
+        CmdArgs.push_back("-lomp");
+        break;
+      case Driver::OMPRT_IOMP5:
+        CmdArgs.push_back("-liomp5");
+        break;
+      case Driver::OMPRT_GOMP:
+        CmdArgs.push_back("-lgomp");
+        break;
+      case Driver::OMPRT_Unknown:
+        // Already diagnosed.
+        break;
+      }
+    }
+
     // Support POSIX threads if "-pthreads" or "-pthread" is present.
     if (Args.hasArg(options::OPT_pthreads, options::OPT_pthread))
       CmdArgs.push_back("-lpthreads");
 
     if (D.CCCIsCXX())
       CmdArgs.push_back("-lm");
 
     CmdArgs.push_back("-lc");

clang/test/Driver/aix-ld.c

 // CHECK-LD64-SHARED-EXPFULL-NOT: "[[SYSROOT]]/usr/lib{{/|\\\\}}crt0_64.o"
 // CHECK-LD64-SHARED-EXPFULL-NOT: "[[SYSROOT]]/usr/lib{{/|\\\\}}crti_64.o"
 // CHECK-LD64-SHARED-EXPFULL:     "-b{{(" ")?}}expfull"
 // CHECK-LD64-SHARED-EXPFULL-NOT: "-bE:{{[^"]+}}"
 // CHECK-LD64-SHARED-EXPFULL:     "-lc++"
 // CHECK-LD64-SHARED-EXPFULL:     "[[RESOURCE_DIR]]{{/|\\\\}}lib{{/|\\\\}}aix{{/|\\\\}}libclang_rt.builtins-powerpc64.a"
 // CHECK-LD64-SHARED-EXPFULL:     "-lm"
 // CHECK-LD64-SHARED-EXPFULL:     "-lc"
+
+// Check powerpc-ibm-aix7.1.0.0. -fopenmp to use default OpenMP runtime libomp.
+// RUN: %clang %s -### 2>&1 \
+// RUN:        -resource-dir=%S/Inputs/resource_dir \
+// RUN:        --target=powerpc-ibm-aix7.1.0.0 \
+// RUN:        --sysroot %S/Inputs/aix_ppc_tree \
+// RUN:        --unwindlib=libunwind \
+// RUN:        -fopenmp \
+// RUN:   | FileCheck --check-prefixes=CHECK-FOPENMP,CHECK-FOPENMP-OMP %s
+// CHECK-FOPENMP-NOT: warning:
+// CHECK-FOPENMP:     "-cc1" "-triple" "powerpc-ibm-aix7.1.0.0"
+// CHECK-FOPENMP:     "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
+// CHECK-FOPENMP:     "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK-FOPENMP:     "{{.*}}ld{{(.exe)?}}"
+// CHECK-FOPENMP-NOT: "-bnso"
+// CHECK-FOPENMP:     "-b32"
+// CHECK-FOPENMP:     "-bpT:0x10000000" "-bpD:0x20000000"
+// CHECK-FOPENMP:     "[[SYSROOT]]/usr/lib{{/|\\\\}}crt0.o"
+// CHECK-FOPENMP:     "[[SYSROOT]]/usr/lib{{/|\\\\}}crti.o"
+// CHECK-FOPENMP-NOT: "-lc++"
+// CHECK-FOPENMP-NOT: "-lc++abi"
+// CHECK-FOPENMP:     "[[RESOURCE_DIR]]{{/|\\\\}}lib{{/|\\\\}}aix{{/|\\\\}}libclang_rt.builtins-powerpc.a"
+// CHECK-FOPENMP-NOT: "--as-needed"
+// CHECK-FOPENMP:     "-lunwind"
+// CHECK-FOPENMP-NOT: "--no-as-needed"
+// CHECK-FOPENMP-NOT: "-lm"
+// CHECK-FOPENMP-OMP:     "-lomp"
+// CHECK-FOPENMP-IOMP5:   "-liomp5"
+// CHECK-FOPENMP-GOMP:    "-lgomp"
+// CHECK-FOPENMP:     "-lc"
+
+// Check powerpc-ibm-aix7.1.0.0. -fopenmp=libomp to specify libomp explicitly.
+// RUN: %clang %s -### 2>&1 \
+// RUN:        -resource-dir=%S/Inputs/resource_dir \
+// RUN:        --target=powerpc-ibm-aix7.1.0.0 \
+// RUN:        --sysroot %S/Inputs/aix_ppc_tree \
+// RUN:        --unwindlib=libunwind \
+// RUN:        -fopenmp=libomp \
+// RUN:   | FileCheck --check-prefixes=CHECK-FOPENMP,CHECK-FOPENMP-OMP %s
+
+// Check powerpc-ibm-aix7.1.0.0. -fopenmp=libiomp5 to specify libgomp explicitly.
+// RUN: %clang %s -### 2>&1 \
+// RUN:        -resource-dir=%S/Inputs/resource_dir \
+// RUN:        --target=powerpc-ibm-aix7.1.0.0 \
+// RUN:        --sysroot %S/Inputs/aix_ppc_tree \
+// RUN:        --unwindlib=libunwind \
+// RUN:        -fopenmp=libiomp5 \
+// RUN:   | FileCheck --check-prefixes=CHECK-FOPENMP,CHECK-FOPENMP-IOMP5 %s
+
+// Check powerpc-ibm-aix7.1.0.0. -fopenmp=libgomp to specify libgomp explicitly.
+// RUN: %clang %s -### 2>&1 \
+// RUN:        -resource-dir=%S/Inputs/resource_dir \
+// RUN:        --target=powerpc-ibm-aix7.1.0.0 \
+// RUN:        --sysroot %S/Inputs/aix_ppc_tree \
+// RUN:        --unwindlib=libunwind \
+// RUN:        -fopenmp=libgomp \
+// RUN:   | FileCheck --check-prefixes=CHECK-FOPENMP,CHECK-FOPENMP-GOMP %s
+
+// Check powerpc-ibm-aix7.1.0.0, 32-bit. -fopenmp=libfoo results an error.
+// RUN: %clang %s 2>&1 -### \
+// RUN:        --target=powerpc-ibm-aix7.1.0.0 \
+// RUN:        --sysroot %S/Inputs/aix_ppc_tree \
+// RUN:        -fopenmp=libfoo \
+// RUN:   | FileCheck --check-prefixes=CHECK-FOPENMP-FOO %s
+// CHECK-FOPENMP-FOO: error: unsupported argument 'libfoo' to option '-fopenmp='