csource: new package

Move C source generation into a separate package.
Prog is too bloated already.

3 files changed, 23 insertions, 144 deletions

diff --git a/prog/encodingc.go b/prog/encodingc.go
deleted file mode 100644
index c22180ce5..000000000
--- a/prog/encodingc.go
+++ /dev/null
@@ -1,117 +0,0 @@
-// 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 prog
-
-import (
-	"bytes"
-	"fmt"
-	"io"
-	"unsafe"
-
-	"github.com/google/syzkaller/sys"
-)
-
-func (p *Prog) WriteCSource() []byte {
-	exec := p.SerializeForExec()
-	buf := new(bytes.Buffer)
-	writeCSource(buf, exec)
-	return buf.Bytes()
-}
-
-func writeCSource(w io.Writer, exec []byte) {
-	fmt.Fprintf(w, `// autogenerated by syzkaller (http://github.com/google/syzkaller)
-#include <syscall.h>
-#include <string.h>
-#include <stdint.h>
-
-int main()
-{
-`)
-	read := func() uintptr {
-		if len(exec) < 8 {
-			panic("exec program overflow")
-		}
-		v := *(*uint64)(unsafe.Pointer(&exec[0]))
-		exec = exec[8:]
-		return uintptr(v)
-	}
-	resultRef := func() string {
-		arg := read()
-		res := fmt.Sprintf("r%v", arg)
-		if opDiv := read(); opDiv != 0 {
-			res = fmt.Sprintf("%v/%v", res, opDiv)
-		}
-		if opAdd := read(); opAdd != 0 {
-			res = fmt.Sprintf("%v+%v", res, opAdd)
-		}
-		return res
-	}
-	lastCall := 0
-	for n := 0; ; n++ {
-		switch instr := read(); instr {
-		case instrEOF:
-			fmt.Fprintf(w, "\treturn 0;\n}\n")
-			return
-		case instrCopyin:
-			addr := read()
-			typ := read()
-			size := read()
-			switch typ {
-			case execArgConst:
-				arg := read()
-				fmt.Fprintf(w, "\t*(uint%v_t*)0x%x = 0x%x;\n", size*8, addr, arg)
-			case execArgResult:
-				fmt.Fprintf(w, "\t*(uint%v_t*)0x%x = %v;\n", size*8, addr, resultRef())
-			case execArgData:
-				data := exec[:size]
-				exec = exec[(size+7)/8*8:]
-				var esc []byte
-				for _, v := range data {
-					hex := func(v byte) byte {
-						if v < 10 {
-							return '0' + v
-						}
-						return 'a' + v - 10
-					}
-					esc = append(esc, '\\', 'x', hex(v>>4), hex(v<<4>>4))
-				}
-				fmt.Fprintf(w, "\tmemcpy((void*)0x%x, \"%s\", %v);\n", addr, esc, size)
-			default:
-				panic("bad argument type")
-			}
-		case instrCopyout:
-			addr := read()
-			size := read()
-			fmt.Fprintf(w, "\tlong r%v = -1;\n", n)
-			fmt.Fprintf(w, "\tif (r%v != -1)\n", lastCall)
-			fmt.Fprintf(w, "\t\tr%v = *(uint%v_t*)0x%x;\n", n, size*8, addr)
-		case instrSetPad, instrCheckPad:
-			read() // addr
-			read() // size
-		default:
-			// Normal syscall.
-			meta := sys.Calls[instr]
-			fmt.Fprintf(w, "\tlong r%v = syscall(SYS_%v", n, meta.CallName)
-			nargs := read()
-			for i := uintptr(0); i < nargs; i++ {
-				typ := read()
-				size := read()
-				_ = size
-				switch typ {
-				case execArgConst:
-					fmt.Fprintf(w, ", 0x%xul", read())
-				case execArgResult:
-					fmt.Fprintf(w, ", %v", resultRef())
-				default:
-					panic("unknown arg type")
-				}
-			}
-			for i := nargs; i < 6; i++ {
-				fmt.Fprintf(w, ", 0")
-			}
-			fmt.Fprintf(w, ");\n")
-			lastCall = n
-		}
-	}
-}
diff --git a/prog/encodingexec.go b/prog/encodingexec.go
index f23d98c5d..7c75eccc9 100644
--- a/prog/encodingexec.go
+++ b/prog/encodingexec.go
@@ -6,18 +6,22 @@
 
 package prog
 
+import (
+	"fmt"
+)
+
 const (
-	instrEOF = ^uintptr(iota)
-	instrCopyin
-	instrCopyout
-	instrSetPad
-	instrCheckPad
+	ExecInstrEOF = ^uintptr(iota)
+	ExecInstrCopyin
+	ExecInstrCopyout
+	ExecInstrSetPad
+	ExecInstrCheckPad
 )
 
 const (
-	execArgConst = uintptr(iota)
-	execArgResult
-	execArgData
+	ExecArgConst = uintptr(iota)
+	ExecArgResult
+	ExecArgData
 )
 
 const (
@@ -28,7 +32,7 @@ const (
 
 func (p *Prog) SerializeForExec() []byte {
 	if err := p.validate(); err != nil {
-		panic("serializing invalid program")
+		panic(fmt.Errorf("serializing invalid program: %v", err))
 	}
 	var instrSeq uintptr
 	w := &execContext{args: make(map[*Arg]*argInfo)}
@@ -61,11 +65,11 @@ func (p *Prog) SerializeForExec() []byte {
 					pad, padSize := arg1.IsPad()
 					if (arg1.Dir == DirIn && !pad) || (arg1.Dir == DirOut && pad) || arg1.Dir == DirInOut {
 						if pad {
-							w.write(instrSetPad)
+							w.write(ExecInstrSetPad)
 							w.write(physicalAddr(arg) + w.args[arg1].Offset)
 							w.write(padSize)
 						} else {
-							w.write(instrCopyin)
+							w.write(ExecInstrCopyin)
 							w.write(physicalAddr(arg) + w.args[arg1].Offset)
 							w.writeArg(arg1)
 						}
@@ -89,7 +93,7 @@ func (p *Prog) SerializeForExec() []byte {
 			if pad && arg.Dir != DirIn {
 				instrSeq++
 				info := w.args[arg]
-				w.write(instrCheckPad)
+				w.write(ExecInstrCheckPad)
 				w.write(physicalAddr(base) + info.Offset)
 				w.write(padSize)
 				return
@@ -108,7 +112,7 @@ func (p *Prog) SerializeForExec() []byte {
 				info := w.args[arg]
 				info.Idx = instrSeq
 				instrSeq++
-				w.write(instrCopyout)
+				w.write(ExecInstrCopyout)
 				w.write(physicalAddr(base) + info.Offset)
 				w.write(arg.Size(arg.Type))
 			default:
@@ -116,7 +120,7 @@ func (p *Prog) SerializeForExec() []byte {
 			}
 		})
 	}
-	w.write(instrEOF)
+	w.write(ExecInstrEOF)
 	return w.buf
 }
 
@@ -151,25 +155,25 @@ func (w *execContext) write(v uintptr) {
 func (w *execContext) writeArg(arg *Arg) {
 	switch arg.Kind {
 	case ArgConst:
-		w.write(execArgConst)
+		w.write(ExecArgConst)
 		w.write(arg.Size(arg.Type))
 		w.write(arg.Val)
 	case ArgResult:
-		w.write(execArgResult)
+		w.write(ExecArgResult)
 		w.write(arg.Size(arg.Type))
 		w.write(w.args[arg.Res].Idx)
 		w.write(arg.OpDiv)
 		w.write(arg.OpAdd)
 	case ArgPointer:
-		w.write(execArgConst)
+		w.write(ExecArgConst)
 		w.write(arg.Size(arg.Type))
 		w.write(physicalAddr(arg))
 	case ArgPageSize:
-		w.write(execArgConst)
+		w.write(ExecArgConst)
 		w.write(arg.Size(arg.Type))
 		w.write(arg.AddrPage * pageSize)
 	case ArgData:
-		w.write(execArgData)
+		w.write(ExecArgData)
 		w.write(uintptr(len(arg.Data)))
 		for i := 0; i < len(arg.Data); i += 8 {
 			var v uintptr
diff --git a/prog/prog_test.go b/prog/prog_test.go
index d308ba36b..7a4abbb3a 100644
--- a/prog/prog_test.go
+++ b/prog/prog_test.go
@@ -54,11 +54,3 @@ func TestSerializeForExec(t *testing.T) {
 		p.SerializeForExec()
 	}
 }
-
-func TestSerializeC(t *testing.T) {
-	rs, iters := initTest(t)
-	for i := 0; i < iters; i++ {
-		p := Generate(rs, 10, nil)
-		p.WriteCSource()
-	}
-}