/* Token-reader for Bison's input parser,
- Copyright (C) 1984, 1986, 1989 Free Software Foundation, Inc.
+ Copyright (C) 1984, 1986, 1989, 1992 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
/*
- lex() is the entry point. It is called from reader.c.
+ lex is the entry point. It is called from reader.c.
It returns one of the token-type codes defined in lex.h.
When an identifier is seen, the code IDENTIFIER is returned
and the name is looked up in the symbol table using symtab.c;
#include <ctype.h>
#include "system.h"
#include "files.h"
+#include "getopt.h" /* for optarg */
#include "symtab.h"
#include "lex.h"
#include "new.h"
+/* flags set by % directives */
+extern int definesflag; /* for -d */
+extern int toknumflag; /* for -k */
+extern int noparserflag; /* for -n */
+extern int fixed_outfiles; /* for -y */
+extern int nolinesflag; /* for -l */
+extern int rawtoknumflag; /* for -r */
+extern int verboseflag; /* for -v */
+extern int debugflag; /* for -t */
+extern char *spec_name_prefix; /* for -p */
+extern char *spec_file_prefix; /* for -b */
+/*spec_outfile is declared in files.h, for -o */
extern int lineno;
extern int translations;
int parse_percent_token();
-extern void fatals();
+/* functions from main.c */
+extern char *printable_version();
extern void fatal();
+extern void warni();
+extern void warn();
/* Buffer for storing the current token. */
char *token_buffer;
{
case '/':
c = getc(finput);
- if (c != '*' && c != '/')
- fatals("unexpected `/%c' found",c);
+ if (c != '*' && c != '/')
+ {
+ warn("unexpected `/' found and ignored");
+ break;
+ }
cplus_comment = (c == '/');
c = getc(finput);
}
}
+/* do a getc, but give error message if EOF encountered */
+int
+safegetc(f)
+ FILE *f;
+{
+ register int c = getc(f);
+ if (c == EOF)
+ fatal("Unexpected end of file");
+ return c;
+}
+
+/* read one literal character from finput. process \ escapes.
+ append the normalized string version of the char to *pp.
+ assign the character code to *pcode
+ return 1 unless the character is an unescaped `term' or \n
+ report error for \n
+*/
+int
+literalchar(pp, pcode, term)
+ char **pp;
+ int *pcode;
+ char term;
+{
+ register int c;
+ register char *p;
+ register int code;
+ int wasquote = 0;
+
+ c = safegetc(finput);
+ if (c == '\n')
+ {
+ warn("unescaped newline in constant");
+ ungetc(c, finput);
+ code = '?';
+ wasquote = 1;
+ }
+ else if (c != '\\')
+ {
+ code = c;
+ if (c == term)
+ wasquote = 1;
+ }
+ else
+ {
+ c = safegetc(finput);
+ if (c == 't') code = '\t';
+ else if (c == 'n') code = '\n';
+ else if (c == 'a') code = '\007';
+ else if (c == 'r') code = '\r';
+ else if (c == 'f') code = '\f';
+ else if (c == 'b') code = '\b';
+ else if (c == 'v') code = 013;
+ else if (c == '\\') code = '\\';
+ else if (c == '\'') code = '\'';
+ else if (c == '\"') code = '\"';
+ else if (c <= '7' && c >= '0')
+ {
+ code = 0;
+ while (c <= '7' && c >= '0')
+ {
+ code = (code * 8) + (c - '0');
+ if (code >= 256 || code < 0)
+ {
+ warni("octal value outside range 0...255: `\\%o'", code);
+ code &= 0xFF;
+ break;
+ }
+ c = safegetc(finput);
+ }
+ ungetc(c, finput);
+ }
+ else if (c == 'x')
+ {
+ c = safegetc(finput);
+ code = 0;
+ while (1)
+ {
+ if (c >= '0' && c <= '9')
+ code *= 16, code += c - '0';
+ else if (c >= 'a' && c <= 'f')
+ code *= 16, code += c - 'a' + 10;
+ else if (c >= 'A' && c <= 'F')
+ code *= 16, code += c - 'A' + 10;
+ else
+ break;
+ if (code >= 256 || code<0)
+ {
+ warni("hexadecimal value above 255: `\\x%x'", code);
+ code &= 0xFF;
+ break;
+ }
+ c = safegetc(finput);
+ }
+ ungetc(c, finput);
+ }
+ else
+ {
+ warni ("unknown escape sequence: `\\' followed by `%s'",
+ printable_version(c));
+ code = '?';
+ }
+ } /* has \ */
+
+ /* now fill token_buffer with the canonical name for this character
+ as a literal token. Do not use what the user typed,
+ so that `\012' and `\n' can be interchangeable. */
+
+ p = *pp;
+ if (code >= 040 && code < 0177)
+ *p++ = code;
+ else if (code == '\\') {*p++ = '\\'; *p++ = '\\';}
+ else if (code == '\'') {*p++ = '\\'; *p++ = '\'';}
+ else if (code == '\"') {*p++ = '\\'; *p++ = '\"';}
+ else if (code == '\t') {*p++ = '\\'; *p++ = 't';}
+ else if (code == '\n') {*p++ = '\\'; *p++ = 'n';}
+ else if (code == '\r') {*p++ = '\\'; *p++ = 'r';}
+ else if (code == '\v') {*p++ = '\\'; *p++ = 'v';}
+ else if (code == '\b') {*p++ = '\\'; *p++ = 'b';}
+ else if (code == '\f') {*p++ = '\\'; *p++ = 'f';}
+ else
+ {
+ *p++ = '\\';
+ *p++ = code / 0100 + '0';
+ *p++ = ((code / 010) & 07) + '0';
+ *p++ = (code & 07) + '0';
+ }
+ *pp = p;
+ *pcode = code;
+ return ! wasquote;
+}
+
void
unlex(token)
-int token;
+ int token;
{
unlexed = token;
unlexed_symval = symval;
}
-
int
lex()
{
register int c;
- register char *p;
+ char *p;
if (unlexed >= 0)
{
}
c = skip_white_space();
+ *token_buffer = c; /* for error messages (token buffer always valid) */
+ token_buffer[1] = 0;
switch (c)
{
case EOF:
+ strcpy(token_buffer, "EOF");
return (ENDFILE);
case 'A': case 'B': case 'C': case 'D': case 'E':
{
numval = 0;
+ p = token_buffer;
while (isdigit(c))
{
+ if (p == token_buffer + maxtoken)
+ p = grow_token_buffer(p);
+
+ *p++ = c;
numval = numval*10 + c - '0';
c = getc(finput);
}
+ *p = 0;
ungetc(c, finput);
return (NUMBER);
}
case '\'':
- translations = -1;
/* parse the literal token and compute character code in code */
- c = getc(finput);
+ translations = -1;
{
- register int code = 0;
-
- if (c == '\\')
- {
- c = getc(finput);
-
- if (c <= '7' && c >= '0')
- {
- while (c <= '7' && c >= '0')
- {
- code = (code * 8) + (c - '0');
- c = getc(finput);
- if (code >= 256 || code < 0)
- fatals("malformatted literal token `\\%03o'", code);
- }
- }
- else
- {
- if (c == 't')
- code = '\t';
- else if (c == 'n')
- code = '\n';
- else if (c == 'a')
- code = '\007';
- else if (c == 'r')
- code = '\r';
- else if (c == 'f')
- code = '\f';
- else if (c == 'b')
- code = '\b';
- else if (c == 'v')
- code = 013;
- else if (c == 'x')
- {
- c = getc(finput);
- while ((c <= '9' && c >= '0')
- || (c >= 'a' && c <= 'z')
- || (c >= 'A' && c <= 'Z'))
- {
- code *= 16;
- if (c <= '9' && c >= '0')
- code += c - '0';
- else if (c >= 'a' && c <= 'z')
- code += c - 'a' + 10;
- else if (c >= 'A' && c <= 'Z')
- code += c - 'A' + 10;
- if (code >= 256 || code<0)/* JF this said if(c>=128) */
- fatals("malformatted literal token `\\x%x'",code);
- c = getc(finput);
- }
- ungetc(c, finput);
- }
- else if (c == '\\')
- code = '\\';
- else if (c == '\'')
- code = '\'';
- else if (c == '\"') /* JF this is a good idea */
- code = '\"';
- else
- {
- if (c >= 040 && c <= 0177)
- fatals ("unknown escape sequence `\\%c'", c);
- else
- fatals ("unknown escape sequence: `\\' followed by char code 0x%x", c);
- }
+ int code, discode;
+ char discard[10], *dp;
+ p = token_buffer;
+ *p++ = '\'';
+ literalchar(&p, &code, '\'');
- c = getc(finput);
- }
- }
- else
+ c = getc(finput);
+ if (c != '\'')
{
- code = c;
- c = getc(finput);
+ warn("use \"...\" for multi-character literal tokens");
+ dp = discard;
+ while (literalchar(&dp, &discode, '\'')) {}
}
- if (c != '\'')
- fatal("multicharacter literal tokens not supported");
+ *p++ = '\'';
+ *p = 0;
+ symval = getsym(token_buffer);
+ symval->class = STOKEN;
+ if (! symval->user_token_number)
+ symval->user_token_number = code;
+ return (IDENTIFIER);
+ }
- /* now fill token_buffer with the canonical name for this character
- as a literal token. Do not use what the user typed,
- so that '\012' and '\n' can be interchangeable. */
+ case '\"':
+ /* parse the literal string token and treat as an identifier */
+
+ translations = -1;
+ {
+ int code; /* ignored here */
p = token_buffer;
- *p++ = '\'';
- if (code == '\\')
- {
- *p++ = '\\';
- *p++ = '\\';
- }
- else if (code == '\'')
- {
- *p++ = '\\';
- *p++ = '\'';
- }
- else if (code >= 040 && code != 0177)
- *p++ = code;
- else if (code == '\t')
- {
- *p++ = '\\';
- *p++ = 't';
- }
- else if (code == '\n')
- {
- *p++ = '\\';
- *p++ = 'n';
- }
- else if (code == '\r')
- {
- *p++ = '\\';
- *p++ = 'r';
- }
- else if (code == '\v')
- {
- *p++ = '\\';
- *p++ = 'v';
- }
- else if (code == '\b')
- {
- *p++ = '\\';
- *p++ = 'b';
- }
- else if (code == '\f')
+ *p++ = '\"';
+ while (literalchar(&p, &code, '\"')) /* read up to and including " */
{
- *p++ = '\\';
- *p++ = 'f';
+ if (p >= token_buffer + maxtoken - 4)
+ p = grow_token_buffer(p);
}
- else
- {
- *p++ = code / 0100 + '0';
- *p++ = ((code / 010) & 07) + '0';
- *p++ = (code & 07) + '0';
- }
- *p++ = '\'';
*p = 0;
+
symval = getsym(token_buffer);
symval->class = STOKEN;
- if (! symval->user_token_number)
- symval->user_token_number = code;
+
return (IDENTIFIER);
}
while(c==' ' || c=='\n' || c=='\t');
if (c == '{')
- return(LEFT_CURLY);
+ {
+ strcpy(token_buffer, "={");
+ return(LEFT_CURLY);
+ }
else
{
ungetc(c, finput);
c = getc(finput);
while (c != '>')
{
- if (c == '\n' || c == EOF)
- fatal("unterminated type name");
+ if (c == EOF)
+ fatal("unterminated type name at end of file");
+ if (c == '\n')
+ {
+ warn("unterminated type name");
+ ungetc(c, finput);
+ break;
+ }
if (p == token_buffer + maxtoken)
p = grow_token_buffer(p);
}
}
-
-/* parse a token which starts with %. Assumes the % has already been read and discarded. */
+/* the following table dictates the action taken for the various
+ % directives. A setflag value causes the named flag to be
+ set. A retval action returns the code.
+*/
+struct percent_table_struct {
+ char *name;
+ void *setflag;
+ int retval;
+} percent_table[] =
+{
+ {"token", NULL, TOKEN},
+ {"term", NULL, TOKEN},
+ {"nterm", NULL, NTERM},
+ {"type", NULL, TYPE},
+ {"guard", NULL, GUARD},
+ {"union", NULL, UNION},
+ {"expect", NULL, EXPECT},
+ {"thong", NULL, THONG},
+ {"start", NULL, START},
+ {"left", NULL, LEFT},
+ {"right", NULL, RIGHT},
+ {"nonassoc", NULL, NONASSOC},
+ {"binary", NULL, NONASSOC},
+ {"semantic_parser", NULL, SEMANTIC_PARSER},
+ {"pure_parser", NULL, PURE_PARSER},
+ {"prec", NULL, PREC},
+
+ {"no_lines", &nolinesflag, NOOP}, /* -l */
+ {"raw", &rawtoknumflag, NOOP}, /* -r */
+ {"token_table", &toknumflag, NOOP}, /* -k */
+
+#if 0
+ /* These can be utilized after main is reoganized so
+ open_files() is deferred 'til after read_declarations().
+ But %{ and %union both put information into files
+ that have to be opened before read_declarations().
+ */
+ {"yacc", &fixed_outfiles, NOOP}, /* -y */
+ {"fixed_output_files", &fixed_outfiles, NOOP}, /* -y */
+ {"defines", &definesflag, NOOP}, /* -d */
+ {"no_parser", &noparserflag, NOOP}, /* -n */
+ {"output_file", &spec_outfile, SETOPT}, /* -o */
+ {"file_prefix", &spec_file_prefix, SETOPT}, /* -b */
+ {"name_prefix", &spec_name_prefix, SETOPT}, /* -p */
+
+ /* These would be acceptable, but they do not affect processing */
+ {"verbose", &verboseflag, NOOP}, /* -v */
+ {"debug", &debugflag, NOOP}, /* -t */
+ /* {"help", <print usage stmt>, NOOP}, /* -h */
+ /* {"version", <print version number> , NOOP}, /* -V */
+#endif
+
+ {NULL, NULL, ILLEGAL}
+};
+
+/* Parse a token which starts with %.
+ Assumes the % has already been read and discarded. */
int
parse_percent_token ()
{
register int c;
register char *p;
+ register struct percent_table_struct *tx;
p = token_buffer;
c = getc(finput);
+ *p++ = '%';
+ *p++ = c; /* for error msg */
+ *p = 0;
switch (c)
{
case '=':
return (PREC);
}
- if (!isalpha(c))
+ if (!isalpha(c))
return (ILLEGAL);
- while (isalpha(c) || c == '_')
+ p = token_buffer;
+ *p++ = '%';
+ while (isalpha(c) || c == '_' || c == '-')
{
if (p == token_buffer + maxtoken)
p = grow_token_buffer(p);
+ if (c == '-') c = '_';
*p++ = c;
c = getc(finput);
}
*p = 0;
- if (strcmp(token_buffer, "token") == 0
- ||
- strcmp(token_buffer, "term") == 0)
- return (TOKEN);
- else if (strcmp(token_buffer, "nterm") == 0)
- return (NTERM);
- else if (strcmp(token_buffer, "type") == 0)
- return (TYPE);
- else if (strcmp(token_buffer, "guard") == 0)
- return (GUARD);
- else if (strcmp(token_buffer, "union") == 0)
- return (UNION);
- else if (strcmp(token_buffer, "expect") == 0)
- return (EXPECT);
- else if (strcmp(token_buffer, "start") == 0)
- return (START);
- else if (strcmp(token_buffer, "left") == 0)
- return (LEFT);
- else if (strcmp(token_buffer, "right") == 0)
- return (RIGHT);
- else if (strcmp(token_buffer, "nonassoc") == 0
- ||
- strcmp(token_buffer, "binary") == 0)
- return (NONASSOC);
- else if (strcmp(token_buffer, "semantic_parser") == 0)
- return (SEMANTIC_PARSER);
- else if (strcmp(token_buffer, "pure_parser") == 0)
- return (PURE_PARSER);
- else if (strcmp(token_buffer, "prec") == 0)
- return (PREC);
- else return (ILLEGAL);
+ /* table lookup % directive */
+ for (tx = percent_table; tx->name; tx++)
+ if (strcmp(token_buffer+1, tx->name) == 0)
+ break;
+ if (tx->retval == SETOPT)
+ {
+ *((char **)(tx->setflag)) = optarg;
+ return NOOP;
+ }
+ if (tx->setflag)
+ {
+ *((int *)(tx->setflag)) = 1;
+ return NOOP;
+ }
+ return tx->retval;
}
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