Golang程序
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12.18 KB
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package syntax
import (
"bytes"
"fmt"
"os"
"strings"
"testing"
)
func TestScanner(t *testing.T) {
if testing.Short() {
t.Skip("skipping test in short mode")
}
src, err := os.Open("parser.go")
if err != nil {
t.Fatal(err)
}
defer src.Close()
var s scanner
s.init(src, nil, 0)
for {
s.next()
if s.tok == _EOF {
break
}
switch s.tok {
case _Name:
fmt.Println(s.line, s.tok, "=>", s.lit)
case _Operator:
fmt.Println(s.line, s.tok, "=>", s.op, s.prec)
default:
fmt.Println(s.line, s.tok)
}
}
}
func TestTokens(t *testing.T) {
// make source
var buf bytes.Buffer
for i, s := range sampleTokens {
buf.WriteString("\t\t\t\t"[:i&3]) // leading indentation
buf.WriteString(s.src) // token
buf.WriteString(" "[:i&7]) // trailing spaces
buf.WriteString("/*line foo:1 */ // bar\n") // comments (don't crash w/o directive handler)
}
// scan source
var got scanner
got.init(&buf, nil, 0)
got.next()
for i, want := range sampleTokens {
nlsemi := false
if got.line != uint(i+linebase) {
t.Errorf("got line %d; want %d", got.line, i+linebase)
}
if got.tok != want.tok {
t.Errorf("got tok = %s; want %s", got.tok, want.tok)
continue
}
switch want.tok {
case _Semi:
if got.lit != "semicolon" {
t.Errorf("got %s; want semicolon", got.lit)
}
case _Name, _Literal:
if got.lit != want.src {
t.Errorf("got lit = %q; want %q", got.lit, want.src)
continue
}
nlsemi = true
case _Operator, _AssignOp, _IncOp:
if got.op != want.op {
t.Errorf("got op = %s; want %s", got.op, want.op)
continue
}
if got.prec != want.prec {
t.Errorf("got prec = %d; want %d", got.prec, want.prec)
continue
}
nlsemi = want.tok == _IncOp
case _Rparen, _Rbrack, _Rbrace, _Break, _Continue, _Fallthrough, _Return:
nlsemi = true
}
if nlsemi {
got.next()
if got.tok != _Semi {
t.Errorf("got tok = %s; want ;", got.tok)
continue
}
if got.lit != "newline" {
t.Errorf("got %s; want newline", got.lit)
}
}
got.next()
}
if got.tok != _EOF {
t.Errorf("got %q; want _EOF", got.tok)
}
}
var sampleTokens = [...]struct {
tok token
src string
op Operator
prec int
}{
// name samples
{_Name, "x", 0, 0},
{_Name, "X123", 0, 0},
{_Name, "foo", 0, 0},
{_Name, "Foo123", 0, 0},
{_Name, "foo_bar", 0, 0},
{_Name, "_", 0, 0},
{_Name, "_foobar", 0, 0},
{_Name, "a۰۱۸", 0, 0},
{_Name, "foo६४", 0, 0},
{_Name, "bar９８７６", 0, 0},
{_Name, "ŝ", 0, 0},
{_Name, "ŝfoo", 0, 0},
// literal samples
{_Literal, "0", 0, 0},
{_Literal, "1", 0, 0},
{_Literal, "12345", 0, 0},
{_Literal, "123456789012345678890123456789012345678890", 0, 0},
{_Literal, "01234567", 0, 0},
{_Literal, "0x0", 0, 0},
{_Literal, "0xcafebabe", 0, 0},
{_Literal, "0.", 0, 0},
{_Literal, "0.e0", 0, 0},
{_Literal, "0.e-1", 0, 0},
{_Literal, "0.e+123", 0, 0},
{_Literal, ".0", 0, 0},
{_Literal, ".0E00", 0, 0},
{_Literal, ".0E-0123", 0, 0},
{_Literal, ".0E+12345678901234567890", 0, 0},
{_Literal, ".45e1", 0, 0},
{_Literal, "3.14159265", 0, 0},
{_Literal, "1e0", 0, 0},
{_Literal, "1e+100", 0, 0},
{_Literal, "1e-100", 0, 0},
{_Literal, "2.71828e-1000", 0, 0},
{_Literal, "0i", 0, 0},
{_Literal, "1i", 0, 0},
{_Literal, "012345678901234567889i", 0, 0},
{_Literal, "123456789012345678890i", 0, 0},
{_Literal, "0.i", 0, 0},
{_Literal, ".0i", 0, 0},
{_Literal, "3.14159265i", 0, 0},
{_Literal, "1e0i", 0, 0},
{_Literal, "1e+100i", 0, 0},
{_Literal, "1e-100i", 0, 0},
{_Literal, "2.71828e-1000i", 0, 0},
{_Literal, "'a'", 0, 0},
{_Literal, "'\\000'", 0, 0},
{_Literal, "'\\xFF'", 0, 0},
{_Literal, "'\\uff16'", 0, 0},
{_Literal, "'\\U0000ff16'", 0, 0},
{_Literal, "`foobar`", 0, 0},
{_Literal, "`foo\tbar`", 0, 0},
{_Literal, "`\r`", 0, 0},
// operators
{_Operator, "||", OrOr, precOrOr},
{_Operator, "&&", AndAnd, precAndAnd},
{_Operator, "==", Eql, precCmp},
{_Operator, "!=", Neq, precCmp},
{_Operator, "<", Lss, precCmp},
{_Operator, "<=", Leq, precCmp},
{_Operator, ">", Gtr, precCmp},
{_Operator, ">=", Geq, precCmp},
{_Operator, "+", Add, precAdd},
{_Operator, "-", Sub, precAdd},
{_Operator, "|", Or, precAdd},
{_Operator, "^", Xor, precAdd},
{_Star, "*", Mul, precMul},
{_Operator, "/", Div, precMul},
{_Operator, "%", Rem, precMul},
{_Operator, "&", And, precMul},
{_Operator, "&^", AndNot, precMul},
{_Operator, "<<", Shl, precMul},
{_Operator, ">>", Shr, precMul},
// assignment operations
{_AssignOp, "+=", Add, precAdd},
{_AssignOp, "-=", Sub, precAdd},
{_AssignOp, "|=", Or, precAdd},
{_AssignOp, "^=", Xor, precAdd},
{_AssignOp, "*=", Mul, precMul},
{_AssignOp, "/=", Div, precMul},
{_AssignOp, "%=", Rem, precMul},
{_AssignOp, "&=", And, precMul},
{_AssignOp, "&^=", AndNot, precMul},
{_AssignOp, "<<=", Shl, precMul},
{_AssignOp, ">>=", Shr, precMul},
// other operations
{_IncOp, "++", Add, precAdd},
{_IncOp, "--", Sub, precAdd},
{_Assign, "=", 0, 0},
{_Define, ":=", 0, 0},
{_Arrow, "<-", 0, 0},
// delimiters
{_Lparen, "(", 0, 0},
{_Lbrack, "[", 0, 0},
{_Lbrace, "{", 0, 0},
{_Rparen, ")", 0, 0},
{_Rbrack, "]", 0, 0},
{_Rbrace, "}", 0, 0},
{_Comma, ",", 0, 0},
{_Semi, ";", 0, 0},
{_Colon, ":", 0, 0},
{_Dot, ".", 0, 0},
{_DotDotDot, "...", 0, 0},
// keywords
{_Break, "break", 0, 0},
{_Case, "case", 0, 0},
{_Chan, "chan", 0, 0},
{_Const, "const", 0, 0},
{_Continue, "continue", 0, 0},
{_Default, "default", 0, 0},
{_Defer, "defer", 0, 0},
{_Else, "else", 0, 0},
{_Fallthrough, "fallthrough", 0, 0},
{_For, "for", 0, 0},
{_Func, "func", 0, 0},
{_Go, "go", 0, 0},
{_Goto, "goto", 0, 0},
{_If, "if", 0, 0},
{_Import, "import", 0, 0},
{_Interface, "interface", 0, 0},
{_Map, "map", 0, 0},
{_Package, "package", 0, 0},
{_Range, "range", 0, 0},
{_Return, "return", 0, 0},
{_Select, "select", 0, 0},
{_Struct, "struct", 0, 0},
{_Switch, "switch", 0, 0},
{_Type, "type", 0, 0},
{_Var, "var", 0, 0},
}
func TestComments(t *testing.T) {
type comment struct {
line, col uint // 0-based
text string
}
for _, test := range []struct {
src string
want comment
}{
// no comments
{"no comment here", comment{0, 0, ""}},
{" /", comment{0, 0, ""}},
{"\n /*/", comment{0, 0, ""}},
//-style comments
{"// line comment\n", comment{0, 0, "// line comment"}},
{"package p // line comment\n", comment{0, 10, "// line comment"}},
{"//\n//\n\t// want this one\r\n", comment{2, 1, "// want this one\r"}},
{"\n\n//\n", comment{2, 0, "//"}},
{"//", comment{0, 0, "//"}},
/*-style comments */
{"/* regular comment */", comment{0, 0, "/* regular comment */"}},
{"package p /* regular comment", comment{0, 0, ""}},
{"\n\n\n/*\n*//* want this one */", comment{4, 2, "/* want this one */"}},
{"\n\n/**/", comment{2, 0, "/**/"}},
{"/*", comment{0, 0, ""}},
} {
var s scanner
var got comment
s.init(strings.NewReader(test.src),
func(line, col uint, msg string) {
if msg[0] != '/' {
// error
if msg != "comment not terminated" {
t.Errorf("%q: %s", test.src, msg)
}
return
}
got = comment{line - linebase, col - colbase, msg} // keep last one
}, comments)
for {
s.next()
if s.tok == _EOF {
break
}
}
want := test.want
if got.line != want.line || got.col != want.col {
t.Errorf("%q: got position %d:%d; want %d:%d", test.src, got.line, got.col, want.line, want.col)
}
if got.text != want.text {
t.Errorf("%q: got %q; want %q", test.src, got.text, want.text)
}
}
}
func TestScanErrors(t *testing.T) {
for _, test := range []struct {
src, msg string
line, col uint // 0-based
}{
// Note: Positions for lexical errors are the earliest position
// where the error is apparent, not the beginning of the respective
// token.
// rune-level errors
{"fo\x00o", "invalid NUL character", 0, 2},
{"foo\n\ufeff bar", "invalid BOM in the middle of the file", 1, 0},
{"foo\n\n\xff ", "invalid UTF-8 encoding", 2, 0},
// token-level errors
{"\u00BD" /* ½ */, "invalid identifier character U+00BD '½'", 0, 0},
{"\U0001d736\U0001d737\U0001d738_½" /* 𝜶𝜷𝜸_½ */, "invalid identifier character U+00BD '½'", 0, 13 /* byte offset */},
{"\U0001d7d8" /* 𝟘 */, "identifier cannot begin with digit U+1D7D8 '𝟘'", 0, 0},
{"foo\U0001d7d8_½" /* foo𝟘_½ */, "invalid identifier character U+00BD '½'", 0, 8 /* byte offset */},
{"x + ~y", "invalid character U+007E '~'", 0, 4},
{"foo$bar = 0", "invalid character U+0024 '$'", 0, 3},
{"const x = 0xyz", "malformed hex constant", 0, 12},
{"0123456789", "malformed octal constant", 0, 10},
{"0123456789. /* foobar", "comment not terminated", 0, 12}, // valid float constant
{"0123456789e0 /*\nfoobar", "comment not terminated", 0, 13}, // valid float constant
{"var a, b = 08, 07\n", "malformed octal constant", 0, 13},
{"(x + 1.0e+x)", "malformed floating-point constant exponent", 0, 10},
{`''`, "empty character literal or unescaped ' in character literal", 0, 1},
{"'\n", "newline in character literal", 0, 1},
{`'\`, "invalid character literal (missing closing ')", 0, 0},
{`'\'`, "invalid character literal (missing closing ')", 0, 0},
{`'\x`, "invalid character literal (missing closing ')", 0, 0},
{`'\x'`, "non-hex character in escape sequence: '", 0, 3},
{`'\y'`, "unknown escape sequence", 0, 2},
{`'\x0'`, "non-hex character in escape sequence: '", 0, 4},
{`'\00'`, "non-octal character in escape sequence: '", 0, 4},
{`'\377' /*`, "comment not terminated", 0, 7}, // valid octal escape
{`'\378`, "non-octal character in escape sequence: 8", 0, 4},
{`'\400'`, "octal escape value > 255: 256", 0, 5},
{`'xx`, "invalid character literal (missing closing ')", 0, 0},
{`'xx'`, "invalid character literal (more than one character)", 0, 0},
{"\"\n", "newline in string", 0, 1},
{`"`, "string not terminated", 0, 0},
{`"foo`, "string not terminated", 0, 0},
{"`", "string not terminated", 0, 0},
{"`foo", "string not terminated", 0, 0},
{"/*/", "comment not terminated", 0, 0},
{"/*\n\nfoo", "comment not terminated", 0, 0},
{`"\`, "string not terminated", 0, 0},
{`"\"`, "string not terminated", 0, 0},
{`"\x`, "string not terminated", 0, 0},
{`"\x"`, "non-hex character in escape sequence: \"", 0, 3},
{`"\y"`, "unknown escape sequence", 0, 2},
{`"\x0"`, "non-hex character in escape sequence: \"", 0, 4},
{`"\00"`, "non-octal character in escape sequence: \"", 0, 4},
{`"\377" /*`, "comment not terminated", 0, 7}, // valid octal escape
{`"\378"`, "non-octal character in escape sequence: 8", 0, 4},
{`"\400"`, "octal escape value > 255: 256", 0, 5},
{`s := "foo\z"`, "unknown escape sequence", 0, 10},
{`s := "foo\z00\nbar"`, "unknown escape sequence", 0, 10},
{`"\x`, "string not terminated", 0, 0},
{`"\x"`, "non-hex character in escape sequence: \"", 0, 3},
{`var s string = "\x"`, "non-hex character in escape sequence: \"", 0, 18},
{`return "\Uffffffff"`, "escape sequence is invalid Unicode code point", 0, 18},
// former problem cases
{"package p\n\n\xef", "invalid UTF-8 encoding", 2, 0},
} {
var s scanner
nerrors := 0
s.init(strings.NewReader(test.src), func(line, col uint, msg string) {
nerrors++
// only check the first error
if nerrors == 1 {
if msg != test.msg {
t.Errorf("%q: got msg = %q; want %q", test.src, msg, test.msg)
}
if line != test.line+linebase {
t.Errorf("%q: got line = %d; want %d", test.src, line, test.line+linebase)
}
if col != test.col+colbase {
t.Errorf("%q: got col = %d; want %d", test.src, col, test.col+colbase)
}
} else if nerrors > 1 {
// TODO(gri) make this use position info
t.Errorf("%q: got unexpected %q at line = %d", test.src, msg, line)
}
}, 0)
for {
s.next()
if s.tok == _EOF {
break
}
}
if nerrors == 0 {
t.Errorf("%q: got no error; want %q", test.src, test.msg)
}
}
}
func TestIssue21938(t *testing.T) {
s := "/*" + strings.Repeat(" ", 4089) + "*/ .5"
var got scanner
got.init(strings.NewReader(s), nil, 0)
got.next()
if got.tok != _Literal || got.lit != ".5" {
t.Errorf("got %s %q; want %s %q", got.tok, got.lit, _Literal, ".5")
}
}