From ffbeb84dfa23ee1da4ad36260628113186d3e0d2 Mon Sep 17 00:00:00 2001
From: Ralf Seidler <ralf.seidler@uni-jena.de>
Date: Mon, 7 Feb 2022 11:12:46 +0000
Subject: [PATCH] Fixing compilation errors with clang 13 and OpenMP and MPI,
 fixing issue #102

---
 .../0_Introduction/UnifiedMemoryStreams/Makefile   | 13 ++++++++++++-
 Samples/0_Introduction/cudaOpenMP/Makefile         | 14 +++++++++++++-
 Samples/0_Introduction/simpleMPI/Makefile          |  4 ++++
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/Samples/0_Introduction/UnifiedMemoryStreams/Makefile b/Samples/0_Introduction/UnifiedMemoryStreams/Makefile
index ba7b78b45..b8bcad3db 100644
--- a/Samples/0_Introduction/UnifiedMemoryStreams/Makefile
+++ b/Samples/0_Introduction/UnifiedMemoryStreams/Makefile
@@ -288,13 +288,24 @@ LIBRARIES :=
 # Attempt to compile a minimal OpenMP application. If a.out exists, OpenMP is properly set up.
 ifneq (,$(filter $(TARGET_OS),linux android))
 
+# Special treatment for Clang to not use standard OMP Library and fix OMP 5 bug in Clang 13
+ifneq (,$(findstring "clang",$(HOST_COMPILER)))
 ifneq (,$(filter $(TARGET_OS), android))
      LIBRARIES += -lomp
 else
      LIBRARIES += -lgomp
 endif
-
 ALL_CCFLAGS += -Xcompiler -fopenmp
+else
+      ALL_CCFLAGS += -Xcompiler -fopenmp
+      ALL_LDFLAGS += -Xcompiler -fopenmp
+      COMPILER_VERSION= $(shell $(HOST_COMPILER) --version)
+ifneq (,$(findstring 13.,$(COMPILER_VERSION)))
+      ALL_CCFLAGS += -Xcompiler -fopenmp -Xcompiler -fopenmp-version=45
+      ALL_LDFLAGS += -Xcompiler -fopenmp -Xcompiler -fopenmp-version=45
+endif
+endif
+
 $(shell echo "#include <omp.h>" > test.c ; echo "int main() { omp_get_num_threads(); return 0; }" >> test.c ; $(HOST_COMPILER) -fopenmp test.c)
 OPENMP ?= $(shell find a.out 2>/dev/null)
 
diff --git a/Samples/0_Introduction/cudaOpenMP/Makefile b/Samples/0_Introduction/cudaOpenMP/Makefile
index 476ddbc9d..43403fe41 100644
--- a/Samples/0_Introduction/cudaOpenMP/Makefile
+++ b/Samples/0_Introduction/cudaOpenMP/Makefile
@@ -294,13 +294,25 @@ LIBRARIES :=
 # Attempt to compile a minimal OpenMP application. If a.out exists, OpenMP is properly set up.
 ifneq (,$(filter $(TARGET_OS),linux android))
 
+
+# Special treatment for Clang to not use standard OMP Library and fix OMP 5 bug in Clang 13
+ifneq (,$(findstring "clang",$(HOST_COMPILER)))
 ifneq (,$(filter $(TARGET_OS), android))
      LIBRARIES += -lomp
 else
      LIBRARIES += -lgomp
 endif
-
 ALL_CCFLAGS += -Xcompiler -fopenmp
+else
+      ALL_CCFLAGS += -Xcompiler -fopenmp
+      ALL_LDFLAGS += -Xcompiler -fopenmp
+      COMPILER_VERSION= $(shell $(HOST_COMPILER) --version)
+ifneq (,$(findstring 13.,$(COMPILER_VERSION)))
+      ALL_CCFLAGS += -Xcompiler -fopenmp -Xcompiler -fopenmp-version=45
+      ALL_LDFLAGS += -Xcompiler -fopenmp -Xcompiler -fopenmp-version=45
+endif
+endif
+
 $(shell echo "#include <omp.h>" > test.c ; echo "int main() { omp_get_num_threads(); return 0; }" >> test.c ; $(HOST_COMPILER) -fopenmp test.c)
 OPENMP ?= $(shell find a.out 2>/dev/null)
 
diff --git a/Samples/0_Introduction/simpleMPI/Makefile b/Samples/0_Introduction/simpleMPI/Makefile
index 49fc56c36..006cc8e10 100644
--- a/Samples/0_Introduction/simpleMPI/Makefile
+++ b/Samples/0_Introduction/simpleMPI/Makefile
@@ -164,6 +164,10 @@ NVCCFLAGS   := -m${TARGET_SIZE}
 CCFLAGS     :=
 LDFLAGS     :=
 
+# Special treatment for Clang 
+ifneq (,$(findstring clang,$(HOST_COMPILER)))
+     CCFLAGS+= -fPIE
+endif
 # build flags
 ifeq ($(TARGET_OS),darwin)
     LDFLAGS += -rpath $(CUDA_PATH)/lib