This was actually a ticking UB bomb: after running the parser, the type
maps contain pointers to children of the current AST, which is
recursively deleted after the pass has executed. This leaves the
pointers in user_type_stack dangling, which just happened to never be a
problem due to another bug that causes typedefs from higher-level type
maps to never be considered.
Rebuilding the type stack from the design's globals ensures the AstNode
pointers are valid.
cell_inputs and cell_outputs retain cell pointers as their keys across
invocations of setup(), which may however be invalidated in the meantime
(as happens in e.g. passes/opt/share.cc:1432). A later rehash of the
dicts (caused by inserting in ModWalker::add_wire()) will cause them to
be dereferenced.
Calling log_signal is problematic for several reasons:
- with recent changes, empty string is serialized as { }, which violates
the "no spaces in IdString" rule
- the type (plain / real / signed / string) is dropped, wrongly conflating
functionally different values and potentially introducing a subtle
elaboration bug
Instead, use a custom simple serialization scheme.
This breaks the ability to use a global typename as a standard
identifier in a subsequent input file. This is otherwise backwards
compatible, including for sources which previously included conflicting
typedefs in each input file.
From IEEE1364-2005, section 7.3 buf and not gates:
> These two logic gates shall have one input and one or more outputs.
> The last terminal in the terminal list shall connect to the input of the
> logic gate, and the other terminals shall connect to the outputs of
> the logic gate.
yosys does not follow this and instead interprets the first argument as
the output, the second as the input and ignores the rest.
Previously, memories were silently discarded by the JSON backend, making
round-tripping modules with them crash.
Since there are already some users using JSON to implement custom
external passes that use memories (and infer width/size from memory
ports), let's fix this by just making JSON backend and frontend support
memories as first-class objects.
Processes are still not supported, and will now cause a hard error.
Fixes#1908.
The already-existing special case for conditionals on clock has been
remade as follows:
- now triggered for the last remaining edge trigger after all others
have been converted to async reset, not just when there is only one
sync rule in the first place
- does not require all contained assignments to be constant, as opposed
to a reset conditional — merely const-folds the condition
In addition, the code has been refactored a bit; as a bonus, the
priority order of async resets found is now preserved in resulting sync
rule ordering (though this is not yet respected by proc_dff).
Fixes#2656.
Among other problems, this also fixes equality comparisons between
SigSpec by enforcing a canonical form.
Also fix another minor issue with possible non-canonical SigSpec.
Fixes#2623.
This defers the simplification of globals so that globals in one file
may depend on globals in other files. Adds a simplify() call downstream
because globals are appended at the end.
It was previously possible to override global parameters on a
per-instance basis. This could be dangerous when using positional
parameter bindings, hiding oversupplied parameters.
Xiretza
Marcelina Kościelnicka
Lofty
Michael Singer
gatecat
Zachary Snow
whitequark
Miodrag Milanovic