Merge pull request #5462 from hannes-steffenhagen-diffblue/refactor/split-up-cmdline-parse

Split up the two parts of cmdlinet::parse into separate functions

Author: tautschnig

src/util/cmdline.cpp

@@ -155,100 +155,56 @@ bool cmdlinet::parse(int argc, const char **argv, const char *optstring)
 {
   clear();
 
-  while(optstring[0]!=0)
+  parse_optstring(optstring);
+  return parse_arguments(argc, argv);
+}
+
+cmdlinet::option_namest cmdlinet::option_names() const
+{
+  return option_namest{*this};
+}
+void cmdlinet::parse_optstring(const char *optstring)
+{
+  while(optstring[0] != 0)
   {
     optiont option;
 
     DATA_INVARIANT(
       optstring[0] != ':', "cmdlinet::parse: Invalid option string\n");
 
-    if(optstring[0]=='(')
+    if(optstring[0] == '(')
     {
-      option.islong=true;
-      option.optchar=0;
-      option.isset=false;
+      option.islong = true;
+      option.optchar = 0;
+      option.isset = false;
       option.optstring.clear();
 
-      for(optstring++; optstring[0]!=')' && optstring[0]!=0; optstring++)
-        option.optstring+=optstring[0];
+      for(optstring++; optstring[0] != ')' && optstring[0] != 0; optstring++)
+        option.optstring += optstring[0];
 
-      if(optstring[0]==')')
+      if(optstring[0] == ')')
         optstring++;
     }
     else
     {
-      option.islong=false;
-      option.optchar=optstring[0];
+      option.islong = false;
+      option.optchar = optstring[0];
       option.optstring.clear();
-      option.isset=false;
+      option.isset = false;
 
       optstring++;
     }
 
-    if(optstring[0]==':')
+    if(optstring[0] == ':')
     {
-      option.hasval=true;
+      option.hasval = true;
       optstring++;
     }
     else
-      option.hasval=false;
+      option.hasval = false;
 
     options.push_back(option);
   }
-
-  for(int i=1; i<argc; i++)
-  {
-    if(argv[i][0]!='-')
-      args.push_back(argv[i]);
-    else
-    {
-      optionalt<std::size_t> optnr;
-
-      if(argv[i][1]!=0 && argv[i][2]==0)
-        optnr=getoptnr(argv[i][1]); // single-letter option -X
-      else if(argv[i][1]=='-')
-        optnr=getoptnr(argv[i]+2); // multi-letter option with --XXX
-      else
-      {
-        // Multi-letter option -XXX, or single-letter with argument -Xval
-        // We first try single-letter.
-        optnr=getoptnr(argv[i][1]);
-
-        if(!optnr.has_value()) // try multi-letter
-          optnr=getoptnr(argv[i]+1);
-      }
-
-      if(!optnr.has_value())
-      {
-        unknown_arg=argv[i];
-        return true;
-      }
-
-      options[*optnr].isset=true;
-
-      if(options[*optnr].hasval)
-      {
-        if(argv[i][2]==0 || options[*optnr].islong)
-        {
-          i++;
-          if(i==argc)
-            return true;
-          if(argv[i][0]=='-' && argv[i][1]!=0)
-            return true;
-          options[*optnr].values.push_back(argv[i]);
-        }
-        else
-          options[*optnr].values.push_back(argv[i]+2);
-      }
-    }
-  }
-
-  return false;
-}
-
-cmdlinet::option_namest cmdlinet::option_names() const
-{
-  return option_namest{*this};
 }
 
 std::vector<std::string>
@@ -311,6 +267,57 @@ cmdlinet::get_argument_suggestions(const std::string &unknown_argument)
   return final_suggestions;
 }
 
+bool cmdlinet::parse_arguments(int argc, const char **argv)
+{
+  for(int i = 1; i < argc; i++)
+  {
+    if(argv[i][0] != '-')
+      args.push_back(argv[i]);
+    else
+    {
+      optionalt<std::size_t> optnr;
+
+      if(argv[i][1] != 0 && argv[i][2] == 0)
+        optnr = getoptnr(argv[i][1]); // single-letter option -X
+      else if(argv[i][1] == '-')
+        optnr = getoptnr(argv[i] + 2); // multi-letter option with --XXX
+      else
+      {
+        // Multi-letter option -XXX, or single-letter with argument -Xval
+        // We first try single-letter.
+        optnr = getoptnr(argv[i][1]);
+
+        if(!optnr.has_value()) // try multi-letter
+          optnr = getoptnr(argv[i] + 1);
+      }
+
+      if(!optnr.has_value())
+      {
+        unknown_arg = argv[i];
+        return true;
+      }
+
+      options[*optnr].isset = true;
+
+      if(options[*optnr].hasval)
+      {
+        if(argv[i][2] == 0 || options[*optnr].islong)
+        {
+          i++;
+          if(i == argc)
+            return true;
+          if(argv[i][0] == '-' && argv[i][1] != 0)
+            return true;
+          options[*optnr].values.push_back(argv[i]);
+        }
+        else
+          options[*optnr].values.push_back(argv[i] + 2);
+      }
+    }
+  }
+  return false;
+}
+
 cmdlinet::option_namest::option_names_iteratort::option_names_iteratort(
   const cmdlinet *command_line,
   std::size_t index)

src/util/cmdline.h

@@ -20,6 +20,58 @@ Author: Daniel Kroening, kroening@kroening.com
 class cmdlinet
 {
 public:
+  /// Parses a commandline according to a specification given in \p optstring.
+  /// \param argc How many arguments there are.
+  /// \param argv An array of C strings.
+  ///             The 0th element is assumed to be the name of the command as
+  ///             it was invoked (e.g. /usr/bin/cmake) and is ignored. It is
+  ///             further assumed the array holds \p argc+1 elements with the C
+  ///             string at index argc being a terminating null pointer.
+  ///             This argument is parsed based on \p optstring.
+  /// \param optstring A specification of allowed command line options.
+  ///                  This is a C string container any number of single
+  ///                  characters other than '(', ')' or ':' signifying a
+  ///                  "short" option consisting of just that character, or
+  ///                  names consisting of any characters other than ')'
+  ///                  surrounded by a matching pair of '(' and ')' signifying a
+  ///                  "long" option with the name being the string between '('
+  ///                  and ')', both of which can be optionally followed by a
+  ///                  single ':' indicating that the option takes a argument,
+  ///                  if not present it does not. arguments must be in the
+  ///                  next array element in \p argv , except for short options
+  ///                  whose argument may also be concatenated directly on them.
+  ///
+  ///                  Option names in \p argv must start with either '-' or "--",
+  ///                  no distinction between long and short options is made
+  ///                  here, although it is customary to use only one '-' for
+  ///                  short options and "--" for long options.
+  ///
+  ///                  All options are optional, if some are required it is up
+  ///                  to the user to check that they are present.
+  ///
+  ///                  Examples:
+  ///
+  ///                  argc = 4
+  ///                  argv = `{"name", "-V", "--name", "CProver", nullptr}`
+  ///                  opstring = `"V(version)(name):"`
+  ///
+  ///                  here the argument to "name" would be "CProver", and
+  ///                  "V" is a short option passed without arguments.
+  ///
+  ///                  argc = 3
+  ///                  argv = `{"other-name", "-fFilename", "--trace", nullptr}`
+  ///                  optstring = `"f:(trace)(some-other-option):G"`
+  ///
+  ///                  here the argument to option "f" would be "Filename",
+  ///                  "trace" is a long option with no argument, and
+  ///                  "some-other-option" and "G" are both allowed options that
+  ///                  don’t appear on the commandline (with and without
+  ///                  argument respectively).
+  ///
+  /// \return true if there was an error while parsing argv, false otherwise. If
+  ///              this failed due to an unknown option name being in argv, the
+  ///              public variable cmdlinet::unknown_arg will be non-empty and
+  ///              contain the name of that option.
   virtual bool parse(int argc, const char **argv, const char *optstring);
 
   std::string get_value(char option) const;
@@ -115,6 +167,18 @@ class cmdlinet
     {}
   };
 
+  /// Parses an optstring and writes the result to cmdlinet::options.
+  /// It is considered a logic error to pass an invalid option string here.
+  /// \see cmdlinet::parse(int,const char**,const char*)
+  ///         for details on the format of the optstring
+  void parse_optstring(const char *optstring);
+
+  /// Parses a commandline according to a previously parsed optstring and
+  /// writes the result to cmdlinet::options.
+  /// \see cmdlinet::parse(int,const char**,const char*)
+  ///         for details the meaning of argc and argv
+  bool parse_arguments(int argc, const char **argv);
+
   std::vector<optiont> options;
 
   optionalt<std::size_t> getoptnr(char option) const;