Add support for specifying build-dependencies in binary package templates

This will allow removing a lot of the repetition introduced in the
preceding commits.

debian/README.source

@@ -189,6 +189,14 @@ into the templates:
 Normally, the arch-specific contents should be controlled by
 adjusting the corresponding defines file.
 
+Build-dependencies that relate to specific binary packages can be
+specified in a Build-Depends field in the template for that binary
+package.  gencontrol.py will append the value to the source package's
+Build-Depends-Arch or Build-Depends-Indep field, as appropriate.  It
+will also use the binary package's Architecture and Build-Profile as
+the architecture-qualification and/or restriction for each build-
+dependency that doesn't already have them.
+
 TODO:
 - Patches applied to the upstream source
 - How to define a flavour

debian/changelog

@@ -11,6 +11,7 @@ linux (4.19~rc3-1~exp2) UNRELEASED; urgency=medium
   * debian/lib/python: Use raw strings for all regexes
   * debian/control: Fix restrictions for build-deps on asciidoctor and
     patchutils
+  * Add support for specifying build-dependencies in binary package templates
 
  -- Ben Hutchings <ben@decadent.org.uk>  Mon, 10 Sep 2018 22:25:53 +0100
 

debian/lib/python/debian_linux/gencontrol.py

@@ -91,6 +91,7 @@ class Gencontrol(object):
         self.do_main(packages, makefile)
         self.do_extra(packages, makefile)
 
+        self.merge_build_depends(packages)
         self.write(packages, makefile)
 
     def do_source(self, packages):
@@ -313,6 +314,34 @@ class Gencontrol(object):
 
         return re.sub(r'@([-_a-z0-9]+)@', subst, str(s))
 
+    def merge_build_depends(self, packages):
+        # Merge Build-Depends pseudo-fields from binary packages into the
+        # source package
+        source = packages["source"]
+        arch_all = PackageArchitecture("all")
+        for name, package in packages.items():
+            if name == "source":
+                continue
+            dep = package.get("Build-Depends")
+            if not dep:
+                continue
+            del package["Build-Depends"]
+            for group in dep:
+                for item in group:
+                    if package["Architecture"] != arch_all and not item.arches:
+                        item.arches = sorted(package["Architecture"])
+                    if package.get("Build-Profiles") and not item.restrictions:
+                        profiles = package["Build-Profiles"]
+                        assert profiles[0] == "<" and profiles[-1] == ">"
+                        item.restrictions = re.split(r"\s+", profiles[1:-1])
+            if package["Architecture"] == arch_all:
+                dep_type = "Build-Depends-Indep"
+            else:
+                dep_type = "Build-Depends-Arch"
+            if dep_type not in source:
+                source[dep_type] = PackageRelation()
+            source[dep_type].extend(dep)
+
     def write(self, packages, makefile):
         self.write_control(packages.values())
         self.write_makefile(makefile)