[gn] Consolidate calls to gypi_to_gn to speed up GN generation

runtime/vm/BUILD.gn

Index: runtime/vm/BUILD.gn
diff --git a/runtime/vm/BUILD.gn b/runtime/vm/BUILD.gn
index 0634496bc59b76a131deec048f35c97d6ad484c1..db212e7660dd10774142df21271602fbd8e78856 100644
--- a/runtime/vm/BUILD.gn
+++ b/runtime/vm/BUILD.gn
@@ -2,6 +2,8 @@
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
+import("gypi_contents.gni")
+
 config("libdart_vm_config") {
   if (defined(is_fuchsia) && is_fuchsia) {
     libs = [ "magenta" ]
@@ -29,30 +31,12 @@ static_library("libdart_platform") {
   ]
   public_configs = [ ":libdart_vm_config" ]
 
-  platform_headers_gypi =
-      exec_script("../../tools/gypi_to_gn.py",
-                  [ rebase_path("../platform/platform_headers.gypi") ],
-                  "scope",
-                  [ "../platform/platform_headers.gypi" ])
-  platform_headers =
-      rebase_path(platform_headers_gypi.sources, ".", "../platform")
-
-  platform_sources_gypi =
-      exec_script("../../tools/gypi_to_gn.py",
-                  [ rebase_path("../platform/platform_sources.gypi") ],
-                  "scope",
-                  [ "../platform/platform_sources.gypi" ])
-  platform_sources =
-      rebase_path(platform_sources_gypi.sources, ".", "../platform")
-
-  sources = platform_headers + platform_sources
+  sources = rebase_path(processed_gypis.platform_sources, ".", "../platform")
+
   include_dirs = [ ".." ]
 }
 
-vm_sources_list = exec_script("../../tools/gypi_to_gn.py",
-                              [ rebase_path("vm_sources.gypi") ],
-                              "scope",
-                              [ "vm_sources.gypi" ])
+vm_sources_list = processed_gypis.vm_sources
 
 static_library("libdart_vm") {
   configs += [
@@ -65,7 +49,7 @@ static_library("libdart_vm") {
                                   "*_test.cc",
                                   "*_test.h",
                                 ])
-  sources = vm_sources_list.sources
+  sources = vm_sources_list
   include_dirs = [ ".." ]
 }
 
@@ -81,7 +65,7 @@ static_library("libdart_vm_noopt") {
                                   "*_test.cc",
                                   "*_test.h",
                                 ])
-  sources = vm_sources_list.sources
+  sources = vm_sources_list
   include_dirs = [ ".." ]
 }
 
@@ -96,7 +80,7 @@ static_library("libdart_vm_precompiled_runtime") {
                                   "*_test.cc",
                                   "*_test.h",
                                 ])
-  sources = vm_sources_list.sources
+  sources = vm_sources_list
   include_dirs = [ ".." ]
 }
 
@@ -112,7 +96,7 @@ static_library("libdart_vm_nosnapshot") {
                                   "*_test.cc",
                                   "*_test.h",
                                 ])
-  sources = vm_sources_list.sources
+  sources = vm_sources_list
   include_dirs = [ ".." ]
 }
 
@@ -128,7 +112,7 @@ static_library("libdart_vm_nosnapshot_precompiled_runtime") {
                                   "*_test.cc",
                                   "*_test.h",
                                 ])
-  sources = vm_sources_list.sources
+  sources = vm_sources_list
   include_dirs = [ ".." ]
 }
 
@@ -144,25 +128,24 @@ static_library("libdart_vm_nosnapshot_with_precompiler") {
                                   "*_test.cc",
                                   "*_test.h",
                                 ])
-  sources = vm_sources_list.sources
+  sources = vm_sources_list
   include_dirs = [ ".." ]
 }
 
 template("process_library_source") {
   assert(defined(invoker.filename), "Need filename in $target_name")
+  assert(defined(invoker.type), "Need type in $target_name")
   assert(defined(invoker.output), "Need output in $target_name")
+  assert(defined(invoker.type), "Need type in $target_name")
   assert(defined(invoker.path), "Need path in $target_name")
   action(target_name) {
     visibility = [ ":*" ]  # Only targets in this file can see this.
     filename = invoker.filename
+    type = invoker.type
     path = invoker.path
 
-    lib_sources_gypi =
-        exec_script("../../tools/gypi_to_gn.py",
-                    [ rebase_path("${path}/${filename}_sources.gypi") ],
-                    "scope",
-                    [ "${path}/${filename}_sources.gypi" ])
-    lib_sources = rebase_path(lib_sources_gypi.sources, ".", path)
+    lib_sources =
+        rebase_path(processed_gypis["${filename}_${type}_sources"], ".", path)
 
     script = invoker.script
     inputs = invoker.inputs + [ script ]
@@ -178,15 +161,21 @@ template("generate_library_source") {
   assert(defined(invoker.libname), "Need libname in $target_name")
   assert(defined(invoker.filename), "Need a filename in $target_name")
   assert(defined(invoker.kind), "Need kind in $target_name")
+  assert(defined(invoker.type), "Need type in $target_name")
   assert(defined(invoker.output), "Need output in $target_name")
-  assert(defined(invoker.path), "Need path in $target_name")
 
   process_library_source(target_name) {
     libname = invoker.libname
     filename = invoker.filename
     kind = invoker.kind
+    type = invoker.type
     output = invoker.output
-    path = invoker.path
+
+    if (type == "sdk") {
+      path = "../../sdk/lib/" + filename
+    } else {
+      path = "../lib"
+    }
     script = "../tools/gen_library_src_paths.py"
     inputs = [
       "../lib/libgen_in.cc",
@@ -223,34 +212,28 @@ template("generate_core_libraries") {
   libdeps = []
   foreach(lib, invoker.sources) {
     libname = lib[0]
-    filename = lib[1]
-    do_patch = lib[2]
-    source_path = lib[3]
+    type = lib[1]
+    filename = lib[2]
+    do_patch = lib[3]
     generate_library_source("generate_${filename}_cc_file") {
       libname = libname
       filename = filename
       kind = "source"
-      path = source_path
+      type = type
       output = "$target_gen_dir/${filename}_gen.cc"
     }
     if (do_patch) {
-      patch_path = lib[4]
       generate_library_source("generate_${filename}_patch_cc_file") {
         libname = libname
         filename = filename
         kind = "patch"
-        path = patch_path
+        type = "runtime"
         output = "$target_gen_dir/${filename}_patch_gen.cc"
       }
     }
-    lib_sources_gypi = {
-    }
-    lib_sources_gypi =
-        exec_script("../../tools/gypi_to_gn.py",
-                    [ rebase_path("../lib/${filename}_sources.gypi") ],
-                    "scope",
-                    [ "../lib/${filename}_sources.gypi" ])
-    libsources += rebase_path(lib_sources_gypi.sources, ".", "../lib")
+    libsources += rebase_path(processed_gypis["${filename}_runtime_sources"],
+                              ".",
+                              "../lib")
     liboutputs += [ "$target_gen_dir/${filename}_gen.cc" ]
     libdeps += [ ":generate_${filename}_cc_file" ]
     if (do_patch) {
@@ -313,85 +296,75 @@ generate_core_libraries("core_libraries") {
   sources = [
     [
       "async",
+      "sdk",
       "async",
       true,
-      "../../sdk/lib/async",
-      "../lib",
     ],
     [
       "core",
+      "sdk",
       "core",
       true,
-      "../../sdk/lib/core",
-      "../lib",
     ],
     [
       "collection",
+      "sdk",
       "collection",
       true,
-      "../../sdk/lib/collection",
-      "../lib",
     ],
     [
       "convert",
+      "sdk",
       "convert",
       true,
-      "../../sdk/lib/convert",
-      "../lib",
     ],
     [
       "developer",
+      "sdk",
       "developer",
       true,
-      "../../sdk/lib/developer",
-      "../lib",
     ],
     [
       "_internal",
+      "sdk",
       "internal",
       true,
-      "../../sdk/lib/internal",
-      "../lib",
     ],
     [
       "isolate",
+      "sdk",
       "isolate",
       true,
-      "../../sdk/lib/isolate",
-      "../lib",
     ],
     [
       "math",
+      "sdk",
       "math",
       true,
-      "../../sdk/lib/math",
-      "../lib",
     ],
     [
       "mirrors",
+      "sdk",
       "mirrors",
       true,
-      "../../sdk/lib/mirrors",
-      "../lib",
     ],
     [
       "profiler",
+      "sdk",
       "profiler",
       false,
-      "../../sdk/lib/profiler",
     ],
     [
       "typed_data",
+      "runtime",
       "typed_data",
       false,
-      "../lib",
     ],
     [
       "_vmservice",
+      "sdk",
       "vmservice",
       true,
-      "../../sdk/lib/vmservice",
-      "../lib",
     ],
   ]
 }
@@ -404,6 +377,7 @@ template("concatenate_patch") {
   process_library_source(target_name) {
     output = invoker.output
     path = "../${invoker.dir}"
+    type = "sdk"
     filename = invoker.libname
     script = "../tools/concatenate_patches.py"
     args = [