This adds a typeswitch statement
typeswitch (e)
case (x1 : Type1) {
...
} case (x2 : Type2) {
} ...
... case (xn : TypeN) {
...
}
This checks to which of the given types the result of evaluating e can
be cast, in the order in which they are listed. So if an earlier
type matches, a value of this type won't reach a later case.
The type-checks are performed by calling the cast<T>() macro.
The type of the argument passed to the cast macro is dependent on the
case and excludes all types checked earlier. For example, in
const x : Object = ...
typeswitch (x)
case (x : Smi) {
...
} case (x : HeapNumber) {
...
} case (x : HeapObject) {
...
}
there will be calls to cast<Smi>(Object) and
cast<HeapNumber>(HeapObject), because after the Smi check we know that
x has to be a HeapObject. With the refactored base.tq definition of
cast, this will generate efficient code and avoid repeating the Smi
check in the second case.
The type system ensures that all cases are reachable and that the type
given to the last case is safe without a runtime check (in other words,
the union of all checked types covers the type of e).
The cases can also be written as
case (Type) { ... }
, in which case the switched value is not re-bound with the checked
type.
Bug: v8:7793
Change-Id: Iea4aed7465d62b445e3ae0d33f52921912e095e3
Reviewed-on: https://chromium-review.googlesource.com/1156506
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54958}
Previously, we requested instantiation of generics prior to selecting
a template overload, which resulted in unused templates being
instantiated, possibly triggering unnecessary compile errors.
Bug: v8:7793
Change-Id: I45f4bdbf8aa93749ece416c6c7458d64e6e051f5
Reviewed-on: https://chromium-review.googlesource.com/1154977
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54950}
This CL changes the for-loop so all parts are optional, allowing
loops like:
for (;;) {}
for (;; ++i) {}
...
R=danno@chromium.org, tebbi@chromium.org
Bug: v8:7793
Change-Id: I7bf9ef9e59d55eb9ae9f38904a1c1106ae50df5a
Reviewed-on: https://chromium-review.googlesource.com/1152727
Commit-Queue: Simon Zünd <szuend@google.com>
Reviewed-by: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54752}
This CL adds local const bindings. This means that instead of
generating TVARIABLEs for variables, we can generate simple TNodes.
Example:
macro FooBar(): {
const kSomeSmi: Smi = 10;
...
}
This CL also enforces that variables with a constexpr type are bound
using 'const' and not 'let'.
R=tebbi@chromium.org
Bug: v8:7793
Change-Id: Id20a18149df9fc374ce718bdb1478e3eabb6e6df
Reviewed-on: https://chromium-review.googlesource.com/1138316
Commit-Queue: Simon Zünd <szuend@google.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54479}
This CL adds constants that can be defined in the module scope:
const kConstexprConst: constexpr int31 = 5;
const kIntptrConst: intptr = 4;
const kSmiConst: Smi = 3;
They are implemented by generating "mini-macros" that return the
expression on the right-hand side of the assignment.
Bug: v8:7793
Change-Id: I0a476cb3111707fad56bf15e9547b377c7adab37
Reviewed-on: https://chromium-review.googlesource.com/1114745
Commit-Queue: Simon Zünd <szuend@google.com>
Reviewed-by: Daniel Clifford <danno@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54430}
Variables/return values with constexpr type cannot have multiple
assignments. We check this now.
For conditionals, it is important to always infer a non-constexpr type.
This CL adds the ability to map any type (including union types) to be
mapped to their non-constexpr variant. Conditionals infer their type as
the non-constexpr version of a combination of the two branch types.
In addition, this improves subtyping for constexpr types:
If A extends B, then constexpr A extends constexpr B.
This makes it necessary to clean up "constexpr String", which has nothing
to do with tagged values.
Bug: v8:7793
Change-Id: Ia4d3cd5dc98f45b0ec89adf05c5c6111a0e51cc6
Reviewed-on: https://chromium-review.googlesource.com/1122864
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54167}
This CL is a proposal to add "checked" casts (CAST in CSA) to the Torque language.
The CL adds the "unsafe_cast<>" operator that emits a "CAST".
Example:
let n: Number = ...;
...
if (TaggedIsSmi(n)) {
let m: Smi = unsafe_cast<Smi>(n);
...
}
The cast wont incur a runtime overhead now.
R=tebbi@chromium.org
Change-Id: I9fca90d1d11e61617ba0270e5022fd66200e2195
Reviewed-on: https://chromium-review.googlesource.com/1070151
Commit-Queue: Simon Zünd <szuend@google.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53416}
This CL adds grammar support for function pointers to generic builtins.
It also instantiates generic specializations when they are only used
in an assignment to a function pointer.
Example:
builtin GenericBuiltinTest<T: type>(c: Context, param: T): Object {
return Null;
}
let fnptr: builtin(Context, Smi) => Object = GenericBuiltinTest<Smi>;
Change-Id: Ib7e5f47ffc05f14eb5d0b789936587263dfb961d
Reviewed-on: https://chromium-review.googlesource.com/1068731
Commit-Queue: Simon Zünd <szuend@google.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53284}
This CL adds the new type expression
builtin(Context, ArgType1, ...) => ReturnType
and allows to use Torque-defined builtins as values of this type, as well
as calling values of this type.
The new function pointer types are subtypes of Code.
Change-Id: Ib7ba3ce6ef7a8591a4c79230dd189fd25698d5b9
Reviewed-on: https://chromium-review.googlesource.com/1060056
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53217}
This CL changes the generated C++ code for LabeledStatementBlocks to
only emit labels if they are used.
Prior to this CL, when a label was only used on one path of an
if constexpr expression, and not at all anywhere else,
the try/label construct would BIND a label that was not used,
causing a CSA verification error.
R=tebbi@chromium.org
Change-Id: Ia81a0cd081b84528c95bbdbdb98b9ab51928e13f
Reviewed-on: https://chromium-review.googlesource.com/1057247
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Daniel Clifford <danno@chromium.org>
Commit-Queue: Simon Zünd <szuend@google.com>
Cr-Commit-Position: refs/heads/master@{#53173}
Change-Id: I37ed9115c099f3d17f23a26348a1bbf5f773ee32
Reviewed-on: https://chromium-review.googlesource.com/1056668
Reviewed-by: Daniel Clifford <danno@chromium.org>
Commit-Queue: Peter Wong <peter.wm.wong@gmail.com>
Cr-Commit-Position: refs/heads/master@{#53136}
In the process, add a few simple tests for "constexpr" expressions, which
identified a few bugs that are also fixed in this CL.
Change-Id: I97486c781572642d2b574b92133b1f9cda3db592
Reviewed-on: https://chromium-review.googlesource.com/1055493
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53135}
