[dev.typeparams] test: add string quoting support to test/run.go

This CL copies go/build's splitQuoted function (used for parsing #cgo
directives within `import "C"` preambles) to parse test recipe
commands. In particular, this now allows writing "build" and "run"
tests that use -gcflags to pass multiple compiler flags.

Change-Id: I0d18a9c13a4ce24bbdfa1da8662c0498c93a6762
Reviewed-on: https://go-review.googlesource.com/c/go/+/327275
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>

1 files changed, 67 insertions, 1 deletions

diff --git a/test/run.go b/test/run.go
index ef1e9de150..ca6a0f5c29 100644
--- a/test/run.go
+++ b/test/run.go
@@ -573,7 +573,11 @@ func (t *test) run() {
 	singlefilepkgs := false
 	setpkgpaths := false
 	localImports := true
-	f := strings.Fields(action)
+	f, err := splitQuoted(action)
+	if err != nil {
+		t.err = fmt.Errorf("invalid test recipe: %v", err)
+		return
+	}
 	if len(f) > 0 {
 		action = f[0]
 		args = f[1:]
@@ -2116,3 +2120,65 @@ var excludedFiles = map[string]bool{
 	"fixedbugs/issue7921.go":  true,
 	"inline.go":               true,
 }
+
+// splitQuoted splits the string s around each instance of one or more consecutive
+// white space characters while taking into account quotes and escaping, and
+// returns an array of substrings of s or an empty list if s contains only white space.
+// Single quotes and double quotes are recognized to prevent splitting within the
+// quoted region, and are removed from the resulting substrings. If a quote in s
+// isn't closed err will be set and r will have the unclosed argument as the
+// last element. The backslash is used for escaping.
+//
+// For example, the following string:
+//
+//     a b:"c d" 'e''f'  "g\""
+//
+// Would be parsed as:
+//
+//     []string{"a", "b:c d", "ef", `g"`}
+//
+// [copied from src/go/build/build.go]
+func splitQuoted(s string) (r []string, err error) {
+	var args []string
+	arg := make([]rune, len(s))
+	escaped := false
+	quoted := false
+	quote := '\x00'
+	i := 0
+	for _, rune := range s {
+		switch {
+		case escaped:
+			escaped = false
+		case rune == '\\':
+			escaped = true
+			continue
+		case quote != '\x00':
+			if rune == quote {
+				quote = '\x00'
+				continue
+			}
+		case rune == '"' || rune == '\'':
+			quoted = true
+			quote = rune
+			continue
+		case unicode.IsSpace(rune):
+			if quoted || i > 0 {
+				quoted = false
+				args = append(args, string(arg[:i]))
+				i = 0
+			}
+			continue
+		}
+		arg[i] = rune
+		i++
+	}
+	if quoted || i > 0 {
+		args = append(args, string(arg[:i]))
+	}
+	if quote != 0 {
+		err = errors.New("unclosed quote")
+	} else if escaped {
+		err = errors.New("unfinished escaping")
+	}
+	return args, err
+}