The $paramod name mangling is not invertible (the \ character, which
separates the module name from the parameters, is valid in the module
name itself), which does not stop people from trying to invert it.
This commit makes it easy to invert the name mangling by storing
the original name explicitly, and fixes the firrtl backend to use
the newly introduced attribute.
This adds the new rewrite rule. But it's still missing a check that makes
sure the new rewrite rule is actually a valid substitute in the always
block being processed. Therefore the new rewrite rule is just disabled
for now.
Signed-off-by: Claire Wolf <claire@symbioticeda.com>
Before this commit, enum values were serialized as attributes of form
\enum_<width>_<value>
where <value> was a decimal signed integer.
This has multiple drawbacks:
* Enums with large values would be hard to process for downstream
tooling that cannot parse arbitrary precision decimals. (In fact
Yosys also did not correctly process enums with large values,
and would overflow `int`.)
* Enum value attributes were not confined to their own namespace,
making it harder for downstream tooling to enumerate all such
attributes, as opposed to looking up any specific value.
* Enum values could not include x or z, which are explicitly
permitted in the SystemVerilog standard.
After this commit, enum values are serialized as attributes of form
\enum_value_<value>
where <value> is a bit sequence of the appropriate width.
(parameters in systemverilog packages can't actually be overridden, so
allowing parameters in addition to localparams doesn't actually add any
new functionality, but it's useful to be able to use the parameter
keyword also)
This patch should support things like
`define foo(a, b = 3, c) a+b+c
`foo(1, ,2)
which will evaluate to 1+3+2. It also spots mistakes like
`foo(1)
(the 3rd argument doesn't have a default value, so a call site is
required to set it).
Most of the patch is a simple parser for the format in preproc.cc, but
I've also taken the opportunity to wrap up the "name -> definition"
map in a type, rather than use multiple std::map's.
Since this type needs to be visible to code that touches defines, I've
pulled it (and the frontend_verilog_preproc declaration) out into a
new file at frontends/verilog/preproc.h and included that where
necessary.
Finally, the patch adds a few tests in tests/various to check that we
are parsing everything correctly.
Eddie Hung
Marcelina Kościelnicka
Claire Wolf
whitequark
Claire Wolf
Alberto Gonzalez
David Shah
Henner Zeller
Jeff Wang
Diego H
N. Engelhardt
Peter Crozier
Rupert Swarbrick