cmake: reorganize source into directories and add cmake build

- add CMakeLists.txt with build equivalent to the Makefile
- emulate getversion to set SOVERSION on the shared library
- update the Makefile to build with the new directory layout

Author: michaeljclark

.gitignore

@@ -4,22 +4,22 @@
 *.la
 *.so
 *.so.*
-gif2raw
-gif2rgb
-gifasm
-gifbg
-gifbuild
-gifclrmp
-gifcolor
-gifecho
-giffilter
-giffix
-gifhisto
-gifinto
-gifsponge
-giftext
-giftool
-gifwedge
+examples/gif2raw
+examples/gif2rgb
+examples/gifasm
+examples/gifbg
+examples/gifbuild
+examples/gifclrmp
+examples/gifcolor
+examples/gifecho
+examples/giffilter
+examples/giffix
+examples/gifhisto
+examples/gifinto
+examples/gifsponge
+examples/giftext
+examples/giftool
+examples/gifwedge
 doc/gif2raw.1
 doc/gif2raw.html
 doc/gif2rgb.1

CMakeLists.txt

@@ -0,0 +1,112 @@
+cmake_minimum_required(VERSION 3.14)
+
+project(giflib)
+
+set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+
+option(GIF_BUILD_SHARED "Build shared library" ON)
+option(GIF_BUILD_STATIC "Build static library" ON)
+option(GIF_BUILD_EXAMPLES "Build examples" ON)
+option(GIF_INSTALL_LIBS "Install libs" ON)
+option(GIF_INSTALL_EXAMPLES "Install exmaples" ON)
+
+include(CheckCSourceCompiles)
+include(CheckLibraryExists)
+
+check_library_exists(m sqrtf "" has_libm)
+check_c_source_compiles("#include <stdlib.h>
+int main(void) { return !!reallocarray(NULL, 1, 1); }" has_reallocarray)
+
+if(has_libm)
+    set(EXTRA_LIBS ${EXTRA_LIBS} m)
+endif()
+
+file(READ include/gif_lib.h gif_lib_h_src)
+string(REGEX MATCH "#define GIFLIB_MAJOR [0-9]+" gif_v_major ${gif_lib_h_src})
+string(REGEX MATCH "#define GIFLIB_MINOR [0-9]+" gif_v_minor ${gif_lib_h_src})
+string(REGEX MATCH "#define GIFLIB_RELEASE [0-9]+" gif_v_release ${gif_lib_h_src})
+string(REGEX REPLACE "#define GIFLIB_MAJOR ([0-9]+)" "\\1" GIF_MAJOR ${gif_v_major})
+string(REGEX REPLACE "#define GIFLIB_MINOR ([0-9]+)" "\\1" GIF_MINOR ${gif_v_minor})
+string(REGEX REPLACE "#define GIFLIB_RELEASE ([0-9]+)" "\\1" GIF_RELEASE ${gif_v_release})
+set(GIF_VERSION "${GIF_MAJOR}.${GIF_MINOR}.${GIF_RELEASE}")
+
+#
+# giflib library
+#
+
+set(gif_source
+	src/dgif_lib.c
+	src/egif_lib.c
+	src/gif_err.c
+	src/gif_font.c
+	src/gif_hash.c
+	src/gifalloc.c)
+
+set(gif_private_headers
+	include/gif_hash.h
+	include/gif_lib_private.h)
+
+if(has_reallocarray)
+	add_definitions(-DHAVE_REALLOCARRAY)
+else()
+	list(APPEND gif_source src/openbsd-reallocarray.c)
+endif()
+
+include_directories(include)
+
+if(GIF_BUILD_SHARED)
+	add_library(gif SHARED)
+	target_sources(gif PRIVATE ${gif_source} ${gif_private_headers}
+		INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/include/gif_lib.h)
+	set_target_properties(gif
+		PROPERTIES SOVERSION ${GIF_MAJOR} VERSION ${GIF_VERSION})
+	list(APPEND GIF_LIB_TARGETS gif)
+endif()
+
+if(GIF_BUILD_STATIC)
+	add_library(gif-static STATIC)
+	target_sources(gif-static PRIVATE ${gif_source})
+	list(APPEND GIF_LIB_TARGETS gif-static)
+endif()
+
+if(GIF_INSTALL_LIBS)
+	install(TARGETS ${GIF_LIB_TARGETS})
+endif()
+
+if(TARGET gif-static)
+	set(GIF_LIBRARY gif-static PARENT_SCOPE)
+elseif(TARGET gif)
+	set(GIF_LIBRARY gif PARENT_SCOPE)
+else()
+	message(FATAL_ERROR "GIF_BUILD_SHARED or GIF_BUILD_STATIC must be set")
+endif()
+
+#
+# giflib examples
+#
+
+set(gifcommon_source
+	examples/qprintf.c
+	examples/quantize.c
+	examples/getarg.c)
+
+set(gifcommon_headers
+	examples/getarg.h)
+
+set(gif_examples gif2rgb gifbg gifbuild gifclrmp gifcolor gifecho
+	giffilter giffix gifhisto gifinto gifsponge giftext giftool gifwedge)
+
+set(gif_installable_examples gif2rgb gifbuild giffix giftext giftool gifclrmp)
+
+if(GIF_BUILD_EXAMPLES)
+	add_library(gifcommon OBJECT)
+	target_sources(gifcommon PRIVATE ${gifcommon_source} ${gifcommon_headers})
+	foreach(example ${gif_examples})
+		add_executable(${example} examples/${example}.c)
+		target_link_libraries(${example} ${EXTRA_LIBS} gifcommon ${GIF_LIBRARY})
+	endforeach()
+endif()
+
+if(GIF_INSTALL_EXAMPLES)
+	install(TARGETS ${gif_installable_examples})
+endif()

Makefile

@@ -8,7 +8,7 @@
 #
 OFLAGS = -O0 -g
 OFLAGS  = -O2
-CFLAGS  = -std=gnu99 -fPIC -Wall -Wno-format-truncation $(OFLAGS)
+CFLAGS  = -std=gnu99 -fPIC -Wall -Wno-format-truncation -Iinclude $(OFLAGS)
 
 SHELL = /bin/sh
 TAR = tar
@@ -28,36 +28,36 @@ LIBMINOR=2
 LIBPOINT=0
 LIBVER=$(LIBMAJOR).$(LIBMINOR).$(LIBPOINT)
 
-SOURCES = dgif_lib.c egif_lib.c gifalloc.c gif_err.c gif_font.c \
-	gif_hash.c openbsd-reallocarray.c
-HEADERS = gif_hash.h  gif_lib.h  gif_lib_private.h
+SOURCES = src/dgif_lib.c src/egif_lib.c src/gifalloc.c src/gif_err.c \
+	src/gif_font.c src/gif_hash.c src/openbsd-reallocarray.c
+HEADERS = include/gif_hash.h include/gif_lib.h include/gif_lib_private.h
 OBJECTS = $(SOURCES:.c=.o)
 
-USOURCES = qprintf.c quantize.c getarg.c 
-UHEADERS = getarg.h
+USOURCES = examples/qprintf.c examples/quantize.c examples/getarg.c
+UHEADERS = examples/getarg.h
 UOBJECTS = $(USOURCES:.c=.o)
 
 # Some utilities are installed
 INSTALLABLE = \
-	gif2rgb \
-	gifbuild \
-	giffix \
-	giftext \
-	giftool \
-	gifclrmp
+	examples/gif2rgb \
+	examples/gifbuild \
+	examples/giffix \
+	examples/giftext \
+	examples/giftool \
+	examples/gifclrmp
 
 # Some utilities are only used internally for testing.
 # There is a parallel list in doc/Makefile.
 # These are all candidates for removal in future releases.
 UTILS = $(INSTALLABLE) \
-	gifbg \
-	gifcolor \
-	gifecho \
-	giffilter \
-	gifhisto \
-	gifinto \
-	gifsponge \
-	gifwedge
+	examples/gifbg \
+	examples/gifcolor \
+	examples/gifecho \
+	examples/giffilter \
+	examples/gifhisto \
+	examples/gifinto \
+	examples/gifsponge \
+	examples/gifwedge
 
 LDLIBS=libgif.a -lm
 
@@ -73,7 +73,7 @@ libgif.a: $(OBJECTS) $(HEADERS)
 	$(AR) rcs libgif.a $(OBJECTS)
 
 libutil.so: $(UOBJECTS) $(UHEADERS)
-	$(CC) $(CFLAGS) -shared $(LDFLAGS) -Wl,-soname -Wl,libutil.so.$(LIBMAJOR) -o libutil.so $(UOBJECTS)
+	$(CC) $(CFLAGS) -shared $(LDFLAGS) -Wl,-soname -Wl,libutil.so.$(LIBMAJOR) -o libutil.so $(UOBJECTS) libgif.so
 
 libutil.a: $(UOBJECTS) $(UHEADERS)
 	$(AR) rcs libutil.a $(UOBJECTS)
@@ -95,7 +95,7 @@ install-bin: $(INSTALLABLE)
 	$(INSTALL) $^ "$(DESTDIR)$(BINDIR)"
 install-include:
 	$(INSTALL) -d "$(DESTDIR)$(INCDIR)"
-	$(INSTALL) -m 644 gif_lib.h "$(DESTDIR)$(INCDIR)"
+	$(INSTALL) -m 644 include/gif_lib.h "$(DESTDIR)$(INCDIR)"
 install-lib:
 	$(INSTALL) -d "$(DESTDIR)$(LIBDIR)"
 	$(INSTALL) -m 644 libgif.a "$(DESTDIR)$(LIBDIR)/libgif.a"

getarg.c examples/getarg.c

@@ -4,7 +4,7 @@
 #
 # Done this way so there's a single point of truth about the version.
 #
-MAJOR=`sed <gif_lib.h -n -e "/MAJOR/s/#define GIFLIB_MAJOR  *//p"`
-MINOR=`sed <gif_lib.h -n -e "/MINOR/s/#define GIFLIB_MINOR  *//p"`
-RELEASE=`sed <gif_lib.h -n -e "/RELEASE/s/#define GIFLIB_RELEASE  *//p"`
+MAJOR=`sed <include/gif_lib.h -n -e "/MAJOR/s/#define GIFLIB_MAJOR  *//p"`
+MINOR=`sed <include/gif_lib.h -n -e "/MINOR/s/#define GIFLIB_MINOR  *//p"`
+RELEASE=`sed <include/gif_lib.h -n -e "/RELEASE/s/#define GIFLIB_RELEASE  *//p"`
 echo ${MAJOR}.${MINOR}.${RELEASE}