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#include "all.h"
struct decl *
envfind(const struct env *env, const char *name) {
if (!env)
return NULL;
for (struct decls *decls = env->decls; decls; decls = decls->next) {
if (!strcmp(decls->decl.name, name))
return &decls->decl;
}
return envfind(env->parent, name);
}
static bool
declsshadowable(const struct decl *a, const struct decl *b) {
return b->t == Dlet;
}
static bool
declscompatible(const struct decl *a, const struct decl *b) {
if (a->t != b->t)
return 0;
if (a->t == Dfn && a->externp == b->externp && a->fn.selfty == b->fn.selfty && !a->fn.body)
return 1;
if (a->t == Dstatic && a->externp == b->externp && a->var.ty == b->var.ty && !a->var.ini)
return 1;
if (a->t == Dtype && a->ty == b->ty)
return 1;
return 0;
}
struct decl *
envput(struct env *env, const struct decl *decl) {
struct decls *decls;
struct env env_noparent = {
.decls = env->decls
};
struct decl *d0;
if ((d0 = envfind(&env_noparent, decl->name))) {
for (int kind = TYstruct; kind <= TYunion; ++kind) {
if (d0->t == Dtype && d0->ty->t == kind
&& decl->t == Dtype && decl->ty->t == kind && d0->ty->agg.fwd) {
// modify existing forward declaration
*(size_t *)&d0->ty->size = decl->ty->size;
*(size_t *)&d0->ty->align = decl->ty->align;
*(bool *)&d0->ty->agg.fwd = 0;
memcpy((void *)&d0->ty->agg.flds, &decl->ty->agg.flds,
sizeof d0->ty->agg.flds);
memcpy((void *)&d0->ty->agg.decls, &decl->ty->agg.decls,
sizeof d0->ty->agg.decls);
d0->span = decl->span;
return d0;
}
}
if (!declsshadowable(d0, decl) && !declscompatible(d0, decl)) {
return NULL;
}
}
decls = xcalloc(1, sizeof *decls);
decls->next = env->decls;
decls->decl = *decl;
env->decls = decls;
return &decls->decl;
}
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