Bug 1464542: Part 1 - Generate symbolic names for XPT interfaces and add lookup function. r=nika,froydnj

This makes it much simpler for the for the static JS services cache to store
and lookup interface IDs for components.

Differential Revision: https://phabricator.services.mozilla.com/D81416

config/makefiles/xpidl/Makefile.in

@@ -29,8 +29,11 @@ idl_deps_dir := .deps
 dist_idl_dir := $(DIST)/idl
 dist_include_dir := $(DIST)/include
 dist_xpcrs_dir := $(DIST)/xpcrs
+stub_file := xptdata.stub
 process_py := $(topsrcdir)/python/mozbuild/mozbuild/action/xpidl-process.py
-generated_file := $(topobjdir)/xpcom/reflect/xptinfo/xptdata.cpp
+target_file := $(topobjdir)/xpcom/reflect/xptinfo/xptdata.cpp
+xptdata_h := $(dist_include_dir)/xptdata.h
+generated_files := $(target_file) $(xptdata_h)
 code_gen_py := $(topsrcdir)/xpcom/reflect/xptinfo/xptcodegen.py
 code_gen_deps := $(topsrcdir)/xpcom/ds/tools/perfecthash.py
 
@@ -59,17 +62,21 @@ xpt_files := $(addsuffix .xpt,$(xpidl_modules))
 
 depends_files := $(foreach root,$(xpidl_modules),$(idl_deps_dir)/$(root).pp)
 
-GARBAGE += $(xpt_files) $(depends_files) $(generated_file)
+GARBAGE += $(stub_file) $(xpt_files) $(depends_files) $(target_file)
 
 ifdef COMPILE_ENVIRONMENT
-xpidl:: $(generated_file)
+xpidl:: $(generated_files)
 endif
 
+# See bug 1420119 for why we need the semicolon.
+$(target_file) $(xptdata_h) : $(stub_file) ;
+
 $(xpt_files): $(process_py) $(call mkdir_deps,$(idl_deps_dir) $(dist_include_dir) $(dist_xpcrs_dir))
 
-$(generated_file): $(xpt_files) $(code_gen_py) $(code_gen_deps)
+$(stub_file) : $(xpt_files) $(code_gen_py) $(code_gen_deps)
 	$(REPORT_BUILD)
-	$(PYTHON3) $(code_gen_py) $(generated_file) $(xpt_files)
+	$(PYTHON3) $(code_gen_py) $(generated_files) $(xpt_files)
+	@touch $@
 
 -include $(depends_files)
 

xpcom/reflect/xptinfo/xptcodegen.py

@@ -179,7 +179,7 @@ utility_types = [
 
 # Core of the code generator. Takes a list of raw JSON XPT interfaces, and
 # writes out a file containing the necessary static declarations into fd.
-def link_to_cpp(interfaces, fd):
+def link_to_cpp(interfaces, fd, header_fd):
     # Perfect Hash from IID to interface.
     iid_phf = PerfectHash(interfaces, PHFSIZE,
                           key=lambda i: iid_bytes(i['uuid']))
@@ -449,8 +449,20 @@ def link_to_cpp(interfaces, fd):
     for iface in iid_phf.entries:
         lower_iface(iface)
 
-    # Write out the final output file
+    # Write out the final output files
     fd.write("/* THIS FILE WAS GENERATED BY xptcodegen.py - DO NOT EDIT */\n\n")
+    header_fd.write("/* THIS FILE WAS GENERATED BY xptcodegen.py - DO NOT EDIT */\n\n")
+
+    header_fd.write("""
+enum class nsXPTInterface : uint16_t {
+""")
+
+    for entry in iid_phf.entries:
+        header_fd.write("  %s,\n" % entry['name'])
+
+    header_fd.write("""
+};
+""")
 
     # Include any bindings files which we need to include for webidl types
     for include in sorted(includes):
@@ -548,7 +560,7 @@ const uint16_t sInterfacesSize = mozilla::ArrayLength(sInterfaces);
 """)
 
 
-def link_and_write(files, outfile):
+def link_and_write(files, outfile, outheader):
     interfaces = []
     for file in files:
         with open(file, 'r') as fd:
@@ -562,7 +574,7 @@ def link_and_write(files, outfile):
         iids.add(interface['uuid'])
         names.add(interface['name'])
 
-    link_to_cpp(interfaces, outfile)
+    link_to_cpp(interfaces, outfile, outheader)
 
 
 def main():
@@ -571,11 +583,12 @@ def main():
 
     parser = ArgumentParser()
     parser.add_argument('outfile', help='Output C++ file to generate')
+    parser.add_argument('outheader', help='Output C++ header file to generate')
     parser.add_argument('xpts', nargs='*', help='source xpt files')
 
     args = parser.parse_args(sys.argv[1:])
-    with open(args.outfile, 'w') as fd:
-        link_and_write(args.xpts, fd)
+    with open(args.outfile, 'w') as fd, open(args.outheader, 'w') as header_fd:
+        link_and_write(args.xpts, fd, header_fd)
 
 
 if __name__ == '__main__':

xpcom/reflect/xptinfo/xptinfo.h

@@ -21,6 +21,7 @@
 #include "js/Value.h"
 #include "nsString.h"
 #include "nsTArray.h"
+#include "xptdata.h"
 
 // Forward Declarations
 namespace mozilla {
@@ -69,6 +70,10 @@ struct nsXPTInterfaceInfo {
     return xpt::detail::InterfaceByName(aName);
   }
 
+  static const nsXPTInterfaceInfo* Get(nsXPTInterface aID) {
+    return ByIndex(uint16_t(aID));
+  }
+
   // These are only needed for Components_interfaces's enumerator.
   static const nsXPTInterfaceInfo* ByIndex(uint16_t aIndex) {
     // NOTE: We add 1 here, as the internal index 0 is reserved for null.