SPDX-FileCopyrightText: 2024 Gábor Stefanik <netrolller.3d@gmail.com>

SPDX-License-Identifier: GPL-3.0-or-later

Remove usages of tmpfile(), rewind(), fgetpos(), fsetpos() and bsearch(),
which are unsupported by meslibc, and add missing declaration for strdup.

License note: Berkeley Yacc is in the public domain, but it's linked with
meslibc, which is GPL-3.0-or-later, so we apply that license here too.

diff -ru ../byacc-20240109.bak/main.c ./main.c
--- ../byacc-20240109.bak/main.c	2024-04-14 16:06:09.646465507 +0200
+++ ./main.c	2024-04-14 20:41:56.227083399 +0200
@@ -788,7 +788,7 @@
 	(void)umask(save_umask);
     }
 #else
-    result = tmpfile();
+    result = fopen(label, "w+");
 #endif
 
     if (result == 0)
diff -ru ../byacc-20240109.bak/output.c ./output.c
--- ../byacc-20240109.bak/output.c	2024-04-14 16:06:09.646465507 +0200
+++ ./output.c	2024-04-14 16:06:24.636465897 +0200
@@ -1289,7 +1289,7 @@
 	{
 	    if (union_file != 0)
 	    {
-		rewind(union_file);
+		fseek(union_file, 0, SEEK_SET);
 		while ((c = getc(union_file)) != EOF)
 		    putc_code(fp, c);
 	    }
@@ -1314,7 +1314,7 @@
 
     if (text_file == NULL)
 	open_error("text_file");
-    rewind(text_file);
+    fseek(text_file, 0, SEEK_SET);
     in = text_file;
     if ((c = getc(in)) == EOF)
 	return;
@@ -1684,7 +1684,7 @@
     int state;
     char line_state[20];
 
-    rewind(action_file);
+    fseek(action_file, 0, SEEK_SET);
     if ((c = getc(action_file)) == EOF)
 	return;
 
diff -ru ../byacc-20240109.bak/reader.c ./reader.c
--- ../byacc-20240109.bak/reader.c	2024-04-14 16:06:09.646465507 +0200
+++ ./reader.c	2024-04-14 20:40:58.387082748 +0200
@@ -70,7 +70,7 @@
     char *line_data;	/* saved input-line */
     size_t line_used;	/* position within saved input-line */
     size_t line_size;	/* length of saved input-line */
-    fpos_t line_fpos;	/* pointer before reading past saved input-line */
+    long line_fpos;	/* pointer before reading past saved input-line */
 }
 SAVE_LINE;
 
@@ -315,7 +315,7 @@
 	line = save_area.line_data;
 	cptr = save_area.line_used + line;
 	linesize = save_area.line_size;
-	if (fsetpos(input_file, &save_area.line_fpos) != 0)
+	if (fseek(input_file, save_area.line_fpos, SEEK_SET) != 0)
 	    on_error();
 	memset(&save_area, 0, sizeof(save_area));
     }
@@ -338,7 +338,7 @@
 	save_area.line_size = linesize;
 	NO_SPACE(save_area.line_data);
 	memcpy(save_area.line_data, line, linesize);
-	if (fgetpos(f, &save_area.line_fpos) != 0)
+	if ((save_area.line_fpos = ftell(f)) == -1)
 	    on_error();
 	must_save = -must_save;
     }
@@ -572,6 +572,36 @@
     return strcmp(p->name, q->name);
 }
 
+/*
+ * Compare keyword to cached token, treating '_' and '-' the same.  Some
+ * grammars rely upon this misfeature.
+ */
+static int
+matchec(const char *name)
+{
+    const char *p = cache;
+    const char *q = name;
+    int code = 0;	/* assume mismatch */
+
+    while (*p != '\0' && *q != '\0')
+    {
+	char a = *p++;
+	char b = *q++;
+	if (a == '_')
+	    a = '-';
+	if (b == '_')
+	    b = '-';
+	if (a != b)
+	    break;
+	if (*p == '\0' && *q == '\0')
+	{
+	    code = 1;
+	    break;
+	}
+    }
+    return code;
+}
+
 static int
 keyword(void)
 {
@@ -612,10 +642,36 @@
 	}
 	cachec(NUL);
 
-	if ((key = bsearch(cache, keywords,
-			   sizeof(keywords) / sizeof(*key),
-			   sizeof(*key), compare_keys)))
-	    return key->token;
+	if (matchec("token") || matchec("term"))
+	    return (TOKEN);
+	if (matchec("type"))
+	    return (TYPE);
+	if (matchec("left"))
+	    return (LEFT);
+	if (matchec("right"))
+	    return (RIGHT);
+	if (matchec("nonassoc") || matchec("binary"))
+	    return (NONASSOC);
+	if (matchec("start"))
+	    return (START);
+	if (matchec("union"))
+	    return (UNION);
+	if (matchec("ident"))
+	    return (IDENT);
+	if (matchec("expect"))
+	    return (EXPECT);
+	if (matchec("expect-rr"))
+	    return (EXPECT_RR);
+	if (matchec("pure-parser"))
+	    return (PURE_PARSER);
+	if (matchec("parse-param"))
+	    return (PARSE_PARAM);
+	if (matchec("lex-param"))
+	    return (LEX_PARAM);
+	if (matchec("token-table"))
+	    return (TOKEN_TABLE);
+	if (matchec("yacc"))
+	    return (POSIX_YACC);
     }
     else
     {
@@ -1178,6 +1234,9 @@
     return result;
 }
 
+char *
+strdup (char const *s);
+
 static void
 save_param(int k, char *buffer, int name, int type2)
 {