[v0.04] Add option to select GPU

src/common/args.cpp

@@ -2,30 +2,81 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <climits>
 
 #include "args.hpp"
 #include "global.hpp"
 
+#define OVERFLOW          -1
+#define UNDERFLOW         -2
+#define INVALID_ARG       -3
 #define NUM_COLORS 4
 
 struct args_struct {
   bool help_flag;
   bool version_flag;
+  int gpu_idx;
   STYLE style;
   struct color** colors;
 };
 
+int errn = 0;
+static struct args_struct args;
+
 const char args_chr[] = {
+  /* [ARG_CHAR_GPU]     = */ 'g',
   /* [ARG_CHAR_HELP]    = */ 'h',
   /* [ARG_CHAR_VERSION] = */ 'V',
 };
 
 const char *args_str[] = {
+  /* [ARG_CHAR_GPU]     = */ "gpu",
   /* [ARG_CHAR_HELP]    = */ "help",
   /* [ARG_CHAR_VERSION] = */ "version",
 };
 
-static struct args_struct args;
+int getarg_int(char* str) {
+  errn = 0;
+
+  char* endptr;
+  long tmp = strtol(str, &endptr, 10);
+
+  if(*endptr) {
+    errn = INVALID_ARG;
+    return -1;
+  }
+  if(tmp == LONG_MIN) {
+    errn = UNDERFLOW;
+    return -1;
+  }
+  if(tmp == LONG_MAX) {
+    errn = OVERFLOW;
+    return -1;
+  }
+  if(tmp >= INT_MIN && tmp <= INT_MAX) {
+    return (int)tmp;
+  }
+
+  errn = OVERFLOW;
+  return -1;
+}
+
+void print_getarg_error() {
+  switch (errn) {
+    case OVERFLOW:
+      printf("overflow detected while parsing the arguments\n");
+      break;
+    case UNDERFLOW:
+      printf("underflow detected while parsing the arguments\n");
+      break;
+    case INVALID_ARG:
+      printf("invalid argument\n");
+      break;
+    default:
+      printf("invalid error: %d\n", errn);
+      break;
+  }
+}
 
 STYLE get_style() {
   return args.style;
@@ -35,6 +86,10 @@ struct color** get_colors() {
   return args.colors;
 }
 
+int get_gpu_idx() {
+  return args.gpu_idx;
+}
+
 bool show_help() {
   return args.help_flag;
 }
@@ -58,7 +113,7 @@ char* build_short_options() {
   char* str = (char *) emalloc(sizeof(char) * (len*2 + 1));
   memset(str, 0, sizeof(char) * (len*2 + 1));
 
-  sprintf(str, "%c%c",
+  sprintf(str, "%c:%c%c", c[ARG_GPU],
   c[ARG_HELP], c[ARG_VERSION]);
 
   return str;
@@ -71,8 +126,10 @@ bool parse_args(int argc, char* argv[]) {
 
   args.version_flag = false;
   args.help_flag = false;
+  args.gpu_idx = 0;
 
   const struct option long_options[] = {
+    {args_str[ARG_GPU],     required_argument, 0, args_chr[ARG_GPU]     },
     {args_str[ARG_HELP],    no_argument,       0, args_chr[ARG_HELP]    },
     {args_str[ARG_VERSION], no_argument,       0, args_chr[ARG_VERSION] },
     {0, 0, 0, 0}
@@ -82,7 +139,16 @@ bool parse_args(int argc, char* argv[]) {
   opt = getopt_long(argc, argv, short_options, long_options, &option_index);
 
   while (!args.help_flag && !args.version_flag && opt != -1) {
-    if(opt == args_chr[ARG_HELP]) {
+    if(opt == args_chr[ARG_GPU]) {
+      args.gpu_idx = getarg_int(optarg);
+      if(errn != 0) {
+        printErr("Option %s: ", args_str[ARG_GPU]);
+        print_getarg_error();
+        args.help_flag  = true;
+        return false;
+      }
+    }
+    else if(opt == args_chr[ARG_HELP]) {
       args.help_flag  = true;
     }
     else if(opt == args_chr[ARG_VERSION]) {