[PATCH rdma-core 2/4] build: Remove warning-causing compilation flag from pyverbs

[Noa Osherovich <noaos@mellanox.com>]

The -fvar-tracking-assignment flag is causing the following
compilation warning:

note: variable tracking size limit exceeded with '-fvar-tracking-assignments', retrying without

Since it's a debug flag and not necessary for pyverbs functionality,
remove it from pyverbs' build.

Signed-off-by: Noa Osherovich <noaos@mellanox.com>
Reviewd-by: Leon Romanovsky <leonro@mellanox.com>
---
 CMakeLists.txt                   | 7 +++++++
 buildlib/pyverbs_functions.cmake | 7 ++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8d2e357c78af..f2cb5c306c04 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -182,6 +182,13 @@ endif()
 
 #-------------------------
 # Setup the basic C compiler
+# Some compilation flags are not supported in clang, lets allow users to know
+# whether gcc or clang is used.
+if ("${CMAKE_C_COMPILER_ID}" STREQUAL "Clang")
+  set(IS_CLANG_BUILD TRUE)
+else()
+  set(IS_CLANG_BUILD FALSE)
+endif()
 RDMA_BuildType()
 include_directories(${BUILD_INCLUDE})
 
diff --git a/buildlib/pyverbs_functions.cmake b/buildlib/pyverbs_functions.cmake
index 1966cf3ba1a3..81cdd86fc020 100644
--- a/buildlib/pyverbs_functions.cmake
+++ b/buildlib/pyverbs_functions.cmake
@@ -16,8 +16,13 @@ function(rdma_cython_module PY_MODULE)
 
     string(REGEX REPLACE "\\.so$" "" SONAME "${FILENAME}${CMAKE_PYTHON_SO_SUFFIX}")
     add_library(${SONAME} SHARED ${CFILE})
+    # We need to disable -fvar-tracking-assignments. It's only supported in gcc
+    # so make sure we're not using clang before doing that.
+    if (NOT ${IS_CLANG_BUILD})
+      set(PYVERBS_DEBUG_FLAGS "-fno-var-tracking-assignments")
+    endif()
     set_target_properties(${SONAME} PROPERTIES
-	    COMPILE_FLAGS "${CMAKE_C_FLAGS} -fPIC -fno-strict-aliasing -Wno-unused-function -Wno-redundant-decls -Wno-shadow -Wno-cast-function-type -Wno-implicit-fallthrough -Wno-unknown-warning -Wno-unknown-warning-option"
+        COMPILE_FLAGS "${CMAKE_C_FLAGS} -fPIC -fno-strict-aliasing -Wno-unused-function -Wno-redundant-decls -Wno-shadow -Wno-cast-function-type -Wno-implicit-fallthrough -Wno-unknown-warning -Wno-unknown-warning-option ${PYVERBS_DEBUG_FLAGS}"
       LIBRARY_OUTPUT_DIRECTORY "${BUILD_PYTHON}/${PY_MODULE}"
       PREFIX "")
     target_link_libraries(${SONAME} LINK_PRIVATE ${PYTHON_LIBRARIES} ibverbs)
-- 
2.21.0