Code clarification

diff --git a/cbs.c b/cbs.c
index eeda20fa2cfbbc6fec0a514784b4933a13aa37bd..bc93ee337b352c643c1ee8463acf4e55cedeb0b8 100644 (file)
--- a/cbs.c
+++ b/cbs.c
@@ -15,11 +15,10 @@ extern char **environ;
 void *alloc(int s) {
    void *r;
 
-   if ((r = malloc(s)) == NULL) {
-       fprintf(stderr, "Out of memory\n");
-       exit(EXIT_FAILURE);
-   }
-   return r;
+   if ((r = malloc(s))) return r;
+
+   fprintf(stderr, "Out of memory\n");
+   exit(EXIT_FAILURE);
 }
 
 char *addext(char *pp, char *ext, int lprf) {
@@ -48,7 +47,7 @@ char *addext(char *pp, char *ext, int lprf) {
    return rp;
 }
 
-int checkmod(char *tar, char *dep) {
+int checkmod(char *targ, char *dep) {
    struct stat dstat, tstat;
 
    if (stat(dep, &dstat) == -1) {
@@ -56,65 +55,58 @@ int checkmod(char *tar, char *dep) {
        exit(EXIT_FAILURE);
    }
    errno = 0;
-   if ((stat(tar, &tstat) == -1) && (errno != ENOENT)) {
-       fprintf(stderr, "Unable to stat `%s': %s\n", tar, strerror(errno));
+   if (stat(targ, &tstat) == -1 && errno != ENOENT) {
+       fprintf(stderr, "Unable to stat `%s': %s\n", targ, strerror(errno));
        exit(EXIT_FAILURE);
    }
-   return (errno == ENOENT) || (dstat.st_mtime > tstat.st_mtime);
+   return errno == ENOENT || dstat.st_mtime > tstat.st_mtime;
 }
 
-void exec(char *path, char **args, char *emsg, char *etar) {
+void exec(char *path, char **args, char *what, char *who) {
    int i;
 
-   for (i = 0; args[i]; ++i)
-       if (*args[i] != '\0') printf("%s ", args[i]);
+   for (i = 0; args[i]; ++i) if (*args[i] != '\0') printf("%s ", args[i]);
    printf("\n");
 
    if (execve(path, args, environ) == -1) {
-       fprintf(stderr, emsg, etar);
+       fprintf(stderr, "Unable to run %s of `%s'\n", what, who);
        exit(EXIT_FAILURE);
    }
 }
 
-void pwait(int cpid, char *emsg, char *etar) {
+void pwait(int cpid, char *what, char *who) {
    int status;
 
    if (cpid == -1) {
-       fprintf(stderr, emsg, etar);
+       fprintf(stderr, "Unable to delegate %s of `%s'\n", what, who);
        exit(EXIT_FAILURE);
    }
    waitpid(cpid, &status, 0);
-   if (WIFEXITED(status) && WEXITSTATUS(status) != 0)
-       exit(EXIT_FAILURE);
+   if (WIFEXITED(status) && WEXITSTATUS(status) != 0) exit(EXIT_FAILURE);
 }
 
 void cc(char *name, ...) {
-   int cpid, status;
-   char *src, *obj, *dep;
+   char *dep, *src, *obj;
    va_list deps;
+   int cpid;
 
-   if ((cpid = fork())) {
-       pwait(cpid, "Unable to delegate compilation of `%s.c'\n", name);
-       return;
-   }
-
-   src = addext(name, "c", 0);
+   dep = src = addext(name, "c", 0);
    obj = addext(name, "o", 0);
 
    va_start(deps, name);
-   dep = src;
-   do if (checkmod(obj, dep))
-       exec("/usr/bin/cc", (char *[]){"cc", CFLAGS, "-c", "-o", obj, src, NULL},
-            "Unable to execute compilation of `%s.c'\n", name);
-   while ((dep = addext(va_arg(deps, char *), "h", 0)));
+   do if (checkmod(obj, dep)) {
+       if ((cpid = fork()) == 0)
+           exec("/usr/bin/cc", (char *[]){"cc", CFLAGS, "-c", "-o", obj, src, NULL},
+                "compilation", src);
+       pwait(cpid, "compilation", src);
+       break;
+   } while ((dep = addext(va_arg(deps, char *), "h", 0)));
    va_end(deps);
-
-   exit(EXIT_SUCCESS);
 }
 
 void ld(char type, char *output, char *input, ...) {
    char **fargs, **args;
-   int cpid, status, vn, fn, i;
+   int fn, vn, i, cpid;
    va_list count, inputs;
 
    input = addext(input, "o", 0);
@@ -130,13 +122,10 @@ void ld(char type, char *output, char *input, ...) {
        output = addext(output, "dylib", 1);
        fargs = (char *[]){"cc", "-dynamiclib", LDFLAGS, "-o", output, input, NULL};
        break;
+   default:
+       fprintf(stderr, "Unknown linking type `%c'\n", type);
+       exit(EXIT_FAILURE);
    }
-
-   if ((cpid = fork())) {
-       pwait(cpid, "Unable to delegate linking phase of `%s'\n", output);
-       return;
-   }
-
    for (fn = 0; fargs[fn]; ++fn);
 
    va_start(count, input);
@@ -151,33 +140,36 @@ void ld(char type, char *output, char *input, ...) {
    args[fn + vn] = NULL;
    va_end(inputs);
 
-   for (i = fn - 1; i < fn + vn; ++i)
-       if (checkmod(output, args[i]))
-           exec(type == 's' ? "/usr/bin/ar" : "/usr/bin/cc", args,
-                "Unable to execute linking phase of `%s'\n", output);
-
-   exit(EXIT_SUCCESS);
+   for (i = fn - 1; i < fn + vn; ++i) if (checkmod(output, args[i])) {
+       if ((cpid = fork()) == 0)
+           exec(type == 's' ? "/usr/bin/ar" : "/usr/bin/cc",
+                args, "linking phase", output);
+       pwait(cpid, "linking phase", output);
+       break;
+   }
 }
 
 void build(char *path) {
    int cpid;
 
-   if (path && (cpid = fork())) {
-       pwait(cpid, "Unable to delegate execution of `%sbuild'\n", path);
-       printf("cd ..\n");
-       return;
+   if (path) {
+       if ((cpid = fork())) {
+           pwait(cpid, "execution", "build");
+           printf("cd ..\n");
+           return;
+       }
+       printf("cd %s\n", path);
+       if (chdir(path))
+           fprintf(stderr, "Unable to make `%s' the current working directory: %s\n",
+                   path, strerror(errno));
    }
 
-   if (path && (printf("cd %s\n", path), chdir(path)))
-       fprintf(stderr, "Unable to make `%s' the current working directory: %s\n",
-               path, strerror(errno));
-
    if (checkmod("build", "build.c")) {
        if ((cpid = fork()) == 0)
            exec("/usr/bin/cc", (char *[]){"cc", "-o", "build", "build.c", NULL},
-                "Unable to execute compilation of `%s.c'\n", "build");
-       pwait(cpid, "Unable to delegate compilation of `%s.c'\n", "build");
+                "compilation", "build.c");
+       pwait(cpid, "compilation", "build.c");
    } else if (!path) return;
 
-   exec("build", (char *[]){"build", NULL}, "Unable to execute `%s'\n", "build");
+   exec("build", (char *[]){"build", NULL}, "execution", "build");
 }