diff options
| -rw-r--r-- | src/cmd/gc/subr.c | 34 | ||||
| -rw-r--r-- | test/fixedbugs/issue4585.go | 60 |
2 files changed, 78 insertions, 16 deletions
diff --git a/src/cmd/gc/subr.c b/src/cmd/gc/subr.c index c032ffae0..afbdd0cca 100644 --- a/src/cmd/gc/subr.c +++ b/src/cmd/gc/subr.c @@ -504,12 +504,17 @@ nod(int op, Node *nleft, Node *nright) return n; } +// ispaddedfield returns whether the given field +// is followed by padding. For the case where t is +// the last field, total gives the size of the enclosing struct. static int -ispaddedfield(Type *t) +ispaddedfield(Type *t, vlong total) { if(t->etype != TFIELD) fatal("ispaddedfield called non-field %T", t); - return t->down != T && t->width + t->type->width != t->down->width; + if(t->down == T) + return t->width + t->type->width != total; + return t->width + t->type->width != t->down->width; } int @@ -591,7 +596,7 @@ algtype1(Type *t, Type **bad) for(t1=t->type; t1!=T; t1=t1->down) { // Blank fields and padding must be ignored, // so need special compare. - if(isblanksym(t1->sym) || ispaddedfield(t1)) { + if(isblanksym(t1->sym) || ispaddedfield(t1, t->width)) { ret = -1; continue; } @@ -2619,7 +2624,7 @@ genhash(Sym *sym, Type *t) Node *hashel; Type *first, *t1; int old_safemode; - int64 size, mul; + int64 size, mul, offend; if(debug['r']) print("genhash %S %T\n", sym, t); @@ -2705,24 +2710,21 @@ genhash(Sym *sym, Type *t) // Walk the struct using memhash for runs of AMEM // and calling specific hash functions for the others. first = T; + offend = 0; for(t1=t->type;; t1=t1->down) { if(t1 != T && algtype1(t1->type, nil) == AMEM && !isblanksym(t1->sym)) { + offend = t1->width + t1->type->width; if(first == T) first = t1; // If it's a memory field but it's padded, stop here. - if(ispaddedfield(t1)) + if(ispaddedfield(t1, t->width)) t1 = t1->down; else continue; } // Run memhash for fields up to this one. if(first != T) { - if(first->down == t1) - size = first->type->width; - else if(t1 == T) - size = t->width - first->width; // first->width is offset - else - size = t1->width - first->width; // both are offsets + size = offend - first->width; // first->width is offset hashel = hashmem(first->type); // hashel(h, size, &p.first) call = nod(OCALL, hashel, N); @@ -2856,6 +2858,7 @@ geneq(Sym *sym, Type *t) Type *t1, *first; int old_safemode; int64 size; + int64 offend; if(debug['r']) print("geneq %S %T\n", sym, t); @@ -2929,12 +2932,14 @@ geneq(Sym *sym, Type *t) // and calling specific equality tests for the others. // Skip blank-named fields. first = T; + offend = 0; for(t1=t->type;; t1=t1->down) { if(t1 != T && algtype1(t1->type, nil) == AMEM && !isblanksym(t1->sym)) { + offend = t1->width + t1->type->width; if(first == T) first = t1; // If it's a memory field but it's padded, stop here. - if(ispaddedfield(t1)) + if(ispaddedfield(t1, t->width)) t1 = t1->down; else continue; @@ -2952,10 +2957,7 @@ geneq(Sym *sym, Type *t) fn->nbody = list(fn->nbody, eqfield(np, nq, newname(first->sym), neq)); } else { // More than two fields: use memequal. - if(t1 == T) - size = t->width - first->width; // first->width is offset - else - size = t1->width - first->width; // both are offsets + size = offend - first->width; // first->width is offset fn->nbody = list(fn->nbody, eqmem(np, nq, newname(first->sym), size, neq)); } first = T; diff --git a/test/fixedbugs/issue4585.go b/test/fixedbugs/issue4585.go index 558bd1e10..ad1242d1e 100644 --- a/test/fixedbugs/issue4585.go +++ b/test/fixedbugs/issue4585.go @@ -32,6 +32,20 @@ type USmall struct { A, _, B int32 } +// V has padding but not on the first field. +type V struct { + A1, A2, A3 int32 + B int16 + C int32 +} + +// W has padding at the end. +type W struct { + A1, A2, A3 int32 + B int32 + C int8 +} + func test1() { var a, b U m := make(map[U]int) @@ -84,8 +98,54 @@ func test3() { } } +func test4() { + var a, b V + m := make(map[V]int) + + copy((*[20]byte)(unsafe.Pointer(&a))[:], "Hello World, Gopher!") + a.A1, a.A2, a.A3, a.B, a.C = 1, 2, 3, 4, 5 + b.A1, b.A2, b.A3, b.B, b.C = 1, 2, 3, 4, 5 + + if a != b { + panic("broken equality: a != b") + } + + m[a] = 1 + m[b] = 2 + if len(m) == 2 { + panic("broken hash: len(m) == 2") + } + if m[a] != 2 { + panic("m[a] != 2") + } +} + +func test5() { + var a, b W + m := make(map[W]int) + + copy((*[20]byte)(unsafe.Pointer(&a))[:], "Hello World, Gopher!") + a.A1, a.A2, a.A3, a.B, a.C = 1, 2, 3, 4, 5 + b.A1, b.A2, b.A3, b.B, b.C = 1, 2, 3, 4, 5 + + if a != b { + panic("broken equality: a != b") + } + + m[a] = 1 + m[b] = 2 + if len(m) == 2 { + panic("broken hash: len(m) == 2") + } + if m[a] != 2 { + panic("m[a] != 2") + } +} + func main() { test1() test2() test3() + test4() + test5() } |