Dexpreopt soong modules inside soong

Port the dexpreopt logic from Make to the dexpreopt package in Soong,
and use it to dexpreopt Soong modules.  The same package is also
compiled into the dexpreopt_gen binary to generate dexpreopt scripts
for Make modules.

Bug: 119412419
Bug: 120273280
Test: no differences to dexpreopt outputs on aosp_sailfish system/,
      only expected changes to dexpreopt outputs on system_other
      (.vdex files for privileged Soong modules no longer incorrectly
      contain .dex contents).
Change-Id: Ib67e2febf9ed921f06e8a86b9ec945c80dff35eb

android/paths.go

@@ -659,11 +659,7 @@ func (p SourcePath) OverlayPath(ctx ModuleContext, path Path) OptionalPath {
 	if len(paths) == 0 {
 		return OptionalPath{}
 	}
-	relPath, err := filepath.Rel(p.config.srcDir, paths[0])
-	if err != nil {
-		reportPathError(ctx, err)
-		return OptionalPath{}
-	}
+	relPath := Rel(ctx, p.config.srcDir, paths[0])
 	return OptionalPathForPath(PathForSource(ctx, relPath))
 }
 
@@ -788,13 +784,7 @@ func (p ModuleSrcPath) resPathWithName(ctx ModuleContext, name string) ModuleRes
 
 func (p ModuleSrcPath) WithSubDir(ctx ModuleContext, subdir string) ModuleSrcPath {
 	subdir = PathForModuleSrc(ctx, subdir).String()
-	var err error
-	rel, err := filepath.Rel(subdir, p.path)
-	if err != nil {
-		ctx.ModuleErrorf("source file %q is not under path %q", p.path, subdir)
-		return p
-	}
-	p.rel = rel
+	p.rel = Rel(ctx, subdir, p.path)
 	return p
 }
 
@@ -932,27 +922,7 @@ func PathForModuleRes(ctx ModuleContext, pathComponents ...string) ModuleResPath
 func PathForModuleInstall(ctx ModuleInstallPathContext, pathComponents ...string) OutputPath {
 	var outPaths []string
 	if ctx.Device() {
-		var partition string
-		if ctx.InstallInData() {
-			partition = "data"
-		} else if ctx.InstallInRecovery() {
-			// the layout of recovery partion is the same as that of system partition
-			partition = "recovery/root/system"
-		} else if ctx.SocSpecific() {
-			partition = ctx.DeviceConfig().VendorPath()
-		} else if ctx.DeviceSpecific() {
-			partition = ctx.DeviceConfig().OdmPath()
-		} else if ctx.ProductSpecific() {
-			partition = ctx.DeviceConfig().ProductPath()
-		} else if ctx.ProductServicesSpecific() {
-			partition = ctx.DeviceConfig().ProductServicesPath()
-		} else {
-			partition = "system"
-		}
-
-		if ctx.InstallInSanitizerDir() {
-			partition = "data/asan/" + partition
-		}
+		partition := modulePartition(ctx)
 		outPaths = []string{"target", "product", ctx.Config().DeviceName(), partition}
 	} else {
 		switch ctx.Os() {
@@ -972,6 +942,36 @@ func PathForModuleInstall(ctx ModuleInstallPathContext, pathComponents ...string
 	return PathForOutput(ctx, outPaths...)
 }
 
+func InstallPathToOnDevicePath(ctx PathContext, path OutputPath) string {
+	rel := Rel(ctx, PathForOutput(ctx, "target", "product", ctx.Config().DeviceName()).String(), path.String())
+
+	return "/" + rel
+}
+
+func modulePartition(ctx ModuleInstallPathContext) string {
+	var partition string
+	if ctx.InstallInData() {
+		partition = "data"
+	} else if ctx.InstallInRecovery() {
+		// the layout of recovery partion is the same as that of system partition
+		partition = "recovery/root/system"
+	} else if ctx.SocSpecific() {
+		partition = ctx.DeviceConfig().VendorPath()
+	} else if ctx.DeviceSpecific() {
+		partition = ctx.DeviceConfig().OdmPath()
+	} else if ctx.ProductSpecific() {
+		partition = ctx.DeviceConfig().ProductPath()
+	} else if ctx.ProductServicesSpecific() {
+		partition = ctx.DeviceConfig().ProductServicesPath()
+	} else {
+		partition = "system"
+	}
+	if ctx.InstallInSanitizerDir() {
+		partition = "data/asan/" + partition
+	}
+	return partition
+}
+
 // validateSafePath validates a path that we trust (may contain ninja variables).
 // Ensures that each path component does not attempt to leave its component.
 func validateSafePath(pathComponents ...string) (string, error) {
@@ -1039,3 +1039,27 @@ func PathsForTesting(strs []string) Paths {
 
 	return p
 }
+
+// Rel performs the same function as filepath.Rel, but reports errors to a PathContext, and reports an error if
+// targetPath is not inside basePath.
+func Rel(ctx PathContext, basePath string, targetPath string) string {
+	rel, isRel := MaybeRel(ctx, basePath, targetPath)
+	if !isRel {
+		reportPathErrorf(ctx, "path %q is not under path %q", targetPath, basePath)
+		return ""
+	}
+	return rel
+}
+
+// MaybeRel performs the same function as filepath.Rel, but reports errors to a PathContext, and returns false if
+// targetPath is not inside basePath.
+func MaybeRel(ctx PathContext, basePath string, targetPath string) (string, bool) {
+	rel, err := filepath.Rel(basePath, targetPath)
+	if err != nil {
+		reportPathError(ctx, err)
+		return "", false
+	} else if rel == ".." || strings.HasPrefix(rel, "../") || strings.HasPrefix(rel, "/") {
+		return "", false
+	}
+	return rel, true
+}