Pull in gtest for unit tests.

.gitignore

@@ -10,7 +10,9 @@ src/**/*.tlog
 out
 out.pgo
 out.pgen
+out.test
 stella
+stella-test
 stella-pgo
 stella-pgo-generate
 *.diff

Makefile

@@ -47,17 +47,38 @@ else
   CFLAGS:= -O2
 endif
 
+ifndef CXXFLAGS_TEST
+	CXXFLAGS_TEST := $(CXXFLAGS)
+endif
+
+ifndef CFLAGS_TEST
+	CFLAGS_TEST := $(CFLAGS)
+endif
+
+ifndef LDFLAGS_TEST
+	LDFLAGS_TEST := $(LDFLAGS)
+endif
+
 CXXFLAGS+= -Wall -Wextra -Wno-unused-parameter
 CFLAGS+= -Wall -Wextra -Wno-unused-parameter
 
+CXXFLAGS_TEST+= -Wall -Wextra -Wno-unused-parameter
+CFLAGS_TEST+= -Wall -Wextra -Wno-unused-parameter
+
 ifdef HAVE_GCC
   CXXFLAGS+= -Wno-multichar -Wunused -Woverloaded-virtual -Wnon-virtual-dtor -std=c++20
   CFLAGS+= -Wno-multichar -Wunused
+
+	CXXFLAGS_TEST+= -Wno-multichar -Wunused -Woverloaded-virtual -Wnon-virtual-dtor -std=c++20
+  CFLAGS_TEST+= -Wno-multichar -Wunused
 endif
 
 ifdef HAVE_CLANG
   CXXFLAGS+= -Wno-multichar -Wunused -Woverloaded-virtual -Wnon-virtual-dtor -std=c++20
   CFLAGS+= -Wno-multichar -Wunused
+
+  CXXFLAGS_TEST+= -Wno-multichar -Wunused -Woverloaded-virtual -Wnon-virtual-dtor -std=c++20
+  CFLAGS_TEST+= -Wno-multichar -Wunused
 endif
 
 ifdef CLANG_WARNINGS
@@ -70,6 +91,9 @@ ifdef CLANG_WARNINGS
 
   CXXFLAGS+= $(EXTRA_WARN)
   CFLAGS+= $(EXTRA_WARN)
+
+	CXXFLAGS_TEST+= $(EXTRA_WARN)
+  CFLAGS_TEST+= $(EXTRA_WARN)
 endif
 
 ifdef PROFILE
@@ -108,12 +132,14 @@ ifdef STELLA_BUILD_ROOT
 else
   OBJECT_ROOT := out
 endif
+OBJECT_ROOT_TEST := out.test
 OBJECT_ROOT_PROFILE_GENERERATE := out.pgen
 OBJECT_ROOT_PROFILE_USE := out.pgo
 
 EXECUTABLE := stella$(EXEEXT)
 EXECUTABLE_PROFILE_GENERATE := stella-pgo-generate$(EXEEXT)
 EXECUTABLE_PROFILE_USE := stella-pgo$(EXEEXT)
+EXECUTABLE_TEST := stella-test$(EXEEXT)
 
 PROFILE_DIR = $(CURDIR)/test/roms/profile
 PROFILE_OUT = $(PROFILE_DIR)/out
@@ -154,6 +180,9 @@ all: $(EXECUTABLE)
 
 pgo: $(EXECUTABLE_PROFILE_USE)
 
+test: $(EXECUTABLE_TEST)
+	./$(EXECUTABLE_TEST)
+
 ######################################################################
 # Various minor settings
 ######################################################################
@@ -195,6 +224,7 @@ DEPDIRS = $(addsuffix /$(DEPDIR),$(MODULE_DIRS))
 DEPFILES =
 
 OBJ=$(addprefix $(OBJECT_ROOT)/,$(OBJS))
+OBJ_TEST=$(addprefix $(OBJECT_ROOT_TEST)/,$(OBJS_TEST))
 OBJ_PROFILE_GENERATE=$(addprefix $(OBJECT_ROOT_PROFILE_GENERERATE)/,$(OBJS))
 OBJ_PROFILE_USE=$(addprefix $(OBJECT_ROOT_PROFILE_USE)/,$(OBJS))
 
@@ -202,6 +232,9 @@ OBJ_PROFILE_USE=$(addprefix $(OBJECT_ROOT_PROFILE_USE)/,$(OBJS))
 $(EXECUTABLE): $(OBJ)
 	$(LD) $(LDFLAGS) $(PRE_OBJS_FLAGS) $+ $(POST_OBJS_FLAGS) $(LIBS) $(PROF) -o $@
 
+$(EXECUTABLE_TEST): $(OBJ_TEST)
+	$(LD) $(LDFLAGS_TEST) $(PRE_OBJS_FLAGS) $+ $(POST_OBJS_FLAGS) $(LIBS) -lgtest -lgtest_main -o $@
+
 $(EXECUTABLE_PROFILE_GENERATE): $(OBJ_PROFILE_GENERATE)
 	$(LD) $(LDFLAGS_PROFILE_GENERATE) $(PRE_OBJS_FLAGS) $+ $(POST_OBJS_FLAGS) $(LIBS) $(PROF) -o $@
 
@@ -216,7 +249,7 @@ clean:
 	-$(RM) -fr \
 		$(OBJECT_ROOT) $(OBJECT_ROOT_PROFILE_GENERERATE) $(OBJECT_ROOT_PROFILE_USE) \
 		$(EXECUTABLE) $(EXECUTABLE_PROFILE_GENERATE) $(EXECUTABLE_PROFILE_USE) \
-		$(PROFILE_OUT) $(PROFILE_STAMP)
+		$(OBJECT_ROOT_TEST) $(PROFILE_OUT) $(PROFILE_STAMP)
 
 .PHONY: all clean dist distclean
 
@@ -244,6 +277,16 @@ $(OBJECT_ROOT)/%.o: %.cxx
 	$(merge_dep)
 
 $(OBJECT_ROOT)/%.o: %.c
+	$(create_dir)
+	$(CC) $(CXX_UPDATE_DEP_FLAG) $(CFLAGS_TEST) $(CPPFLAGS) -c $(<) -o $@
+	$(merge_dep)
+
+$(OBJECT_ROOT_TEST)/%.o: %.cxx
+	$(create_dir)
+	$(CXX) $(CXX_UPDATE_DEP_FLAG) $(CXXFLAGS_TEST) $(CPPFLAGS) -c $(<) -o $@
+	$(merge_dep)
+
+$(OBJECT_ROOT_TEST)/%.o: %.c
 	$(create_dir)
 	$(CC) $(CXX_UPDATE_DEP_FLAG) $(CFLAGS) $(CPPFLAGS) -c $(<) -o $@
 	$(merge_dep)
@@ -281,6 +324,14 @@ $(OBJECT_ROOT)/%.o: %.c
 	$(create_dir)
 	$(CC) $(CXX_UPDATE_DEP_FLAG) $(CFLAGS) $(CPPFLAGS) -c $(<) -o $@
 
+$(OBJECT_ROOT_TEST)/%.o: %.cxx
+	$(create_dir)
+	$(CXX) $(CXX_UPDATE_DEP_FLAG) $(CXXFLAGS_TEST) $(CPPFLAGS) -c $(<) -o $@
+
+$(OBJECT_ROOT_TEST)/%.o: %.c
+	$(create_dir)
+	$(CC) $(CXX_UPDATE_DEP_FLAG) $(CFLAGS_TEST) $(CPPFLAGS) -c $(<) -o $@
+
 $(OBJECT_ROOT_PROFILE_GENERERATE)/%.o: %.cxx
 	$(create_dir)
 	$(CXX) $(CXX_UPDATE_DEP_FLAG) $(CXXFLAGS_PROFILE_GENERATE) $(CPPFLAGS) -c $(<) -o $@

common.rules

@@ -4,7 +4,9 @@
 # contains the module name, a trick we use so we can keep multiple different
 # module object lists, one for each module.
 MODULE_OBJS-$(MODULE) := $(MODULE_OBJS)
+MODULE_TEST_OBJS-$(MODULE) := $(MODULE_TEST_OBJS)
 
 # If not building as a plugin, add the object files to the main OBJS list
 #OBJS += $(MODULE_LIB-$(MODULE))
 OBJS += $(MODULE_OBJS)
+OBJS_TEST := $(MODULE_TEST_OBJS)

configure

@@ -13,6 +13,16 @@
 # use environment vars if set
 CXXFLAGS="$CXXFLAGS $CPPFLAGS"
 
+if test -n "$CXXFLAGS_TEST"; then
+	CXXFLAGS_TEST="$CXXFLAGS_TEST $CPPFLAGS"
+else
+	CXXFLAGS_TEST="$CXXFLAGS"
+fi
+
+if test -z "$LDFLAGS_TEST"; then
+	LDFLAGS_TEST="$LDFLAGS"
+fi
+
 # default option behaviour yes/no
 _build_gui=yes
 _build_windowed=yes
@@ -225,6 +235,7 @@ Optional Libraries:
   --with-sdl-prefix=DIR    Prefix where the sdl2-config script is installed (optional)
   --with-libpng-prefix=DIR Prefix where libpng is installed (optional)
   --with-zlib-prefix=DIR   Prefix where zlib is installed (optional)
+  --with-gtest-prefix=DIR	 Prefix where googletest is installed (optional)
 
 Some influential environment variables:
   LDFLAGS	linker flags, e.g. -L<lib dir> if you have libraries in a
@@ -233,6 +244,8 @@ Some influential environment variables:
   CXXFLAGS	C++ compiler flags
   CPPFLAGS	C++ preprocessor flags, e.g. -I<include dir> if you have
   		headers in a nonstandard directory <include dir>
+  LDFLAGS_TEST linker flags for unit tests
+  CXXFLAGS_TEST C++ compiler flags for unit tests
 
 EOF
     exit 0
@@ -280,6 +293,11 @@ for ac_option in $@; do
         _prefix=`echo $ac_option | cut -d '=' -f 2`
         ZLIB_CFLAGS="-I$_prefix/include"
         ZLIB_LIBS="-L$_prefix/lib"
+        ;;
+			--with-gtest-prefix=*)
+        _prefix=`echo $ac_option | cut -d '=' -f 2`
+        CXXFLAGS_TEST="$CXXFLAGS_TEST -I$_prefix/include"
+        LDFLAGS_TEST="$LDFLAGS_TEST -L$_prefix/lib"
         ;;
       --host=*)
         _host=`echo $ac_option | cut -d '=' -f 2`
@@ -841,6 +859,9 @@ case $_host_os in
 			INCLUDES="$INCLUDES -I$SRC_OS/unix"
 			if test "$have_clang" == yes; then
 				CXXFLAGS="$CXXFLAGS -Wno-poison-system-directories"
+				if test -n "$CXXFLAGS_TEST"; then
+					CXXFLAGS_TEST="$CXXFLAGS_TEST -Wno-poison-system-directories"
+				fi
 			fi
 			_libsqlite3=no
 			;;
@@ -954,6 +975,7 @@ cat > config.mak << EOF
 CC := $CC
 CXX := $CXX
 CXXFLAGS := $CXXFLAGS
+CXXFLAGS_TEST := $CXXFLAGS_TEST
 LD := $LD
 LIBS += $LIBS
 RANLIB := $_ranlib
@@ -991,6 +1013,7 @@ INCLUDES += $INCLUDES
 OBJS += $OBJS
 DEFINES += $DEFINES
 LDFLAGS += $LDFLAGS
+LDFLAGS_TEST += $LDFLAGS_TEST
 $_config_mk_data
 EOF
 

src/emucore/elf/EncodingTest.cxx

@@ -0,0 +1,20 @@
+//============================================================================
+//
+//   SSSS    tt          lll  lll
+//  SS  SS   tt           ll   ll
+//  SS     tttttt  eeee   ll   ll   aaaa
+//   SSSS    tt   ee  ee  ll   ll      aa
+//      SS   tt   eeeeee  ll   ll   aaaaa  --  "An Atari 2600 VCS Emulator"
+//  SS  SS   tt   ee      ll   ll  aa  aa
+//   SSSS     ttt  eeeee llll llll  aaaaa
+//
+// Copyright (c) 1995-2024 by Bradford W. Mott, Stephen Anthony
+// and the Stella Team
+//
+// See the file "License.txt" for information on usage and redistribution of
+// this file, and for a DISCLAIMER OF ALL WARRANTIES.
+//============================================================================
+
+#include <gtest/gtest.h>
+
+TEST(HelloWorld, Passes) {}

src/emucore/elf/module.mk

@@ -5,8 +5,12 @@ MODULE_OBJS = \
 	src/emucore/elf/ElfLinker.o \
 	src/emucore/elf/ElfUtil.o
 
+MODULE_TEST_OBJS = \
+	src/emucore/elf/ElfUtil.o \
+	src/emucore/elf/EncodingTest.o
+
 MODULE_DIRS += \
-	src/emucore/elf
+	src/emucore/elf/EncodingTest.o
 
 # Include common rules
 include $(srcdir)/common.rules