From 5c07fdcc2e02e328920d1ab5c399d8027bf7bd6c Mon Sep 17 00:00:00 2001
From: Dodji Seketeli <dodji@redhat.com>
Date: Thu, 11 Feb 2016 13:46:57 +0100
Subject: [PATCH] Bug 19606 - Need better error message for invalid options

This patch instructs abidiff to mentions the wrong option when it
encounters an unknown option.

It also instructs it to mention the option when reporting about
a missing option argument.

	* tools/abidiff.cc (options::wrong_option): New data member.
	(parse_command_line): Record the name of the unknown option and of
	the option which value is missing.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
---
 tools/abidiff.cc | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/tools/abidiff.cc b/tools/abidiff.cc
index f18a29d2..09a5a77b 100644
--- a/tools/abidiff.cc
+++ b/tools/abidiff.cc
@@ -60,6 +60,7 @@ struct options
   bool display_usage;
   bool display_version;
   bool missing_operand;
+  string		wrong_option;
   string		file1;
   string		file2;
   vector<string>	suppression_paths;
@@ -196,6 +197,7 @@ parse_command_line(int argc, char* argv[], options& opts)
 	  if (j >= argc)
 	    {
 	      opts.missing_operand = true;
+	      opts.wrong_option = argv[i];
 	      return true;
 	    }
 	  // elfutils wants the root path to the debug info to be
@@ -211,6 +213,7 @@ parse_command_line(int argc, char* argv[], options& opts)
 	  if (j >= argc)
 	    {
 	      opts.missing_operand = true;
+	      opts.wrong_option = argv[i];
 	      return true;
 	    }
 	  // elfutils wants the root path to the debug info to be
@@ -278,7 +281,11 @@ parse_command_line(int argc, char* argv[], options& opts)
 	{
 	  int j = i + 1;
 	  if (j >= argc)
-	    return false;
+	    {
+	      opts.missing_operand = true;
+	      opts.wrong_option = argv[i];
+	      return true;
+	    }
 	  opts.suppression_paths.push_back(argv[j]);
 	  ++i;
 	}
@@ -286,7 +293,11 @@ parse_command_line(int argc, char* argv[], options& opts)
 	{
 	  int j = i + 1;
 	  if (j >= argc)
-	    return false;
+	    {
+	      opts.missing_operand = true;
+	      opts.wrong_option = argv[i];
+	      return true;
+	    }
 	  opts.drop_fn_regex_patterns.push_back(argv[j]);
 	  opts.drop_var_regex_patterns.push_back(argv[j]);
 	  ++i;
@@ -297,6 +308,7 @@ parse_command_line(int argc, char* argv[], options& opts)
 	  if (j >= argc)
 	    {
 	      opts.missing_operand = true;
+	      opts.wrong_option = argv[i];
 	      return true;
 	    }
 	  opts.drop_fn_regex_patterns.push_back(argv[j]);
@@ -308,6 +320,7 @@ parse_command_line(int argc, char* argv[], options& opts)
 	  if (j >= argc)
 	    {
 	      opts.missing_operand = true;
+	      opts.wrong_option = argv[i];
 	      return true;
 	    }
 	  opts.drop_var_regex_patterns.push_back(argv[j]);
@@ -319,6 +332,7 @@ parse_command_line(int argc, char* argv[], options& opts)
 	  if (j >= argc)
 	    {
 	      opts.missing_operand = true;
+	      opts.wrong_option = argv[i];
 	      return true;
 	    }
 	  opts.keep_fn_regex_patterns.push_back(argv[j]);
@@ -331,6 +345,7 @@ parse_command_line(int argc, char* argv[], options& opts)
 	  if (j >= argc)
 	    {
 	      opts.missing_operand = true;
+	      opts.wrong_option = argv[i];
 	      return true;
 	    }
 	  opts.keep_fn_regex_patterns.push_back(argv[j]);
@@ -341,6 +356,7 @@ parse_command_line(int argc, char* argv[], options& opts)
 	  if (j >= argc)
 	    {
 	      opts.missing_operand = true;
+	      opts.wrong_option = argv[i];
 	      return true;
 	    }
 	  opts.keep_var_regex_patterns.push_back(argv[j]);
@@ -358,7 +374,11 @@ parse_command_line(int argc, char* argv[], options& opts)
       else if (!strcmp(argv[i], "--stats"))
 	opts.show_stats = true;
       else
-	return false;
+	{
+	  if (strlen(argv[i]) >= 2 && argv[i][0] == '-' && argv[i][1] == '-')
+	    opts.wrong_option = argv[i];
+	  return false;
+	}
     }
 
   return true;
@@ -514,7 +534,7 @@ main(int argc, char* argv[])
   options opts;
   if (!parse_command_line(argc, argv, opts))
     {
-      cerr << "unrecognized option\n"
+      cerr << "unrecognized option: " << opts.wrong_option << "\n"
 	"try the --help option for more information\n";
       return (abigail::tools_utils::ABIDIFF_USAGE_ERROR
 	      | abigail::tools_utils::ABIDIFF_ERROR);
@@ -522,7 +542,7 @@ main(int argc, char* argv[])
 
   if (opts.missing_operand)
     {
-      cerr << "missing operand\n"
+      cerr << "missing operand to option: " << opts.wrong_option <<"\n"
 	"try the --help option for more information\n";
       return (abigail::tools_utils::ABIDIFF_USAGE_ERROR
 	      | abigail::tools_utils::ABIDIFF_ERROR);