[hackers] [scc] [driver] add support for custom runtime libexec path || Quentin Rameau

[git]

commit e93f759a6bcd0d6e812a3f6c6f6146c637f7145c
Author:     Quentin Rameau <quinq@fifth.space>
AuthorDate: Mon Jan 23 14:31:04 2017 +0100
Commit:     Quentin Rameau <quinq@fifth.space>
CommitDate: Mon Jan 23 14:47:51 2017 +0100

    [driver] add support for custom runtime libexec path
    
    Now scc will lookup the env for SCCEXECPATH and search there for exec
    lib tools.

diff --git a/driver/posix/scc.c b/driver/posix/scc.c
index 647affb..beaed6f 100644
--- a/driver/posix/scc.c
+++ b/driver/posix/scc.c
@@ -38,9 +38,9 @@ static struct tool {
        int    in, out, init;
        pid_t  pid;
 } tools[] = {
-       [CC1]    = { .bin = "cc1",   .cmd = PREFIX "/libexec/scc/", },
+       [CC1]    = { .bin = "cc1" },
        [TEEIR]  = { .bin = "tee",   .cmd = "tee", },
-       [CC2]    = { .bin = "cc2",   .cmd = PREFIX "/libexec/scc/", },
+       [CC2]    = { .bin = "cc2" },
        [TEEQBE] = { .bin = "tee",   .cmd = "tee", },
        [QBE]    = { .bin = "qbe",   .cmd = "qbe", },
        [TEEAS]  = { .bin = "tee",   .cmd = "tee", },
@@ -50,7 +50,7 @@ static struct tool {
 };
 
 char *argv0;
-static char *arch, *objfile, *outfile;
+static char *arch, *execpath, *objfile, *outfile;
 static char *tmpdir;
 static size_t tmpdirln;
 static struct items objtmp, objout;
@@ -114,9 +114,11 @@ inittool(int tool)
                        die("scc: target tool bin too long");
                binln = strlen(t->bin);
 
-               if (strlen(t->cmd) + binln + 1 > sizeof(t->cmd))
+               if (!execpath)
+                       execpath = PREFIX "/libexec/scc";
+               n = snprintf(t->cmd, sizeof(t->cmd), "%s/%s", execpath, t->bin);
+               if (n < 0 || n >= sizeof(t->cmd))
                        die("scc: target tool path too long");
-               strcat(t->cmd, t->bin);
                break;
        case LD:
                addarg(tool, "-no-pie");
@@ -425,6 +427,7 @@ main(int argc, char *argv[])
        atexit(terminate);
 
        arch = getenv("ARCH");
+       execpath = getenv("SCCEXECPATH");
 
        ARGBEGIN {
        case 'D':