Pull in r248379 from upstream clang trunk (by Jörg Sonnenberger):

  Refactor library decision for -fopenmp support from Darwin into a
  function for sharing with other platforms.

Pull in r248424 from upstream clang trunk (by Jörg Sonnenberger):

  Push OpenMP linker flags after linker input on Darwin. Don't add any
  libraries if -nostdlib is specified. Test.

Pull in r248426 from upstream clang trunk (by Jörg Sonnenberger):

  Support linking against OpenMP runtime on NetBSD.

Pull in r250657 from upstream clang trunk (by Dimitry Andric):

  Support linking against OpenMP runtime on FreeBSD.

Introduced here: http://svnweb.freebsd.org/changeset/base/289523

Index: tools/clang/lib/Driver/Tools.cpp
===================================================================
--- tools/clang/lib/Driver/Tools.cpp
+++ tools/clang/lib/Driver/Tools.cpp
@@ -2460,6 +2460,28 @@ static OpenMPRuntimeKind getOpenMPRuntime(const To
   return RT;
 }
 
+static void addOpenMPRuntime(ArgStringList &CmdArgs, const ToolChain &TC,
+                              const ArgList &Args) {
+  if (!Args.hasFlag(options::OPT_fopenmp, options::OPT_fopenmp_EQ,
+                    options::OPT_fno_openmp, false))
+    return;
+
+  switch (getOpenMPRuntime(TC, Args)) {
+  case OMPRT_OMP:
+    CmdArgs.push_back("-lomp");
+    break;
+  case OMPRT_GOMP:
+    CmdArgs.push_back("-lgomp");
+    break;
+  case OMPRT_IOMP5:
+    CmdArgs.push_back("-liomp5");
+    break;
+  case OMPRT_Unknown:
+    // Already diagnosed.
+    break;
+  }
+}
+
 static void addSanitizerRuntime(const ToolChain &TC, const ArgList &Args,
                                 ArgStringList &CmdArgs, StringRef Sanitizer,
                                 bool IsShared) {
@@ -6527,24 +6549,6 @@ void darwin::Linker::ConstructJob(Compilation &C,
 
   Args.AddAllArgs(CmdArgs, options::OPT_L);
 
-  if (Args.hasFlag(options::OPT_fopenmp, options::OPT_fopenmp_EQ,
-                   options::OPT_fno_openmp, false)) {
-    switch (getOpenMPRuntime(getToolChain(), Args)) {
-    case OMPRT_OMP:
-      CmdArgs.push_back("-lomp");
-      break;
-    case OMPRT_GOMP:
-      CmdArgs.push_back("-lgomp");
-      break;
-    case OMPRT_IOMP5:
-      CmdArgs.push_back("-liomp5");
-      break;
-    case OMPRT_Unknown:
-      // Already diagnosed.
-      break;
-    }
-  }
-
   AddLinkerInputs(getToolChain(), Inputs, Args, CmdArgs);
   // Build the input file for -filelist (list of linker input files) in case we
   // need it later
@@ -6563,6 +6567,10 @@ void darwin::Linker::ConstructJob(Compilation &C,
     InputFileList.push_back(II.getFilename());
   }
 
+  if (!Args.hasArg(options::OPT_nostdlib) &&
+      !Args.hasArg(options::OPT_nodefaultlibs))
+    addOpenMPRuntime(CmdArgs, getToolChain(), Args);
+
   if (isObjCRuntimeLinked(Args) && !Args.hasArg(options::OPT_nostdlib) &&
       !Args.hasArg(options::OPT_nodefaultlibs)) {
     // We use arclite library for both ARC and subscripting support.
@@ -7358,6 +7366,7 @@ void freebsd::Linker::ConstructJob(Compilation &C,
 
   if (!Args.hasArg(options::OPT_nostdlib) &&
       !Args.hasArg(options::OPT_nodefaultlibs)) {
+    addOpenMPRuntime(CmdArgs, ToolChain, Args);
     if (D.CCCIsCXX()) {
       ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
       if (Args.hasArg(options::OPT_pg))
@@ -7673,6 +7682,7 @@ void netbsd::Linker::ConstructJob(Compilation &C,
 
   if (!Args.hasArg(options::OPT_nostdlib) &&
       !Args.hasArg(options::OPT_nodefaultlibs)) {
+    addOpenMPRuntime(CmdArgs, getToolChain(), Args);
     if (D.CCCIsCXX()) {
       getToolChain().AddCXXStdlibLibArgs(Args, CmdArgs);
       CmdArgs.push_back("-lm");
Index: tools/clang/test/Driver/fopenmp.c
===================================================================
--- tools/clang/test/Driver/fopenmp.c
+++ tools/clang/test/Driver/fopenmp.c
@@ -1,6 +1,15 @@
 // RUN: %clang -target x86_64-linux-gnu -fopenmp=libomp -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CC1-OPENMP
 // RUN: %clang -target x86_64-linux-gnu -fopenmp=libgomp -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CC1-NO-OPENMP
 // RUN: %clang -target x86_64-linux-gnu -fopenmp=libiomp5 -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CC1-OPENMP
+// RUN: %clang -target x86_64-apple-darwin -fopenmp=libomp -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CC1-OPENMP
+// RUN: %clang -target x86_64-apple-darwin -fopenmp=libgomp -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CC1-NO-OPENMP
+// RUN: %clang -target x86_64-apple-darwin -fopenmp=libiomp5 -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CC1-OPENMP
+// RUN: %clang -target x86_64-freebsd -fopenmp=libomp -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CC1-OPENMP
+// RUN: %clang -target x86_64-freebsd -fopenmp=libgomp -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CC1-NO-OPENMP
+// RUN: %clang -target x86_64-freebsd -fopenmp=libiomp5 -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CC1-OPENMP
+// RUN: %clang -target x86_64-netbsd -fopenmp=libomp -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CC1-OPENMP
+// RUN: %clang -target x86_64-netbsd -fopenmp=libgomp -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CC1-NO-OPENMP
+// RUN: %clang -target x86_64-netbsd -fopenmp=libiomp5 -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CC1-OPENMP
 //
 // CHECK-CC1-OPENMP: "-cc1"
 // CHECK-CC1-OPENMP: "-fopenmp"
@@ -12,6 +21,30 @@
 // RUN: %clang -target x86_64-linux-gnu -fopenmp=libgomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-LD-GOMP
 // RUN: %clang -target x86_64-linux-gnu -fopenmp=libiomp5 %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-LD-IOMP5
 //
+// RUN: %clang -nostdlib -target x86_64-linux-gnu -fopenmp=libomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-OMP
+// RUN: %clang -nostdlib -target x86_64-linux-gnu -fopenmp=libgomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-GOMP
+// RUN: %clang -nostdlib -target x86_64-linux-gnu -fopenmp=libiomp5 %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-IOMP5
+//
+// RUN: %clang -target x86_64-darwin -fopenmp=libomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-LD-OMP
+// RUN: %clang -target x86_64-darwin -fopenmp=libgomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-LD-GOMP
+// RUN: %clang -target x86_64-darwin -fopenmp=libiomp5 %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-LD-IOMP5
+//
+// RUN: %clang -nostdlib -target x86_64-darwin -fopenmp=libomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-OMP
+// RUN: %clang -nostdlib -target x86_64-darwin -fopenmp=libgomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-GOMP
+// RUN: %clang -nostdlib -target x86_64-darwin -fopenmp=libiomp5 %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-IOMP5
+//
+// RUN: %clang -target x86_64-netbsd -fopenmp=libomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-LD-OMP
+// RUN: %clang -target x86_64-netbsd -fopenmp=libgomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-LD-GOMP
+// RUN: %clang -target x86_64-netbsd -fopenmp=libiomp5 %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-LD-IOMP5
+//
+// RUN: %clang -nostdlib -target x86_64-freebsd -fopenmp=libomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-OMP
+// RUN: %clang -nostdlib -target x86_64-freebsd -fopenmp=libgomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-GOMP
+// RUN: %clang -nostdlib -target x86_64-freebsd -fopenmp=libiomp5 %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-IOMP5
+//
+// RUN: %clang -nostdlib -target x86_64-netbsd -fopenmp=libomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-OMP
+// RUN: %clang -nostdlib -target x86_64-netbsd -fopenmp=libgomp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-GOMP
+// RUN: %clang -nostdlib -target x86_64-netbsd -fopenmp=libiomp5 %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-IOMP5
+//
 // CHECK-LD-OMP: "{{.*}}ld{{(.exe)?}}"
 // CHECK-LD-OMP: "-lomp"
 //
@@ -21,6 +54,15 @@
 // CHECK-LD-IOMP5: "{{.*}}ld{{(.exe)?}}"
 // CHECK-LD-IOMP5: "-liomp5"
 //
+// CHECK-NO-OMP: "{{.*}}ld{{(.exe)?}}"
+// CHECK-NO-OMP-NOT: "-lomp"
+//
+// CHECK-NO-GOMP: "{{.*}}ld{{(.exe)?}}"
+// CHECK-NO-GOMP-NOT: "-lgomp"
+//
+// CHECK-NO-IOMP5: "{{.*}}ld{{(.exe)?}}"
+// CHECK-NO-IOMP5-NOT: "-liomp5"
+//
 // We'd like to check that the default is sane, but until we have the ability
 // to *always* semantically analyze OpenMP without always generating runtime
 // calls (in the event of an unsupported runtime), we don't have a good way to
@@ -28,6 +70,9 @@
 // OpenMP runtime.
 //
 // RUN: %clang -target x86_64-linux-gnu -fopenmp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-LD-ANY
+// RUN: %clang -target x86_64-darwin -fopenmp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-LD-ANY
+// RUN: %clang -target x86_64-freebsd -fopenmp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-LD-ANY
+// RUN: %clang -target x86_64-netbsd -fopenmp %s -o %t -### 2>&1 | FileCheck %s --check-prefix=CHECK-LD-ANY
 //
 // CHECK-LD-ANY: "{{.*}}ld{{(.exe)?}}"
 // CHECK-LD-ANY: "-l{{(omp|gomp|iomp5)}}"