Write the list of ndk libraries to cc_toolchain/ndk_libs.bzl

Soong adds "--no-ndk" to cc stubs for apexes if the library is not an
NDK library. In order to port this logic, emit the list to a .bzl file.

We cannot use the exportedVars.Export* soong_injection api for this
since we need to visit all modules to get this list.

Test: m nothing
Bug: 299501496
Change-Id: If8487db85e08b32b9b40aef3371d9f3f7d5a77e0

bp2build/bp2build_product_config.go

@@ -12,6 +12,7 @@ import (
 	"android/soong/android/soongconfig"
 	"android/soong/starlark_import"
 
+	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
 	"go.starlark.net/starlark"
 )
@@ -45,6 +46,15 @@ func CreateProductConfigFiles(
 		return nil, nil, err
 	}
 
+	// Visit all modules to determine the list of ndk libraries
+	// This list will be used to add additional flags for cc stub generation
+	ndkLibsStringFormatted := []string{}
+	ctx.Context().VisitAllModules(func(m blueprint.Module) {
+		if ctx.Context().ModuleType(m) == "ndk_library" {
+			ndkLibsStringFormatted = append(ndkLibsStringFormatted, fmt.Sprintf(`"%s"`, m.Name())) // name will be `"libc.ndk"`
+		}
+	})
+
 	// TODO(b/249685973): the name is product_config_platforms because product_config
 	// was already used for other files. Deduplicate them.
 	currentProductFolder := fmt.Sprintf("product_config_platforms/products/%s-%s", targetProduct, targetBuildVariant)
@@ -154,6 +164,11 @@ build --host_platform @soong_injection//{PRODUCT_FOLDER}:{PRODUCT}-{VARIANT}_lin
 			productReplacer.Replace(`
 build --host_platform @soong_injection//{PRODUCT_FOLDER}:{PRODUCT}-{VARIANT}_darwin_x86_64
 `)),
+		newFile(
+			"cc_toolchain",
+			"ndk_libs.bzl",
+			fmt.Sprintf("ndk_libs = [%v]", strings.Join(ndkLibsStringFormatted, ", ")),
+		),
 	}
 	bp2buildDirFiles := []BazelFile{
 		newFile(