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#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <stdalign.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include "errors.h"
#include "parser.h"
/* #define AST_DFLT_CAP (2048) */
#define AST_DFLT_CAP (8)
#define SIZE_WDTH (sizeof(size_t) * CHAR_BIT)
static struct ast_soa mk_ast_soa(void);
static void ast_soa_resz(struct ast_soa *);
struct ast_soa
parsetoks(struct lexemes_soa toks)
{
struct ast_soa ast = mk_ast_soa();
return ast;
}
struct ast_soa
mk_ast_soa(void)
{
struct ast_soa soa;
static_assert(offsetof(struct ast_soa, kinds)
< offsetof(struct ast_soa, lexemes),
"KINDS is not the first field before LEXEMES");
static_assert(offsetof(struct ast_soa, kinds)
< offsetof(struct ast_soa, kids),
"KINDS is not the first field before KIDS");
static_assert(AST_DFLT_CAP * sizeof(*soa.kinds) % alignof(*soa.lexemes)
== 0,
"Additional padding is required to properly align LEXEMES");
static_assert(AST_DFLT_CAP * (sizeof(*soa.kinds) + sizeof(*soa.lexemes))
% alignof(*soa.kids)
== 0,
"Additional padding is required to properly align KIDS");
soa.len = 0;
soa.cap = AST_DFLT_CAP;
if ((soa.kinds = malloc(soa.cap * AST_SOA_BLKSZ)) == NULL)
err("malloc:");
soa.lexemes = (void *)((char *)soa.kinds + soa.cap * sizeof(*soa.kinds));
soa.kids = (void *)((char *)soa.lexemes + soa.cap * sizeof(*soa.lexemes));
return soa;
}
void
ast_soa_resz(struct ast_soa *soa)
{
static_assert(offsetof(struct ast_soa, kinds)
< offsetof(struct ast_soa, lexemes),
"KINDS is not the first field before LEXEMES");
static_assert(offsetof(struct ast_soa, kinds)
< offsetof(struct ast_soa, kids),
"KINDS is not the first field before KIDS");
static_assert(offsetof(struct ast_soa, lexemes)
< offsetof(struct ast_soa, kids),
"LEXEMES is not the second field before KIDS");
size_t ncap, pad1, pad2, newsz;
ptrdiff_t lexemes_off, kids_off;
lexemes_off = (char *)soa->lexemes - (char *)soa->kinds;
kids_off = (char *)soa->kids - (char *)soa->kinds;
/* The capacity is always going to be a power of 2, so checking for overflow
becomes pretty trivial */
if ((soa->cap >> (SIZE_WDTH - 1)) != 0) {
errno = EOVERFLOW;
err("ast_soa_resz:");
}
ncap = soa->cap << 1;
/* Ensure that soa->lexemes is properly aligned */
pad1 = alignof(*soa->lexemes)
- ncap * sizeof(*soa->kinds) % alignof(*soa->lexemes);
if (pad1 == alignof(*soa->lexemes))
pad1 = 0;
pad2 = alignof(*soa->kids)
- (ncap * (sizeof(*soa->kinds) + sizeof(*soa->lexemes)) + pad1)
% alignof(*soa->kids);
if (pad2 != alignof(*soa->kids))
pad2 = 0;
newsz = ncap * AST_SOA_BLKSZ + pad1 + pad2;
if ((soa->kinds = realloc(soa->kinds, newsz)) == NULL)
err("realloc:");
soa->lexemes = (void *)((char *)soa->kinds + ncap * sizeof(*soa->kinds)
+ pad1);
soa->kids = (void *)((char *)soa->lexemes + ncap * sizeof(*soa->lexemes)
+ pad2);
memmove(soa->kids, (char *)soa->kinds + kids_off,
soa->len * sizeof(*soa->kids));
memmove(soa->lexemes, (char *)soa->kinds + lexemes_off,
soa->len * sizeof(*soa->lexemes));
soa->cap = ncap;
}
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