[hackers] [scc] [driver] simplify tools handling readability || Quentin Rameau

[git]

commit 471425feb4a5703deb60456e359b216c0491e301
Author:     Quentin Rameau <quinq@fifth.space>
AuthorDate: Mon May 30 18:34:06 2016 +0200
Commit:     Quentin Rameau <quinq@fifth.space>
CommitDate: Mon May 30 18:37:09 2016 +0200

    [driver] simplify tools handling readability
    
    Add local pointers to the current tool in settool() and spawn().
    Add a macro for adding parameters to a tool.

diff --git a/driver/posix/scc.c b/driver/posix/scc.c
index eec985d..0ddae9d 100644
--- a/driver/posix/scc.c
+++ b/driver/posix/scc.c
@@ -14,6 +14,7 @@
 #include "../../inc/arg.h"
 #include "../../inc/cc.h"
 
+#define ADDARG(t, p) ((tools[t].args[++tools[t].nargs]) = (p))
 #define NARGS 64
 
 enum {
@@ -23,7 +24,7 @@ enum {
        NR_TOOLS,
 };
 
-static struct {
+static struct tool {
        char cmd[PATH_MAX];
        char *args[NARGS];
        int nargs;
@@ -53,64 +54,67 @@ terminate(void)
 }
 
 int
-settool(int tool, int pipeout)
+settool(int t, int pipeout)
 {
+       struct tool *tool = &tools[t];
        int fds[2], n;
        static int fdin;
 
-       switch (tool) {
+       switch (t) {
        case CC1:
        case CC2:
-               n = snprintf(tools[tool].bin, sizeof(tools[tool].bin),
-                            arch ? "%s-%s" : "%s", tools[tool].name, arch);
-               if (n < 0 || n >= sizeof(tools[tool].bin))
+               n = snprintf(tool->bin, sizeof(tool->bin),
+                            arch ? "%s-%s" : "%s", tool->name, arch);
+               if (n < 0 || n >= sizeof(tool->bin))
                        die("scc: target tool name too long");
 
-               n = snprintf(tools[tool].cmd, sizeof(tools[tool].cmd),
-                            "%s/libexec/scc/%s", PREFIX, tools[tool].bin);
-               if (n < 0 || n >= sizeof(tools[tool].cmd))
+               n = snprintf(tool->cmd, sizeof(tool->cmd),
+                            "%s/libexec/scc/%s", PREFIX, tool->bin);
+               if (n < 0 || n >= sizeof(tool->cmd))
                        die("scc: target tool path too long");
                break;
        default:
                break;
        }
 
-       tools[tool].args[0] = tools[tool].bin;
+       tool->args[0] = tool->bin;
 
        if (fdin) {
-               tools[tool].in = fdin;
+               tool->in = fdin;
                fdin = 0;
        }
        if (pipeout) {
                if (pipe(fds))
                        die("scc: pipe: %s", strerror(errno));
-               tools[tool].out = fds[1];
+               tool->out = fds[1];
                fdin = fds[0];
        }
 
-       return tool;
+       return t;
 }
 
 void
-spawn(int tool)
+spawn(int t)
 {
-       switch (tools[tool].pid = fork()) {
+       struct tool *tool = &tools[t];
+
+       switch (tool->pid = fork()) {
        case -1:
-               die("scc: %s: %s", tools[tool].name, strerror(errno));
+               die("scc: %s: %s", tool->name, strerror(errno));
        case 0:
-               if (tools[tool].out)
-                       dup2(tools[tool].out, 1);
-               if (tools[tool].in)
-                       dup2(tools[tool].in, 0);
-               execvp(tools[tool].cmd, tools[tool].args);
+               if (tool->out)
+                       dup2(tool->out, 1);
+               if (tool->in)
+                       dup2(tool->in, 0);
+               execvp(tool->cmd, tool->args);
                fprintf(stderr, "scc: execv %s: %s\n",
-                       tools[tool].cmd, strerror(errno));
+                       tool->cmd, strerror(errno));
                _exit(1);
        default:
-               if (tools[tool].in)
-                       close(tools[tool].in);
-               if (tools[tool].out)
-                       close(tools[tool].out);
+               if (tool->in)
+                       close(tool->in);
+               if (tool->out)
+                       close(tool->out);
                break;
        }
 }
@@ -134,7 +138,7 @@ main(int argc, char *argv[])
        ARGBEGIN {
        case 'E':
                Eflag = 1;
-               tools[CC1].args[++tools[CC1].nargs] = "-E";
+               ADDARG(CC1, "-E");
                break;
        case 'm':
                arch = EARGF(usage());
@@ -149,7 +153,7 @@ main(int argc, char *argv[])
        if (!argc)
                die("scc: fatal error: no input files");
 
-       tools[CC1].args[++tools[CC1].nargs] = *argv;
+       ADDARG(CC1, *argv);
 
        if (Eflag) {
                spawn(settool(CC1, 0));