Turn the compiler into a protoc plugin

Using the old "protoc-c" command directly is still supported
through a symlink.

LICENSE

@@ -25,7 +25,8 @@ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-The code generated by the protoc-c compiler is owned by the owner of the
-input files used when generating it. This code is not standalone and
-requires a support library to be linked with it. This support library is
-covered by the above license.
+The code generated by the protoc-gen-c code generator and by the
+protoc-c compiler is owned by the owner of the input files used when
+generating it. This code is not standalone and requires a support
+library to be linked with it. This support library is covered by the
+above license.

Makefile.am

@@ -66,13 +66,13 @@ CLEANFILES += protobuf-c/libprotobuf-c.pc
 EXTRA_DIST += protobuf-c/libprotobuf-c.pc.in
 
 #
-# protoc-c
+# protoc-gen-c
 #
 
 if BUILD_COMPILER
 
-bin_PROGRAMS += protoc-c/protoc-c
-protoc_c_protoc_c_SOURCES = \
+bin_PROGRAMS += protoc-c/protoc-gen-c
+protoc_c_protoc_gen_c_SOURCES = \
 	protoc-c/c_bytes_field.cc \
 	protoc-c/c_bytes_field.h \
 	protoc-c/c_enum.cc \
@@ -100,13 +100,21 @@ protoc_c_protoc_c_SOURCES = \
 	protoc-c/c_string_field.cc \
 	protoc-c/c_string_field.h \
 	protoc-c/main.cc
-protoc_c_protoc_c_CXXFLAGS = \
+protoc_c_protoc_gen_c_CXXFLAGS = \
 	$(AM_CXXFLAGS) \
 	$(protobuf_CFLAGS)
-protoc_c_protoc_c_LDADD = \
+protoc_c_protoc_gen_c_LDADD = \
 	$(protobuf_LIBS) \
 	-lprotoc
 
+#
+# protoc-c compat link
+#
+
+install-exec-hook:
+	rm -f $(DESTDIR)$(bindir)/protoc-c
+	ln -s protoc-gen-c $(DESTDIR)$(bindir)/protoc-c
+
 #
 # protobuf-c tests
 #
@@ -155,14 +163,14 @@ t_generated_code2_cxx_generate_packed_data_CXXFLAGS = \
 t_generated_code2_cxx_generate_packed_data_LDADD = \
 	$(protobuf_LIBS)
 
-t/test.pb-c.c t/test.pb-c.h: $(top_builddir)/protoc-c/protoc-c$(EXEEXT) $(top_srcdir)/t/test.proto
-	$(AM_V_GEN)$(top_builddir)/protoc-c/protoc-c$(EXEEXT) -I$(top_srcdir) --c_out=$(top_builddir) $(top_srcdir)/t/test.proto
+t/test.pb-c.c t/test.pb-c.h: $(top_builddir)/protoc-c/protoc-gen-c$(EXEEXT) $(top_srcdir)/t/test.proto
+	$(AM_V_GEN)@PROTOC@ --plugin=$(top_builddir)/protoc-c/protoc-gen-c$(EXEEXT) -I$(top_srcdir) --c_out=$(top_builddir) $(top_srcdir)/t/test.proto
 
-t/test-optimized.pb-c.c t/test-optimized.pb-c.h: $(top_builddir)/protoc-c/protoc-c$(EXEEXT) $(top_srcdir)/t/test-optimized.proto
-	$(AM_V_GEN)$(top_builddir)/protoc-c/protoc-c$(EXEEXT) -I$(top_srcdir) --c_out=$(top_builddir) $(top_srcdir)/t/test-optimized.proto
+t/test-optimized.pb-c.c t/test-optimized.pb-c.h: $(top_builddir)/protoc-c/protoc-gen-c$(EXEEXT) $(top_srcdir)/t/test-optimized.proto
+	$(AM_V_GEN)@PROTOC@ --plugin=$(top_builddir)/protoc-c/protoc-gen-c$(EXEEXT) -I$(top_srcdir) --c_out=$(top_builddir) $(top_srcdir)/t/test-optimized.proto
 
-t/test-full.pb-c.c t/test-full.pb-c.h: $(top_builddir)/protoc-c/protoc-c$(EXEEXT) $(top_srcdir)/t/test-full.proto
-	$(AM_V_GEN)$(top_builddir)/protoc-c/protoc-c$(EXEEXT) -I$(top_srcdir) --c_out=$(top_builddir) $(top_srcdir)/t/test-full.proto
+t/test-full.pb-c.c t/test-full.pb-c.h: $(top_builddir)/protoc-c/protoc-gen-c$(EXEEXT) $(top_srcdir)/t/test-full.proto
+	$(AM_V_GEN)@PROTOC@ --plugin=$(top_builddir)/protoc-c/protoc-gen-c$(EXEEXT) -I$(top_srcdir) --c_out=$(top_builddir) $(top_srcdir)/t/test-full.proto
 
 t/test-full.pb.cc t/test-full.pb.h: @PROTOC@ $(top_srcdir)/t/test-full.proto
 	$(AM_V_GEN)@PROTOC@ -I$(top_srcdir) --cpp_out=$(top_builddir) $(top_srcdir)/t/test-full.proto

README.md

@@ -28,9 +28,9 @@ See the [online Doxygen documentation here](http://lib.protobuf-c.io) or [the Wi
 
 ## Synopsis
 
-Use the `protoc-c` command to generate `.pb-c.c` and `.pb-c.h` output files from your `.proto` input file.
+Use the `protoc` command to generate `.pb-c.c` and `.pb-c.h` output files from your `.proto` input file. The `--c_out` options instructs `protoc` to use the protobuf-c plugin.
 
-    protoc-c --c_out=. example.proto
+    protoc --c_out=. example.proto
 
 Include the `.pb-c.h` file from your C source code.
 

build-cmake/CMakeLists.txt

@@ -39,31 +39,35 @@ INCLUDE_DIRECTORIES(${CMAKE_BINARY_DIR}) # for generated files
 FIND_PACKAGE(Protobuf REQUIRED)
 INCLUDE_DIRECTORIES(${PROTOBUF_INCLUDE_DIR})
 
-file(GLOB PROTOC_SRC ${MAIN_DIR}/protoc-c/*.h ${MAIN_DIR}/protoc-c/*.cc )
-ADD_EXECUTABLE(protoc-c ${PROTOC_SRC})
+FILE(GLOB PROTOC_GEN_C_SRC ${MAIN_DIR}/protoc-c/*.h ${MAIN_DIR}/protoc-c/*.cc )
+ADD_EXECUTABLE(protoc-gen-c ${PROTOC_GEN_C_SRC})
 
-TARGET_LINK_LIBRARIES(protoc-c ${PROTOBUF_PROTOC_LIBRARY} ${PROTOBUF_LIBRARY})
+TARGET_LINK_LIBRARIES(protoc-gen-c ${PROTOBUF_PROTOC_LIBRARY} ${PROTOBUF_LIBRARY})
+
+IF(CMAKE_HOST_UNIX)
+ADD_CUSTOM_COMMAND(TARGET ${PROJECT_NAME} POST_BUILD
+                   COMMAND ln -sf protoc-gen-c protoc-c
+                   DEPENDS protoc-gen-c)
+ENDIF()
 
 IF(CMAKE_BUILD_TYPE MATCHES Debug)
 ENABLE_TESTING()
 ADD_CUSTOM_COMMAND(OUTPUT t/test.pb-c.c t/test.pb-c.h
-                   COMMAND protoc-c -I${MAIN_DIR} ${TEST_DIR}/test.proto --c_out=${CMAKE_BINARY_DIR}
-                   DEPENDS protoc-c
-                   )
-
+                   COMMAND ${PROTOBUF_PROTOC_EXECUTABLE}
+                   ARGS --plugin=${CMAKE_CURRENT_BINARY_DIR}/protoc-gen-c -I${MAIN_DIR} ${TEST_DIR}/test.proto --c_out=${CMAKE_BINARY_DIR}
+                   DEPENDS protoc-gen-c)
 
 ADD_EXECUTABLE(test-generated-code ${TEST_DIR}/generated-code/test-generated-code.c t/test.pb-c.c t/test.pb-c.h )
 TARGET_LINK_LIBRARIES(test-generated-code protobuf-c)
 
-
 ADD_CUSTOM_COMMAND(OUTPUT t/test-full.pb.cc t/test-full.pb.h
                    COMMAND ${PROTOBUF_PROTOC_EXECUTABLE}
-		   ARGS --cpp_out ${CMAKE_BINARY_DIR} -I${MAIN_DIR} ${TEST_DIR}/test-full.proto)
+                   ARGS --cpp_out ${CMAKE_BINARY_DIR} -I${MAIN_DIR} ${TEST_DIR}/test-full.proto)
 
 ADD_CUSTOM_COMMAND(OUTPUT t/test-full.pb-c.c t/test-full.pb-c.h
-                   COMMAND protoc-c -I${MAIN_DIR} ${TEST_DIR}/test-full.proto --c_out=${CMAKE_BINARY_DIR}
-                   DEPENDS protoc-c
-                   )
+                   COMMAND ${PROTOBUF_PROTOC_EXECUTABLE}
+                   ARGS --plugin=${CMAKE_CURRENT_BINARY_DIR}/protoc-gen-c -I${MAIN_DIR} ${TEST_DIR}/test-full.proto --c_out=${CMAKE_BINARY_DIR}
+                   DEPENDS protoc-gen-c)
 
 ADD_EXECUTABLE(cxx-generate-packed-data ${TEST_DIR}/generated-code2/cxx-generate-packed-data.cc t/test-full.pb.h t/test-full.pb.cc)
 TARGET_LINK_LIBRARIES(cxx-generate-packed-data ${PROTOBUF_LIBRARY})
@@ -74,19 +78,27 @@ ADD_CUSTOM_COMMAND(OUTPUT t/generated-code2/test-full-cxx-output.inc
                    DEPENDS cxx-generate-packed-data
                    )
 
-ADD_EXECUTABLE(test-generated-code2 ${TEST_DIR}/generated-code2/test-generated-code2.c t/generated-code2/test-full-cxx-output.inc t/test-full.pb-c.h t/test-full.pb-c.c)
-TARGET_LINK_LIBRARIES(test-generated-code2  protobuf-c)
+ADD_CUSTOM_COMMAND(OUTPUT t/test-optimized.pb-c.c t/test-optimized.pb-c.h
+                   COMMAND ${PROTOBUF_PROTOC_EXECUTABLE}
+                   ARGS --plugin=${CMAKE_CURRENT_BINARY_DIR}/protoc-gen-c -I${MAIN_DIR} ${TEST_DIR}/test-optimized.proto --c_out=${CMAKE_BINARY_DIR}
+                   DEPENDS protoc-gen-c)
+
+ADD_EXECUTABLE(test-generated-code2 ${TEST_DIR}/generated-code2/test-generated-code2.c t/generated-code2/test-full-cxx-output.inc t/test-full.pb-c.h t/test-full.pb-c.c t/test-optimized.pb-c.h t/test-optimized.pb-c.c)
+TARGET_LINK_LIBRARIES(test-generated-code2 protobuf-c)
 
 ADD_EXECUTABLE(test-version ${TEST_DIR}/version/version.c)
 TARGET_LINK_LIBRARIES(test-version protobuf-c)
 
-
 ENDIF()
 
-
-INSTALL(TARGETS protoc-c protobuf-c RUNTIME DESTINATION bin LIBRARY DESTINATION lib ARCHIVE DESTINATION lib)
+INSTALL(TARGETS protoc-gen-c protobuf-c RUNTIME DESTINATION bin LIBRARY DESTINATION lib ARCHIVE DESTINATION lib)
 INSTALL(FILES ${MAIN_DIR}/protobuf-c/protobuf-c.h DESTINATION include/protobuf-c)
 INSTALL(FILES ${MAIN_DIR}/protobuf-c/protobuf-c.h DESTINATION include)
+
+IF(CMAKE_HOST_UNIX)
+INSTALL(CODE "EXECUTE_PROCESS (COMMAND ln -sf protoc-gen-c protoc-c WORKING_DIRECTORY ${CMAKE_INSTALL_PREFIX}/bin)")
+ENDIF()
+
 INCLUDE(Dart)
 
 SET(DART_TESTING_TIMEOUT 5)

protoc-c/main.cc

+#include <string>
+
+#include <google/protobuf/compiler/plugin.h>
 #include <google/protobuf/compiler/command_line_interface.h>
 #include <protoc-c/c_generator.h>
 
-
 int main(int argc, char* argv[]) {
-  google::protobuf::compiler::CommandLineInterface cli;
-
-  // Support generation of Foo code.
   google::protobuf::compiler::c::CGenerator c_generator;
-  cli.RegisterGenerator("--c_out", &c_generator,
-  "Generate C/H files.");
 
-  // Add version info generated by automake
-  cli.SetVersionInfo(PACKAGE_STRING);
-  
-  return cli.Run(argc, argv);
+  std::string invocation_name = argv[0];
+  std::string invocation_basename = invocation_name.substr(invocation_name.find_last_of("/") + 1);
+  const std::string legacy_name = "protoc-c";
+
+  if (invocation_basename == legacy_name) {
+    google::protobuf::compiler::CommandLineInterface cli;
+    cli.RegisterGenerator("--c_out", &c_generator, "Generate C/H files.");
+    cli.SetVersionInfo(PACKAGE_STRING);
+    return cli.Run(argc, argv);
+  }
+
+  return google::protobuf::compiler::PluginMain(argc, argv, &c_generator);
 }