poafloc

commit 394aa9e76ad447d967bf40ddef9eecd1fef06735
parent a23c8139cf1ef9d4141701edc0385ab26b07cebd
Author: Dimitrije Dobrota <mail@dimitrijedobrota.com>
Date:   Thu,  6 Jun 2024 14:25:22 +0200

Options with optional arguments

* Long options with optional argument require '='
* Short options with optional argument cannot be ganged together

Diffstat:
M
args.hpp
 | 
25
++++++++++++++++---------
M
demo.cpp
 | 
14
++++++++------

2 files changed, 24 insertions(+), 15 deletions(-)
diff --git a/args.hpp b/args.hpp
@@ -13,6 +13,13 @@ class Parser {
         const char *name;
         const char key;
         const char *arg;
+        const uint8_t options;
+    };
+
+    enum Option {
+        ARG_OPTIONAL = 0x1,
+        HIDDEN = 0x2,
+        ALIAS = 0x3,
     };
 
     struct argp_t {
@@ -58,11 +65,10 @@ class Parser {
 
                     const char *arg = nullptr;
                     if (option->arg) {
-                        if (opt[j + 1] == 0) {
+                        if (opt[j + 1] != 0) arg = opt + j + 1;
+                        else if ((option->options & ARG_OPTIONAL) == 0) {
                             if (i == argc) goto missing;
                             arg = argv[++i];
-                        } else {
-                            arg = opt + j + 1;
                         }
                     }
 
@@ -82,12 +88,13 @@ class Parser {
                 const auto *option = options[key - 'a'];
                 const char *arg = nullptr;
 
-                if (eq) {
-                    if (!option->arg) goto excess;
-                    arg = eq + 1;
-                } else if (option->arg) {
-                    if (i == argc) goto missing;
-                    arg = argv[++i];
+                if (!option->arg && eq) goto excess;
+                if (option->arg) {
+                    if (eq) arg = eq + 1;
+                    else if ((option->options & ARG_OPTIONAL) == 0) {
+                        if (i == argc) goto missing;
+                        arg = argv[++i];
+                    }
                 }
 
                 argp->parser(key, arg, input);
diff --git a/demo.cpp b/demo.cpp
@@ -29,7 +29,7 @@ int parse_opt(int key, const char *arg, void *input) {
         if (arguments->hex) error("cannot mix -hex and -relocatable");
         arguments->relocatable = true;
         break;
-    case 'o': arguments->output_file = arg; break;
+    case 'o': arguments->output_file = arg ? arg : "stdout"; break;
     case 'i': arguments->input_file = arg; break;
     default: arguments->args.push_back(arg);
     }
@@ -37,13 +37,15 @@ int parse_opt(int key, const char *arg, void *input) {
     return 0;
 }
 
+using enum Parser::Option;
+
 // clang-format off
 static const Parser::option_t options[] = {
-    {            0, 'o', "file"},
-    {      "input", 'i', "file"},
-    {      "debug", 'd',      0},
-    {        "hex", 'h',      0},
-    {"relocatable", 'r',      0},
+    {     "output", 'o', "file", ARG_OPTIONAL},
+    {            0, 'i', "file",            0},
+    {      "debug", 'd',      0,            0},
+    {        "hex", 'h',      0,            0},
+    {"relocatable", 'r',      0,            0},
     {0},
 };
 // clang-format on