Add a license file for impellerc, rename font-subset license (flutter/engine#33859)

engine/src/flutter/ci/licenses_golden/tool_signature

@@ -1,2 +1,2 @@
-Signature: 96de64fbd5966f7a30ec61d47d1ac204
+Signature: 2b69b9b3b985d18a9c148d38f9cefb46
 

engine/src/flutter/impeller/compiler/BUILD.gn

@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 import("//flutter/impeller/tools/impeller.gni")
+import("//flutter/shell/version/version.gni")
 
 impeller_component("compiler_lib") {
   sources = [
@@ -31,12 +32,52 @@ impeller_component("compiler_lib") {
     "../base",
     "../geometry",
     "//flutter/fml",
+
+    # All third_party deps must be reflected below in the impellerc_license
+    # target.
     "//third_party/inja",
     "//third_party/shaderc_flutter",
     "//third_party/spirv_cross_flutter",
   ]
 }
 
+generated_file("impellerc_license") {
+  source_path = rebase_path(".", "//flutter")
+  git_url = "https://github.com/flutter/engine/tree/$engine_version"
+  outputs = [ "$target_gen_dir/LICENSE.impellerc.md" ]
+  contents = [
+    "# impellerc",
+    "",
+    "This tool is used by the Flutter SDK to compile shaders.",
+    "",
+    "Source code for this tool: [flutter/engine/$source_path]($git_url/$source_path).",
+    "",
+    "## Licenses",
+    "",
+    "### impellerc",
+    "",
+    read_file("//flutter/sky/packages/sky_engine/LICENSE", "string"),
+    "",
+
+    # These licenses are ignored by the main license checker, since they are not
+    # shipped to end-application binaries and only shipped as part of developer
+    # tooling in impellerc. Add them here.
+    "## Additional open source licenses",
+    "",
+    "### inja",
+    "",
+    read_file("//third_party/inja/LICENSE", "string"),
+    "",
+    "### shaderc",
+    "",
+    read_file("//third_party/shaderc/LICENSE", "string"),
+    "",
+    "### spirv_cross",
+    "",
+    read_file("//third_party/spirv_cross/LICENSE", "string"),
+  ]
+}
+
 impeller_component("impellerc") {
   target_type = "executable"
 
@@ -46,7 +87,10 @@ impeller_component("impellerc") {
 }
 
 group("compiler") {
-  deps = [ ":impellerc" ]
+  deps = [
+    ":impellerc",
+    ":impellerc_license",
+  ]
 }
 
 impeller_component("compiler_unittests") {

engine/src/flutter/tools/font-subset/BUILD.gn

@@ -29,7 +29,7 @@ generated_file("_font-subset-license") {
   license_path =
       rebase_path("//flutter/sky/packages/sky_engine/LICENSE", "//flutter")
   git_url = "https://github.com/flutter/engine/tree/$engine_version"
-  outputs = [ "$target_gen_dir/README.md" ]
+  outputs = [ "$target_gen_dir/LICENSE.font-subset.md" ]
   contents = [
     "# font-subset",
     "",
@@ -64,8 +64,8 @@ zip_bundle("font-subset") {
       destination = "const_finder.dart.snapshot"
     },
     {
-      source = "$target_gen_dir/README.md"
-      destination = "README.md"
+      source = "$target_gen_dir/LICENSE.font-subset.md"
+      destination = "LICENSE.font-subset.md"
     },
   ]
 

engine/src/flutter/tools/licenses/lib/main.dart

@@ -1916,14 +1916,14 @@ class _RepositoryRootThirdPartyDirectory extends _RepositoryGenericThirdPartyDir
         && entry.name != 'skia' // treated as a separate component
         && entry.name != 'fontconfig' // not used in standard configurations
         && entry.name != 'swiftshader' // only used on hosts for tests
-        && entry.name != 'shaderc' // only used on hosts for tests
+        && entry.name != 'shaderc' // Used by impellerc with separate license and host tests. See //flutter/impeller/compiler:impellerc_license
         && entry.name != 'glslang' // only used on hosts for tests
         && entry.name != 'spirv_tools' // only used on hosts for tests
         && entry.name != 'spirv_headers' // only used on hosts for tests
-        && entry.name != 'spirv_cross' // only used on hosts for tests
+        && entry.name != 'spirv_cross' // Used by impellerc with separate license and host tests. See //flutter/impeller/compiler:impellerc_license
         && entry.name != 'ocmock' // only used for tests
         && entry.name != 'java' // only used for Android builds
-        && entry.name != 'inja' // only used on hosts for builds
+        && entry.name != 'inja' // Only used by impellerc, which ships a separate license. See //flutter/impeller/compiler:impellerc_license
         && super.shouldRecurse(entry);
   }