Refactor named group handling for conditional tests.

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@1365 2f5784b3-3f2a-0410-8824-cb99058d5e15

1 files changed, 87 insertions, 171 deletions

diff --git a/pcre_exec.c b/pcre_exec.c
index 1607fed..36f0a7a 100644
--- a/pcre_exec.c
+++ b/pcre_exec.c
@@ -1274,25 +1274,32 @@ for (;;)
 
     /* Control never reaches here. */
 
-    /* Conditional group: compilation checked that there are no more than
-    two branches. If the condition is false, skipping the first branch takes us
-    past the end if there is only one branch, but that's OK because that is
-    exactly what going to the ket would do. */
+    /* Conditional group: compilation checked that there are no more than two
+    branches. If the condition is false, skipping the first branch takes us
+    past the end of the item if there is only one branch, but that's exactly
+    what we want. */
 
     case OP_COND:
     case OP_SCOND:
-    codelink = GET(ecode, 1);
+    
+    /* The variable codelink will be added to ecode when the condition is 
+    false, to get to the second branch. Setting it to the offset to the ALT 
+    or KET, then incrementing ecode achieves this effect. We now have ecode 
+    pointing to the condition or callout. */
+ 
+    codelink = GET(ecode, 1);   /* Offset to the second branch */
+    ecode += 1 + LINK_SIZE;     /* From this opcode */
 
     /* Because of the way auto-callout works during compile, a callout item is
     inserted between OP_COND and an assertion condition. */
 
-    if (ecode[LINK_SIZE+1] == OP_CALLOUT)
+    if (*ecode == OP_CALLOUT)
       {
       if (PUBL(callout) != NULL)
         {
         PUBL(callout_block) cb;
         cb.version          = 2;   /* Version 1 of the callout block */
-        cb.callout_number   = ecode[LINK_SIZE+2];
+        cb.callout_number   = ecode[1];
         cb.offset_vector    = md->offset_vector;
 #if defined COMPILE_PCRE8
         cb.subject          = (PCRE_SPTR)md->start_subject;
@@ -1304,8 +1311,8 @@ for (;;)
         cb.subject_length   = (int)(md->end_subject - md->start_subject);
         cb.start_match      = (int)(mstart - md->start_subject);
         cb.current_position = (int)(eptr - md->start_subject);
-        cb.pattern_position = GET(ecode, LINK_SIZE + 3);
-        cb.next_item_length = GET(ecode, 3 + 2*LINK_SIZE);
+        cb.pattern_position = GET(ecode, 2);
+        cb.next_item_length = GET(ecode, 2 + LINK_SIZE);
         cb.capture_top      = offset_top/2;
         cb.capture_last     = md->capture_last & CAPLMASK;
         /* Internal change requires this for API compatibility. */
@@ -1315,207 +1322,119 @@ for (;;)
         if ((rrc = (*PUBL(callout))(&cb)) > 0) RRETURN(MATCH_NOMATCH);
         if (rrc < 0) RRETURN(rrc);
         }
+        
+      /* Advance ecode past the callout, so it now points to the condition. We 
+      must adjust codelink so that the value of ecode+codelink is unchanged. */
+       
       ecode += PRIV(OP_lengths)[OP_CALLOUT];
       codelink -= PRIV(OP_lengths)[OP_CALLOUT];
       }
 
-    condcode = ecode[LINK_SIZE+1];
+    /* Test the various possible conditions */
 
-    /* Now see what the actual condition is */
-
-    if (condcode == OP_RREF || condcode == OP_NRREF)    /* Recursion test */
-      {
-      if (md->recursive == NULL)                /* Not recursing => FALSE */
+    condition = FALSE;
+    switch(condcode = *ecode)
+      { 
+      case OP_RREF:         /* Numbered group recursion test */
+      if (md->recursive != NULL)     /* Not recursing => FALSE */
         {
-        condition = FALSE;
-        ecode += GET(ecode, 1);
-        }
-      else
-        {
-        unsigned int recno = GET2(ecode, LINK_SIZE + 2);   /* Recursion group number*/
+        unsigned int recno = GET2(ecode, 1);   /* Recursion group number*/
         condition = (recno == RREF_ANY || recno == md->recursive->group_num);
+        }
+      break;
 
-        /* If the test is for recursion into a specific subpattern, and it is
-        false, but the test was set up by name, scan the table to see if the
-        name refers to any other numbers, and test them. The condition is true
-        if any one is set. */
-
-        if (!condition && condcode == OP_NRREF)
+      case OP_DNRREF:       /* Duplicate named group recursion test */
+      if (md->recursive != NULL)
+        {       
+        int count = GET2(ecode, 1 + IMM2_SIZE); 
+        pcre_uchar *slot = md->name_table + GET2(ecode, 1) * md->name_entry_size;
+        while (count-- > 0)
           {
-          pcre_uchar *slotA = md->name_table;
-          for (i = 0; i < md->name_count; i++)
-            {
-            if (GET2(slotA, 0) == recno) break;
-            slotA += md->name_entry_size;
-            }
-
-          /* Found a name for the number - there can be only one; duplicate
-          names for different numbers are allowed, but not vice versa. First
-          scan down for duplicates. */
-
-          if (i < md->name_count)
-            {
-            pcre_uchar *slotB = slotA;
-            while (slotB > md->name_table)
-              {
-              slotB -= md->name_entry_size;
-              if (STRCMP_UC_UC(slotA + IMM2_SIZE, slotB + IMM2_SIZE) == 0)
-                {
-                condition = GET2(slotB, 0) == md->recursive->group_num;
-                if (condition) break;
-                }
-              else break;
-              }
-
-            /* Scan up for duplicates */
-
-            if (!condition)
-              {
-              slotB = slotA;
-              for (i++; i < md->name_count; i++)
-                {
-                slotB += md->name_entry_size;
-                if (STRCMP_UC_UC(slotA + IMM2_SIZE, slotB + IMM2_SIZE) == 0)
-                  {
-                  condition = GET2(slotB, 0) == md->recursive->group_num;
-                  if (condition) break;
-                  }
-                else break;
-                }
-              }
-            }
+          unsigned int recno = GET2(slot, 0);
+          condition = recno == md->recursive->group_num;
+          if (condition) break;
+          slot += md->name_entry_size;
           }
+        }   
+      break;
 
-        /* Chose branch according to the condition */
-
-        ecode += condition? 1 + IMM2_SIZE : GET(ecode, 1);
-        }
-      }
-
-    else if (condcode == OP_CREF || condcode == OP_NCREF)  /* Group used test */
-      {
-      offset = GET2(ecode, LINK_SIZE+2) << 1;  /* Doubled ref number */
+      case OP_CREF:         /* Numbered group used test */
+      offset = GET2(ecode, 1) << 1;  /* Doubled ref number */
       condition = offset < offset_top && md->offset_vector[offset] >= 0;
+      break;
 
-      /* If the numbered capture is unset, but the reference was by name,
-      scan the table to see if the name refers to any other numbers, and test
-      them. The condition is true if any one is set. This is tediously similar
-      to the code above, but not close enough to try to amalgamate. */
-
-      if (!condition && condcode == OP_NCREF)
+      case OP_DNCREF:      /* Duplicate named group used test */
         {
-        unsigned int refno = offset >> 1;
-        pcre_uchar *slotA = md->name_table;
-
-        for (i = 0; i < md->name_count; i++)
+        int count = GET2(ecode, 1 + IMM2_SIZE); 
+        pcre_uchar *slot = md->name_table + GET2(ecode, 1) * md->name_entry_size;
+        while (count-- > 0)
           {
-          if (GET2(slotA, 0) == refno) break;
-          slotA += md->name_entry_size;
-          }
-
-        /* Found a name for the number - there can be only one; duplicate names
-        for different numbers are allowed, but not vice versa. First scan down
-        for duplicates. */
-
-        if (i < md->name_count)
-          {
-          pcre_uchar *slotB = slotA;
-          while (slotB > md->name_table)
-            {
-            slotB -= md->name_entry_size;
-            if (STRCMP_UC_UC(slotA + IMM2_SIZE, slotB + IMM2_SIZE) == 0)
-              {
-              offset = GET2(slotB, 0) << 1;
-              condition = offset < offset_top &&
-                md->offset_vector[offset] >= 0;
-              if (condition) break;
-              }
-            else break;
-            }
-
-          /* Scan up for duplicates */
-
-          if (!condition)
-            {
-            slotB = slotA;
-            for (i++; i < md->name_count; i++)
-              {
-              slotB += md->name_entry_size;
-              if (STRCMP_UC_UC(slotA + IMM2_SIZE, slotB + IMM2_SIZE) == 0)
-                {
-                offset = GET2(slotB, 0) << 1;
-                condition = offset < offset_top &&
-                  md->offset_vector[offset] >= 0;
-                if (condition) break;
-                }
-              else break;
-              }
-            }
+          offset = GET2(slot, 0) << 1;
+          condition = offset < offset_top && md->offset_vector[offset] >= 0;
+          if (condition) break;
+          slot += md->name_entry_size;
           }
         }
+      break;   
 
-      /* Chose branch according to the condition */
-
-      ecode += condition? 1 + IMM2_SIZE : GET(ecode, 1);
-      }
-
-    else if (condcode == OP_DEF)     /* DEFINE - always false */
-      {
-      condition = FALSE;
-      ecode += GET(ecode, 1);
-      }
-
-    /* The condition is an assertion. Call match() to evaluate it - setting
-    md->match_function_type to MATCH_CONDASSERT causes it to stop at the end of
-    an assertion. */
+      case OP_DEF:     /* DEFINE - always false */
+      break;
 
-    else
-      {
+      /* The condition is an assertion. Call match() to evaluate it - setting
+      md->match_function_type to MATCH_CONDASSERT causes it to stop at the end
+      of an assertion. */
+      
+      default: 
       md->match_function_type = MATCH_CONDASSERT;
-      RMATCH(eptr, ecode + 1 + LINK_SIZE, offset_top, md, NULL, RM3);
+      RMATCH(eptr, ecode, offset_top, md, NULL, RM3);
       if (rrc == MATCH_MATCH)
         {
         if (md->end_offset_top > offset_top)
           offset_top = md->end_offset_top;  /* Captures may have happened */
         condition = TRUE;
-        ecode += 1 + LINK_SIZE + GET(ecode, LINK_SIZE + 2);
+         
+        /* Advance ecode past the assertion to the start of the first branch, 
+        but adjust it so that the general choosing code below works. */
+ 
+        ecode += GET(ecode, 1);
         while (*ecode == OP_ALT) ecode += GET(ecode, 1);
+        ecode += 1 + LINK_SIZE - PRIV(OP_lengths)[condcode]; 
         }
 
       /* PCRE doesn't allow the effect of (*THEN) to escape beyond an
-      assertion; it is therefore treated as NOMATCH. */
+      assertion; it is therefore treated as NOMATCH. Any other return is an 
+      error. */
 
       else if (rrc != MATCH_NOMATCH && rrc != MATCH_THEN)
         {
         RRETURN(rrc);         /* Need braces because of following else */
         }
-      else
-        {
-        condition = FALSE;
-        ecode += codelink;
-        }
+      break;   
       }
-
-    /* We are now at the branch that is to be obeyed. As there is only one, can
-    use tail recursion to avoid using another stack frame, except when there is
-    unlimited repeat of a possibly empty group. In the latter case, a recursive
-    call to match() is always required, unless the second alternative doesn't
-    exist, in which case we can just plough on. Note that, for compatibility
-    with Perl, the | in a conditional group is NOT treated as creating two
-    alternatives. If a THEN is encountered in the branch, it propagates out to
-    the enclosing alternative (unless nested in a deeper set of alternatives,
-    of course). */
-
-    if (condition || *ecode == OP_ALT)
+      
+    /* Choose branch according to the condition */
+      
+    ecode += condition? PRIV(OP_lengths)[condcode] : codelink;
+ 
+    /* We are now at the branch that is to be obeyed. As there is only one, we
+    can use tail recursion to avoid using another stack frame, except when
+    there is unlimited repeat of a possibly empty group. In the latter case, a
+    recursive call to match() is always required, unless the second alternative
+    doesn't exist, in which case we can just plough on. Note that, for
+    compatibility with Perl, the | in a conditional group is NOT treated as
+    creating two alternatives. If a THEN is encountered in the branch, it
+    propagates out to the enclosing alternative (unless nested in a deeper set
+    of alternatives, of course). */
+    
+    if (condition || ecode[-(1+LINK_SIZE)] == OP_ALT)
       {
       if (op != OP_SCOND)
         {
-        ecode += 1 + LINK_SIZE;
         goto TAIL_RECURSE;
         }
 
       md->match_function_type = MATCH_CBEGROUP;
-      RMATCH(eptr, ecode + 1 + LINK_SIZE, offset_top, md, eptrb, RM49);
+      RMATCH(eptr, ecode, offset_top, md, eptrb, RM49);
       RRETURN(rrc);
       }
 
@@ -1523,7 +1442,6 @@ for (;;)
 
     else
       {
-      ecode += 1 + LINK_SIZE;
       }
     break;
 
@@ -2783,8 +2701,6 @@ for (;;)
     caseless = op == OP_REFI;
     offset = GET2(ecode, 1) << 1;               /* Doubled ref number */
     ecode += 1 + IMM2_SIZE;
-
-
     if (offset >= offset_top || md->offset_vector[offset] < 0)
       length = (md->jscript_compat)? 0 : -1;
     else