Author: kjs
Date: Tue Mar 27 10:02:47 2007
New Revision: 17786
Modified:
trunk/compilers/pirc/src/pirlexer.c
trunk/compilers/pirc/src/pirparser.c
Log:
compilers/pirc:
* added assertions
* did some layout of code cleaning
* minor code cleanups
Modified: trunk/compilers/pirc/src/pirlexer.c
==============================================================================
--- trunk/compilers/pirc/src/pirlexer.c (original)
+++ trunk/compilers/pirc/src/pirlexer.c Tue Mar 27 10:02:47 2007
@@ -17,9 +17,10 @@
#include <assert.h>
-
-#define EOF_MARKER '\0' /* marker is put at end of file buffer to
indicate end of file */
-#define ERROR_CONTEXT_SIZE 30 /* number of characters being displayed in
syntax errors */
+/* end of file marker. Just use "EOF" (defined as -1) */
+#define EOF_MARKER -1
+/* number of characters being displayed in syntax errors */
+#define ERROR_CONTEXT_SIZE 30
/*
@@ -60,10 +61,12 @@
The following are flags for subroutines and parameters/arguments.
+TODO: put the dictionary into a hash table (maybe a Hash PMC?).
+
=cut
*/
-char const * dictionary[] = {
+static char const * dictionary[] = {
"global", /* T_GLOBAL, */
"goto", /* T_GOTO, */
"if", /* T_IF, */
@@ -226,14 +229,14 @@
*/
typedef struct file_buffer {
- char *filename; /* the name of this file */
- char *buffer; /* buffer holding contents of this file */
- char *curchar; /* pointer to the current char. */
- unsigned filesize; /* size of this file */
- unsigned int line; /* line number */
- unsigned short linepos; /* position on the current line */
- char lastchar; /* the previous character that was read. */
- struct file_buffer *prevbuffer; /* pointer to 'including' file if any */
+ char *filename; /* the name of this file
*/
+ char *buffer; /* buffer holding contents of this file
*/
+ char *curchar; /* pointer to the current char.
*/
+ unsigned filesize; /* size of this file in bytes
*/
+ unsigned long line; /* line number
*/
+ unsigned short linepos; /* position on the current line
*/
+ char lastchar; /* the previous character that was read.
*/
+ struct file_buffer *prevbuffer; /* pointer to 'including' file if any
*/
} file_buffer;
@@ -277,15 +280,9 @@
*/
char const *
-find_keyword(token t) {
- if ((t >= 0) && (t <= MAX_TOKEN)) {
- return dictionary[t];
- }
- else { /* this should never happen; error in dictionary */
- fprintf(stderr, "FATAL: invalid token in find_keyword()\n");
- fprintf(stderr, "No entry for token %d\n", t);
- exit(1);
- }
+find_keyword(token t) {
+ assert((t >= 0) && (t <= MAX_TOKEN));
+ return dictionary[t];
}
/*
@@ -298,7 +295,8 @@
*/
char * const
-get_current_token(lexer_state *s) {
+get_current_token(lexer_state *s) {
+ assert(s->token_chars);
return s->token_chars;
}
@@ -313,6 +311,7 @@
*/
char * const
get_current_file(struct lexer_state *s) {
+ assert(s->curfile->filename);
return s->curfile->filename;
}
@@ -345,14 +344,17 @@
void
print_error_context(struct lexer_state *s) {
/* print context of max. size ERROR_CONTEXT_SIZE */
- int read_chars = s->curfile->curchar - s->curfile->buffer;
- int context_length = read_chars > ERROR_CONTEXT_SIZE ? ERROR_CONTEXT_SIZE
: read_chars;
- char *start = s->curfile->curchar - context_length;
- char *end = s->curfile->curchar;
+ int read_chars = s->curfile->curchar - s->curfile->buffer; /* get no.
of read chars. */
+ int context_length = (read_chars > ERROR_CONTEXT_SIZE) ?
ERROR_CONTEXT_SIZE : read_chars;
+ char *start = s->curfile->curchar - context_length;
+ char *end = s->curfile->curchar;
/* print all characters from start to end */
while (start < end ) {
- fprintf(stderr, "%c", *start++);
+ /* print tab characters as spaces to make the "^" indicator fit nicely
*/
+ if (*start == '\t') fprintf(stderr, " ");
+ else fprintf(stderr, "%c", *start);
+ ++start;
}
/* print an indicator like "^" on the next line */
fprintf(stderr, "\n%*s\n", s->curfile->linepos - 1, "^");
@@ -376,6 +378,7 @@
*/
static void
buffer_char(lexer_state *lexer, char c) {
+ /* put c into *lexer->charptr and increment the pointer */
*lexer->charptr++ = c;
}
@@ -401,6 +404,7 @@
=item read_char()
Return the next character from the buffer.
+It's a good idea to check for "c == EOF_MARKER" after each call.
=cut
@@ -482,8 +486,14 @@
*/
char *
clone_string(char const * src) {
- int srclen = strlen(src);
+ int srclen;
char * dest, *ptr;
+
+ assert(src != NULL);
+ srclen = strlen(src);
+ /* dest is used as an iterator, ptr - still pointing to the beginning
+ * of the string - is returned
+ */
dest = ptr = (char *)calloc(srclen + 1, sizeof(char));
while(*src) {
*dest++ = *src++;
@@ -504,11 +514,15 @@
*/
static file_buffer *
read_file(char const * filename) {
- FILE *fileptr = NULL;
+ FILE *fileptr = NULL;
+ file_buffer *filebuff = NULL;
struct stat filestatus;
-
- file_buffer *filebuff = (file_buffer *)malloc(sizeof(file_buffer));
-
+
+
+ assert(filename != NULL);
+
+ filebuff = (file_buffer *)malloc(sizeof(file_buffer));
+
if (filebuff == NULL) {
fprintf(stderr, "Error in read_file(): failed to allocate memory for
file buffer\n");
exit(1);
@@ -527,6 +541,7 @@
/* allocate memory for this file. Reserve 1 more byte to store the EOF
marker */
stat(filename, &filestatus);
filebuff->filesize = filestatus.st_size;
+
/* printf("file size: %ld\n", filebuff->filesize); */
filebuff->buffer = (char *)calloc(filebuff->filesize + 1, sizeof(char));
@@ -564,7 +579,9 @@
static void
destroy_buffer(file_buffer *buf) {
free(buf->buffer);
+ buf->buffer = NULL; /* good programming practice :-) */
free(buf);
+ buf = NULL;
}
@@ -583,8 +600,8 @@
static void
do_include_file(lexer_state *lexer, char const * filename) {
file_buffer *newfile = read_file(filename);
- newfile->prevbuffer = lexer->curfile;
- lexer->curfile = newfile;
+ newfile->prevbuffer = lexer->curfile;
+ lexer->curfile = newfile;
}
@@ -665,18 +682,13 @@
*/
static void
switch_buffer(lexer_state *lexer) {
+ file_buffer *tmp = NULL;
+
+ assert(lexer->curfile->prevbuffer != NULL);
/* destroy this buffer, set 'buf' to its previous buffer */
- if (lexer->curfile->prevbuffer == NULL) {
- fprintf(stderr, "Error: cannot switch buffers; no more buffers\n");
- exit(1);
- }
- else {
- file_buffer *tmp = lexer->curfile;
- lexer->curfile = lexer->curfile->prevbuffer;
- destroy_buffer(tmp);
- /* printf("switching to buffer '%s'\n", lexer->curfile->filename);
- */
- }
+ tmp = lexer->curfile;
+ lexer->curfile = lexer->curfile->prevbuffer;
+ destroy_buffer(tmp);
}
@@ -693,7 +705,8 @@
static int
read_digits(lexer_state *lexer) {
int count = 0;
- char c = read_char(lexer->curfile);
+ char c = read_char(lexer->curfile);
+
while ( isdigit(c) ) {
buffer_char(lexer, c);
c = read_char(lexer->curfile);
@@ -736,15 +749,15 @@
*/
static token
read_token(lexer_state *lexer) {
- char c;
- int ok = 1;
- int count;
+ int ok = 1;
+ int count = 0;
/* before reading a new token, first clear the buffer */
clear_buffer(lexer);
while (ok) {
-
+ char c; /* holds the "current" character */
+
/* read the first character of the next token */
c = read_char(lexer->curfile);
@@ -1353,6 +1366,7 @@
return T_IDENTIFIER;
}
else {
+
fprintf(stderr, "BUG IN LEXER: Unknown character: %c", c);
fprintf(stderr, "Was parsing file: '%s'\n",
lexer->curfile->filename);
if (lexer->curfile->curchar >=
lexer->curfile->buffer+lexer->curfile->filesize) {
@@ -1516,10 +1530,9 @@
char *filename = lexer->token_chars;
int len = strlen(filename);
- /* make sure it's a string */
- char firstchar = filename[0];
- char lastchar = filename[len - 1];
- assert( (firstchar == '"' && lastchar == '"') || (firstchar == '\'' &&
lastchar == '\''));
+ /* make sure it's a string */
+ assert((filename[0] == '"' && filename[len - 1] == '"')
+ || (filename[0] == '\'' && filename[len -1] == '\''));
filename[len - 1] = '\0'; /* remove last quote */
++filename; /* skip first quote */
@@ -1537,14 +1550,9 @@
*/
void
-close_include_file(lexer_state *lexer) {
- if (lexer->curfile->prevbuffer) { /* this was an .include'd file */
- switch_buffer(lexer);
- }
- else { /* no more buffers. */
- fprintf(stderr, "FATAL: attempt to close file '%s' without any open
files left\n",
- lexer->curfile->filename);
- }
+close_include_file(lexer_state *lexer) {
+ assert(lexer->curfile->prevbuffer);
+ switch_buffer(lexer);
}
Modified: trunk/compilers/pirc/src/pirparser.c
==============================================================================
--- trunk/compilers/pirc/src/pirparser.c (original)
+++ trunk/compilers/pirc/src/pirparser.c Tue Mar 27 10:02:47 2007
@@ -24,10 +24,10 @@
The parser_state structure has the following fields:
typedef struct parser_state {
- struct lexer_state *lexer; -- the lexer
- token curtoken; -- the current token as returned by the
lexer
- char *heredoc_ids[10]; -- array for holding heredoc arguments.
XXX Limited to 10 currently XXX
- int heredoc_index; -- index to keep track of heredoc ids in
the array
+ struct lexer_state *lexer; -- the lexer
+ token curtoken; -- the current token as returned by the
lexer
+ char *heredoc_ids[10]; -- array for holding heredoc arguments.
XXX Limited to 10 currently XXX
+ unsigned heredoc_index; -- index to keep track of heredoc ids in
the array
unsigned parse_errors; -- parse_errors
}
@@ -36,10 +36,10 @@
*/
typedef struct parser_state {
- struct lexer_state *lexer;
- token curtoken;
- char *heredoc_ids[10];
- int heredoc_index;
+ struct lexer_state *lexer;
+ token curtoken;
+ char *heredoc_ids[10];
+ unsigned heredoc_index;
unsigned parse_errors;
} parser_state;
@@ -73,6 +73,7 @@
exit_parser(parser_state *p) {
destroy_lexer(p->lexer);
free(p);
+ p = NULL;
exit(0);
}
@@ -502,12 +503,13 @@
/* check whehter there are any heredocs to be parsed */
if ( p->heredoc_index > 0) {
- int i;
+ unsigned i;
for (i = 0; i < p->heredoc_index; i++) {
char *heredocid = p->heredoc_ids[i];
p->curtoken = read_heredoc(p->lexer, heredocid);
match(p, T_HEREDOC_STRING);
free(heredocid); /* clean up memory of this string */
+ heredocid = NULL;
}
/* clear heredoc index */
@@ -661,6 +663,7 @@
p->curtoken = read_heredoc(p->lexer, heredocid);
match(p, T_HEREDOC_STRING);
free(heredocid); /* clean up */
+ heredocid = NULL;
break;
}
default: /* general case for 'expression binop expression' */
