bug fix: parse embeds in files that contain the double quote rune (#3672)

* test: embed parsing break on double quote rune

rename fixture file

* fix: embed parsing now handles double quote rune

Author: andyscott

go/tools/builders/BUILD.bazel

@@ -9,6 +9,13 @@ go_test(
         "filter.go",
         "filter_test.go",
         "read.go",
+        "read_test.go",
+    ],
+    data = [
+        "read_test_fixture.go",
+    ],
+    deps = [
+        "//go/runfiles",
     ],
 )
 

go/tools/builders/read.go

@@ -198,6 +198,28 @@ func (r *importReader) findEmbed(first bool) bool {
 		case ' ', '\t':
 			// leave startLine alone
 
+		case '\'':
+			startLine = false
+			for r.err == nil {
+				if r.eof {
+					r.syntaxError()
+				}
+				c = r.readByteNoBuf()
+				if c == '\\' {
+					_ = r.readByteNoBuf()
+					if r.err != nil {
+						r.syntaxError()
+						return false
+					}
+					continue
+				}
+				if c == '\'' {
+					c = r.readByteNoBuf()
+					goto Reswitch
+				}
+			}
+			goto Reswitch
+
 		case '"':
 			startLine = false
 			for r.err == nil {
@@ -206,7 +228,7 @@ func (r *importReader) findEmbed(first bool) bool {
 				}
 				c = r.readByteNoBuf()
 				if c == '\\' {
-					r.readByteNoBuf()
+					_ = r.readByteNoBuf()
 					if r.err != nil {
 						r.syntaxError()
 						return false

go/tools/builders/read_test.go

@@ -0,0 +1,45 @@
+/* Copyright 2016 The Bazel Authors. 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 main
+
+import (
+	"go/build"
+	"testing"
+
+	"github.com/bazelbuild/rules_go/go/runfiles"
+)
+
+func TestReadFileInfoEmbeds(t *testing.T) {
+	rf, err := runfiles.New()
+	if err != nil {
+		t.Fatalf("Error creating runfiles: %v", err)
+	}
+
+	f, err := rf.Rlocation("io_bazel_rules_go/go/tools/builders/read_test_fixture.go")
+	if err != nil {
+		t.Fatalf("Unable to get test file: %v", err)
+	}
+
+	fileInfo, err := readFileInfo(build.Default, f)
+	if err != nil {
+		t.Fatalf("readFileInfo: %v", err)
+	}
+
+	numExpectedEmbeds := 2
+	if len(fileInfo.embeds) != numExpectedEmbeds {
+		t.Fatalf("did not find expected number of file embeds! found %d got %d", len(fileInfo.embeds), numExpectedEmbeds)
+	}
+}

go/tools/builders/read_test_fixture.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	_ "embed"
+)
+
+//go:embed before.sql
+var beforeDoubleQuoteRune string
+
+func doubleQuoteRune() {
+	rune := '"'
+}
+
+//go:embed after.sql
+var afterDoubleQuoteRune string