Make Steam binary location configurable

Signed-off-by: Ikey Doherty <ikey@solus-project.com>

configure.ac

@@ -27,6 +27,14 @@ else
         use_new_abi="no"
 fi
 
+# Shadow location of real Steam
+AC_ARG_WITH([real-steam-binary], AS_HELP_STRING([--with-real-steam-binary],
+        [the real Steam binary to use]), [steambin=${withval}],
+        [steambin="$libdir/steam/steam"])
+
+AC_SUBST(steambin)
+AC_DEFINE_UNQUOTED(STEAM_BINARY, "$steambin",
+                   [The location of the real Steam binary])
 AC_OUTPUT
 
 AC_MSG_RESULT([
@@ -41,6 +49,7 @@ AC_MSG_RESULT([
         datarootdir:            ${datarootdir}
 
         New C++ ABI:            ${use_new_abi}
+        Real Steam binary:      ${steambin}
 
         compiler:               ${CC}
         cflags:                 ${CFLAGS}

src/shim/shim.c

@@ -11,17 +11,18 @@
 
 #define _GNU_SOURCE
 
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
+#include "config.h"
 #include "lsi.h"
 
 /**
  * Temporary.
  */
-#define STEAM_BIN "/usr/bin/steam"
 #define EMUL32BIN "/usr/bin/linux32"
 
 int main(int argc, char **argv)
@@ -58,12 +59,12 @@ int main(int argc, char **argv)
         if (config.force_32 && is_x86_64) {
                 exec_command = EMUL32BIN;
                 n_argv[0] = EMUL32BIN;
-                n_argv[1] = STEAM_BIN;
+                n_argv[1] = STEAM_BINARY;
                 off = 1;
         } else {
-                /* Directly call STEAM_BIN */
-                exec_command = STEAM_BIN;
-                n_argv[0] = STEAM_BIN;
+                /* Directly call STEAM_BINARY */
+                exec_command = STEAM_BINARY;
+                n_argv[0] = STEAM_BINARY;
         }
 
         /* Point arguments to arguments passed to us */
@@ -74,6 +75,8 @@ int main(int argc, char **argv)
 
         /* Go execute steam. */
         if (execv(exec_command, (char **)n_argv) < 0) {
+                /* TODO: Use Zenity when we have a UI */
+                fprintf(stderr, "Failed to launch Steam: %s [%s]\n", strerror(errno), STEAM_BINARY);
                 return EXIT_FAILURE;
         }
 }