Refactor a lot of the proto stuff.

build/protobuf.py

@@ -1,7 +1,7 @@
 from build.ab import Rule, Targets, emit, simplerule, filenamesof
 from build.utils import filenamesmatchingof, collectattrs
 from types import SimpleNamespace
-from os.path import join
+from os.path import join, abspath, dirname
 import build.pkg  # to get the protobuf package check
 
 emit(
@@ -14,18 +14,54 @@ endif
 )
 
 
+def _getprotodeps(deps):
+    r = set()
+    for d in deps:
+        r.update(d.args.get("protodeps", {d}))
+    return sorted(r)
+
+
 @Rule
 def proto(self, name, srcs: Targets = [], deps: Targets = []):
+    protodeps = _getprotodeps(deps)
+    descriptorlist = ":".join(
+        [abspath(f) for f in filenamesmatchingof(protodeps, "*.descriptor")]
+    )
+
+    dirs = sorted({"{dir}/" + dirname(f) for f in filenamesof(srcs)})
     simplerule(
         replaces=self,
         ins=srcs,
-        outs=[f"={name}.descriptor"],
-        deps=deps,
-        commands=[
-            "$(PROTOC) --include_source_info --descriptor_set_out={outs[0]} {ins}"
-        ],
+        outs=[f"={self.localname}.descriptor"],
+        deps=protodeps,
+        commands=(
+            ["mkdir -p " + (" ".join(dirs))]
+            + [f"$(CP) {f} {{dir}}/{f}" for f in filenamesof(srcs)]
+            + [
+                "cd {dir} && "
+                + (
+                    " ".join(
+                        [
+                            "$(PROTOC)",
+                            "--proto_path=.",
+                            "--include_source_info",
+                            f"--descriptor_set_out={self.localname}.descriptor",
+                        ]
+                        + (
+                            [f"--descriptor_set_in={descriptorlist}"]
+                            if descriptorlist
+                            else []
+                        )
+                        + ["{ins}"]
+                    )
+                )
+            ]
+        ),
         label="PROTO",
-        args={"protosrcs": filenamesof(srcs)},
+        args={
+            "protosrcs": filenamesof(srcs),
+            "protodeps": set(protodeps) | {self},
+        },
     )
 
 
@@ -40,16 +76,33 @@ def protocc(self, name, srcs: Targets = [], deps: Targets = []):
         cc = f.replace(".proto", ".pb.cc")
         h = f.replace(".proto", ".pb.h")
         protos += [f]
-        srcs += [f]
         outs += ["=" + cc, "=" + h]
 
+    protodeps = _getprotodeps(deps + srcs)
+    descriptorlist = ":".join(
+        [abspath(f) for f in filenamesmatchingof(protodeps, "*.descriptor")]
+    )
+
     r = simplerule(
         name=f"{self.localname}_srcs",
         cwd=self.cwd,
-        ins=protos,
+        ins=srcs,
         outs=outs,
-        deps=deps,
-        commands=["$(PROTOC) --cpp_out={dir} {ins}"],
+        deps=protodeps,
+        commands=[
+            "cd {dir} && "
+            + (
+                " ".join(
+                    [
+                        "$(PROTOC)",
+                        "--proto_path=.",
+                        "--cpp_out=.",
+                        f"--descriptor_set_in={descriptorlist}",
+                    ]
+                    + protos
+                )
+            )
+        ],
         label="PROTOCC",
     )
 
@@ -76,6 +129,10 @@ def protojava(self, name, srcs: Targets = [], deps: Targets = []):
         protos += [f]
         srcs += [f]
 
+    descriptorlist = ":".join(
+        [abspath(f) for f in filenamesmatchingof(srcs + deps, "*.descriptor")]
+    )
+
     r = simplerule(
         name=f"{self.localname}_srcs",
         cwd=self.cwd,
@@ -84,7 +141,18 @@ def protojava(self, name, srcs: Targets = [], deps: Targets = []):
         deps=deps,
         commands=[
             "mkdir -p {dir}/srcs",
-            "$(PROTOC) --java_out={dir}/srcs {ins}",
+            "cd {dir} && "
+            + (
+                " ".join(
+                    [
+                        "$(PROTOC)",
+                        "--proto_path=.",
+                        "--java_out=.",
+                        f"--descriptor_set_in={descriptorlist}",
+                    ]
+                    + protos
+                )
+            ),
             "$(JAR) cf {outs[0]} -C {dir}/srcs .",
         ],
         traits={"srcjar"},