llcppcfg: libs -L path support in ubuntu

cmd/llcppcfg/llcppgcfg/cfg.go

@@ -9,6 +9,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime"
 	"sort"
 	"strings"
 	"unicode"
@@ -408,6 +409,16 @@ func GenCfg(name string, cpp bool, expand CfgMode, exts []string) (*bytes.Buffer
 
 	cfg.Name = NormalizePackageName(cfg.Name)
 
+	if runtime.GOOS == "linux" {
+		libpath, _ := SearchLib(name)
+		if len(libpath) > 0 {
+			libs, err := CmdOutString(ExecCommand("pkg-config", "--libs", name), "")
+			if err == nil {
+				cfg.Libs = fmt.Sprintf("-L%s %s", libpath, strings.TrimSpace(libs))
+			}
+		}
+	}
+
 	buf := bytes.NewBuffer([]byte{})
 	jsonEncoder := json.NewEncoder(buf)
 	jsonEncoder.SetIndent("", "\t")

cmd/llcppcfg/llcppgcfg/llcpplibpath.go

@@ -0,0 +1,73 @@
+package llcppgcfg
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"runtime"
+	"strings"
+)
+
+const LINUX = "linux"
+
+func IsLibInDir(dir string, lib string) bool {
+	if runtime.GOOS != LINUX {
+		return false
+	}
+	cmd := ExecCommand("find", dir, "-name", lib+".so*")
+	out, err := CmdOutString(cmd, "")
+	if err != nil {
+		return false
+	}
+	if out == "" {
+		return false
+	}
+	return strings.Contains(out, lib)
+}
+
+func SearchLib(lib string) (string, error) {
+	if runtime.GOOS != LINUX {
+		return "", fmt.Errorf("only support linux")
+	}
+	ldCmd := ExecCommand("ld", "--verbose")
+	ldRes, err := CmdOutString(ldCmd, "")
+	if err != nil {
+		log.Fatal(err)
+	}
+	cmd := ExecCommand("grep", "SEARCH_DIR")
+	stdin, err := cmd.StdinPipe()
+	if err != nil {
+		log.Fatal(err)
+	}
+	go func() {
+		defer stdin.Close()
+		_, wrErr := io.WriteString(stdin, ldRes)
+		panic(wrErr)
+	}()
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		log.Fatal(err)
+	}
+	searchDirs := strings.Split(string(out), ";")
+	libs := ""
+	findDirs := make([]string, 0, len(searchDirs))
+	for _, searchDir := range searchDirs {
+		eqIndex := strings.Index(searchDir, "=")
+		endQuoteIndex := strings.LastIndex(searchDir, "\"")
+		if eqIndex != -1 && endQuoteIndex != -1 {
+			dir := searchDir[eqIndex+1 : endQuoteIndex]
+			if IsLibInDir(dir, lib) {
+				findDirs = append(findDirs, dir)
+			}
+		}
+	}
+	maxDir := 0
+	for _, dir := range findDirs {
+		cnt := strings.Count(dir, "/")
+		if cnt > maxDir {
+			maxDir = cnt
+			libs = dir
+		}
+	}
+	return libs, nil
+}