definite assignment: reading a local before it is initialized is a compile error (spec 4.1.5, b.1.9)

track linited per local alongside the ownership state; snapshots, exit records and joins carry it, and a join keeps a local set only when every reaching path set it. x = e, a declaration initializer, &x (out-parameter), a full array initializer, or using an aggregate as an address set a local; field and element writes do not set the aggregate. while/for bodies that may run zero times do not count; do/while does. compiler, runtime, std, actor and lsp sources initialize the locals the rule flagged; zc0 accepts = {} brace lists (zeroed). tests: tests/errors/uninit_*.zc, tests/conformance/4-statements/uninit_*.zc

1 files changed, 3 insertions, 3 deletions

diff --git a/src/compiler/builtins.zc b/src/compiler/builtins.zc
index f40e223..56895e9 100644
--- a/src/compiler/builtins.zc
+++ b/src/compiler/builtins.zc
@@ -464,7 +464,7 @@ int embed_bind(int n, int off, word t, int a, int kind) {
 		return 0;
 	}
 	i = newloc(n); lrsoff[i] = off; rs_note(RS_LOCAL, off);
-	ltag[i] = LDECL; lpos[i] = tpack(); lnsz[i] = 0; lleaf[i] = 0; ltype[i] = t;
+	ltag[i] = LDECL; lpos[i] = tpack(); lnsz[i] = 0; lleaf[i] = 0; ltype[i] = t; mark_inited(i);
 	if (kind == 1) {
 		larr[i] = 1; fslots = fslots + tsz(t); capture_cell(i, 0);
 		vaddr(i); lit(a); lit(tsz(t)); callname(s_copy_w); op(O_DROP);
@@ -1094,7 +1094,7 @@ int ckind(int skipname) {
 int ckindfloat(int k) { return k == 2 || k == 5; }
 // parse an extern declaration: a c function with its signature, and a zc stub for it.
 int kw_extern() {
-	int rk; word[16] ks; word[16] kst; char*[16] ksn; int np = 0, k; char* fname; char* cname; int i, a, j, n, w, sig, bad = 0; char* buf; word oldimports = module_imports; int pos, len, g; word st, rst; int rn, rsd, sret = 0;
+	int rk; word[16] ks = {}; word[16] kst = {}; char*[16] ksn = {}; int np = 0, k; char* fname; char* cname; int i, a, j, n, w, sig, bad = 0; char* buf; word oldimports = module_imports; int pos, len, g; word st, rst = 0; int rn = 0, rsd, sret = 0;
 	stmtonly();
 	next();
 	rk = ckind(0);
@@ -1544,7 +1544,7 @@ word targ(word t, int i) { return t[6][1 + i]; }
 // ---- function types by address ----
 
 word sigof(int f) {
-	int i = nsym, s = -1; word[24] ws; int n, k;
+	int i = nsym, s = -1; word[24] ws = {}; int n, k;
 	while (i) { i--; if (skind[i] == K_FN && sval[i] == f && (sflag[i] & F_DEF)) { s = i; break; } }
 	if (s < 0) return 0;
 	if (stype[s]) return stype[s];