Update ab.

build/protobuf.py

@@ -1,17 +1,9 @@
-from os.path import join
-from build.ab import (
-    Rule,
-    Targets,
-    emit,
-    normalrule,
-    filenamesof,
-    filenamesmatchingof,
-    bubbledattrsof,
-    targetswithtraitsof,
-)
+from build.ab import Rule, Targets, emit, simplerule, filenamesof
+from build.utils import filenamesmatchingof, collectattrs
 from build.c import cxxlibrary
 from types import SimpleNamespace
-from build.pkg import package
+from os.path import join
+import build.pkg  # to get the protobuf package check
 
 emit(
     """
@@ -22,52 +14,51 @@ endif
 """
 )
 
-lib = package(name="protobuf_lib", package="protobuf")
 
 @Rule
-def proto(self, name, srcs: Targets = None, deps: Targets = None):
-    normalrule(
+def proto(self, name, srcs: Targets = [], deps: Targets = []):
+    simplerule(
         replaces=self,
         ins=srcs,
-        outs=[f"{name}.descriptor"],
+        outs=[f"={name}.descriptor"],
         deps=deps,
         commands=[
             "$(PROTOC) --include_source_info --descriptor_set_out={outs[0]} {ins}"
         ],
         label="PROTO",
+        protosrcs=filenamesof(srcs),
     )
-    self.attr.protosrcs = filenamesof(srcs)
-    self.bubbleattr("protosrcs", deps)
 
 
 @Rule
-def protocc(self, name, srcs: Targets = None, deps: Targets = None):
+def protocc(self, name, srcs: Targets = [], deps: Targets = []):
     outs = []
     protos = []
 
-    for f in filenamesmatchingof(bubbledattrsof(srcs, "protosrcs"), "*.proto"):
+    allsrcs = collectattrs(targets=srcs, name="protosrcs")
+    assert allsrcs, "no sources provided"
+    for f in filenamesmatchingof(allsrcs, "*.proto"):
         cc = f.replace(".proto", ".pb.cc")
         h = f.replace(".proto", ".pb.h")
         protos += [f]
         srcs += [f]
-        outs += [cc, h]
+        outs += ["=" + cc, "=" + h]
 
-    srcname = f"{name}_srcs"
-    objdir = join("$(OBJ)", srcname)
-    r = normalrule(
-        name=srcname,
+    r = simplerule(
+        name=f"{self.localname}_srcs",
+        cwd=self.cwd,
         ins=protos,
         outs=outs,
         deps=deps,
-        commands=["$(PROTOC) --cpp_out={self.attr.objdir} {ins}"],
+        commands=["$(PROTOC) --cpp_out={dir} {ins}"],
         label="PROTOCC",
     )
 
-    headers = {f: join(objdir, f) for f in outs if f.endswith(".pb.h")}
+    headers = {f[1:]: join(r.dir, f[1:]) for f in outs if f.endswith(".pb.h")}
 
     cxxlibrary(
         replaces=self,
         srcs=[r],
-        deps=targetswithtraitsof(deps, "cheaders") + [lib],
+        deps=deps,
         hdrs=headers,
     )