/*
* The main RegexCode generator. It does a depth-first walk
* through the tree and calls EmitFragment to emits code before
* and after each child of an interior node, and at each leaf.
*/
internal void EmitFragment(int nodetype, RegexNode node, int CurIndex)
{
int bits = 0;
if (nodetype <= RegexNode.Ref)
{
if (node.UseOptionR())
{
bits |= RegexCode.Rtl;
}
if ((node._options & RegexOptions.IgnoreCase) != 0)
{
bits |= RegexCode.Ci;
}
}
switch (nodetype)
{
case RegexNode.Concatenate | BeforeChild:
case RegexNode.Concatenate | AfterChild:
case RegexNode.Empty:
break;
case RegexNode.Alternate | BeforeChild:
if (CurIndex < node._children.Count - 1)
{
PushInt(CurPos());
Emit(RegexCode.Lazybranch, 0);
}
break;
case RegexNode.Alternate | AfterChild: {
if (CurIndex < node._children.Count - 1)
{
int LBPos = PopInt();
PushInt(CurPos());
Emit(RegexCode.Goto, 0);
PatchJump(LBPos, CurPos());
}
else
{
int I;
for (I = 0; I < CurIndex; I++)
{
PatchJump(PopInt(), CurPos());
}
}
break;
}
case RegexNode.Testref | BeforeChild:
switch (CurIndex)
{
case 0:
Emit(RegexCode.Setjump);
PushInt(CurPos());
Emit(RegexCode.Lazybranch, 0);
Emit(RegexCode.Testref, MapCapnum(node._m));
Emit(RegexCode.Forejump);
break;
}
break;
case RegexNode.Testref | AfterChild:
switch (CurIndex)
{
case 0: {
int Branchpos = PopInt();
PushInt(CurPos());
Emit(RegexCode.Goto, 0);
PatchJump(Branchpos, CurPos());
Emit(RegexCode.Forejump);
if (node._children.Count > 1)
{
break;
}
// else fallthrough
goto case 1;
}
case 1:
PatchJump(PopInt(), CurPos());
break;
}
break;
case RegexNode.Testgroup | BeforeChild:
switch (CurIndex)
{
case 0:
Emit(RegexCode.Setjump);
Emit(RegexCode.Setmark);
PushInt(CurPos());
Emit(RegexCode.Lazybranch, 0);
break;
}
break;
case RegexNode.Testgroup | AfterChild:
switch (CurIndex)
{
case 0:
Emit(RegexCode.Getmark);
Emit(RegexCode.Forejump);
break;
case 1:
int Branchpos = PopInt();
PushInt(CurPos());
Emit(RegexCode.Goto, 0);
PatchJump(Branchpos, CurPos());
Emit(RegexCode.Getmark);
Emit(RegexCode.Forejump);
if (node._children.Count > 2)
{
break;
}
// else fallthrough
goto case 2;
case 2:
PatchJump(PopInt(), CurPos());
break;
}
break;
case RegexNode.Loop | BeforeChild:
case RegexNode.Lazyloop | BeforeChild:
if (node._n < Int32.MaxValue || node._m > 1)
{
Emit(node._m == 0 ? RegexCode.Nullcount : RegexCode.Setcount, node._m == 0 ? 0 : 1 - node._m);
}
else
{
Emit(node._m == 0 ? RegexCode.Nullmark : RegexCode.Setmark);
}
if (node._m == 0)
{
PushInt(CurPos());
Emit(RegexCode.Goto, 0);
}
PushInt(CurPos());
break;
case RegexNode.Loop | AfterChild:
case RegexNode.Lazyloop | AfterChild: {
int StartJumpPos = CurPos();
int Lazy = (nodetype - (RegexNode.Loop | AfterChild));
if (node._n < Int32.MaxValue || node._m > 1)
{
Emit(RegexCode.Branchcount + Lazy, PopInt(), node._n == Int32.MaxValue ? Int32.MaxValue : node._n - node._m);
}
else
{
Emit(RegexCode.Branchmark + Lazy, PopInt());
}
if (node._m == 0)
{
PatchJump(PopInt(), StartJumpPos);
}
}
break;
case RegexNode.Group | BeforeChild:
case RegexNode.Group | AfterChild:
break;
case RegexNode.Capture | BeforeChild:
Emit(RegexCode.Setmark);
break;
case RegexNode.Capture | AfterChild:
Emit(RegexCode.Capturemark, MapCapnum(node._m), MapCapnum(node._n));
break;
case RegexNode.Require | BeforeChild:
// NOTE: the following line causes lookahead/lookbehind to be
// NON-BACKTRACKING. It can be commented out with (*)
Emit(RegexCode.Setjump);
Emit(RegexCode.Setmark);
break;
case RegexNode.Require | AfterChild:
Emit(RegexCode.Getmark);
// NOTE: the following line causes lookahead/lookbehind to be
// NON-BACKTRACKING. It can be commented out with (*)
Emit(RegexCode.Forejump);
break;
case RegexNode.Prevent | BeforeChild:
Emit(RegexCode.Setjump);
PushInt(CurPos());
Emit(RegexCode.Lazybranch, 0);
break;
case RegexNode.Prevent | AfterChild:
Emit(RegexCode.Backjump);
PatchJump(PopInt(), CurPos());
Emit(RegexCode.Forejump);
break;
case RegexNode.Greedy | BeforeChild:
Emit(RegexCode.Setjump);
break;
case RegexNode.Greedy | AfterChild:
Emit(RegexCode.Forejump);
break;
case RegexNode.One:
case RegexNode.Notone:
Emit(node._type | bits, (int)node._ch);
break;
case RegexNode.Notoneloop:
case RegexNode.Notonelazy:
case RegexNode.Oneloop:
case RegexNode.Onelazy:
if (node._m > 0)
{
Emit(((node._type == RegexNode.Oneloop || node._type == RegexNode.Onelazy) ?
RegexCode.Onerep : RegexCode.Notonerep) | bits, (int)node._ch, node._m);
}
if (node._n > node._m)
{
Emit(node._type | bits, (int)node._ch, node._n == Int32.MaxValue ?
Int32.MaxValue : node._n - node._m);
}
break;
case RegexNode.Setloop:
case RegexNode.Setlazy:
if (node._m > 0)
{
Emit(RegexCode.Setrep | bits, StringCode(node._str), node._m);
}
if (node._n > node._m)
{
Emit(node._type | bits, StringCode(node._str),
(node._n == Int32.MaxValue) ? Int32.MaxValue : node._n - node._m);
}
break;
case RegexNode.Multi:
Emit(node._type | bits, StringCode(node._str));
break;
case RegexNode.Set:
Emit(node._type | bits, StringCode(node._str));
break;
case RegexNode.Ref:
Emit(node._type | bits, MapCapnum(node._m));
break;
case RegexNode.Nothing:
case RegexNode.Bol:
case RegexNode.Eol:
case RegexNode.Boundary:
case RegexNode.Nonboundary:
case RegexNode.ECMABoundary:
case RegexNode.NonECMABoundary:
case RegexNode.Beginning:
case RegexNode.Start:
case RegexNode.EndZ:
case RegexNode.End:
Emit(node._type);
break;
default:
throw MakeException(SR.GetString(SR.UnexpectedOpcode, nodetype.ToString(CultureInfo.CurrentCulture)));
}
}
