Migrate some of the validation logic over to use the results of behavior
analysis.
The most significant changes are:
* Unreachable-statements now consider merge-points of control flow. For
example, if all branches of a if-statement or switch-statement either
return or discard, the next statement will be considered unreachable.
* Unreachable statements are no longer an error, but a warning. See
https://github.com/gpuweb/gpuweb/issues/2378.
* Statements that follow a loops that does not break, or have a
conditional will now be considered unreachable.
* Unreachable statements produced by the SPIR-V reader are now removed
using the new RemoveUnreachableStatements transform.
Some other new changes include additional validation for the continuing
block for for-loops, to match the rules of a loop continuing block.
The new cases this validation is testing for are not expressible in
WGSL, but some transforms may produce complex continuing statements that
might violate these rules. All the writers are able to decay these
complex for-loop continuing statements to regular loops.
Bug: tint:1302
Change-Id: I0d8a48c73d5d5c30a1cddf92cc3383a692a58e61
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/71500
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
This change implements the behavior analysis for expressions and
statements as described in:
https://www.w3.org/TR/WGSL/#behaviors
This CL makes no changes to the validation rules. This will be done as a
followup change.
Bug: tint:1302
Change-Id: If0a251a7982ea15ff5d93b54a5cc5ed03ba60608
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/68408
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: David Neto <dneto@google.com>
Nothing currently does the analysis to calculate these.
Change-Id: Ia2103102fbf36109f357aebf32cdfda24d6d8155
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/68407
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: Ben Clayton <bclayton@chromium.org>
The semantic nodes cannot be fully immutable, as they contain cyclic
references. Remove Resolver::CreateSemanticNodes(), and instead
construct and mutate the semantic nodes in the single traversal pass.
Give up on trying to maintain the 'authored' type names (aliased names).
These are a nightmare to maintain, and provided limited use.
Significantly simplfies the Resolver, and allows us to generate more
semantic to semantic references, reducing sem -> ast -> sem hops.
Note: This change introduces constant value propagation across constant
variables. This is unlocked by the earlier construction of the
sem::Variable.
Change-Id: I592092fdc47fe24d30e512952511c9ab7c16d7a1
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/68406
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Check they do not contain returns, discards
Check they do not directly contain continues, however a nested loop can have its own continue.
Bug: chromium:1229976
Change-Id: Ia3c4ac118ffdaa6cca6025366c19f9897718c930
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/58384
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: David Neto <dneto@google.com>
Auto-Submit: Ben Clayton <bclayton@google.com>
This change introduces sem::CompoundStatement, a new base class for
statements that can hold other statements.
sem::BlockStatements now derives from sem::CompoundStatement, and
this change introduces the following new CompoundStatements:
* `sem::IfStatement`
* `sem::ElseStatement`
* `sem::ForLoopStatement`
* `sem::LoopStatement`
* `sem::SwitchStatement`.
These new CompoundStatements are now inserted into the semantic
tree as now documented in `docs/compound_statements.md`.
The `sem::BlockStatement::FindFirstParent()` methods have been
moved down to `sem::Statement`.
The `Resolver::BlockScope()` method has been replaced with
`Resolver::Scope()` which now maintains the `current_statement_`,
`current_compound_statement_ ` and `current_block_`. This
simplifies statement nesting.
The most significant change in behavior is that statements now
always have a parent, so calling Block() on the initializer or
continuing of a for-loop statement will now return the
BlockStatement that holds the for-loop. Before this would
return nullptr.
Fixed: tint:979
Change-Id: I90e38fd719da2a281ed9210e975ab96171cb6842
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/57707
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: James Price <jrprice@google.com>
BlockStatement for the root block of a function
Add some basic tests for this lot.
Bug: tint:812
Change-Id: I26b65717798cbff576a44bd78fbcb5c8f0d013e6
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/51368
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Reviewed-by: Alastair Donaldson <allydonaldson@googlemail.com>
Semantic information about block statements the resolver would
temporarily create while resolving is now exposed in a
sem::BlockStatement class.
In the process, semantic information about statements in general is
overhauled so that a statement has a reference to its parent
statement, regardless of whether this is a block.
Bug: tint:799
Bug: tint:800
Change-Id: I8771511c5274ea74741b8c86f0f55cbc39810888
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/50904
Commit-Queue: Alastair Donaldson <allydonaldson@googlemail.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
