From df96e022e95b8540c51e1bdaed03f66d851c6f93 Mon Sep 17 00:00:00 2001
From: Chandler Carruth <chandlerc@gmail.com>
Date: Thu, 17 Jan 2013 13:19:29 +0000
Subject: [PATCH] Add initial rough support for synthesizing linker options
when passed -fopenmp in the link step on Linux. There is probably more
tweaking that will need to take place to get good support for linking the
relevant libraries on all Linux distributions and/or on other platforms, but
this get's the ball moving and allows Clang to build programs which contain
OpenMP pragmas that can be safely ignored by a compiler that doesn't
implement them, and yet makes direct calls into the OpenMP runtime.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172715 91177308-0d34-0410-b5e6-96231b3b80d8
---
lib/Driver/Tools.cpp | 11 ++++++++++-
test/OpenMP/linking.c | 16 ++++++++++++++++
2 files changed, 26 insertions(+), 1 deletion(-)
create mode 100644 test/OpenMP/linking.c
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 30562f1ba39..199bb719dea 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -5705,10 +5705,19 @@ void linuxtools::Link::ConstructJob(Compilation &C, const JobAction &JA,
if (Args.hasArg(options::OPT_static))
CmdArgs.push_back("--start-group");
+ bool OpenMP = Args.hasArg(options::OPT_fopenmp);
+ if (OpenMP) {
+ CmdArgs.push_back("-lgomp");
+
+ // FIXME: Exclude this for platforms whith libgomp that doesn't require
+ // librt. Most modern Linux platfroms require it, but some may not.
+ CmdArgs.push_back("-lrt");
+ }
+
AddLibgcc(ToolChain.getTriple(), D, CmdArgs, Args);
if (Args.hasArg(options::OPT_pthread) ||
- Args.hasArg(options::OPT_pthreads))
+ Args.hasArg(options::OPT_pthreads) || OpenMP)
CmdArgs.push_back("-lpthread");
CmdArgs.push_back("-lc");
diff --git a/test/OpenMP/linking.c b/test/OpenMP/linking.c
new file mode 100644
index 00000000000..31fd57de926
--- /dev/null
+++ b/test/OpenMP/linking.c
@@ -0,0 +1,16 @@
+// Test the that the driver produces reasonable linker invocations with
+// -fopenmp.
+//
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN: -fopenmp -target i386-unknown-linux \
+// RUN: | FileCheck --check-prefix=CHECK-LD-32 %s
+// CHECK-LD-32: "{{.*}}ld{{(.exe)?}}"
+// CHECK-LD-32: "-lgomp" "-lrt" "-lgcc"
+// CHECK-LD-32: "-lpthread" "-lc"
+//
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN: -fopenmp -target x86_64-unknown-linux \
+// RUN: | FileCheck --check-prefix=CHECK-LD-64 %s
+// CHECK-LD-64: "{{.*}}ld{{(.exe)?}}"
+// CHECK-LD-64: "-lgomp" "-lrt" "-lgcc"
+// CHECK-LD-64: "-lpthread" "-lc"
--
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