Add a make flag to produce a seperate debug archive

.github/workflows/matrix.yml

@@ -123,7 +123,6 @@ jobs:
             libbacktrace: 1
             native: linux64
             pch: 1
-            cxxflags: -gsplit-dwarf
             title: GCC 9, Curses, LTO
             # ~850MB in a clean build
             # ~370MB compressed

Makefile

@@ -92,6 +92,10 @@
 #  make RUNTESTS=1
 # Build source files in order of how often the matching header is included
 #  make HEADERPOPULARITY=1
+# Split debug symbols to seperate files. Can improve linker overheads.
+#  make SPLIT_DEBUG=1
+# Generate debug symbols even in release builds.
+#  make DEBUG_SYMBOLS=1
 
 # comment these to toggle them as one sees fit.
 # DEBUG is best turned on if you plan to debug in gdb -- please do!
@@ -481,6 +485,15 @@ else
   CXXFLAGS += $(OPTLEVEL)
 endif
 
+ifeq ($(SPLIT_DEBUG), 1)
+  # macos already does this by default.
+  ifneq ($(NATIVE), osx)
+    ifneq ($(LTO), 1)
+      CXX_OFLAGS = -gsplit-dwarf -gz=zlib
+    endif
+  endif
+endif
+
 ifeq ($(shell sh -c 'uname -o 2>/dev/null || echo not'),Cygwin)
   OTHERS += -std=gnu++17
 else
@@ -1039,6 +1052,13 @@ all: version prefix $(CHECKS) $(TARGET) $(L10N) $(TESTSTARGET)
 
 $(TARGET): $(OBJS)
 	+$(LD) $(W32FLAGS) -o $(TARGET) $(OBJS) $(LDFLAGS)
+ifeq ($(SPLIT_DEBUG), 1)
+  ifneq ($(NATIVE), osx)
+    ifneq ($(LTO), 1)
+	+dwp --exec $(TARGET)
+    endif
+  endif
+endif
 ifeq ($(RELEASE), 1)
   ifndef DEBUG_SYMBOLS
     ifneq ($(BACKTRACE),1)
@@ -1089,13 +1109,13 @@ includes: $(OBJS:.o=.inc)
 	+make -C tests includes
 
 $(ODIR)/third-party/imgui/%.o: $(IMGUI_DIR)/%.cpp
-	$(CXX) $(CPPFLAGS) $(DEFINES) $(CXXFLAGS) -w -MMD -MP -c $< -o $@
+	$(CXX) $(CPPFLAGS) $(DEFINES) $(CXXFLAGS) $(CXX_OFLAGS) -w -MMD -MP -c $< -o $@
 
 $(ODIR)/third-party/imtui/%.o: $(IMTUI_DIR)/%.cpp
-	$(CXX) $(CPPFLAGS) $(DEFINES) $(CXXFLAGS) -w -MMD -MP -c $< -o $@
+	$(CXX) $(CPPFLAGS) $(DEFINES) $(CXXFLAGS) $(CXX_OFLAGS) -w -MMD -MP -c $< -o $@
 
 $(ODIR)/%.o: $(SRC_DIR)/%.cpp $(PCH_P)
-	$(CXX) $(CPPFLAGS) $(DEFINES) $(CXXFLAGS) -MMD -MP $(PCHFLAGS) -c $< -o $@
+	$(CXX) $(CPPFLAGS) $(DEFINES) $(CXXFLAGS) $(CXX_OFLAGS) -MMD -MP $(PCHFLAGS) -c $< -o $@
 
 $(ODIR)/%.o: $(SRC_DIR)/%.rc
 	$(RC) $(RFLAGS) $< -o $@
@@ -1129,7 +1149,7 @@ json-check: $(CHKJSON_BIN)
 	./$(CHKJSON_BIN)
 
 clean: clean-tests clean-object_creator clean-pch clean-lang
-	rm -rf *$(TARGET_NAME) *$(TILES_TARGET_NAME)
+	rm -rf *$(TARGET_NAME) *$(TILES_TARGET_NAME) *$(TARGET_NAME).dwp
 	rm -rf *$(TILES_TARGET_NAME).exe *$(TARGET_NAME).exe *$(TARGET_NAME).a
 	rm -rf *obj *objwin
 	rm -rf *$(BINDIST_DIR) *cataclysmdda-*.tar.gz *cataclysmdda-*.zip

build-scripts/gha_compile_only.sh

@@ -64,7 +64,7 @@ then
         ..
     make -j$num_jobs
 else
-    make -j "$num_jobs" CCACHE=1 CROSS="$CROSS_COMPILATION" LINTJSON=0 FRAMEWORK=1 UNIVERSAL_BINARY=1 DEBUG_SYMBOLS=1
+    make -j "$num_jobs" CCACHE=1 CROSS="$CROSS_COMPILATION" LINTJSON=0 FRAMEWORK=1 UNIVERSAL_BINARY=1 DEBUG_SYMBOLS=1 SPLIT_DEBUG=1
 
     # For CI on macOS, patch the test binary so it can find SDL2 libraries.
     if [[ ! -z "$OS" && "$OS" = "macos-12" ]]

tests/Makefile

@@ -56,6 +56,13 @@ tests: $(TEST_TARGET)
 
 $(TEST_TARGET): $(OBJS) $(CATA_LIB)
 	+$(CXX) $(W32FLAGS) -o $@ $(DEFINES) $(OBJS) $(CATA_LIB) $(CPPFLAGS) $(CXXFLAGS) $(LDFLAGS)
+ifeq ($(SPLIT_DEBUG), 1)
+  ifneq ($(NATIVE), osx)
+    ifneq ($(LTO), 1)
+	cd .. && dwp --exec tests/$(TEST_TARGET) -o tests/$(TEST_TARGET).dwp
+    endif
+  endif
+endif
 
 $(PCH_P): $(PCH_H)
 	-$(CXX) $(CPPFLAGS) $(DEFINES) $(CXXFLAGS) -MMD -MP -Wno-error -Wno-non-virtual-dtor -Wno-unused-macros -I. -c $(PCH_H) -o $(PCH_P)
@@ -84,7 +91,7 @@ $(shell mkdir -p $(ODIR))
 
 # Adding ../tests/ so that the directory appears in __FILE__ for log messages
 $(ODIR)/%.o: %.cpp $(PCH_P)
-	$(CXX) $(CPPFLAGS) $(DEFINES) $(CXXFLAGS) -MMD -MP $(subst main-pch,tests-pch,$(PCHFLAGS)) -c ../tests/$< -o $@
+	$(CXX) $(CPPFLAGS) $(DEFINES) $(CXXFLAGS) $(CXX_OFLAGS) -MMD -MP $(subst main-pch,tests-pch,$(PCHFLAGS)) -c ../tests/$< -o $@
 
 $(ODIR)/%.inc: %.cpp
 	$(CXX) $(CPPFLAGS) $(DEFINES) $(CXXFLAGS) -H -E $< -o /dev/null 2> $@