Supports bit-array register delcaration - #41
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Scope identifiers and variable references in real VCD files routinely
contain characters that IEEE 1800-2023 21.7 admits only within escaped
identifiers, e.g. verilator's mem_array[0] and genblock[3].mod, UVM's
uvm_phase::m_wait_for_pred, and cva6's scope_name(432). Extending the
simple identifier character set once per newly reported character does
not converge, so lex these names as everything up to whitespace instead,
and keep the identifier lexer for keywords, types, and units, where the
character set of a simple identifier does apply. For scopes this also
matches the grammar, which gives scope_identifier ::= { ASCII character }
rather than an identifier.
A variable reference is ambiguous once brackets are part of a name:
mem_array[0] is indistinguishable from a bit select of mem_array.
Whitespace cannot separate the two, as the reference in the standard's
own example is unspaced:
$var reg 32 (k accumulator[31:0] $end
So only the final bracketed section of a reference is treated as a bit
index, and only when it holds decimal indices. This preserves the
existing interpretation of accumulator[31:0] and foo [17] while
admitting references such as varname[1423][SOMENAME][2]. Brackets within
an escaped identifier are always part of the name.
Resolves issues #22 and #35 and supersedes PRs #29, #40, and #41.
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Thanks for this PR. Sorry for the long delay. Fixed in 92b8181. Took the same view that Your example is now a test case. Closing in favor of the version on master. |
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Example:
$var reg 178 /Y mem_array[0] [177:0] $end
In above expression, mem_array[0] is saved as VAR, instead raising ParserError