danmar · firewave · Mar 31, 2025
diff --git a/Makefile b/Makefile
@@ -45,7 +45,6 @@ endif
 
 RDYNAMIC?=-rdynamic
 # Set the CPPCHK_GLIBCXX_DEBUG flag. This flag is not used in release Makefiles.
-# The _GLIBCXX_DEBUG define doesn't work in Cygwin or other Win32 systems.
 ifndef COMSPEC
     ifeq ($(VERBOSE),1)
         $(info COMSPEC not found)
@@ -74,10 +73,7 @@ ifdef WINNT
     ifeq ($(VERBOSE),1)
         $(info WINNT found)
     endif
-    #### Maybe Windows
-    ifndef CPPCHK_GLIBCXX_DEBUG
-        CPPCHK_GLIBCXX_DEBUG=
-    endif # !CPPCHK_GLIBCXX_DEBUG
+    #### May be Windows
 
     ifeq ($(VERBOSE),1)
         $(info MSYSTEM=$(MSYSTEM))
@@ -99,22 +95,14 @@ else # !WINNT
         $(info uname_S=$(uname_S))
     endif
 
-    ifeq ($(uname_S),Linux)
-        ifndef CPPCHK_GLIBCXX_DEBUG
-            CPPCHK_GLIBCXX_DEBUG=-D_GLIBCXX_DEBUG
-        endif # !CPPCHK_GLIBCXX_DEBUG
-    endif # Linux
-
-    ifeq ($(uname_S),GNU/kFreeBSD)
-        ifndef CPPCHK_GLIBCXX_DEBUG
-            CPPCHK_GLIBCXX_DEBUG=-D_GLIBCXX_DEBUG
-        endif # !CPPCHK_GLIBCXX_DEBUG
-    endif # GNU/kFreeBSD
-
     LDFLAGS+=-pthread
 
 endif # WINNT
 
+ifndef CPPCHK_GLIBCXX_DEBUG
+    CPPCHK_GLIBCXX_DEBUG=-D_GLIBCXX_DEBUG
+endif # !CPPCHK_GLIBCXX_DEBUG
+
 ifdef CYGWIN
     ifeq ($(VERBOSE),1)
         $(info CYGWIN found)
@@ -128,9 +116,6 @@ ifndef CXX
     CXX=g++
 endif
 
-ifeq (clang++, $(findstring clang++,$(CXX)))
-    CPPCHK_GLIBCXX_DEBUG=
-endif
 ifndef CXXFLAGS
     CXXFLAGS=-pedantic -Wall -Wextra -Wcast-qual -Wfloat-equal -Wmissing-declarations -Wmissing-format-attribute -Wno-long-long -Wpacked -Wredundant-decls -Wundef -Wno-sign-compare -Wno-multichar -Woverloaded-virtual -g
 endif

diff --git a/cmake/compilerCheck.cmake b/cmake/compilerCheck.cmake
@@ -2,12 +2,16 @@ if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.1)
         message(ERROR "GCC >= 5.1 required - detected ${CMAKE_CXX_COMPILER_VERSION} not supported")
     endif()
-elseif(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
     if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.5)
         message(ERROR "Clang >= 3.5 required - detected ${CMAKE_CXX_COMPILER_VERSION} not supported")
     endif()
+elseif(CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
+    # TODO: AppleClang versions do not align with Clang versions - add check for proper version
 elseif(MSVC)
     if(MSVC_VERSION VERSION_LESS 1900)
         message(ERROR "Visual Studio >= 2015 (19.0) required - detected ${MSVC_VERSION} not supported")
     endif()
+else()
+    message(WARNING "Unknown compiler ${CMAKE_CXX_COMPILER_ID}")
 endif()
diff --git a/cmake/compilerDefinitions.cmake b/cmake/compilerDefinitions.cmake
@@ -8,27 +8,30 @@ if(MSVC)
     add_definitions(-DWIN32_LEAN_MEAN)
 endif()
 
-# TODO: this should probably apply to the compiler and not the platform - I think it is only "broken" with MinGW
-# TODO: AppleClang only has libc++
-# TODO: what about clang-cl and native Win32 clang?
-if(CPPCHK_GLIBCXX_DEBUG AND UNIX AND CMAKE_BUILD_TYPE STREQUAL "Debug")
-    if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-        if(USE_LIBCXX)
-            if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 18)
-                add_definitions(-D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_DEBUG)
-            else()
-                add_definitions(-D_LIBCPP_ENABLE_ASSERTIONS=1)
-            endif()
-            # TODO: also add _LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS?
-        endif()
-    else()
-        # TODO: check if this can be enabled again for Clang - also done in Makefile
+# libstdc++-specific flags
+if(CMAKE_CXX_COMPILER_ID MATCHES "GNU" OR (NOT USE_LIBCXX AND CMAKE_CXX_COMPILER_ID MATCHES "Clang"))
+    if(CPPCHK_GLIBCXX_DEBUG AND CMAKE_BUILD_TYPE STREQUAL "Debug")
         add_definitions(-D_GLIBCXX_DEBUG)
     endif()
 endif()
 
-if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND USE_LIBCXX)
+# TODO: what about clang-cl?
+# libc++-specific flags - AppleClang only has libc++
+if ((USE_LIBCXX AND CMAKE_CXX_COMPILER_ID MATCHES "Clang") OR CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
     add_definitions(-D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES)
+
+    if(CPPCHK_GLIBCXX_DEBUG AND CMAKE_BUILD_TYPE STREQUAL "Debug")
+        # TODO: AppleClang versions do not align with Clang versions - add check for proper version
+        if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 18)
+            add_definitions(-D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_DEBUG)
+        else()
+            add_definitions(-D_LIBCPP_ENABLE_ASSERTIONS=1)
+        endif()
+        # TODO: also add _LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS?
+    else()
+        # TODO: check if this can be enabled again for Clang - also done in Makefile
+        add_definitions(-D_GLIBCXX_DEBUG)
+    endif()
 endif()
 
 if(HAVE_RULES)

diff --git a/cmake/options.cmake b/cmake/options.cmake
@@ -104,6 +104,10 @@ if (NOT USE_BOOST AND USE_BOOST_INT128)
 endif()
 option(USE_LIBCXX           "Use libc++ instead of libstdc++"                               OFF)
 
+if(USE_LIBCXX AND NOT CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+    message(FATAL_ERROR "libc++ can only be used with a Clang-based compiler")
+endif()
+
 option(NO_UNIX_SIGNAL_HANDLING "Disable usage of Unix Signal Handling"                      OFF)
 option(NO_UNIX_BACKTRACE_SUPPORT "Disable usage of Unix Backtrace support"                  OFF)
 option(NO_WINDOWS_SEH       "Disable usage of Windows SEH"                                  OFF)

diff --git a/lib/config.h b/lib/config.h
@@ -96,6 +96,7 @@
 #  define UNUSED
 #endif
 
+// TODO: AppleClang versions do not align with Clang versions - add check for proper version
 // warn_unused
 #if __has_cpp_attribute (gnu::warn_unused) || \
     (defined(__clang__) && (__clang_major__ >= 15))
@@ -115,6 +116,7 @@
 #  define DEPRECATED
 #endif
 
+// TODO: AppleClang versions do not align with Clang versions - add check for proper version
 // returns_nonnull
 #if __has_cpp_attribute (gnu::returns_nonnull)
 #  define RET_NONNULL [[gnu::returns_nonnull]]

diff --git a/tools/dmake/dmake.cpp b/tools/dmake/dmake.cpp
@@ -638,7 +638,6 @@ int main(int argc, char **argv)
 
     // The _GLIBCXX_DEBUG doesn't work in cygwin or other Win32 systems.
     fout << "# Set the CPPCHK_GLIBCXX_DEBUG flag. This flag is not used in release Makefiles.\n"
-         << "# The _GLIBCXX_DEBUG define doesn't work in Cygwin or other Win32 systems.\n"
          << "ifndef COMSPEC\n"
          << "    ifeq ($(VERBOSE),1)\n"
          << "        $(info COMSPEC not found)\n"
@@ -667,10 +666,7 @@ int main(int argc, char **argv)
          << "    ifeq ($(VERBOSE),1)\n"
          << "        $(info WINNT found)\n"
          << "    endif\n"
-         << "    #### Maybe Windows\n"
-         << "    ifndef CPPCHK_GLIBCXX_DEBUG\n"
-         << "        CPPCHK_GLIBCXX_DEBUG=\n"
-         << "    endif # !CPPCHK_GLIBCXX_DEBUG\n"
+         << "    #### May be Windows\n"
          << "\n"
          << "    ifeq ($(VERBOSE),1)\n"
          << "        $(info MSYSTEM=$(MSYSTEM))\n"
@@ -692,21 +688,13 @@ int main(int argc, char **argv)
          << "        $(info uname_S=$(uname_S))\n"
          << "    endif\n"
          << "\n"
-         << "    ifeq ($(uname_S),Linux)\n"
-         << "        ifndef CPPCHK_GLIBCXX_DEBUG\n"
-         << "            CPPCHK_GLIBCXX_DEBUG=-D_GLIBCXX_DEBUG\n"
-         << "        endif # !CPPCHK_GLIBCXX_DEBUG\n"
-         << "    endif # Linux\n"
-         << "\n"
-         << "    ifeq ($(uname_S),GNU/kFreeBSD)\n"
-         << "        ifndef CPPCHK_GLIBCXX_DEBUG\n"
-         << "            CPPCHK_GLIBCXX_DEBUG=-D_GLIBCXX_DEBUG\n"
-         << "        endif # !CPPCHK_GLIBCXX_DEBUG\n"
-         << "    endif # GNU/kFreeBSD\n"
-         << "\n"
          << "    LDFLAGS+=-pthread\n"
          << "\n"
          << "endif # WINNT\n"
+         << "\n"
+         << "ifndef CPPCHK_GLIBCXX_DEBUG\n"
+         << "    CPPCHK_GLIBCXX_DEBUG=-D_GLIBCXX_DEBUG\n"
+         << "endif # !CPPCHK_GLIBCXX_DEBUG\n"
          << "\n";
 
     fout << "ifdef CYGWIN\n"
@@ -719,11 +707,7 @@ int main(int argc, char **argv)
          << "endif # CYGWIN\n"
          << "\n";
 
-    // skip "-D_GLIBCXX_DEBUG" if clang, since it breaks the build
     makeConditionalVariable(fout, "CXX", "g++");
-    fout << "ifeq (clang++, $(findstring clang++,$(CXX)))\n"
-         << "    CPPCHK_GLIBCXX_DEBUG=\n"
-         << "endif\n";
 
     // Makefile settings..
     if (release) {