v5.0

Language Support

• Added support for specifying a modport when connecting an interface array port
• Implicitly typed parameters that have range specifications are now considered assignment-like contexts (this behavior is not specified in the LRM but more intuitively matches user expectations)
• Added support for using assignment patterns as lvalues (which finally finishes full support for assignment patterns)
• Added partial support for SystemVerilog configurations. Support is incomplete and may be buggy.
• Index selects after range/part selects are now disallowed, to conform to the LRM as well as match the behavior of other tools
• An error is now issued for interface ports that connect hierarchically through a generate or instance array, as mandated by the LRM
• An error is now issued for generic interface ports that are connected via a wildcard connection, as mandated by the LRM
• Rules about where classes with private members are allowed to be used in bitstream casts are now enforced
• Relaxed requirement that DPI import declarations have an explicit return type to match behavior of other tools
• Added -Wdpi-pure-task to allow downgrading the error that DPI import tasks cannot be marked pure
• Added --relax-string-conversions (included in "vcs" compat mode) to allow strings to implicitly convert to integers
• Added --allow-recursive-implicit-call to allow implicit call expressions to be recursive function calls for compatibility with other tools

General Features

• Minimum required compiler versions have been bumped to GCC 11, clang 16, and Xcode 15 (should be the last bump for a while)
• Minimum required cmake version has been bumped to 3.20
• Added --allow-toplevel-iface-ports to allow top level modules that have interface ports
• Added -Wconstant-conversion which warns about conversions inside constant expressions that lose information
• Added -Wsign-conversion which warns about implicit integral conversions that change sign
• Added a -L option to control the default source library search order
• The --diag-hierarchy option now takes a parameter of "always", "never", or "auto" to allow forcing or hiding instance paths in diagnostics

Improvements

• Made several improvements to -Wimplicit-conv to make it less noisy
• Cleaned up internal code related to wide character support for Windows. slang now relies on the relatively new utf-8 code page support in Windows; this does mean that Unicode paths will now only be handled correctly on or after Windows Version 1903 (May 2019 Update).
• The maximum size of a type has been increased to 2^31 bytes (which matches VCS)
• The --suppress-warnings feature has been optimized to not perform unnecessary filesystem operations

Fixes

• Fixed a case where -Wimplicit-conv would not be issued for mismatching struct types
• Fixed a crash when $static_assert condition is parenthesized
• Fixed the count of compilation errors reported when using -Werror along with --suppress-warnings
• Fixed -Wvector-overflow to work correctly with signed literals
• Fixed the type infered for parameters that are assigned vector literals larger than 32-bits wide
• SystemVerilog class types (and other types that contain them) are now limited to the max object size supported by slang (the same limit for structs and arrays that was already present)
• Fixed a few places where large types or expressions could result in internal overflow of variables tracking their sizes, which could cause crashes or other strange behavior. Now a proper error is issued.
• A proper error is now issued for duplicate local variables inside of properties and sequences
• Fixed a crash when trying to connect an extern subroutine implementation to an interface array port
• Fixed a spurious error about signals being multi-driven from uninstantiated generate blocks
• Fixed a spurious error when streaming concatenations are used in port connections of uninstantiated modules
• An appropriate parse error is now issued for generate blocks that are missing a body
• Fixed a crash when classes with cycles in their members are used in a cast expression
• Fixed a bug in parsing parameter ports when their type was explicitly package scoped and the parameter keyword was elided
• Fixed a bug in the slang driver that prevented showing instance paths in diagnostics
• An error is now issued for invalid use of the unique and priority keywords in else blocks

New Contributors

• @alexeyvoh made their first contribution in #856
• @Badhi made their first contribution in #858
• @likeamahoney made their first contribution in #861

Full Changelog: v4.0...v5.0