Hojun-Cho
1657bdeda3
C bootstrap (phases 0-9):
cmd/wwc, cmd/6c, cmd/6a, cmd/6l, cmd/ww, rt, lib/*.
ww-side self-host (phase 10):
selfhost/cmd/wwc — ww-cgen frontend; bootstrap fixed point.
selfhost/cmd/6a — assembler; byte-identical to C 6a (test 991).
selfhost/cmd/6l — linker w/ archive (.a) support; byte-identical
to C 6l (test 992).
selfhost/cmd/ww — driver (build/run/version); byte-identical to
C ww (test 993).
make test: 15/15. make bootstrap: ww2.s == ww3.s, ww2.o == ww3.o,
ww2 == ww3 byte-identical, with the full ww-tooled chain.
75 lines
1.5 KiB
C
75 lines
1.5 KiB
C
/*
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* sym.c — symbol table. Plan 9-flavoured: a per-scope hashtable
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* chained to the parent scope. Lookup walks up. Duplicate definitions
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* within the same scope are flagged by the caller (we just refuse the
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* insert and return the first one).
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*/
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#include "ww.h"
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#include <string.h>
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#define INIT_BUCKETS 16
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static u64
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hashstr(const char *s)
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{
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/* FNV-1a 64-bit; small fixed footprint, decent distribution */
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u64 h = 0xcbf29ce484222325ULL;
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for (; *s; s++) {
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h ^= (unsigned char)*s;
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h *= 0x100000001b3ULL;
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}
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return h;
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}
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Scope *
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newscope(Arena *a, Scope *parent)
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{
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Scope *s = amalloc(a, sizeof *s);
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s->parent = parent;
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s->a = a;
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s->nbuckets = INIT_BUCKETS;
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s->buckets = amalloc(a, s->nbuckets * sizeof(Sym *));
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return s;
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}
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Sym *
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scope_lookup_local(Scope *s, const char *name)
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{
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if (s == NULL) return NULL;
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u64 h = hashstr(name) % s->nbuckets;
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for (Sym *b = s->buckets[h]; b; b = b->hashnext)
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if (strcmp(b->name, name) == 0)
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return b;
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return NULL;
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}
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Sym *
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scope_lookup(Scope *s, const char *name)
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{
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for (; s; s = s->parent) {
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Sym *r = scope_lookup_local(s, name);
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if (r) return r;
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}
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return NULL;
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}
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Sym *
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scope_define(Scope *s, const char *name, Skind k, Type *t, Node *decl)
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{
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if (scope_lookup_local(s, name) != NULL)
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return NULL;
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Sym *sy = amalloc(s->a, sizeof *sy);
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sy->name = name;
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sy->kind = k;
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sy->type = t;
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sy->decl = decl;
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sy->scope = s;
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u64 h = hashstr(name) % s->nbuckets;
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sy->hashnext = s->buckets[h];
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s->buckets[h] = sy;
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if (s->first == NULL) s->first = sy;
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else s->last->next = sy;
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s->last = sy;
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return sy;
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}
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