initial commit

1 files changed, 92 insertions, 0 deletions

diff --git a/sysgen/parser.go b/sysgen/parser.go
new file mode 100644
index 000000000..92c27c58a
--- /dev/null
+++ b/sysgen/parser.go
@@ -0,0 +1,92 @@
+// Copyright 2015 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+)
+
+type Parser struct {
+	r *bufio.Scanner
+	s string
+	i int
+	l int
+}
+
+func NewParser(r io.Reader) *Parser {
+	return &Parser{r: bufio.NewScanner(r)}
+}
+
+func (p *Parser) Scan() bool {
+	if !p.r.Scan() {
+		if err := p.r.Err(); err != nil {
+			failf("failed to read input file: %v", err)
+		}
+		return false
+	}
+	p.s = p.r.Text()
+	p.i = 0
+	p.l++
+	return true
+}
+
+func (p *Parser) Str() string {
+	return p.s
+}
+
+func (p *Parser) EOF() bool {
+	return p.i == len(p.s)
+}
+
+func (p *Parser) Char() byte {
+	if p.EOF() {
+		p.failf("unexpected eof")
+	}
+	return p.s[p.i]
+}
+
+func (p *Parser) Parse(ch byte) {
+	if p.EOF() {
+		p.failf("want %s, got EOF", string(ch))
+	}
+	if p.s[p.i] != ch {
+		p.failf("want '%v', got '%v'", string(ch), string(p.s[p.i]))
+	}
+	p.i++
+	p.SkipWs()
+}
+
+func (p *Parser) SkipWs() {
+	for p.i < len(p.s) && (p.s[p.i] == ' ' || p.s[p.i] == '\t') {
+		p.i++
+	}
+}
+
+func (p *Parser) Ident() string {
+	i := p.i
+	for p.i < len(p.s) &&
+		(p.s[p.i] >= 'a' && p.s[p.i] <= 'z' ||
+			p.s[p.i] >= 'A' && p.s[p.i] <= 'Z' ||
+			p.s[p.i] >= '0' && p.s[p.i] <= '9' ||
+			p.s[p.i] == '_' || p.s[p.i] == '$') { // $ is for n-way syscalls (like ptrace$peek)
+		p.i++
+	}
+	if i == p.i {
+		p.failf("failed to parse identifier at pos %v", i)
+	}
+	if ch := p.s[i]; ch >= '0' && ch <= '9' {
+		// p.failf("identifier starts with a digit at pos %v", i)
+	}
+	s := p.s[i:p.i]
+	p.SkipWs()
+	return s
+}
+
+func (p *Parser) failf(msg string, args ...interface{}) {
+	fmt.Fprintf(os.Stderr, "line #%v: %v\n", p.l, p.s)
+	failf(msg, args...)
+}