all: add anonymous function support and fix build behavior (#10)

Author: katsusan

Makefile

@@ -5,7 +5,7 @@ all: clean
 	./$(NAME) -conf configs/config.yaml
 build:
 	docker build -t $(NAME):$(VERSION) -t $(NAME):latest -f docker/Dockerfile .
-up: down
+up:
 	docker-compose -f docker/deploy.yml up -d
 down:
 	docker-compose -f docker/deploy.yml down

public/main.js

@@ -30,7 +30,7 @@ function build() {
         console.log('no changes, do not submit')
         return
     }
-    if (!code.includes('func '+funcname)) {
+    if (!findSSAFunc(code, funcname)) {
         setMessageBox('GOFUNCNAME does not exist in your code.', false)
         return
     }
@@ -67,6 +67,25 @@ function build() {
     .catch(res => setMessageBox(res.data.msg, false));
 }
 
+const methodPattern = /^\([\w\*]+\)\.\w+$/
+const globPattern = /^glob\.\.func\d+(\.\d)*$/
+const anonyPattern = /^\w+\.func\d+(\.\d)*$/
+
+function findSSAFunc(code, funcname) {
+    if (funcname.indexOf('.') != -1) {
+        if (funcname[0] == '(') {
+            return methodPattern.test(funcname)
+        } else if (funcname.startsWith("glob")) {
+            return globPattern.test(funcname)
+        } else {
+            return anonyPattern.test(funcname)
+        }
+    }
+
+    let funcDclPattern = new RegExp(`func[ \\t]+${funcname}[ \\t]*\\(`)
+    return funcDclPattern.test(code)
+}
+
 function setMessageBox(msg, hide) {
     msgbox.innerText = msg
     if (hide) {

src/route/api.go

@@ -134,7 +134,50 @@ func BuildSSA(c *gin.Context) {
 	c.JSON(http.StatusOK, out)
 }
 
+/*
+According to spec there are two cases we need to handle:
+
+- Function declaration, in the form of 'func f() {...}' , see:
+	https://golang.org/ref/spec#Function_declarations
+
+- Function literal/anonymous function, in the form of
+ 'myfunc := func() {...}' or 'go func() {...}', see:
+	https://golang.org/ref/spec#Function_literals
+
+As users can use some tricks like raw string to bypass our check, we
+only do check conservatively, which means it is mainly used for
+preventing misspell and wrong format.
+
+All cases:
+// <i>,<j>,<k> means unique function index in the scope of outer function, see:
+https://github.com/golang/go/blob/84162b88324aa7993fe4a8580a2b65c6a7055f88/src/cmd/compile/internal/typecheck/func.go#L182
+
+- func foo()	// most common case
+- glob..func<i>	// global function literal
+	+ glob..func<i>.<j>.<k>...		// inner anonymous function
+- foo.func<i>	// anonymous function inside function 'foo'
+	+ foo.func<i>.<j>.<k>...
+- (*T).foo()	// method expression with explicit receiver, see
+https://golang.org/ref/spec#Method_expressions
+
+Note that non-ascii letters are unsupported, as our intention is to dig
+into go ssa IR.
+*/
 func findSSAFunc(code, funcname string) bool {
+	// The dot character is not allowed to appear in function name.
+	// See https://golang.org/ref/spec#Identifiers
+	if strings.IndexByte(funcname, '.') != -1 {
+		if funcname[0] == '(' {
+			methodReg := regexp.MustCompile(`^\([\w\*]+\)\.\w+$`)
+			return methodReg.MatchString(funcname)
+		} else if strings.HasPrefix(funcname, "glob") {
+			globReg := regexp.MustCompile(`^glob\.\.func\d+(\.\d)*$`)
+			return globReg.MatchString(funcname)
+		} else {
+			anonyReg := regexp.MustCompile(`^\w+\.func\d+(\.\d)*$`)
+			return anonyReg.MatchString(funcname)
+		}
+	}
 	// func Foo (
 	re := regexp.MustCompile(fmt.Sprintf(`func[ \t]+%s[ \t]*\(`, funcname))
 	return re.FindString(code) != ""
@@ -185,12 +228,23 @@ func initModules(path string) error {
 }
 
 func buildSSA(funcname, gcflags, outf, buildf string, isTest bool) error {
-	var cmd *exec.Cmd
+	var (
+		cmd      *exec.Cmd
+		buildDir string
+	)
+
+	// Restrict the ssa.html target to the target ssa build folder.
+	// See https://github.com/golang-design/ssaplayground/issues/9
+	buildDir = filepath.Dir(buildf)
+	outf = filepath.Base(outf)
+	buildf = filepath.Base(buildf)
+
 	if !isTest {
 		cmd = exec.Command("go", "build", "-mod=readonly", fmt.Sprintf(`-gcflags=%s`, gcflags), "-o", outf, buildf)
 	} else {
 		cmd = exec.Command("go", "test", "-mod=readonly", fmt.Sprintf(`-gcflags=%s`, gcflags), buildf)
 	}
+	cmd.Dir = buildDir
 	cmd.Env = append(os.Environ(), fmt.Sprintf("GOSSAFUNC=%s", funcname))
 	cmd.Stderr = &bytes.Buffer{}
 	err := cmd.Run()