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Commit ce4e9911 authored by Jakob Kummerow's avatar Jakob Kummerow Committed by V8 LUCI CQ
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[wasm-gc] Non-nullable locals with end-of-block semantics 

a.k.a. "option 1a". Reflects the resolution of this discussion:
https://github.com/WebAssembly/function-references/issues/44

Bug: v8:7748
Change-Id: I6b53c353a1ace2aaf5b852addead51b9f76c9d64
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3782674Reviewed-by: 's avatarManos Koukoutos <manoskouk@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81925}
parent efac35f3
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Showing with 123 additions and 122 deletions
src/wasm/function-body-decoder-impl.h
View file @ ce4e9911
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src/wasm/graph-builder-interface.cc
View file @ ce4e9911
......@@ -160,9 +160,7 @@ class WasmGraphBuildingInterface {
while (index < num_locals) {
ValueType type = decoder->local_type(index);
TFNode* node;
if ((decoder->enabled_.has_nn_locals() ||
decoder->enabled_.has_unsafe_nn_locals()) &&
!type.is_defaultable()) {
if (!type.is_defaultable()) {
DCHECK(type.is_reference());
// TODO(jkummerow): Consider using "the hole" instead, to make any
// illegal uses more obvious.
......
src/wasm/wasm-feature-flags.h
View file @ ce4e9911
......@@ -31,12 +31,6 @@
\
/* Non-specified, V8-only experimental additions to the GC proposal */ \
/* V8 side owner: jkummerow */ \
V(nn_locals, \
"allow non-defaultable/non-nullable locals, validated with 'until end of " \
"block' semantics", \
false) \
V(unsafe_nn_locals, \
"allow non-defaultable/non-nullable locals, no validation", false) \
V(assume_ref_cast_succeeds, \
"assume ref.cast always succeeds and skip the related type check " \
"(unsafe)", \
......
test/unittests/wasm/function-body-decoder-unittest.cc
View file @ ce4e9911
......@@ -3628,20 +3628,15 @@ TEST_F(FunctionBodyDecoderTest, DefaultableLocal) {
ExpectValidates(sigs.v_v(), {});
}
TEST_F(FunctionBodyDecoderTest, NonDefaultableLocal) {
TEST_F(FunctionBodyDecoderTest, NonDefaultableLocals) {
WASM_FEATURE_SCOPE(typed_funcref);
AddLocals(ValueType::Ref(HeapType::kAny), 1);
ExpectFailure(sigs.v_v(), {}, kAppendEnd,
"Cannot define function-level local of non-defaultable type");
}
TEST_F(FunctionBodyDecoderTest, AllowingNonDefaultableLocals) {
WASM_FEATURE_SCOPE(typed_funcref);
WASM_FEATURE_SCOPE(nn_locals);
WASM_FEATURE_SCOPE(eh);
WASM_FEATURE_SCOPE(gc);
byte struct_type_index = builder.AddStruct({F(kWasmI32, true)});
ValueType rep = ref(struct_type_index);
FunctionSig sig(0, 1, &rep);
AddLocals(rep, 2);
byte ex = builder.AddException(sigs.v_v());
// Declaring non-defaultable locals is fine.
ExpectValidates(&sig, {});
// Loading from an uninitialized non-defaultable local fails.
......@@ -3656,48 +3651,60 @@ TEST_F(FunctionBodyDecoderTest, AllowingNonDefaultableLocals) {
ExpectFailure(&sig, {WASM_LOCAL_SET(1, WASM_REF_NULL(struct_type_index))},
kAppendEnd,
"expected type (ref 0), found ref.null of type (ref null 0)");
// Initialization status is propagated into inner blocks.
ExpectValidates(&sig, {WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)),
WASM_BLOCK(WASM_LOCAL_GET(1), WASM_DROP),
WASM_LOCAL_GET(1), WASM_DROP});
// Initialization status is forgotten at the end of a block.
// Initialization is propagated into inner blocks.
ExpectValidates(
&sig,
{WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)),
WASM_BLOCK(WASM_LOCAL_GET(1), WASM_DROP),
WASM_LOOP(WASM_LOCAL_GET(1), WASM_DROP),
WASM_IF_ELSE(WASM_ZERO, WASM_SEQ(WASM_LOCAL_GET(1), WASM_DROP),
WASM_SEQ(WASM_LOCAL_GET(1), WASM_DROP)),
kExprTry, kVoidCode, WASM_LOCAL_GET(1), WASM_DROP, kExprCatch, ex,
WASM_LOCAL_GET(1), WASM_DROP, kExprEnd, WASM_LOCAL_GET(1), WASM_DROP});
// Initialization is forgotten at the end of a block.
ExpectFailure(&sig,
{WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)),
WASM_BLOCK(WASM_LOCAL_SET(2, WASM_LOCAL_GET(0))),
WASM_LOCAL_GET(1), WASM_DROP, // OK
WASM_LOCAL_GET(2), WASM_DROP}, // Error
kAppendEnd, "uninitialized non-defaultable local: 2");
}
TEST_F(FunctionBodyDecoderTest, UnsafeNonDefaultableLocals) {
WASM_FEATURE_SCOPE(typed_funcref);
WASM_FEATURE_SCOPE(unsafe_nn_locals);
byte struct_type_index = builder.AddStruct({F(kWasmI32, true)});
ValueType rep = ref(struct_type_index);
FunctionSig sig(0, 1, &rep);
AddLocals(rep, 2);
// Declaring non-defaultable locals is fine.
ExpectValidates(&sig, {});
// Loading from an uninitialized non-defaultable local validates (but crashes
// when executed).
ExpectValidates(&sig, {WASM_LOCAL_GET(1), WASM_DROP});
// Loading from an initialized local is fine.
ExpectValidates(&sig, {WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)),
WASM_LOCAL_GET(1), WASM_DROP});
ExpectValidates(&sig, {WASM_LOCAL_TEE(1, WASM_LOCAL_GET(0)),
WASM_LOCAL_GET(1), WASM_DROP, WASM_DROP});
// Non-nullable locals must be initialized with non-null values.
ExpectFailure(&sig, {WASM_LOCAL_SET(1, WASM_REF_NULL(struct_type_index))},
kAppendEnd,
"expected type (ref 0), found ref.null of type (ref null 0)");
// Block structure doesn't matter, everything validates.
ExpectValidates(&sig, {WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)),
WASM_BLOCK(WASM_LOCAL_GET(1), WASM_DROP),
WASM_LOCAL_GET(1), WASM_DROP});
ExpectValidates(&sig,
{WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)),
WASM_BLOCK(WASM_LOCAL_SET(2, WASM_LOCAL_GET(0))),
WASM_LOCAL_GET(1), WASM_DROP, WASM_LOCAL_GET(2), WASM_DROP});
// Initialization is forgotten at the end of if/else, even if both
// branches initialized the local.
ExpectFailure(&sig,
{WASM_IF_ELSE(WASM_ZERO, WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)),
WASM_LOCAL_SET(1, WASM_LOCAL_GET(0))),
WASM_LOCAL_GET(1), WASM_DROP},
kAppendEnd, "uninitialized non-defaultable local: 1");
// Initialization does not carry from the "then" branch to the "else" branch.
ExpectFailure(&sig,
{WASM_IF_ELSE(WASM_ONE, WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)),
WASM_SEQ(WASM_LOCAL_GET(1), WASM_DROP))},
kAppendEnd, "uninitialized non-defaultable local: 1");
// Initialization is forgotten at the end of a loop.
ExpectFailure(&sig,
{WASM_LOOP(WASM_LOCAL_SET(1, WASM_LOCAL_GET(0))),
WASM_LOCAL_GET(1), WASM_DROP},
kAppendEnd, "uninitialized non-defaultable local: 1");
// Initialization is forgotten at the end of a try, with or without catch.
ExpectFailure(&sig,
{kExprTry, kVoidCode, WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)),
kExprEnd, WASM_LOCAL_GET(1), WASM_DROP},
kAppendEnd, "uninitialized non-defaultable local: 1");
ExpectFailure(&sig,
{kExprTry, kVoidCode, WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)),
kExprCatch, ex, WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)), kExprEnd,
WASM_LOCAL_GET(1), WASM_DROP},
kAppendEnd, "uninitialized non-defaultable local: 1");
ExpectFailure(&sig,
{kExprTry, kVoidCode, WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)),
kExprCatchAll, WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)), kExprEnd,
WASM_LOCAL_GET(1), WASM_DROP},
kAppendEnd, "uninitialized non-defaultable local: 1");
// Initialization does not carry from a "try" block to its "catch" block.
ExpectFailure(&sig,
{kExprTry, kVoidCode, WASM_LOCAL_SET(1, WASM_LOCAL_GET(0)),
kExprCatch, ex, WASM_LOCAL_GET(1), WASM_DROP, kExprEnd},
kAppendEnd, "uninitialized non-defaultable local: 1");
}
TEST_F(FunctionBodyDecoderTest, RefEq) {
......
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