Use WalkDeps instead of VisitDepsDepthFirst

VisitDepsDepthFirst is almost never correct, as it can't query
dependency tags of multiple dependencies between the same two modules.
Replace VisitDepsDepthFirst with WalkDeps in sanitize.go and
python.go.  Also verify the dependency tag before continuing to
recurse to ensure that they don't recurse through genrules and into
unrelated modules.

Test: m checkbuild
Change-Id: I2f7560126f56b51a40ec39dfbdcc18b5891489f7

5 files changed, 54 insertions, 29 deletions

diff --git a/android/module.go b/android/module.go
index 3316a444..b6220dc3 100644
--- a/android/module.go
+++ b/android/module.go
@@ -144,7 +144,9 @@ type ModuleContext interface {
 	VisitDirectDeps(visit func(Module))
 	VisitDirectDepsWithTag(tag blueprint.DependencyTag, visit func(Module))
 	VisitDirectDepsIf(pred func(Module) bool, visit func(Module))
+	// Deprecated: use WalkDeps instead to support multiple dependency tags on the same module
 	VisitDepsDepthFirst(visit func(Module))
+	// Deprecated: use WalkDeps instead to support multiple dependency tags on the same module
 	VisitDepsDepthFirstIf(pred func(Module) bool, visit func(Module))
 	WalkDeps(visit func(Module, Module) bool)
 
@@ -539,6 +541,7 @@ func (a *ModuleBase) computeInstallDeps(
 	ctx blueprint.ModuleContext) Paths {
 
 	result := Paths{}
+	// TODO(ccross): we need to use WalkDeps and have some way to know which dependencies require installation
 	ctx.VisitDepsDepthFirstIf(isFileInstaller,
 		func(m blueprint.Module) {
 			fileInstaller := m.(fileInstaller)
diff --git a/android/singleton.go b/android/singleton.go
index f577b0a3..fa1efdc0 100644
--- a/android/singleton.go
+++ b/android/singleton.go
@@ -50,7 +50,9 @@ type SingletonContext interface {
 
 	VisitAllModules(visit func(Module))
 	VisitAllModulesIf(pred func(Module) bool, visit func(Module))
+	// Deprecated: use WalkDeps instead to support multiple dependency tags on the same module
 	VisitDepsDepthFirst(module Module, visit func(Module))
+	// Deprecated: use WalkDeps instead to support multiple dependency tags on the same module
 	VisitDepsDepthFirstIf(module Module, pred func(Module) bool,
 		visit func(Module))
 
diff --git a/cc/cc.go b/cc/cc.go
index b7183d7a..592f373a 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -52,7 +52,7 @@ func init() {
 		ctx.TopDown("tsan_deps", sanitizerDepsMutator(tsan))
 		ctx.BottomUp("tsan", sanitizerMutator(tsan)).Parallel()
 
-		ctx.TopDown("sanitize_runtime_deps", sanitizerRuntimeDepsMutator())
+		ctx.TopDown("sanitize_runtime_deps", sanitizerRuntimeDepsMutator)
 
 		ctx.BottomUp("coverage", coverageLinkingMutator).Parallel()
 		ctx.TopDown("vndk_deps", sabiDepsMutator)
diff --git a/cc/sanitize.go b/cc/sanitize.go
index 38f4fc28..080ac094 100644
--- a/cc/sanitize.go
+++ b/cc/sanitize.go
@@ -21,6 +21,8 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/google/blueprint"
+
 	"android/soong/android"
 	"android/soong/cc/config"
 )
@@ -610,43 +612,54 @@ func (sanitize *sanitize) isSanitizerEnabled(t sanitizerType) bool {
 	return sanitizerVal != nil && *sanitizerVal == true
 }
 
+func isSanitizableDependencyTag(tag blueprint.DependencyTag) bool {
+	t, ok := tag.(dependencyTag)
+	return ok && t.library || t == reuseObjTag
+}
+
 // Propagate asan requirements down from binaries
 func sanitizerDepsMutator(t sanitizerType) func(android.TopDownMutatorContext) {
 	return func(mctx android.TopDownMutatorContext) {
 		if c, ok := mctx.Module().(*Module); ok && c.sanitize.isSanitizerEnabled(t) {
-			mctx.VisitDepsDepthFirst(func(module android.Module) {
-				if d, ok := module.(*Module); ok && d.sanitize != nil &&
+			mctx.WalkDeps(func(child, parent android.Module) bool {
+				if !isSanitizableDependencyTag(mctx.OtherModuleDependencyTag(child)) {
+					return false
+				}
+				if d, ok := child.(*Module); ok && d.sanitize != nil &&
 					!Bool(d.sanitize.Properties.Sanitize.Never) &&
 					!d.sanitize.isSanitizerExplicitlyDisabled(t) {
 					if (t == cfi && d.static()) || t != cfi {
 						d.sanitize.Properties.SanitizeDep = true
 					}
 				}
+				return true
 			})
 		}
 	}
 }
 
 // Propagate the ubsan minimal runtime dependency when there are integer overflow sanitized static dependencies.
-func sanitizerRuntimeDepsMutator() func(android.TopDownMutatorContext) {
-	return func(mctx android.TopDownMutatorContext) {
-		if c, ok := mctx.Module().(*Module); ok && c.sanitize != nil {
-			mctx.VisitDepsDepthFirst(func(module android.Module) {
-				if d, ok := module.(*Module); ok && d.static() && d.sanitize != nil {
-
-					if enableMinimalRuntime(d.sanitize) {
-						// If a static dependency is built with the minimal runtime,
-						// make sure we include the ubsan minimal runtime.
-						c.sanitize.Properties.MinimalRuntimeDep = true
-					} else if Bool(d.sanitize.Properties.Sanitize.Diag.Integer_overflow) ||
-						len(d.sanitize.Properties.Sanitize.Diag.Misc_undefined) > 0 {
-						// If a static dependency runs with full ubsan diagnostics,
-						// make sure we include the ubsan runtime.
-						c.sanitize.Properties.UbsanRuntimeDep = true
-					}
+func sanitizerRuntimeDepsMutator(mctx android.TopDownMutatorContext) {
+	if c, ok := mctx.Module().(*Module); ok && c.sanitize != nil {
+		mctx.WalkDeps(func(child, parent android.Module) bool {
+			if !isSanitizableDependencyTag(mctx.OtherModuleDependencyTag(child)) {
+				return false
+			}
+			if d, ok := child.(*Module); ok && d.static() && d.sanitize != nil {
+
+				if enableMinimalRuntime(d.sanitize) {
+					// If a static dependency is built with the minimal runtime,
+					// make sure we include the ubsan minimal runtime.
+					c.sanitize.Properties.MinimalRuntimeDep = true
+				} else if Bool(d.sanitize.Properties.Sanitize.Diag.Integer_overflow) ||
+					len(d.sanitize.Properties.Sanitize.Diag.Misc_undefined) > 0 {
+					// If a static dependency runs with full ubsan diagnostics,
+					// make sure we include the ubsan runtime.
+					c.sanitize.Properties.UbsanRuntimeDep = true
 				}
-			})
-		}
+			}
+			return true
+		})
 	}
 }
 
diff --git a/python/python.go b/python/python.go
index 4b9111f3..feb17da0 100644
--- a/python/python.go
+++ b/python/python.go
@@ -574,32 +574,39 @@ func (p *Module) walkTransitiveDeps(ctx android.ModuleContext) {
 		destToPyData[path.dest] = path.src.String()
 	}
 
+	seen := make(map[android.Module]bool)
+
 	// visit all its dependencies in depth first.
-	ctx.VisitDepsDepthFirst(func(module android.Module) {
-		if ctx.OtherModuleDependencyTag(module) != pythonLibTag {
-			return
+	ctx.WalkDeps(func(child, parent android.Module) bool {
+		if ctx.OtherModuleDependencyTag(child) != pythonLibTag {
+			return false
 		}
+		if seen[child] {
+			return false
+		}
+		seen[child] = true
 		// Python modules only can depend on Python libraries.
-		if !isPythonLibModule(module) {
+		if !isPythonLibModule(child) {
 			panic(fmt.Errorf(
 				"the dependency %q of module %q is not Python library!",
-				ctx.ModuleName(), ctx.OtherModuleName(module)))
+				ctx.ModuleName(), ctx.OtherModuleName(child)))
 		}
-		if dep, ok := module.(PythonDependency); ok {
+		if dep, ok := child.(PythonDependency); ok {
 			srcs := dep.GetSrcsPathMappings()
 			for _, path := range srcs {
 				if !fillInMap(ctx, destToPySrcs,
-					path.dest, path.src.String(), ctx.ModuleName(), ctx.OtherModuleName(module)) {
+					path.dest, path.src.String(), ctx.ModuleName(), ctx.OtherModuleName(child)) {
 					continue
 				}
 			}
 			data := dep.GetDataPathMappings()
 			for _, path := range data {
 				fillInMap(ctx, destToPyData,
-					path.dest, path.src.String(), ctx.ModuleName(), ctx.OtherModuleName(module))
+					path.dest, path.src.String(), ctx.ModuleName(), ctx.OtherModuleName(child))
 			}
 			p.depsSrcsZips = append(p.depsSrcsZips, dep.GetSrcsZip())
 		}
+		return true
 	})
 }