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Diffstat (limited to 'agen5/scmStrings.c')
| -rw-r--r-- | agen5/scmStrings.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/agen5/scmStrings.c b/agen5/scmStrings.c new file mode 100644 index 0000000..1d9ac0b --- /dev/null +++ b/agen5/scmStrings.c @@ -0,0 +1,203 @@ + +/** + * @file scmStrings.c + * + * Temporary SCM strings. + * + * Time-stamp: "2012-08-11 08:29:47 bkorb" + * + * This file is part of AutoGen. + * AutoGen Copyright (c) 1992-2012 by Bruce Korb - all rights reserved + * + * AutoGen is free software: you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * AutoGen is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#define ROUND_SCRIBBLE(_v, _sz) (((_v) + ((_sz) - 1)) & ~((_sz) - 1)) + +typedef struct string_buf_s string_buf_t; + +struct string_buf_s { + string_buf_t * next_p; + ssize_t const sb_size; + ssize_t sb_off; + unsigned char sb_buf[1]; +}; + +static string_buf_t * ag_strbufs = NULL; +static string_buf_t ** next_strbuf = &ag_strbufs; +static size_t const str_buf_hdr_sz = + (&(((string_buf_t *)NULL)->sb_buf[0])) - ((unsigned char *)NULL); + +/** + * Initialize the scribble string library + */ +LOCAL void +ag_scribble_init(void) +{ + ag_strbufs = NULL; + next_strbuf = &ag_strbufs; +} + +/** + * Free up the scribble strings memory pool. + */ +LOCAL void +ag_scribble_deinit(void) +{ + string_buf_t* sb = ag_strbufs; + ag_scribble_init(); + + while (sb != NULL) { + string_buf_t* sb_next_p = sb->next_p; + free(sb); + sb = sb_next_p; + } +} + +/** + * Free up the scribble strings used during the processing of one macro. + */ +LOCAL void +ag_scribble_free(void) +{ + string_buf_t* sb = ag_strbufs; + + while (sb != NULL) { + sb->sb_off = 0; + sb = sb->next_p; + } +} + +/** + * allocate a new scribble block. Multiple of 8K bytes. + */ +static string_buf_t * +new_scribble_block(size_t min_size) +{ + string_buf_t * res = NULL; + + /* + * allow space for allocation header and round up + */ + min_size += str_buf_hdr_sz; + min_size = ROUND_SCRIBBLE(min_size, 0x2000); + + /* + * Allocate and link into list. Advance pointer to next entry. + */ + *next_strbuf = res = AGALOC(min_size, "scribble buf"); + next_strbuf = &(res->next_p); + res->next_p = NULL; + res->sb_off = 0; + /* + * The "sb_size" field is read-only. Override this. + */ + { + size_t * psz = (void *)&(res->sb_size); + *psz = min_size - str_buf_hdr_sz; + } + + return res; +} + +/** + * Allocate a scribble string. It will be deallocated when a macro finishes. + * Therefore, *DO NOT* use these at the start of a block macro expecting + * the space to still be usable at the end of the block macro. + * These allocations are intended for temporary space needs that cannot + * be kept on the stack. Expression processing. + * + * @param size the number of bytes needed + * @return the memory as a pointer to character + */ +LOCAL char * +ag_scribble(ssize_t size) +{ + string_buf_t* sb = ag_strbufs; + char* buf; + + size += 1; // allow for NUL byte & round to word boundary + size = ROUND_SCRIBBLE(size, sizeof(void *)); + + for (;;) { + if (sb == NULL) { + sb = new_scribble_block(size); + break; + } + + if ((sb->sb_size - sb->sb_off) >= size) + break; + + sb = sb->next_p; + } + + buf = (char*)(sb->sb_buf + sb->sb_off); + sb->sb_off += size; + return buf; +} + +/** + * As of Guile 1.7.x, access to the NUL terminated string referenced by + * an SCM is no longer guaranteed. Therefore, we must extract the string + * into one of our "scribble" buffers. + * + * @param s the string to convert + * @param type a string describing the string + * @return a NUL terminated string, or it aborts. + */ +LOCAL char * +ag_scm2zchars(SCM s, const char * type) +{ +#if GUILE_VERSION < 107000 /* pre-Guile 1.7.x */ + + if (! AG_SCM_STRING_P(s)) + AG_ABEND(aprf(NOT_STR_FMT, type)); + + if (SCM_SUBSTRP(s)) + s = scm_makfromstr(SCM_CHARS(s), SCM_LENGTH(s), 0); + return SCM_CHARS(s); + +#else + size_t len; + char * buf; + + if (! AG_SCM_STRING_P(s)) + AG_ABEND(aprf(NOT_STR_FMT, type)); + + len = scm_c_string_length(s); + if (len == 0) { + static char z = NUL; + return &z; + } + + buf = ag_scribble(len); + + { + size_t buflen = scm_to_locale_stringbuf(s, buf, len); + if (buflen != len) + AG_ABEND(aprf(SCM2ZCHARS_BAD_VAL, buflen, len)); + } + + buf[len] = NUL; + return buf; +#endif +} + +/* + * Local Variables: + * mode: C + * c-file-style: "stroustrup" + * indent-tabs-mode: nil + * End: + * end of agen5/scmStrings.c */ |