Inital pass at generating Protocol Buffer headers/source for C

[hazen]

Here is a basic attempt to generate C header and source file from .proto files.

Note: This now requires the protoc-c package

Currently c_release does nothing, but in the future could install into a configurable location, such as /usr/local

[seancribbs]

Couldn't this be simpler by (since protoc is required already) using:

protoc --c_out=c src/*.proto

Google's protoc will search the path for the protoc-c plugin.

[hazen]

That's basically what the script does. I was just trying to be consistent with the other languages, which check for the tool and build. Could easily put all of the steps in the Makefile instead.

[seancribbs]

I was wrong about protobuff-c, it doesn't include a protoc-gen-c binary. 😦

[seancribbs]

This works as intended, but I'd like to see it make less use of the shell script and more use of the Makefile. e.g.

PROTOS := $(wildcard src/*.proto)
C_FILES := $(patsubst src/%.proto,c/%.pb-c.c,$(PROTOS))
c_compile: c_announce c $(C_FILES)

c_announce:
    echo "==> C (compile)"

c:
    mkdir -p c/

c/%.pb-c.c c/%.pb-c.h: c src/%.proto
    echo "Generating $@ from $<"
    protoc-c -Isrc $< --c_out=c

If the protoc-c binary is not present, the error will happen at the generation stage. Of course, there are likely errors and improvements to be made in the example because I'm not a Makefile guru.

[seancribbs]

I'd also remove targets that don't do anything, e.g. c_release. 😄

[seancribbs]

This could use an @.

[hazen]

I debated about that. Thought it was useful to actually see the call, but am happy to hide it.

[seancribbs]

Ok, maybe you could omit the echo on the previous line then. Either is fine by me.

[seancribbs]

This works as expected, maybe just add that @ to the line that invokes protoc-c, then 👍 to merge.