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checkpoint on string realloc bug fix attempt

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In preparation to fix issue #47, we:

Fix a minor typo in `Makefile.config`.

Move `stringindex(char *format, char *test)` from `str.c` into `codegen.c`
as static function.

Expand `STR_TABLECHUNK` from `1<<10` to `1<<16`.

Identify with an XXX comment, a problematic `realloc()` call in the
`addstr(STRINGHEAD *hp, char *str)` function of `str.c`.

Move the `charstr(int ch)` in `str.c` above the only function that uses
it, `addliteral(char *str)`, and make it a static function.

Improved comments about return values for `str.c` functions that
work on STRINGHEAD pointers.
This commit is contained in:
Landon Curt Noll
2025-08-17 02:18:10 -07:00
parent 077ba65285
commit 95793c3150
4 changed files with 77 additions and 63 deletions
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98
str.c
View File

@@ -1,7 +1,7 @@
/*
* str - string list routines
*
* Copyright (C) 1999-2007,2021-2023 David I. Bell and Ernest Bowen
* Copyright (C) 1999-2007,2021-2023,2025 David I. Bell and Ernest Bowen
*
* Primary author: David I. Bell
*
@@ -42,7 +42,7 @@
#include "banned.h" /* include after system header <> includes */
#define STR_TABLECHUNK (1<<10) /* how often to reallocate string table */
#define STR_TABLECHUNK (1<<16) /* how often to reallocate string literal table */
#define STR_CHUNK (1<<16) /* size of string storage allocation */
#define OCTET_VALUES 256 /* number of different values in a OCTET */
#define STR_UNIQUE (1<<7) /* size of string to allocate separately */
@@ -97,6 +97,10 @@ initstr(STRINGHEAD *hp)
* given:
* hp header of string storage
* str string to be added
*
* returns:
* != NULL ==> pointer to newly added string
* NULL ==> unable to add string
*/
char *
addstr(STRINGHEAD *hp, char *str)
@@ -113,6 +117,10 @@ addstr(STRINGHEAD *hp, char *str)
/* alloc + 1 guard paranoia */
newsize = len + STR_CHUNK + hp->h_used + hp->h_avail + 1;
/* alloc + 1 guard paranoia */
/*
* XXX - doing a realloc can cause problems if the larger list has to be
* relocated due the recalloc() call and stuff point to old location
*/
list = (char *)realloc(hp->h_list, newsize + 1);
if (list == NULL)
return NULL;
@@ -130,35 +138,6 @@ addstr(STRINGHEAD *hp, char *str)
}
/*
* Return a null-terminated string which consists of a single character.
* The table is initialized on the first call.
*/
char *
charstr(int ch)
{
char *cp;
int i;
if (chartable == NULL) {
/* alloc + 1 guard paranoia */
cp = (char *)malloc((OCTET_VALUES + 1)*2);
if (cp == NULL) {
math_error("Cannot allocate character table");
not_reached();
}
for (i = 0; i < OCTET_VALUES; i++) {
*cp++ = (char)i;
*cp++ = '\0';
}
chartable = cp - (OCTET_VALUES*2);
*cp++ = '\0'; /* guard paranoia */
*cp++ = '\0'; /* guard paranoia */
}
return &chartable[(ch & 0xff) * 2];
}
/*
* Find a string with the specified name and return its number in the
* string list. The first string is numbered zero. Minus one is returned
@@ -166,7 +145,11 @@ charstr(int ch)
*
* given:
* hp header of string storage
* str string to be added
* str string to be searched for
*
* returns:
* >= 0 ==> index of string
* -1 ==> unable to find string
*/
int
findstr(STRINGHEAD *hp, char *str)
@@ -200,6 +183,10 @@ findstr(STRINGHEAD *hp, char *str)
* given:
* hp header of string storage
* n string index
*
* returns:
* non-empty string ==> string at index n
* "" ==> no strings or string at index n
*/
char *
namestr(STRINGHEAD *hp, long n)
@@ -219,36 +206,31 @@ namestr(STRINGHEAD *hp, long n)
/*
* Useful routine to return the index of one string within another one
* which has the format: "str1\000str2\000str3\000...strn\0\0". Index starts
* at one for the first string. Returns zero if the string being checked
* is not contained in the formatted string.
*
* Be sure to use \000 instead of \0. ANSI-C compilers interpret "foo\0foo..."
* as "foo\017oo...".
*
* given:
* format string formatted into substrings
* test string to be found in formatted string
* Return a null-terminated string which consists of a single character.
* The table is initialized on the first call.
*/
long
stringindex(char *format, char *test)
S_FUNC char *
charstr(int ch)
{
long index; /* found index */
size_t len; /* length of current piece of string */
size_t testlen; /* length of test string */
char *cp;
int i;
testlen = strlen(test);
index = 1;
while (*format) {
len = strlen(format);
if ((len == testlen) && (*format == *test) &&
(strcmp(format, test) == 0))
return index;
format += (len + 1);
index++;
if (chartable == NULL) {
/* alloc + 1 guard paranoia */
cp = (char *)malloc((OCTET_VALUES + 1)*2);
if (cp == NULL) {
math_error("Cannot allocate character table");
not_reached();
}
for (i = 0; i < OCTET_VALUES; i++) {
*cp++ = (char)i;
*cp++ = '\0';
}
chartable = cp - (OCTET_VALUES*2);
*cp++ = '\0'; /* guard paranoia */
*cp++ = '\0'; /* guard paranoia */
}
return 0;
return &chartable[(ch & 0xff) * 2];
}