- Change to two pass generation which allows to avoid warnings about unused

  labels. We first generate virtually everything and store which labels are
  used and then generate the stuff while only writing used labels.

diff --git a/code.cc b/code.cc
index 13198019c9dfc6b87577beae74223d0fae9724cf..26982b1437fe3b851cc387f29b64963d8e1a7f1f 100644 (file)
--- a/code.cc
+++ b/code.cc
@@ -260,6 +260,7 @@ void genGoTo(std::ostream &o, State *from, State *to, bool & readCh)
 
        o << "\tgoto yy" << to->label << ";\n";
        ++oline;
+       vUsedLabels.append(to->label);
 }
 
 void genIf(std::ostream &o, char *cmp, uint v, bool &readCh)
@@ -715,7 +716,10 @@ void Go::genGoto(std::ostream &o, State *from, State *next, bool &readCh)
 
 void State::emit(std::ostream &o, bool &readCh)
 {
-       o << "yy" << label << ":";
+       if (vUsedLabels.contains(label))
+       {
+               o << "yy" << label << ":";
+       }
        /*    o << "\nfprintf(stderr, \"<" << label << ">\");\n";*/
        action->emit(o, readCh);
 }
@@ -947,6 +951,38 @@ void DFA::split(State *s)
        s->go.span[0].to = move;
 }
 
+class null_stream: public std::ostream
+{
+public:
+       null_stream()
+               : std::ostream(&ns)
+       {
+       }
+
+       null_stream& put(char_type)
+       {
+               // nothing to do
+               return *this;
+       }
+       
+       null_stream& write(const char_type *, std::streamsize)
+       {
+               // nothing to do
+               return *this;
+       }
+
+protected:
+       class null_streambuf: public std::streambuf
+       {
+       public:
+               null_streambuf()
+                       : std::streambuf()
+               {
+               }       
+       };
+       null_streambuf   ns;
+};
+
 void DFA::emit(std::ostream &o)
 {
        static uint label = 0;
@@ -1114,6 +1150,7 @@ void DFA::emit(std::ostream &o)
 
        o << "\tgoto yy" << label << ";\n";
        ++oline;
+       vUsedLabels.append(label);
        (void) new Enter(head, label++);
 
        for (s = head; s; s = s->next)
@@ -1121,6 +1158,17 @@ void DFA::emit(std::ostream &o)
                s->label = label++;
        }
 
+       null_stream noWhere;
+
+       unsigned int nOrgOline = oline;
+       for (s = head; s; s = s->next)
+       {
+               bool readCh = false;
+               s->emit(noWhere, readCh);
+               s->go.genGoto(noWhere, s, s->next, readCh);
+       }
+       oline = nOrgOline;
+
        for (s = head; s; s = s->next)
        {
                bool readCh = false;

diff --git a/globals.h b/globals.h
index 8a59104dd600952ef5f8a5d99768f70e7b0f7058..39f6f1db2d9454b66bc09d6541e4d53e56cf4955 100644 (file)
--- a/globals.h
+++ b/globals.h
@@ -3,6 +3,30 @@
 #define        _globals_h
 
 #include "basics.h"
+#include <list>
+#include <algorithm>
+
+template<typename _Ty>
+class label_list: protected std::list<_Ty>
+{
+public:
+       label_list()
+               : std::list<_Ty>()
+       {
+       }
+       
+       void append(const _Ty &val)
+       {
+               push_back(val);
+               sort();
+               unique();
+       }
+       
+       bool contains(const _Ty &val)
+       {
+               return std::find(begin(), end(), val) != end();
+       }
+};
 
 namespace re2c
 {
@@ -18,6 +42,8 @@ extern uchar ebc2asc[256];
 
 extern uchar *xlat, *talx;
 
+extern label_list<uint> vUsedLabels;
+
 } // end namespace re2c
 
 #endif

diff --git a/main.cc b/main.cc
index 78452626c96056647858443a52d6f7e98545a021..77c7747a9dea1f0b94991e2e49ea01c0f682b866 100644 (file)
--- a/main.cc
+++ b/main.cc
@@ -21,6 +21,7 @@ char *outputFileName = 0;
 bool sFlag = false;
 bool bFlag = false;
 unsigned int oline = 1;
+label_list<uint> vUsedLabels;
 
 using namespace std;