rust: generate headers as part of build

rust/.gitignore

@@ -3,3 +3,4 @@
 /Cargo.toml
 /target
 /vendor
+/gen

rust/Makefile.am

@@ -1,7 +1,9 @@
 EXTRA_DIST = 	Cargo.toml \
 		Cargo.lock \
-		src/lib.rs \
-		.cargo/config.in
+		src \
+		.cargo/config.in \
+		gen-c-headers.py \
+		gen/c-headers
 
 if HAVE_RUST
 EXTRA_DIST +=	vendor
@@ -15,10 +17,23 @@ if !DEBUG
 RELEASE = --release
 endif
 
+gen/c-headers:
+if HAVE_PYTHON
+	cd $(top_srcdir)/rust && python ./gen-c-headers.py
+else
+	@echo "python not available, will not generate headers"
+endif
+
 if HAVE_RUST
 all-local:
+if HAVE_PYTHON
 	cd $(top_srcdir)/rust && CARGO_TARGET_DIR=$(abs_builddir)/target \
+		python ./gen-c-headers.py && \
 		cargo build $(RELEASE) $(FROZEN)
+else
+	cd $(top_srcdir)/rust && CARGO_TARGET_DIR=$(abs_builddir)/target \
+		cargo build $(RELEASE) $(FROZEN)
+endif
 
 clean-local:
 	cd $(top_srcdir)/rust && CARGO_TARGET_DIR=$(abs_builddir)/target \
@@ -26,6 +41,7 @@ clean-local:
 
 distclean-local:
 	rm -rf vendor
+	rm -rf gen
 
 check:
 	cd $(top_srcdir)/rust && CARGO_TARGET_DIR=$(abs_builddir)/target \

rust/gen-c-headers.py

@@ -105,7 +105,7 @@ def convert_type(rs_type):
 def make_output_filename(filename):
     parts = filename.split(os.path.sep)[2:]
     last = os.path.splitext(parts.pop())[0]
-    outpath = "../src/rust-%s-%s.h" % (
+    outpath = "./gen/c-headers/rust-%s-%s-gen.h" % (
         "-".join(parts), last)
     return outpath.replace("--", "-")
 
@@ -172,6 +172,8 @@ def gen_headers(filename):
 
     if writer.tell() > 0:
         print("Writing %s" % (output_filename))
+        if not os.path.exists(os.path.dirname(output_filename)):
+            os.makedirs(os.path.dirname(output_filename))
         with open(output_filename, "w") as output:
             output.write(template % {
                 "prototypes": writer.getvalue(),