diff --git a/android/Android.bp b/android/Android.bp
index 985ffa9..3c38148 100644
--- a/android/Android.bp
+++ b/android/Android.bp
@@ -113,6 +113,7 @@
         "androidmk_test.go",
         "apex_test.go",
         "arch_test.go",
+        "blueprint_e2e_test.go",
         "config_test.go",
         "configured_jars_test.go",
         "csuite_config_test.go",
diff --git a/android/blueprint_e2e_test.go b/android/blueprint_e2e_test.go
new file mode 100644
index 0000000..b274512
--- /dev/null
+++ b/android/blueprint_e2e_test.go
@@ -0,0 +1,105 @@
+// Copyright 2024 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package android
+
+import (
+	"testing"
+)
+
+var testCases []struct {
+	name          string
+	fs            MockFS
+	expectedError string
+} = []struct {
+	name          string
+	fs            MockFS
+	expectedError string
+}{
+	{
+		name: "Can't reference variable before assignment",
+		fs: map[string][]byte{
+			"Android.bp": []byte(`
+x = foo
+foo = "hello"
+`),
+		},
+		expectedError: "undefined variable foo",
+	},
+	{
+		name: "Can't append to variable before assigned to",
+		fs: map[string][]byte{
+			"Android.bp": []byte(`
+foo += "world"
+foo = "hello"
+`),
+		},
+		expectedError: "modified non-existent variable \"foo\" with \\+=",
+	},
+	{
+		name: "Can't reassign variable",
+		fs: map[string][]byte{
+			"Android.bp": []byte(`
+foo = "hello"
+foo = "world"
+`),
+		},
+		expectedError: "variable already set, previous assignment:",
+	},
+	{
+		name: "Can't reassign variable in inherited scope",
+		fs: map[string][]byte{
+			"Android.bp": []byte(`
+foo = "hello"
+`),
+			"foo/Android.bp": []byte(`
+foo = "world"
+`),
+		},
+		expectedError: "variable already set in inherited scope, previous assignment:",
+	},
+	{
+		name: "Can't modify variable in inherited scope",
+		fs: map[string][]byte{
+			"Android.bp": []byte(`
+foo = "hello"
+`),
+			"foo/Android.bp": []byte(`
+foo += "world"
+`),
+		},
+		expectedError: "modified non-local variable \"foo\" with \\+=",
+	},
+	{
+		name: "Can't modify variable after referencing",
+		fs: map[string][]byte{
+			"Android.bp": []byte(`
+foo = "hello"
+x = foo
+foo += "world"
+`),
+		},
+		expectedError: "modified variable \"foo\" with \\+= after referencing",
+	},
+}
+
+func TestBlueprintErrors(t *testing.T) {
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			fixtures := FixtureMergeMockFs(tc.fs)
+			fixtures = fixtures.ExtendWithErrorHandler(FixtureExpectsOneErrorPattern(tc.expectedError))
+			fixtures.RunTest(t)
+		})
+	}
+}
diff --git a/android/selects_test.go b/android/selects_test.go
index e2dc403..bfaabd1 100644
--- a/android/selects_test.go
+++ b/android/selects_test.go
@@ -98,6 +98,26 @@
 			},
 		},
 		{
+			name: "Expression in select",
+			bp: `
+			my_module_type {
+				name: "foo",
+				my_string: select(soong_config_variable("my_namespace", "my_variable"), {
+					"a": "foo" + "bar",
+					default: "baz",
+				}),
+			}
+			`,
+			provider: selectsTestProvider{
+				my_string: proptools.StringPtr("foobar"),
+			},
+			vendorVars: map[string]map[string]string{
+				"my_namespace": {
+					"my_variable": "a",
+				},
+			},
+		},
+		{
 			name: "paths with module references",
 			bp: `
 			my_module_type {
@@ -112,20 +132,6 @@
 			expectedError: `"foo" depends on undefined module "c"`,
 		},
 		{
-			name: "Differing types",
-			bp: `
-			my_module_type {
-				name: "foo",
-				my_string: select(soong_config_variable("my_namespace", "my_variable"), {
-					"a": "a.cpp",
-					"b": true,
-					default: "c.cpp",
-				}),
-			}
-			`,
-			expectedError: `Android.bp:8:5: Found select statement with differing types "string" and "bool" in its cases`,
-		},
-		{
 			name: "Select type doesn't match property type",
 			bp: `
 			my_module_type {
@@ -137,7 +143,7 @@
 				}),
 			}
 			`,
-			expectedError: `can't assign bool value to string property "my_string\[0\]"`,
+			expectedError: `can't assign bool value to string property`,
 		},
 		{
 			name: "String list non-default",
@@ -825,6 +831,24 @@
 				my_string_list: &[]string{"a.cpp", "c.cpp", "foo.cpp"},
 			},
 		},
+		{
+			name: "Arch variant bool",
+			bp: `
+			my_variable = ["b.cpp"]
+			my_module_type {
+				name: "foo",
+				arch_variant_configurable_bool: false,
+				target: {
+					bionic_arm64: {
+						enabled: true,
+					},
+				},
+			}
+			`,
+			provider: selectsTestProvider{
+				arch_variant_configurable_bool: proptools.BoolPtr(false),
+			},
+		},
 	}
 
 	for _, tc := range testCases {
@@ -873,6 +897,7 @@
 	my_string_list                 *[]string
 	my_paths                       *[]string
 	replacing_string_list          *[]string
+	arch_variant_configurable_bool *bool
 	my_nonconfigurable_bool        *bool
 	my_nonconfigurable_string      *string
 	my_nonconfigurable_string_list []string
@@ -897,6 +922,7 @@
     my_string_list: %s,
     my_paths: %s,
 	replacing_string_list %s,
+	arch_variant_configurable_bool %v
 	my_nonconfigurable_bool: %v,
 	my_nonconfigurable_string: %s,
 	my_nonconfigurable_string_list: %s,
@@ -906,6 +932,7 @@
 		p.my_string_list,
 		p.my_paths,
 		p.replacing_string_list,
+		p.arch_variant_configurable_bool,
 		p.my_nonconfigurable_bool,
 		myNonconfigurableStringStr,
 		p.my_nonconfigurable_string_list,
@@ -920,6 +947,7 @@
 	My_string_list                 proptools.Configurable[[]string]
 	My_paths                       proptools.Configurable[[]string] `android:"path"`
 	Replacing_string_list          proptools.Configurable[[]string] `android:"replace_instead_of_append,arch_variant"`
+	Arch_variant_configurable_bool proptools.Configurable[bool]     `android:"replace_instead_of_append,arch_variant"`
 	My_nonconfigurable_bool        *bool
 	My_nonconfigurable_string      *string
 	My_nonconfigurable_string_list []string
@@ -950,6 +978,7 @@
 		my_string_list:                 optionalToPtr(p.properties.My_string_list.Get(ctx)),
 		my_paths:                       optionalToPtr(p.properties.My_paths.Get(ctx)),
 		replacing_string_list:          optionalToPtr(p.properties.Replacing_string_list.Get(ctx)),
+		arch_variant_configurable_bool: optionalToPtr(p.properties.Arch_variant_configurable_bool.Get(ctx)),
 		my_nonconfigurable_bool:        p.properties.My_nonconfigurable_bool,
 		my_nonconfigurable_string:      p.properties.My_nonconfigurable_string,
 		my_nonconfigurable_string_list: p.properties.My_nonconfigurable_string_list,
diff --git a/androidmk/androidmk/android.go b/androidmk/androidmk/android.go
index 8a8bb2e..570f36c 100644
--- a/androidmk/androidmk/android.go
+++ b/androidmk/androidmk/android.go
@@ -341,9 +341,6 @@
 
 		firstOperand := v.Args[0]
 		secondOperand := v.Args[1]
-		if firstOperand.Type() != bpparser.StringType {
-			return "global", value, nil
-		}
 
 		if _, ok := firstOperand.(*bpparser.Operator); ok {
 			return "global", value, nil
diff --git a/androidmk/androidmk/androidmk.go b/androidmk/androidmk/androidmk.go
index 2e8810f..6fb20dc 100644
--- a/androidmk/androidmk/androidmk.go
+++ b/androidmk/androidmk/androidmk.go
@@ -493,7 +493,6 @@
 				Name:      name,
 				NamePos:   pos,
 				Value:     value,
-				OrigValue: value,
 				EqualsPos: pos,
 				Assigner:  "+=",
 			}
@@ -506,7 +505,6 @@
 				Name:      name,
 				NamePos:   pos,
 				Value:     value,
-				OrigValue: value,
 				EqualsPos: pos,
 				Assigner:  "=",
 			}
diff --git a/androidmk/androidmk/values.go b/androidmk/androidmk/values.go
index 9618142..701c708 100644
--- a/androidmk/androidmk/values.go
+++ b/androidmk/androidmk/values.go
@@ -81,7 +81,7 @@
 			}
 			tmp := &bpparser.Variable{
 				Name:  name,
-				Value: &bpparser.String{},
+				Type_: bpparser.StringType,
 			}
 
 			if tmp.Name == "TOP" {
@@ -150,7 +150,7 @@
 					}
 					listOfListValues = append(listOfListValues, &bpparser.Variable{
 						Name:  name,
-						Value: &bpparser.List{},
+						Type_: bpparser.ListType,
 					})
 					listValue = &bpparser.List{}
 				}
@@ -215,7 +215,7 @@
 			}
 			return &bpparser.Variable{
 				Name:  name,
-				Value: &bpparser.Bool{},
+				Type_: bpparser.BoolType,
 			}, nil
 		} else {
 			return nil, fmt.Errorf("non-const bool expression %s", ms.Dump())
diff --git a/bpfix/bpfix/bpfix.go b/bpfix/bpfix/bpfix.go
index ddaa98a..9163ab7 100644
--- a/bpfix/bpfix/bpfix.go
+++ b/bpfix/bpfix/bpfix.go
@@ -286,7 +286,7 @@
 }
 
 func parse(name string, r io.Reader) (*parser.File, error) {
-	tree, errs := parser.Parse(name, r, parser.NewScope(nil))
+	tree, errs := parser.Parse(name, r)
 	if errs != nil {
 		s := "parse error: "
 		for _, err := range errs {
diff --git a/bpfix/bpfix/bpfix_test.go b/bpfix/bpfix/bpfix_test.go
index b5b49b1..f487d3c 100644
--- a/bpfix/bpfix/bpfix_test.go
+++ b/bpfix/bpfix/bpfix_test.go
@@ -46,7 +46,7 @@
 	}
 	`,
 		printListOfStrings(local_include_dirs), printListOfStrings(export_include_dirs))
-	tree, errs := parser.Parse("", strings.NewReader(input), parser.NewScope(nil))
+	tree, errs := parser.Parse("", strings.NewReader(input))
 	if len(errs) > 0 {
 		errs = append([]error{fmt.Errorf("failed to parse:\n%s", input)}, errs...)
 	}
@@ -167,7 +167,7 @@
 		return fixer, err
 	}
 
-	tree, errs := parser.Parse("<testcase>", bytes.NewBufferString(in), parser.NewScope(nil))
+	tree, errs := parser.Parse("<testcase>", bytes.NewBufferString(in))
 	if errs != nil {
 		return fixer, err
 	}
diff --git a/bpfix/cmd_lib/bpfix.go b/bpfix/cmd_lib/bpfix.go
index 1106d4a..41430f8 100644
--- a/bpfix/cmd_lib/bpfix.go
+++ b/bpfix/cmd_lib/bpfix.go
@@ -66,7 +66,7 @@
 		return err
 	}
 	r := bytes.NewBuffer(append([]byte(nil), src...))
-	file, errs := parser.Parse(filename, r, parser.NewScope(nil))
+	file, errs := parser.Parse(filename, r)
 	if len(errs) > 0 {
 		for _, err := range errs {
 			fmt.Fprintln(os.Stderr, err)