Add API versioning and add macro to register plugins.

If the plugin interface changes ZATHURA_API_VERSION has to be bumped before a
release.

.gitignore

@@ -12,3 +12,4 @@ zathura.pc
 *.gcda
 gcov/
 *.swp
+version.h

Makefile

@@ -28,6 +28,12 @@ options:
 	@echo "DFLAGS  = ${DFLAGS}"
 	@echo "CC      = ${CC}"
 
+version.h: version.h.in config.mk
+	$(QUIET)sed 's/ZVMAJOR/${ZATHURA_VERSION_MAJOR}/' < version.h.in | \
+		sed 's/ZVMINOR/${ZATHURA_VERSION_MINOR}/' | \
+		sed 's/ZVREV/${ZATHURA_VERSION_REV}/' | \
+		sed 's/ZVAPI/${ZATHURA_API_VERSION}/' > version.h
+
 %.o: %.c
 	$(ECHO) CC $<
 	@mkdir -p .depend
@@ -41,8 +47,8 @@ options:
 # force recompilation of database.o if DATABASE has changed
 database.o: database-${DATABASE}.o
 
-${OBJECTS}:  config.mk
+${OBJECTS}:  config.mk version.h
-${DOBJECTS}: config.mk
+${DOBJECTS}: config.mk version.h
 
 ${PROJECT}: ${OBJECTS}
 	$(ECHO) CC -o $@
@@ -50,7 +56,8 @@ ${PROJECT}: ${OBJECTS}
 
 clean:
 	$(QUIET)rm -rf ${PROJECT} ${OBJECTS} ${PROJECT}-${VERSION}.tar.gz \
-		${DOBJECTS} ${PROJECT}-debug .depend ${PROJECT}.pc doc *gcda *gcno $(PROJECT).info gcov
+		${DOBJECTS} ${PROJECT}-debug .depend ${PROJECT}.pc doc version.h \
+		*gcda *gcno $(PROJECT).info gcov
 	$(QUIET)make -C tests clean
 
 ${PROJECT}-debug: ${DOBJECTS}
@@ -62,6 +69,7 @@ debug: ${PROJECT}-debug
 ${PROJECT}.pc: ${PROJECT}.pc.in config.mk
 	$(QUIET)echo project=${PROJECT} > ${PROJECT}.pc
 	$(QUIET)echo version=${VERSION} >> ${PROJECT}.pc
+	$(QUIET)echo apiversion=${ZATHHRA_API_VERSION} >> ${PROJECT}.pc
 	$(QUIET)echo includedir=${PREFIX}/include >> ${PROJECT}.pc
 	$(QUIET)echo plugindir=${PLUGINDIR} >> ${PROJECT}.pc
 	$(QUIET)echo GTK_VERSION=${ZATHURA_GTK_VERSION} >> ${PROJECT}.pc
@@ -82,7 +90,7 @@ dist: clean
 	$(QUIET)mkdir -p ${PROJECT}-${VERSION}/tests
 	$(QUIET)cp LICENSE Makefile config.mk common.mk README AUTHORS Doxyfile \
 			${PROJECT}.1.rst ${PROJECT}rc.5.rst ${SOURCE} ${HEADER} ${PROJECT}.pc.in \
-			${PROJECT}.desktop \
+			${PROJECT}.desktop version.h.in \
 			${PROJECT}-${VERSION}
 	$(QUIET)cp tests/Makefile tests/config.mk tests/*.c \
 			${PROJECT}-${VERSION}/tests

config.mk

@@ -1,7 +1,11 @@
 # See LICENSE file for license and copyright information
 # zathura make config
 
-VERSION = 0.1.0
+ZATHURA_VERSION_MAJOR = 0
+ZATHURA_VERSION_MINOR = 1
+ZATHURA_VERSION_REV = 0
+ZATHURA_API_VERSION = 1
+VERSION = ${ZATHURA_VERSION_MAJOR}.${ZATHURA_VERSION_MINOR}.${ZATHURA_VERSION_REV}
 
 # the GTK version to use
 ZATHURA_GTK_VERSION ?= 2
@@ -29,7 +33,7 @@ SQLITE_LIB ?= $(shell pkg-config --libs sqlite3)
 DL_LIB ?= -ldl
 
 INCS = ${GIRARA_INC} ${GTK_INC}
-LIBS = ${GIRARA_LIB} ${GTK_LIB} $(DL_LIB) -lpthread -lm
+LIBS = ${GIRARA_LIB} ${GTK_LIB} ${DL_LIB} -lpthread -lm
 
 # flags
 CFLAGS += -std=c99 -pedantic -Wall -Wno-format-zero-length -Wextra $(INCS)

document.c

@@ -87,7 +87,21 @@ zathura_document_plugins_load(zathura_t* zathura)
         continue;
       }
 
-      /* resolve symbol */
+      /* resolve symbol and check API version*/
+      zathura_plugin_api_version_t api_version;
+      *(void**)(&api_version) = dlsym(handle, PLUGIN_API_VERSION_FUNCTION);
+      if (api_version != NULL) {
+        if (api_version() != ZATHURA_API_VERSION) {
+          girara_error("plugin %s has been built againt zathura with a different API version (plugin: %d, zathura: %d)",
+              path, api_version(), ZATHURA_API_VERSION);
+          g_free(path);
+          dlclose(handle);
+          continue;
+        }
+      } else {
+        girara_warning("could not find '%s' function in plugin %s ... loading anyway", PLUGIN_API_VERSION_FUNCTION, path);
+      }
+
       zathura_plugin_register_service_t register_plugin;
       *(void**)(&register_plugin) = dlsym(handle, PLUGIN_REGISTER_FUNCTION);
 

document.h

@@ -9,8 +9,38 @@
 
 #include <girara/types.h>
 #include "zathura.h"
+#include "version.h"
 
 #define PLUGIN_REGISTER_FUNCTION "plugin_register"
+#define PLUGIN_API_VERSION_FUNCTION "plugin_api_version"
+
+/**
+ * Register a plugin.
+ *
+ * @param plugin_name the name of the plugin
+ * @param major the plugin's major version
+ * @param minor the plugin's minor version
+ * @param rev the plugin's revision
+ * @param plugin_open_function the plugin's open function
+ * @param mimetypes a char array of mime types supported by the plugin
+ */
+#define PLUGIN_REGISTER(plugin_name, major, minor, rev, plugin_open_function, mimetypes) \
+  unsigned int plugin_version_major() { return major; } \
+  unsigned int plugin_version_minor() { return minor; } \
+  unsigned int plugin_version_revision() { return rev; } \
+  unsigned int plugin_api_version() { return ZATHURA_API_VERSION; } \
+  \
+  void plugin_register(zathura_document_plugin_t* plugin) \
+  { \
+    if (plugin == NULL) { \
+      return; \
+    } \
+    plugin->open_function  = (plugin_open_function); \
+    static const char* mime_types[] = mimetypes; \
+    for (size_t s = 0; s != sizeof(mime_types) / sizeof(const char*); ++s) { \
+      girara_list_append(plugin->content_types, g_content_type_from_mime_type(mime_types[s])); \
+    } \
+  } \
 
 /**
  * Error types for plugins
@@ -80,6 +110,13 @@ typedef struct zathura_password_dialog_info_s
  */
 typedef void (*zathura_plugin_register_service_t)(zathura_document_plugin_t*);
 
+/**
+ * Function prototype that is called to get the plugin's API version.
+ *
+ * @return plugin's API version
+ */
+typedef unsigned int (*zathura_plugin_api_version_t)();
+
 /**
  * Image buffer
  */

version.h.in

@@ -0,0 +1,12 @@
+/* See LICENSE file for license and copyright information */
+
+#ifndef ZATHURA_VERSION_H
+#define ZATHURA_VERSION_H
+
+#define ZATHURA_VERSION_MAJOR ZVMAJOR
+#define ZATHUAR_VERSION_MINOR ZVMINOR
+#define ZATHURA_VERSION_REV ZVREV
+#define ZATHURA_VERSION "ZVMAJOR.ZVMINOR.ZVREV"
+#define ZATHURA_API_VERSION ZVAPI
+
+#endif