[cmake] Clean up flags and treat warnings as errors in the ci.

.github/workflows/ci.yml

@@ -80,7 +80,7 @@ jobs:
             clang-runtime: '11'
             coverage: true
             cuda: true
-            extra_cmake_options: '-DLLVM_ENABLE_WERROR=On -DCLAD_ENABLE_ENZYME_BACKEND=On'
+            extra_cmake_options: '-DCLAD_ENABLE_ENZYME_BACKEND=On'
             #clang-format: true
 
           - name: ubu20-gcc7-runtime11-benchmarks
@@ -739,6 +739,7 @@ jobs:
           -DCMAKE_BUILD_TYPE=$([[ -z "$BUILD_TYPE" ]] && echo RelWithDebInfo || echo $BUILD_TYPE) \
           -DCLAD_CODE_COVERAGE=${CLAD_CODE_COVERAGE}  \
           -DLLVM_EXTERNAL_LIT="`which lit`" \
+          -DLLVM_ENABLE_WERROR=On           \
           $GITHUB_WORKSPACE                 \
           ${{ matrix.extra_cmake_options }}
 

CMakeLists.txt

@@ -163,8 +163,8 @@ if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
   # In rare cases we might want to have clang installed in a different place
   # than llvm and the header files should be found first (even though the
   # LLVM_INCLUDE_DIRS) contain clang headers, too.
-  include_directories(${CLANG_INCLUDE_DIRS})
-  include_directories(${LLVM_INCLUDE_DIRS})
+  include_directories(SYSTEM ${CLANG_INCLUDE_DIRS})
+  include_directories(SYSTEM ${LLVM_INCLUDE_DIRS})
   add_definitions(${LLVM_DEFINITIONS})
 
   # If the llvm sources are present add them with higher priority.
@@ -176,13 +176,13 @@ if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
     #
     # FIXME: We only support in-tree builds of clang, that is clang being built
     # in llvm_src/tools/clang.
-    include_directories(${LLVM_BUILD_MAIN_SRC_DIR}/tools/clang/include/)
+    include_directories(SYSTEM ${LLVM_BUILD_MAIN_SRC_DIR}/tools/clang/include/)
 
     if (NOT LLVM_BUILD_BINARY_DIR)
       message(FATAL "LLVM_BUILD_* values should be available for the build tree")
     endif()
 
-    include_directories(${LLVM_BUILD_BINARY_DIR}/tools/clang/include/)
+    include_directories(SYSTEM ${LLVM_BUILD_BINARY_DIR}/tools/clang/include/)
   endif()
 
   set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib/)
@@ -224,24 +224,19 @@ if( CMAKE_SOURCE_DIR STREQUAL CMAKE_BINARY_DIR AND NOT MSVC_IDE )
 "`CMakeFiles'. Please delete them.")
 endif()
 
-# Add appropriate flags for GCC
-if (LLVM_COMPILER_IS_GCC_COMPATIBLE)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-common -Woverloaded-virtual -Wcast-qual -fno-strict-aliasing -pedantic -Wno-long-long -Wall -W -Wno-unused-parameter -Wwrite-strings")
-endif ()
-
 if (APPLE)
   set(CMAKE_MODULE_LINKER_FLAGS "-Wl,-undefined -Wl,dynamic_lookup")
 endif ()
 
 # FIXME: Use merge this with the content from the LLVMConfig and ClangConfig.
 if (NOT CLAD_BUILT_STANDALONE)
-include_directories(BEFORE
+include_directories(BEFORE SYSTEM
   ${CMAKE_CURRENT_BINARY_DIR}/../clang/include
   ${CMAKE_CURRENT_SOURCE_DIR}/../clang/include
   )
 endif()
 
-include_directories(BEFORE
+include_directories(BEFORE SYSTEM
   ${CMAKE_CURRENT_BINARY_DIR}/include
   ${CMAKE_CURRENT_SOURCE_DIR}/include
   )
@@ -312,6 +307,7 @@ if (NOT CLAD_BUILD_STATIC_ONLY)
   set(CMAKE_CXX_COMPILER ${LLVM_TOOLS_BINARY_DIR}/clang)
   # Filter some unsupported flags by clang.
   string(REPLACE "-fno-lifetime-dse" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+  string(REPLACE "-Wno-class-memaccess" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
 
   add_subdirectory(unittests)
   add_subdirectory(test)

cmake/modules/CladGoogleTest.cmake

@@ -21,10 +21,22 @@ endif()
 
 # Remove the coverage flags when compiling external libraries.
 string(REPLACE "${GCC_COVERAGE_COMPILE_FLAGS}" "" CMAKE_CXX_FLAGS_NOCOV "${CMAKE_CXX_FLAGS}")
+string(REPLACE "${GCC_COVERAGE_COMPILE_FLAGS}" "" CMAKE_C_FLAGS_NOCOV "${CMAKE_C_FLAGS}")
 string(REPLACE "${GCC_COVERAGE_COMPILE_FLAGS}" "" CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS_NOCOV "${CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS}")
 string(REPLACE "${GCC_COVERAGE_LINK_FLAGS}" "" CMAKE_EXE_LINKER_FLAGS_NOCOV "${CMAKE_EXE_LINKER_FLAGS}")
 string(REPLACE "${GCC_COVERAGE_LINK_FLAGS}" "" CMAKE_SHARED_LINKER_FLAGS_NOCOV "${CMAKE_SHARED_LINKER_FLAGS}")
 
+# Turn off -Werror for external packages.
+if (LLVM_ENABLE_WERROR)
+  if (MSVC)
+    set(CMAKE_CXX_FLAGS_NOCOV "${CMAKE_CXX_FLAGS_NOCOV} /w ")
+    set(CMAKE_C_FLAGS_NOCOV "${CMAKE_C_FLAGS_NOCOV} /w ")
+  elseif(LLVM_COMPILER_IS_GCC_COMPATIBLE)
+    set(CMAKE_CXX_FLAGS_NOCOV "${CMAKE_CXX_FLAGS_NOCOV} -Wno-error ")
+    set(CMAKE_C_FLAGS_NOCOV "${CMAKE_C_FLAGS_NOCOV} -Wno-error ")
+  endif()
+endif(LLVM_ENABLE_WERROR)
+
 include(ExternalProject)
 ExternalProject_Add(
   googletest
@@ -41,7 +53,7 @@ ExternalProject_Add(
   CMAKE_ARGS -G ${CMAKE_GENERATOR}
                 -DCMAKE_BUILD_TYPE=Release
                 -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
-                -DCMAKE_C_FLAGS=${CMAKE_C_FLAGS}
+                -DCMAKE_C_FLAGS=${CMAKE_C_FLAGS_NOCOV}
                 -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
                 -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS_NOCOV}
                 -DCMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS=${CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS_NOCOV}

lib/Differentiator/CladUtils.cpp

@@ -557,13 +557,8 @@ namespace clad {
         }
 
         void VisitBinaryOperator(clang::BinaryOperator* BO) {
-          if (BO->isAssignmentOp() || BO->isCompoundAssignmentOp()) {
+          if (BO->isAssignmentOp() || BO->isCompoundAssignmentOp())
             Visit(BO->getLHS());
-          } else if (BO->getOpcode() == clang::BO_Comma) {
-            /**/
-          } else {
-            assert("Unexpected binary operator!!");
-          }
         }
 
         void VisitConditionalOperator(clang::ConditionalOperator* CO) {

lib/Differentiator/VisitorBase.cpp

@@ -72,7 +72,9 @@ namespace clad {
 #pragma warning(push, 0)
 #endif // MSVC
 #pragma GCC diagnostic push
+#ifdef __clang__
 #pragma clang diagnostic ignored "-Wunknown-warning-option"
+#endif // __clang__
 #pragma GCC diagnostic ignored "-Wnon-template-friend"
     friend type get(Tag);
 #pragma GCC diagnostic pop