rust: modify linting properties

Move the linting properties to an enum with 4 possible options:
"default", "android", "vendor" or "none". The previous logic for
default, based on the module's location, is kept. It is now possible to
force the upgrade to a certain lint level for some modules (e.g.
external/[...]/android). Update the unit tests and documentation.

Bug: 163400111
Test: m
Change-Id: I8e464b04401158ed2d3c518a9b72f145a9835c99

1 files changed, 11 insertions, 5 deletions

diff --git a/rust/clippy.go b/rust/clippy.go
index e1f567d99..6f0ed7ff1 100644
--- a/rust/clippy.go
+++ b/rust/clippy.go
@@ -19,8 +19,14 @@ import (
 )
 
 type ClippyProperties struct {
-	// whether to run clippy.
-	Clippy *bool
+	// name of the lint set that should be used to validate this module.
+	//
+	// Possible values are "default" (for using a sensible set of lints
+	// depending on the module's location), "android" (for the strictest
+	// lint set that applies to all Android platform code), "vendor" (for a
+	// relaxed set) and "none" (to disable the execution of clippy).  The
+	// default value is "default". See also the `lints` property.
+	Clippy_lints *string
 }
 
 type clippy struct {
@@ -32,10 +38,10 @@ func (c *clippy) props() []interface{} {
 }
 
 func (c *clippy) flags(ctx ModuleContext, flags Flags, deps PathDeps) (Flags, PathDeps) {
-	if c.Properties.Clippy != nil && !*c.Properties.Clippy {
-		return flags, deps
+	enabled, lints, err := config.ClippyLintsForDir(ctx.ModuleDir(), c.Properties.Clippy_lints)
+	if err != nil {
+		ctx.PropertyErrorf("clippy_lints", err.Error())
 	}
-	enabled, lints := config.ClippyLintsForDir(ctx.ModuleDir())
 	flags.Clippy = enabled
 	flags.ClippyFlags = append(flags.ClippyFlags, lints)
 	return flags, deps