remove 100-levels config nesting limit

The actual reason for this commit isn't the limit – there isn't much
point in using that much nesting – its in shutting up gcc mostly:

apt/apt-pkg/contrib/configuration.cc: In function ‘bool ReadConfigFile(Configuration&, const string&, const bool&, const unsigned int&)’:
apt/apt-pkg/contrib/configuration.cc:686:20: warning: cannot optimize loop, the loop counter may overflow [-Wunsafe-loop-optimizations]
    string Stack[100];
                    ^
by replacing this with C++s handy std::stack container (adapter).
Also cleans some whitespace noise from the file in the process.

diff --git a/apt-pkg/contrib/configuration.cc b/apt-pkg/contrib/configuration.cc
index d4bb72a8b61ea606e161163308f008e2941b588b..3cb7fde06507740ea8c8886ddd12444eb9cf5f76 100644 (file)
--- a/apt-pkg/contrib/configuration.cc
+++ b/apt-pkg/contrib/configuration.cc
@@ -29,8 +29,10 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+
 #include <algorithm>
 #include <string>
+#include <stack>
 #include <vector>
 #include <fstream>
 
@@ -674,6 +676,16 @@ string Configuration::Item::FullTag(const Item *Stop) const
    sections like 'zone "foo.org" { .. };' This causes each section to be
    added in with a tag like "zone::foo.org" instead of being split 
    tag/value. AsSectional enables Sectional parsing.*/
+static void leaveCurrentScope(std::stack<std::string> &Stack, std::string &ParentTag)
+{
+   if (Stack.empty())
+      ParentTag.clear();
+   else
+   {
+      ParentTag = Stack.top();
+      Stack.pop();
+   }
+}
 bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectional,
                    unsigned const &Depth)
 {
@@ -683,8 +695,7 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectio
       return _error->Errno("ifstream::ifstream",_("Opening configuration file %s"),FName.c_str());
 
    string LineBuffer;
-   string Stack[100];
-   unsigned int StackPos = 0;
+   std::stack<std::string> Stack;
 
    // Parser state
    string ParentTag;
@@ -753,12 +764,12 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectio
               Start = I + 2;
               InComment = false;
               break;
-           }       
+           }
         }
         if (InComment == true)
            continue;
       }
-      
+
       // Discard single line comments
       bool InQuote = false;
       for (std::string::const_iterator I = Start;
@@ -803,9 +814,9 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectio
                  I = J + 1;
                  InComment = false;
                  break;
-              }               
+              }
            }
-           
+
            if (InComment == true)
              break;
         }
@@ -816,7 +827,7 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectio
       // Skip blank lines.
       if (Fragment.empty())
         continue;
-      
+
       // The line has actual content; interpret what it means.
       InQuote = false;
       Start = Fragment.begin();
@@ -826,7 +837,7 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectio
       {
         if (*I == '"')
            InQuote = !InQuote;
-        
+
         if (InQuote == false && (*I == '{' || *I == ';' || *I == '}'))
         {
            // Put the last fragment into the buffer
@@ -845,24 +856,19 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectio
            // brace or a semicolon)
            char TermChar = *I;
            Start = I + 1;
-           
+
            // Syntax Error
            if (TermChar == '{' && LineBuffer.empty() == true)
               return _error->Error(_("Syntax error %s:%u: Block starts with no name."),FName.c_str(),CurLine);
-           
+
            // No string on this line
            if (LineBuffer.empty() == true)
            {
               if (TermChar == '}')
-              {
-                 if (StackPos == 0)
-                    ParentTag = string();
-                 else
-                    ParentTag = Stack[--StackPos];
-              }
+                 leaveCurrentScope(Stack, ParentTag);
               continue;
            }
-           
+
            // Parse off the tag
            string Tag;
            const char *Pos = LineBuffer.c_str();
@@ -889,25 +895,23 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectio
            // Go down a level
            if (TermChar == '{')
            {
-              if (StackPos < sizeof(Stack)/sizeof(std::string))
-                 Stack[StackPos++] = ParentTag;
-              
+              Stack.push(ParentTag);
+
               /* Make sectional tags incorperate the section into the
                  tag string */
               if (AsSectional == true && Word.empty() == false)
               {
-                 Tag += "::" ;
-                 Tag += Word;
-                 Word = "";
+                 Tag.append("::").append(Word);
+                 Word.clear();
               }
-              
+
               if (ParentTag.empty() == true)
                  ParentTag = Tag;
               else
-                 ParentTag += string("::") + Tag;
-              Tag = string();
+                 ParentTag.append("::").append(Tag);
+              Tag.clear();
            }
-           
+
            // Generate the item name
            string Item;
            if (ParentTag.empty() == true)
@@ -919,7 +923,7 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectio
               else
                  Item = ParentTag;
            }
-           
+
            // Specials
            if (Tag.length() >= 1 && Tag[0] == '#')
            {
@@ -941,7 +945,7 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectio
                  {
                     if (ReadConfigFile(Conf,Word,AsSectional,Depth+1) == false)
                        return _error->Error(_("Syntax error %s:%u: Included from here"),FName.c_str(),CurLine);
-                 }               
+                 }
               }
               else
                  return _error->Error(_("Syntax error %s:%u: Unsupported directive '%s'"),FName.c_str(),CurLine,Tag.c_str());
@@ -954,19 +958,13 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectio
               if (NoWord == false)
                  Conf.Set(Item,Word);
            }
-           
+
            // Empty the buffer
            LineBuffer.clear();
-           
+
            // Move up a tag, but only if there is no bit to parse
            if (TermChar == '}')
-           {
-              if (StackPos == 0)
-                 ParentTag.clear();
-              else
-                 ParentTag = Stack[--StackPos];
-           }
-           
+              leaveCurrentScope(Stack, ParentTag);
         }
       }