migrate to gitlab

1 files changed, 281 insertions, 0 deletions

diff --git a/lex.c b/lex.c
new file mode 100644
index 0000000..d5e8e56
--- /dev/null
+++ b/lex.c
@@ -0,0 +1,281 @@
+#define _XOPEN_SOURCE 700
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#define MAYBEADDLINE(buf, lineno, filename) do { if (needline) { \
+	char ppline[LINE_MAX] = {0}; \
+	sprintf(ppline, "#line %d \"%s\"\n", lineno, filename); \
+	buf = append(buf, ppline); \
+	needline = 0; \
+	} } while (0)
+
+#define RESETLINE(buf) do { \
+	needline = 1; \
+	buf = append(buf, "%%\n"); \
+	} while (0)
+
+#define OUTPUTFILENAME "lex.yy.c"
+
+#define MIN_POSITIONS	2500
+#define MIN_STATES	500
+#define MIN_TRANSITIONS	2000
+#define MIN_NODES	1000
+#define MIN_CLASSES	1000
+#define MIN_OUTPUTSIZE	3000
+
+struct parser {
+	enum { UNSPECIFIED, POINTER, ARRAY } yytexttype;
+	int maxpositions;
+	int maxstates;
+	int maxtransitions;
+	int maxnodes;
+	int maxclasses;
+	int maxoutput;
+
+	int npositions;
+	int nstates;
+	int ntransitions;
+	int nnodes;
+	int nclasses;
+	int outputsize;
+
+	char *states;
+	char *top;
+	char *init;
+	char *bottom;
+};
+
+char *append(char *buf, const char *add)
+{
+	size_t oldlen = buf ? strlen(buf) : 0;
+	size_t newlen = strlen(add);
+	char *tmp = realloc(buf, oldlen + newlen);
+	if (tmp == NULL) {
+		perror("lex");
+		exit(EXIT_FAILURE);
+	}
+	buf = tmp;
+	memcpy(buf + oldlen, add, newlen);
+	return buf;
+}
+
+struct parser *parse(struct parser *parser, const char *file)
+{
+	struct parser p = {0};
+	FILE *input = stdin;
+	char *buf = NULL;
+	int line = 0;
+	size_t n = 0;
+	ssize_t len = 0;
+	int needline = 1;
+	enum { DEFINITIONS, RULES, SUBROUTINES } section = DEFINITIONS;
+
+	if (strcmp("-", file)) {
+		if ((input = fopen(file, "r")) == NULL) {
+			fprintf(stderr, "Couldn't open %s: %s\n", file,
+				strerror(errno));
+			return parser;
+		}
+	}
+
+	while (!feof(input)) {
+		len = getline(&buf, &n, input);
+		if (len == -1) {
+			if (errno == 0) {
+				buf = NULL;
+				n = 0;
+				continue;
+			}
+			perror("lex");
+			exit(EXIT_FAILURE);
+		}
+		line++;
+
+		if (section == DEFINITIONS) {
+			if (!strcmp("%%\n", buf)) {
+				section = RULES;
+			} else if (!strcmp("%{\n", buf)) {
+				MAYBEADDLINE(p.top, line, file);
+				while ((len = getline(&buf, &n, input)) != -1
+					&& strcmp("%}\n", buf))
+				{
+					line++;
+					p.top = append(p.top, buf);
+				}
+				line++;
+				RESETLINE(p.top);
+			}
+		} else if (section == RULES) {
+			if (!strcmp("%%\n", buf)) {
+				section = SUBROUTINES;
+			}
+		} else if (section == SUBROUTINES) {
+			if (!strcmp("%%\n", buf)) {
+				fprintf(stderr, "%s:%d:Unexpected %%%% "
+					"after processing user subroutines\n",
+					file, line);
+				free(buf);
+				free(p.top);
+				free(p.init);
+				free(p.bottom);
+				return parser;
+			}
+			MAYBEADDLINE(p.bottom, line, file);
+			p.bottom = append(p.bottom, buf);
+		}
+	}
+
+	if (input != stdin) {
+		fclose(input);
+	}
+
+	if (section == DEFINITIONS) {
+		fprintf(stderr, "%s:%d reach EOF without rules section\n", file, line);
+		return parser;
+	}
+
+	/* merge successful stuff */
+	if (parser == NULL) {
+		parser = calloc(1, sizeof(*parser));
+	}
+
+	if (p.top) {
+		parser->top = append(parser->top, p.top);
+		free(p.top);
+	}
+
+	if (p.init) {
+		parser->init = append(parser->init, p.init);
+		free(p.init);
+	}
+
+	if (p.bottom) {
+		parser->bottom = append(parser->bottom, p.bottom);
+		free(p.bottom);
+	}
+
+	return parser;
+}
+
+int output(struct parser *p, FILE *f)
+{
+	/* write the data */
+	if (p->top) {
+		fprintf(f, "%s\n", p->top);
+	}
+
+	fprintf(f, "#include <stdio.h>\n");
+	fprintf(f, "\n");
+
+	fprintf(f, "static struct {\n");
+	fprintf(f, "\tconst struct {\n");
+	fprintf(f, "\t\tint INITIAL;\n");
+	for (int i = 0; i < p->nstates; i++) {
+		fprintf(f, "\t\tint %s;\n", p->states[i]);
+	}
+	fprintf(f, "\t} state;\n");
+	fprintf(f, "\tint condition;\n");
+	fprintf(f, "} YY = {\n");
+	fprintf(f, "\t{ 0, ");
+	for (int i = 0; i < p->nstates; i++) {
+		fprintf(f, "%d, ", i + 1);
+	}
+	fprintf(f, "},\n");
+	fprintf(f, "};\n");
+	fprintf(f, "\n");
+
+	fprintf(f, "#define ECHO fputs(yytext, yyout)\n");
+	fprintf(f, "#define REJECT /* something complex */\n");
+	fprintf(f, "#define BEGIN YY.condition = YY.state.\n");
+	fprintf(f, "\n");
+
+	if (p->yytexttype == ARRAY) {
+		fprintf(f, "char yytext[YYARRAYSIZE];\n");
+	} else {
+		fprintf(f, "char *yytext = NULL;\n");
+	}
+	fprintf(f, "int yyleng = 0;\n");
+	fprintf(f, "FILE *yyin = NULL;\n");
+	fprintf(f, "FILE *yyout = NULL;\n");
+	fprintf(f, "\n");
+
+	/* int yymore(void) */
+	/* int yyless(int n) */
+	/* int input(void) */
+	/* int unput(int c) */
+
+	fprintf(f, "int yylex(void)\n{\n");
+	if (p->init) {
+		fputs(p->init, f);
+	}
+	/* generated code */
+	fprintf(f, "}\n");
+
+	if (p->bottom) {
+		fputs(p->bottom, f);
+	}
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	struct parser *parser = NULL;
+	FILE *outfile = NULL;
+	int verbose = 0;
+	int c;
+
+	while ((c = getopt(argc, argv, "tnv")) != -1) {
+		switch (c) {
+		case 't':
+			/* Output to stdout */
+			outfile = stdout;
+			break;
+
+		case 'n':	/* MUTEX: v */
+			/* Suppress statistics summary */
+			verbose = -1;
+			break;
+
+		case 'v':	/* MUTEX: n */
+			/* Show statistics summary */
+			verbose = 1;
+			break;
+			
+		default:
+			return 1;
+		}
+	}
+
+	if (outfile == NULL) {
+		if ((outfile = fopen(OUTPUTFILENAME, "w")) == NULL) {
+			perror("lex: Couldn't open output file");
+			return 1;
+		}
+	}
+
+	if (optind >= argc) {
+		parser = parse(parser, "-");
+	} else {
+		while (optind < argc) {
+			parser = parse(parser, argv[optind++]);
+		}
+	}
+
+	if (parser) {
+		output(parser, outfile);
+		/* if (verbose == 1 || (verbose == 0 && parser->tables_are_set) { */
+		/* output_statistics(parser); */
+		/* } */
+	}
+
+	if (outfile != stdout) {
+		fclose(outfile);
+	}
+
+	return 0;
+}