--- /dev/null
+/** Support functions for traversing cyclic DFA states as laid\r
+ * out in static initialized structures by the code generator.\r
+ *\r
+ * A DFA implemented as a set of transition tables.\r
+ *\r
+ * Any state that has a semantic predicate edge is special; those states\r
+ * are generated with if-then-else structures in a ->specialStateTransition()\r
+ * which is generated by cyclicDFA template.\r
+ *\r
+ * There are at most 32767 states (16-bit signed short).\r
+ * Could get away with byte sometimes but would have to generate different\r
+ * types and the simulation code too. For a point of reference, the Java\r
+ * lexer's Tokens rule DFA has 326 states roughly.\r
+ */\r
+\r
+// [The "BSD licence"]\r
+// Copyright (c) 2005-2009 Jim Idle, Temporal Wave LLC\r
+// http://www.temporal-wave.com\r
+// http://www.linkedin.com/in/jimidle\r
+//\r
+// All rights reserved.\r
+//\r
+// Redistribution and use in source and binary forms, with or without\r
+// modification, are permitted provided that the following conditions\r
+// are met:\r
+// 1. Redistributions of source code must retain the above copyright\r
+// notice, this list of conditions and the following disclaimer.\r
+// 2. Redistributions in binary form must reproduce the above copyright\r
+// notice, this list of conditions and the following disclaimer in the\r
+// documentation and/or other materials provided with the distribution.\r
+// 3. The name of the author may not be used to endorse or promote products\r
+// derived from this software without specific prior written permission.\r
+//\r
+// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR\r
+// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES\r
+// OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.\r
+// IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,\r
+// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT\r
+// NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,\r
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY\r
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT\r
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF\r
+// THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.\r
+\r
+#include <antlr3defs.h>\r
+#include <antlr3cyclicdfa.h>\r
+\r
+#ifdef ANTLR3_WINDOWS\r
+#pragma warning( disable : 4100 )\r
+#endif\r
+\r
+static void\r
+noViableAlt(pANTLR3_BASE_RECOGNIZER rec, pANTLR3_CYCLIC_DFA cdfa, ANTLR3_UINT32 s)\r
+{\r
+ // In backtracking mode, we just set the failed flag so that the\r
+ // alt can just exit right now. If we are parsing though, then \r
+ // we want the exception to be raised.\r
+ //\r
+ if (rec->state->backtracking > 0)\r
+ {\r
+ rec->state->failed = ANTLR3_TRUE;\r
+ }\r
+ else\r
+ {\r
+ rec->exConstruct(rec);\r
+ rec->state->exception->type = ANTLR3_NO_VIABLE_ALT_EXCEPTION;\r
+ rec->state->exception->message = cdfa->description;\r
+ rec->state->exception->decisionNum = cdfa->decisionNumber;\r
+ rec->state->exception->state = s;\r
+ }\r
+}\r
+\r
+/** From the input stream, predict what alternative will succeed\r
+ * using this DFA (representing the covering regular approximation\r
+ * to the underlying CFL). Return an alternative number 1..n. Throw\r
+ * an exception upon error.\r
+ */\r
+ANTLR3_API ANTLR3_INT32\r
+antlr3dfapredict (void * ctx, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_INT_STREAM is, pANTLR3_CYCLIC_DFA cdfa)\r
+{\r
+ ANTLR3_MARKER mark;\r
+ ANTLR3_INT32 s;\r
+ ANTLR3_INT32 specialState;\r
+ ANTLR3_INT32 c;\r
+\r
+ mark = is->mark(is); /* Store where we are right now */\r
+ s = 0; /* Always start with state 0 */\r
+ \r
+ for (;;)\r
+ {\r
+ /* Pick out any special state entry for this state\r
+ */\r
+ specialState = cdfa->special[s];\r
+\r
+ /* Transition the special state and consume an input token\r
+ */\r
+ if (specialState >= 0)\r
+ {\r
+ s = cdfa->specialStateTransition(ctx, rec, is, cdfa, specialState);\r
+\r
+ // Error?\r
+ //\r
+ if (s<0)\r
+ {\r
+ // If the predicate/rule raised an exception then we leave it\r
+ // in tact, else we have an NVA.\r
+ //\r
+ if (rec->state->error != ANTLR3_TRUE)\r
+ {\r
+ noViableAlt(rec,cdfa, s);\r
+ }\r
+ is->rewind(is, mark);\r
+ return 0;\r
+ }\r
+ is->consume(is);\r
+ continue;\r
+ }\r
+\r
+ /* Accept state?\r
+ */\r
+ if (cdfa->accept[s] >= 1)\r
+ {\r
+ is->rewind(is, mark);\r
+ return cdfa->accept[s];\r
+ }\r
+\r
+ /* Look for a normal transition state based upon the input token element\r
+ */\r
+ c = is->_LA(is, 1);\r
+\r
+ /* Check against min and max for this state\r
+ */\r
+ if (c>= cdfa->min[s] && c <= cdfa->max[s])\r
+ {\r
+ ANTLR3_INT32 snext;\r
+\r
+ /* What is the next state?\r
+ */\r
+ snext = cdfa->transition[s][c - cdfa->min[s]];\r
+\r
+ if (snext < 0)\r
+ {\r
+ /* Was in range but not a normal transition\r
+ * must check EOT, which is like the else clause.\r
+ * eot[s]>=0 indicates that an EOT edge goes to another\r
+ * state.\r
+ */\r
+ if (cdfa->eot[s] >= 0)\r
+ {\r
+ s = cdfa->eot[s];\r
+ is->consume(is);\r
+ continue;\r
+ }\r
+ noViableAlt(rec,cdfa, s);\r
+ is->rewind(is, mark);\r
+ return 0;\r
+ }\r
+\r
+ /* New current state - move to it\r
+ */\r
+ s = snext;\r
+ is->consume(is);\r
+ continue;\r
+ }\r
+ /* EOT Transition?\r
+ */\r
+ if (cdfa->eot[s] >= 0)\r
+ {\r
+ s = cdfa->eot[s];\r
+ is->consume(is);\r
+ continue;\r
+ }\r
+ /* EOF transition to accept state?\r
+ */\r
+ if ( c == ANTLR3_TOKEN_EOF && cdfa->eof[s] >= 0)\r
+ {\r
+ is->rewind(is, mark);\r
+ return cdfa->accept[cdfa->eof[s]];\r
+ }\r
+\r
+ /* No alt, so bomb\r
+ */\r
+ noViableAlt(rec, cdfa, s);\r
+ is->rewind(is, mark);\r
+ return 0;\r
+ }\r
+\r
+}\r
+\r
+/** Default special state implementation\r
+ */\r
+ANTLR3_API ANTLR3_INT32 \r
+antlr3dfaspecialStateTransition (void * ctx, pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_INT_STREAM is, pANTLR3_CYCLIC_DFA dfa, ANTLR3_INT32 s)\r
+{\r
+ return -1;\r
+}\r
+\r
+/* Default special transition implementation\r
+ */\r
+ANTLR3_API ANTLR3_INT32\r
+antlr3dfaspecialTransition (void * ctx, pANTLR3_BASE_RECOGNIZER recognizer, pANTLR3_INT_STREAM is, pANTLR3_CYCLIC_DFA dfa, ANTLR3_INT32 s)\r
+{\r
+ return 0;\r
+}\r
Code Review / simantics / platform.git / blobdiff