Switch PackageContext functions to take a ctx

So that the Path and similar functions can be used directly, without
manually adding something like configErrorWrapper (it just uses it all
the time now).

Test: out/soong/build.ninja is identical
Change-Id: I8cb524b09a84d0b8357d7c3501c71270af411e17
diff --git a/cc/config/x86_darwin_host.go b/cc/config/x86_darwin_host.go
index dbaa6fa..cae9757 100644
--- a/cc/config/x86_darwin_host.go
+++ b/cc/config/x86_darwin_host.go
@@ -15,7 +15,6 @@
 package config
 
 import (
-	"fmt"
 	"os/exec"
 	"path/filepath"
 	"strings"
@@ -107,26 +106,28 @@
 )
 
 func init() {
-	pctx.VariableFunc("macSdkPath", func(config android.Config) (string, error) {
-		xcodeselect := config.HostSystemTool("xcode-select")
+	pctx.VariableFunc("macSdkPath", func(ctx android.PackageVarContext) string {
+		xcodeselect := ctx.Config().HostSystemTool("xcode-select")
 		bytes, err := exec.Command(xcodeselect, "--print-path").Output()
-		return strings.TrimSpace(string(bytes)), err
+		if err != nil {
+			ctx.Errorf("xcode-select failed with: %q", err.Error())
+		}
+		return strings.TrimSpace(string(bytes))
 	})
-	pctx.VariableFunc("macSdkRoot", func(config android.Config) (string, error) {
-		return xcrunSdk(config, "--show-sdk-path")
+	pctx.VariableFunc("macSdkRoot", func(ctx android.PackageVarContext) string {
+		return xcrunSdk(ctx, "--show-sdk-path")
 	})
 	pctx.StaticVariable("macMinVersion", "10.8")
-	pctx.VariableFunc("MacArPath", func(config android.Config) (string, error) {
-		return xcrun(config, "--find", "ar")
+	pctx.VariableFunc("MacArPath", func(ctx android.PackageVarContext) string {
+		return xcrun(ctx, "--find", "ar")
 	})
 
-	pctx.VariableFunc("MacStripPath", func(config android.Config) (string, error) {
-		return xcrun(config, "--find", "strip")
+	pctx.VariableFunc("MacStripPath", func(ctx android.PackageVarContext) string {
+		return xcrun(ctx, "--find", "strip")
 	})
 
-	pctx.VariableFunc("MacToolPath", func(config android.Config) (string, error) {
-		path, err := xcrun(config, "--find", "ld")
-		return filepath.Dir(path), err
+	pctx.VariableFunc("MacToolPath", func(ctx android.PackageVarContext) string {
+		return filepath.Dir(xcrun(ctx, "--find", "ld"))
 	})
 
 	pctx.StaticVariable("DarwinGccVersion", darwinGccVersion)
@@ -156,33 +157,38 @@
 	pctx.StaticVariable("DarwinX8664YasmFlags", "-f macho -m amd64")
 }
 
-func xcrun(config android.Config, args ...string) (string, error) {
-	xcrun := config.HostSystemTool("xcrun")
+func xcrun(ctx android.PackageVarContext, args ...string) string {
+	xcrun := ctx.Config().HostSystemTool("xcrun")
 	bytes, err := exec.Command(xcrun, args...).Output()
-	return strings.TrimSpace(string(bytes)), err
+	if err != nil {
+		ctx.Errorf("xcrun failed with: %q", err.Error())
+	}
+	return strings.TrimSpace(string(bytes))
 }
 
-func xcrunSdk(config android.Config, arg string) (string, error) {
-	xcrun := config.HostSystemTool("xcrun")
-	if selected := config.Getenv("MAC_SDK_VERSION"); selected != "" {
+func xcrunSdk(ctx android.PackageVarContext, arg string) string {
+	xcrun := ctx.Config().HostSystemTool("xcrun")
+	if selected := ctx.Config().Getenv("MAC_SDK_VERSION"); selected != "" {
 		if !inList(selected, darwinSupportedSdkVersions) {
-			return "", fmt.Errorf("MAC_SDK_VERSION %s isn't supported: %q", selected, darwinSupportedSdkVersions)
+			ctx.Errorf("MAC_SDK_VERSION %s isn't supported: %q", selected, darwinSupportedSdkVersions)
+			return ""
 		}
 
 		bytes, err := exec.Command(xcrun, "--sdk", "macosx"+selected, arg).Output()
-		if err == nil {
-			return strings.TrimSpace(string(bytes)), err
+		if err != nil {
+			ctx.Errorf("MAC_SDK_VERSION %s is not installed", selected)
 		}
-		return "", fmt.Errorf("MAC_SDK_VERSION %s is not installed", selected)
+		return strings.TrimSpace(string(bytes))
 	}
 
 	for _, sdk := range darwinSupportedSdkVersions {
 		bytes, err := exec.Command(xcrun, "--sdk", "macosx"+sdk, arg).Output()
 		if err == nil {
-			return strings.TrimSpace(string(bytes)), err
+			return strings.TrimSpace(string(bytes))
 		}
 	}
-	return "", fmt.Errorf("Could not find a supported mac sdk: %q", darwinSupportedSdkVersions)
+	ctx.Errorf("Could not find a supported mac sdk: %q", darwinSupportedSdkVersions)
+	return ""
 }
 
 type toolchainDarwin struct {