qlalr: replace QLinkedList with std::list

This is in preparation of deprecating QLinkedList.

Most is straight-forward, except where operator+ was used on linked-list
iterators. In one case, replaced this with std::next, in the other, with
prefix increments, since the advancement was always equal to the loop
control variable. Since advancing a linked-list iterator is a linear
operation, this removes a source of quadratic complexity.

Another obstacle was the overloaded op< set, which was in the Qt namespace
while the iterator is from std and the payload, as before, was global.
This breaks ADL, so move these operators to namespace std. This violates
the standard, but the functions are tagged with our distinct types, so it
shouldn't cause any trouble.

Change-Id: Ifec0a927bfdabb002838cdf86fb8d23b32a38ff7
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

1 files changed, 9 insertions, 8 deletions

diff --git a/src/tools/qlalr/cppgenerator.cpp b/src/tools/qlalr/cppgenerator.cpp
index ee17be041e..95f70dc988 100644
--- a/src/tools/qlalr/cppgenerator.cpp
+++ b/src/tools/qlalr/cppgenerator.cpp
@@ -36,6 +36,8 @@
 #include <QtCore/qfile.h>
 #include <QtCore/qmap.h>
 
+#include <iterator>
+
 namespace {
 
 void generateSeparator(int i, QTextStream &out)
@@ -126,7 +128,7 @@ QString CppGenerator::endIncludeGuard(const QString &fileName)
 void CppGenerator::operator () ()
 {
   // action table...
-  state_count = aut.states.size ();
+  state_count = static_cast<int>(aut.states.size());
   terminal_count = static_cast<int>(grammar.terminals.size());
   non_terminal_count = static_cast<int>(grammar.non_terminals.size());
 
@@ -156,7 +158,7 @@ void CppGenerator::operator () ()
 
           if (grammar.isNonTerminal (a.key ()))
             {
-              Q_ASSERT (symbol >= terminal_count && symbol < grammar.names.size ());
+              Q_ASSERT(symbol >= terminal_count && symbol < static_cast<int>(grammar.names.size()));
               GOTO (q, symbol - terminal_count) = r;
             }
 
@@ -245,7 +247,7 @@ void CppGenerator::operator () ()
              << Qt::endl;
     }
 
-  QBitArray used_rules (grammar.rules.count ());
+  QBitArray used_rules{static_cast<int>(grammar.rules.size())};
 
   int q = 0;
   for (StatePointer state = aut.states.begin (); state != aut.states.end (); ++state, ++q)
@@ -259,12 +261,11 @@ void CppGenerator::operator () ()
         }
     }
 
-  for (int i = 0; i < used_rules.count (); ++i)
+  auto rule = grammar.rules.begin();
+  for (int i = 0; i < used_rules.count (); ++i, ++rule)
     {
       if (! used_rules.testBit (i))
         {
-          RulePointer rule = grammar.rules.begin () + i;
-
           if (rule != grammar.goal)
             qerr() << "*** Warning: Rule ``" << *rule << "'' is useless!" << Qt::endl;
         }
@@ -280,7 +281,7 @@ void CppGenerator::operator () ()
           if (u >= 0)
             continue;
 
-          RulePointer rule = grammar.rules.begin () + (- u - 1);
+          RulePointer rule = std::next(grammar.rules.begin(), - u - 1);
 
           if (state->defaultReduce == rule)
             u = 0;
@@ -619,7 +620,7 @@ void CppGenerator::generateImpl (QTextStream &out)
 
       out << "const int " << grammar.table_name << "::rule_index [] = {";
       idx = 0;
-      int offset = 0;
+      size_t offset = 0;
       for (RulePointer rule = grammar.rules.begin (); rule != grammar.rules.end (); ++rule, ++idx)
         {
           generateSeparator(idx, out);