rust: Refactor cfg and feature flag calculation

Move the cfg and feature flag calculation out of compilerFlags so that
it's a separate step.

The previous arrangement resulted in overridden compilerFlags which
must to set any additional cfgs/features before calling the base.
This is a bit confusing and undocumented behavior, so instead break
it out into a separate call that can itself be overriden.

Bug: N/A
Test: Soong tests pass
Change-Id: I28e4f707b3b3ca6eb621b7613c3737817f877bb8

1 files changed, 19 insertions, 8 deletions

diff --git a/rust/compiler.go b/rust/compiler.go
index 7bd9af4a8..1ce71f60b 100644
--- a/rust/compiler.go
+++ b/rust/compiler.go
@@ -231,6 +231,7 @@ func (compiler *baseCompiler) cfgsToFlags() []string {
 	for _, cfg := range compiler.Properties.Cfgs {
 		flags = append(flags, "--cfg '"+cfg+"'")
 	}
+
 	return flags
 }
 
@@ -239,6 +240,24 @@ func (compiler *baseCompiler) featuresToFlags() []string {
 	for _, feature := range compiler.Properties.Features {
 		flags = append(flags, "--cfg 'feature=\""+feature+"\"'")
 	}
+
+	return flags
+}
+
+func (compiler *baseCompiler) featureFlags(ctx ModuleContext, flags Flags) Flags {
+	flags.RustFlags = append(flags.RustFlags, compiler.featuresToFlags()...)
+	flags.RustdocFlags = append(flags.RustdocFlags, compiler.featuresToFlags()...)
+
+	return flags
+}
+
+func (compiler *baseCompiler) cfgFlags(ctx ModuleContext, flags Flags) Flags {
+	if ctx.RustModule().UseVndk() {
+		compiler.Properties.Cfgs = append(compiler.Properties.Cfgs, "android_vndk")
+	}
+
+	flags.RustFlags = append(flags.RustFlags, compiler.cfgsToFlags()...)
+	flags.RustdocFlags = append(flags.RustdocFlags, compiler.cfgsToFlags()...)
 	return flags
 }
 
@@ -269,10 +288,6 @@ func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags) Flag
 
 	flags.RustFlags = append(flags.RustFlags, lintFlags)
 	flags.RustFlags = append(flags.RustFlags, compiler.Properties.Flags...)
-	flags.RustFlags = append(flags.RustFlags, compiler.cfgsToFlags()...)
-	flags.RustFlags = append(flags.RustFlags, compiler.featuresToFlags()...)
-	flags.RustdocFlags = append(flags.RustdocFlags, compiler.cfgsToFlags()...)
-	flags.RustdocFlags = append(flags.RustdocFlags, compiler.featuresToFlags()...)
 	flags.RustFlags = append(flags.RustFlags, "--edition="+compiler.edition())
 	flags.RustdocFlags = append(flags.RustdocFlags, "--edition="+compiler.edition())
 	flags.LinkFlags = append(flags.LinkFlags, compiler.Properties.Ld_flags...)
@@ -296,10 +311,6 @@ func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags) Flag
 		flags.LinkFlags = append(flags.LinkFlags, "-Wl,-rpath,"+rpathPrefix+"../"+rpath)
 	}
 
-	if ctx.RustModule().UseVndk() {
-		flags.RustFlags = append(flags.RustFlags, "--cfg 'android_vndk'")
-	}
-
 	return flags
 }