Recently I’ve been doing a lot of work on my VHDL simulator and I’ve just released the first new major version in over a year and a half.
This release contains many improvements and bug fixes detailed below, but the highlights are much improved language support, especially for configurations and some VHDL-2008 features, as well as better debugging support.
- Name resolution and overload resolution has been completely rewritten which should fix a number of long-standing issues.
- The elaboration phase was largely written which fixes a number of long-standing issues and significantly improves elaboration speed.
- VHDL-2008 IEEE standard libraries are now built and installed in addition to the VHDL-1993 libraries.
- The VHDL-1993 standard libraries are now derived from the Apache 2.0 licensed sources from VHDL-2019.
- There is now a project website at https://www.nickg.me.uk/nvc/. Please link to this in preference to the GitHub project page.
- Compiled VHDL code now includes DWARF debug information which is used for runtime stack trace if libdw or libdwarf is installed.
- Added support for VHDL-2008 reduction operators, match operators, and condition conversion.
- Added support for VHDL-2008 element resolution.
- Variable assignment now supports aggregate targets.
--relax=impureoption allows pure functions to call impure functions.
- Added support for VHDL-2008 “all” sensitised processes.
- Added support for ports and generics in block statements.
- Added support for the ’BASE attribute.
- Type name now allowed in element association choice (#407).
- Implement textio READ procedure for REAL.
- LLVM 6.0 or later is now required to build.
- Added support for MINIMUM, MAXIMUM, and TO_STRING predefined operators in VHDL-2008.
- VCD files are now generated from FST data in a similar manner to
fst2vcd(1). This should improve compatibility with other tools.
- Added support for ’LAST_ACTIVE attribute (#423).
- Added support for ’DRIVING and ’DRIVING_VALUE attributes.
- Added a new option
--ieee-warnings=offto disable warning messages from the standard IEEE packages.
- Support for configurations has been significantly improved (#372).
- Added support for VHDL-2008 delimited comments.
- Added support for guard expressions on blocks.
- Added support for guarded signals.
- Added support for HREAD, HWRITE, and other TEXTIO additions in VHDL-2008.
- Code generation now happens in parallel when LLVM is built with multi-threading enabled.
- Link time optimisation (LTO) is now enabled for release builds where supported.
- The default assertion failure message for certain simple scalar comparisons now shows the values of the left and right hand sides.
- Added support for VHDL-2008 conditional variable assignment statements.
- Added support for VHDL-2008 extended bit string literals.
- Non-globally-static actuals allowed in port maps in VHDL-2008 mode.
- Added support for VHDL-2008 sequential conditional signal assignment statements.
- Added basic support for package generics and package instantiation.
- Nested arrays can now be included in the waveform dump but only if the
--dump-arraysoption is passed. This is disabled my default due the significant performance and memory overhead.
- Added support for record types in waveform dump (#216).
- Added support for foreign subprograms using the VHPIDIRECT protocol.
- Library build is now reproducible when running
- Fix a constant folding crash with nested records.
- Fixed a crash when a record aggregate contains an “others” association and the fields have array types with different lengths.
- Fixed a stack overflow when a subprogram with unconstrained array arguments is called repeatedly in a loop (#414).
- Fixed intermittent crash when evaluating nested constant records (#425).
- Fixed missing import libraries on Windows (#424).
- Standard libraries are now installed under
- New configure option
--disable-vitaldisables building the VITAL packages whose license status is unclear.
- Support for the LXT wave output format, which was deprecated in version 1.5, has been removed. Use the default FST format instead.
fetch-ieee.shscript which did nothing since the last release has been removed.
--codegencommand, which has been deprecated since 1.3, was removed.
--profileoption now prints internal simulation statistics instead of the top processes by CPU time.