Replace FSM_ADVANCE_HOOK macro with optional hooks->advance callback.

Author: silentbicycle

include/fsm/print.h

@@ -78,6 +78,12 @@ struct fsm_hooks {
 		const struct fsm_state_metadata *state_metadata,
 		void *lang_opaque, void *hook_opaque);
 
+	/* If non-NULL, this will be called to generate code
+	 * in scope immediately after advancing to the
+	 * next character of input. */
+	int (*advance)(FILE *, const struct fsm_options *opt,
+		const char *cur_char_var, void *hook_opaque);
+
 	int (*comment)(FILE *, const struct fsm_options *opt,
 		const struct fsm_state_metadata *state_metadata,
 		void *hook_opaque);

src/libfsm/print/c.c

@@ -495,30 +495,6 @@ fsm_print_c_body(FILE *f, const struct ir *ir,
 	 * input loop was skipped it would still be NONE. */
 	fprintf(f, "\tint has_consumed_input = 0;\n");
 
-	/* For FSM_IO_STR and FSM_IO_PAIR, define a macro that will be
-	 * called with the new character every time iteration advances.
-	 * This is used by lx's internal bookkeeping to track token
-	 * positions in the input stream. For FSM_IO_GETC, the generated
-	 * getc function handles this directly.
-	 *
-	 * This defaults to a no-op unless defined. */
-	switch (opt->io) {
-	case FSM_IO_GETC:
-		break;		/* nothing to do */
-
-	case FSM_IO_STR:
-		fprintf(f, "#ifndef FSM_ADVANCE_HOOK\n");
-		fprintf(f, "#define FSM_ADVANCE_HOOK(C) /* no-op */ (void)C\n");
-		fprintf(f, "#endif\n");
-		break;
-
-	case FSM_IO_PAIR:
-		fprintf(f, "#ifndef FSM_ADVANCE_HOOK\n");
-		fprintf(f, "#define FSM_ADVANCE_HOOK(C) /* no-op */ (void)C\n");
-		fprintf(f, "#endif\n");
-		break;
-	}
-
 	/* enum of states */
 	print_stateenum(f, ir->n);
 	fprintf(f, "\n");
@@ -536,13 +512,21 @@ fsm_print_c_body(FILE *f, const struct ir *ir,
 	case FSM_IO_STR:
 		fprintf(f, "\tfor (p = s; *p != '\\0'; p++) {\n");
 		fprintf(f, "\t\thas_consumed_input = 1;\n");
-		fprintf(f, "\t\tFSM_ADVANCE_HOOK(%s);\n", cp);
+		if (hooks->advance != NULL) {
+			if (-1 == hooks->advance(f, opt, cp, hooks->hook_opaque)) {
+				return -1;
+			}
+		}
 		break;
 
 	case FSM_IO_PAIR:
 		fprintf(f, "\tfor (p = b; p != e; p++) {\n");
 		fprintf(f, "\t\thas_consumed_input = 1;\n");
-		fprintf(f, "\t\tFSM_ADVANCE_HOOK(%s);\n", cp);
+		if (hooks->advance != NULL) {
+			if (-1 == hooks->advance(f, opt, cp, hooks->hook_opaque)) {
+				return -1;
+			}
+		}
 		break;
 	}
 

src/lx/print/c.c

@@ -297,6 +297,26 @@ reject_c(FILE *f, const struct fsm_options *opt,
 	return 0;
 }
 
+static int
+advance_c(FILE *f, const struct fsm_options *opt, const char *cur_char_var, void *hook_opaque)
+{
+	(void)hook_opaque;
+
+	switch (opt->io) {
+	case FSM_IO_GETC:
+		break;
+
+	case FSM_IO_STR:
+	case FSM_IO_PAIR:
+		/* When libfsm's generated code advances a character, update
+		 * lx's token name buffer and position bookkeeping. */
+		fprintf(f, "\t\tif (!%sadvance_end(lx, %s)) { return %sERROR; }\n",
+		    prefix.api, cur_char_var, prefix.tok);
+		break;
+	}
+	return 0;
+}
+
 static void
 print_proto(FILE *f, const struct ast *ast, const struct ast_zone *z)
 {
@@ -485,8 +505,7 @@ print_io(FILE *f, const struct fsm_options *opt)
 	fprintf(f, "}\n");
 	fprintf(f, "\n");
 
-	switch (opt->io) {
-	case FSM_IO_GETC:
+	if (opt->io == FSM_IO_GETC) {
 		/* TODO: consider passing char *c, and return int 0/-1 for error */
 		if (opt->comments) {
 			fprintf(f, "/* This wrapper manages one character of lookahead/pushback\n");
@@ -536,17 +555,6 @@ print_io(FILE *f, const struct fsm_options *opt)
 		fprintf(f, "\treturn %sgetc((struct %slx *)getc_opaque);\n", prefix.api, prefix.lx);
 		fprintf(f, "}\n");
 		fprintf(f, "\n");
-		break;
-
-	case FSM_IO_PAIR:
-	case FSM_IO_STR:
-		/* When libfsm's generated code advances a character, update
-		 * lx's token name buffer and position bookkeeping. */
-		fprintf(f, "#ifndef FSM_ADVANCE_HOOK\n");
-		fprintf(f, "#define FSM_ADVANCE_HOOK(C) if (!%sadvance_end(lx, C)) { return %sERROR; }\n", prefix.api, prefix.tok);
-		fprintf(f, "#endif\n");
-		fprintf(f, "\n");
-		break;
 	}
 
 	fprintf(f, "#if __STDC_VERSION__ >= 199901L\n");
@@ -831,6 +839,7 @@ print_zone(FILE *f, const struct ast *ast, const struct ast_zone *z,
 
 		hooks.accept      = accept_c;
 		hooks.reject      = reject_c;
+		hooks.advance     = advance_c;
 		hooks.hook_opaque = &hook_env;
 
 		fsm_print(f, z->fsm, opt, &hooks, FSM_PRINT_C);