pkg/csource: refactor

csource.go is too large and messy.
Move Build/Format into buid.go.
Move generation of common header into common.go.
Split generation of common header into smaller managable functions.

1 files changed, 2 insertions, 179 deletions

diff --git a/pkg/csource/csource.go b/pkg/csource/csource.go
index d8a4a5a01..d99a0168d 100644
--- a/pkg/csource/csource.go
+++ b/pkg/csource/csource.go
@@ -6,16 +6,11 @@ package csource
 
 import (
 	"bytes"
-	"errors"
 	"fmt"
-	"io/ioutil"
-	"os"
-	"os/exec"
 	"regexp"
 	"strings"
 	"unsafe"
 
-	"github.com/google/syzkaller/pkg/osutil"
 	"github.com/google/syzkaller/prog"
 	"github.com/google/syzkaller/sys/targets"
 )
@@ -24,19 +19,6 @@ func Write(p *prog.Prog, opts Options) ([]byte, error) {
 	if err := opts.Check(); err != nil {
 		return nil, fmt.Errorf("csource: invalid opts: %v", err)
 	}
-	commonHeader := ""
-	switch p.Target.OS {
-	case "linux":
-		commonHeader = commonHeaderLinux
-	case "akaros":
-		commonHeader = commonHeaderAkaros
-	case "freebsd":
-		commonHeader = commonHeaderFreebsd
-	case "netbsd":
-		commonHeader = commonHeaderNetbsd
-	default:
-		return nil, fmt.Errorf("unsupported OS: %v", p.Target.OS)
-	}
 	ctx := &context{
 		p:         p,
 		opts:      opts,
@@ -51,11 +33,11 @@ func Write(p *prog.Prog, opts Options) ([]byte, error) {
 
 	ctx.print("// autogenerated by syzkaller (http://github.com/google/syzkaller)\n\n")
 
-	hdr, err := ctx.preprocessCommonHeader(commonHeader)
+	hdr, err := createCommonHeader(p, opts)
 	if err != nil {
 		return nil, err
 	}
-	ctx.print(hdr)
+	ctx.w.Write(hdr)
 	ctx.print("\n")
 
 	ctx.generateSyscallDefines()
@@ -424,162 +406,3 @@ loop:
 	newCall()
 	return calls, n
 }
-
-func (ctx *context) preprocessCommonHeader(commonHeader string) (string, error) {
-	var defines []string
-	if prog.RequiresBitmasks(ctx.p) {
-		defines = append(defines, "SYZ_USE_BITMASKS")
-	}
-	if prog.RequiresChecksums(ctx.p) {
-		defines = append(defines, "SYZ_USE_CHECKSUMS")
-	}
-	opts := ctx.opts
-	switch opts.Sandbox {
-	case "":
-		// No sandbox, do nothing.
-	case "none":
-		defines = append(defines, "SYZ_SANDBOX_NONE")
-	case "setuid":
-		defines = append(defines, "SYZ_SANDBOX_SETUID")
-	case "namespace":
-		defines = append(defines, "SYZ_SANDBOX_NAMESPACE")
-	default:
-		return "", fmt.Errorf("unknown sandbox mode: %v", opts.Sandbox)
-	}
-	if opts.Threaded {
-		defines = append(defines, "SYZ_THREADED")
-	}
-	if opts.Collide {
-		defines = append(defines, "SYZ_COLLIDE")
-	}
-	if opts.Repeat {
-		defines = append(defines, "SYZ_REPEAT")
-	}
-	if opts.Fault {
-		defines = append(defines, "SYZ_FAULT_INJECTION")
-	}
-	if opts.EnableTun {
-		defines = append(defines, "SYZ_TUN_ENABLE")
-	}
-	if opts.UseTmpDir {
-		defines = append(defines, "SYZ_USE_TMP_DIR")
-	}
-	if opts.HandleSegv {
-		defines = append(defines, "SYZ_HANDLE_SEGV")
-	}
-	if opts.WaitRepeat {
-		defines = append(defines, "SYZ_WAIT_REPEAT")
-	}
-	if opts.Debug {
-		defines = append(defines, "SYZ_DEBUG")
-	}
-	for name, _ := range ctx.calls {
-		defines = append(defines, "__NR_"+name)
-	}
-	defines = append(defines, ctx.sysTarget.CArch...)
-
-	cmd := osutil.Command("cpp", "-nostdinc", "-undef", "-fdirectives-only", "-dDI", "-E", "-P", "-")
-	for _, def := range defines {
-		cmd.Args = append(cmd.Args, "-D"+def)
-	}
-	cmd.Stdin = strings.NewReader(commonHeader)
-	stderr := new(bytes.Buffer)
-	stdout := new(bytes.Buffer)
-	cmd.Stderr = stderr
-	cmd.Stdout = stdout
-	if err := cmd.Run(); len(stdout.Bytes()) == 0 {
-		return "", fmt.Errorf("cpp failed: %v\n%v\n%v\n", err, stdout.String(), stderr.String())
-	}
-	remove := append(defines, []string{
-		"__STDC__",
-		"__STDC_HOSTED__",
-		"__STDC_UTF_16__",
-		"__STDC_UTF_32__",
-	}...)
-	out := stdout.String()
-	for _, def := range remove {
-		out = strings.Replace(out, "#define "+def+" 1\n", "", -1)
-	}
-	// strip: #define __STDC_VERSION__ 201112L
-	for _, def := range []string{"__STDC_VERSION__"} {
-		pos := strings.Index(out, "#define "+def)
-		if pos == -1 {
-			continue
-		}
-		end := strings.IndexByte(out[pos:], '\n')
-		if end == -1 {
-			continue
-		}
-		out = strings.Replace(out, out[pos:end+1], "", -1)
-	}
-	return out, nil
-}
-
-// Build builds a C/C++ program from source src and returns name of the resulting binary.
-// lang can be "c" or "c++".
-func Build(target *prog.Target, lang, src string) (string, error) {
-	bin, err := ioutil.TempFile("", "syzkaller")
-	if err != nil {
-		return "", fmt.Errorf("failed to create temp file: %v", err)
-	}
-	bin.Close()
-	sysTarget := targets.List[target.OS][target.Arch]
-	compiler := sysTarget.CCompilerPrefix + "gcc"
-	if _, err := exec.LookPath(compiler); err != nil {
-		return "", NoCompilerErr
-	}
-	flags := []string{
-		"-x", lang, "-Wall", "-Werror", "-O1", "-g", "-o", bin.Name(),
-		src, "-pthread",
-	}
-	flags = append(flags, sysTarget.CrossCFlags...)
-	if sysTarget.PtrSize == 4 {
-		// We do generate uint64's for syscall arguments that overflow longs on 32-bit archs.
-		flags = append(flags, "-Wno-overflow")
-	}
-	out, err := osutil.Command(compiler, append(flags, "-static")...).CombinedOutput()
-	if err != nil {
-		// Some distributions don't have static libraries.
-		out, err = osutil.Command(compiler, flags...).CombinedOutput()
-	}
-	if err != nil {
-		os.Remove(bin.Name())
-		data, _ := ioutil.ReadFile(src)
-		return "", fmt.Errorf("failed to build program:\n%s\n%s\ncompiler invocation: %v %v\n",
-			data, out, compiler, flags)
-	}
-	return bin.Name(), nil
-}
-
-var NoCompilerErr = errors.New("no target compiler")
-
-// Format reformats C source using clang-format.
-func Format(src []byte) ([]byte, error) {
-	stdout, stderr := new(bytes.Buffer), new(bytes.Buffer)
-	cmd := osutil.Command("clang-format", "-assume-filename=/src.c", "-style", style)
-	cmd.Stdin = bytes.NewReader(src)
-	cmd.Stdout = stdout
-	cmd.Stderr = stderr
-	if err := cmd.Run(); err != nil {
-		return src, fmt.Errorf("failed to format source: %v\n%v", err, stderr.String())
-	}
-	return stdout.Bytes(), nil
-}
-
-// Something acceptable for kernel developers and email-friendly.
-var style = `{
-BasedOnStyle: LLVM,
-IndentWidth: 2,
-UseTab: Never,
-BreakBeforeBraces: Linux,
-IndentCaseLabels: false,
-DerivePointerAlignment: false,
-PointerAlignment: Left,
-AlignTrailingComments: true,
-AllowShortBlocksOnASingleLine: false,
-AllowShortCaseLabelsOnASingleLine: false,
-AllowShortFunctionsOnASingleLine: false,
-AllowShortIfStatementsOnASingleLine: false,
-AllowShortLoopsOnASingleLine: false,
-ColumnLimit: 72,
-}`