Unreleased changes
- ZSTD is now a build dependency. Install
libzstd-dev
or similar.
- The
integer
type is now 64-bit in VHDL-2019 mode.
- The VUnit VHDL libraries can now be installed with
nvc --install vunit
but please note this does not install the Python infrastructure.
- Updated to OSVVM 2023.04 and UVVM 2023.03.21 for
nvc --install
.
- Conditional expressions are now allowed in constant, signal, and variable declarations in VHDL-2019 mode.
- Conditional return statements are now supported in VHDL-2019.
- Added support for the “function knows vector size” feature in VHDL-2019.
- Entity ports with variable class and protected type are now supported in VHDL-2019 mode.
- The xpm_vhdl project which provides VHDL models of the Xilinx XPM macros can now be installed with
nvc --install xpm_vhdl
.
- Many improvements to the VHPI implementation (from @Forty-Bot).
vhpi_put_value
with vhpiDepositPropagate
mode is now supported.
- The Synopsys
std_logic_misc
package is now compiled for 2008 (#696).
- Fixed an issue where leading
NUL
characters in a report message would prevent the entire message being printed (#700).
- Added support for interfaces in VHDL-2019 including mode view declarations, mode view indications, and the
'converse
attribute.
- Added support for VHDL-2008 matching
select?
statements (#705).
- Added support for the new
'designated_subtype
and 'index
attributes in VHDL-2019.
- Implemented the date/time functions from
std.env
in VHDL-2019.
- The default exit severity was changed from
error
to failure
. This means a failing assertion no longer immediately terminates the simulation. The old behaviour can be restored with --exit-severity=error
.
- Comparison operators as well as
minimum
/maximum
functions are now defined for all scalar array types in VHDL-2019.
- Added support for selected sequential statements in VHDL-2008.
- The
-a
analysis command now accepts an -f list
option where list
is a text file containing a list of files to analyse. Alternatively this may be written @list
.
Version 1.9.2 - 2023-05-01
- Fix elaboration errors with recursive entity instantiation (#668).
- Updated to latest GtkWave FST writer library.
- Fix crash when an external name is used in a wait expression (#674).
- Fix stack corruption when passing large numbers of arguments (#665).
- Protected procedure calls with
out
or inout
signal arguments now create drivers (#675).
- Fixed a crash when a
next
or exit
statement appears inside process (all)
(#676).
- The
--jit
elaboration options now works on Intel Macs (#680).
- Fixed a corner case where a forced signal with no drivers had the wrong effective value after
release
(#681).
- Fixed a crash when a signal assignment statement contains only
unaffected
(#677).
Version 1.9.1 - 2023-04-15
- Fix build errors and warnings on MSYS2 Clang x64 environment.
- Fix build failure due to missing
SHT_X86_64_UNWIND
on Alpine and Ubuntu 18.04 (#666).
- Elaboration now works correctly when the
--with-system-cc=
configure argument is given a non-absolute path (#667).
- Fixed a crash when a subprogram declared in a for-generate block is called during elaboration (#668).
- Real to physical or 64-bit integer conversion now produces the correct result when evaluated during elaboration (#669).
- Matching
case?
statements are now handled correctly in inside process (all)
(#670).
- Pass
-no_fixup_chains
to linker on macOS to avoid warning.
;
can now be used as a separator in the --work
and --map
arguments on Windows in addition to :
(#671).
Version 1.9.0 - 2023-04-07
- Code generation has been rewritten to enable faster elaboration and “just-in-time” compilation in the future.
- Now compatible with LLVM 16.
- Implemented the VHDL-2019 call path reporting API.
- The
elsif
VHDL-2019 conditional analysis directive now works correctly (#604).
- The
'transaction
implicit signal no longer incurs a delta-cycle delay.
x'ascending
now reports the correct result if x
has unconstrained array type and null range.
- The predefined
"="
operator on record types now always uses the predefined equality comparison for fields even in the presence of a user-defined "="
operator.
- It is no longer necessary on Windows to link VHPI plugins at elaboration time with
NVC_FOREIGN_OBJ
. Use the --load
option to load the plugin at run time as on other operating systems.
- The experimental
--jit
elaboration option defers native code generation until run time. This can dramatically reduce total test time for short-running simulations.
- Statements like
wait for X
where X
is negative but not a constant now produce an error at run time (#633).
- NVC is now supported by VUnit.
- Implicit signal attributes like
'transaction
are now considered static signal names (#640).
- Added support for fine-grained coverage collection via
--coverage-spec
elaboration option (from @Blebowski).
- The ABI for passing unconstrained arrays to foreign subprograms changed slightly, see the manual for details.
- Implemented new file I/O operations from VHDL-2019.
- Added analysis option
--define
to set user-defined conditional analysis identifiers (from @Blebowski).
- Optional support for using ZSTD to compress library files if
libzstd-dev
is installed.
- ISO-8859-1 extended characters are now handled properly in identifiers and when printing to the terminal.
- The new
configure
option --disable-default-paths
disables the default library search paths (#652).
- Subtype indications used as case range choices no longer crash during analysis (#655).
- The default standard version was changed to VHDL-2002 and will likely change again to -2008 in a future release. Users are recommended to use the
--std=
option to specify an explicit standard revision to avoid any compatibility issues.
- Fixed a crash when elaborating a port map which contains a subtype of a record (#662).
- Implemented VHDL-2019 syntax relaxations for empty records and trailing semicolon in interface lists (from @bpadalino).
- A Bash auto-completion script is now installed by default. Run
configure
with --without-bash-completion
to disable this.
Version 1.8.2 - 2023-02-14
- Fixed “failed to suspend thread” crash on macOS.
- Fix incorrect coverage scope nesting with array case statements (from @Blebowski).
- Expressions like
FOO(X)'DELAYED
now work as expected rather than producing a fatal error (#603).
- Fixed a bug where data was not propagated through inout ports in certain conditions (#609).
- The
-gNAME=VALUE
option to set generic values from the command line now works correctly for subtypes of enumeration types (#618).
- Fixed crash when creating an array of record subtypes where the subtype declaration has an element constraint (#615).
Version 1.8.1 - 2023-01-23
- Initial signal values for certain types were not dumped correctly in FST files on Windows (#596).
- Missing
thirdparty/str-two-way.h
from distribution tarball (#599).
Version 1.8.0 - 2023-01-22
- The
--disable-opt
and --native
elaborate options which were deprecated in version 1.3 have been removed.
- The JSON dumper which was unmaintained for several years has been removed.
- VHDL-2019 mode can be enabled with
--std=2019
. Please note there is very limited support for this standard at present.
- The new
--no-save
elaboration option skips saving the elaborated design and other generated files to the working library.
- Added support for
else
and elsif
in generate statements (#510).
- Xilinx Vivado vendor libraries can now be compiled with
nvc --install vivado
.
- LLVM 8.0 or later is now required due to deprecation of non-opaque pointers.
- Altera/Intel Quartus vendor libraries can now be compiled with
nvc --install quartus
.
- The
nvc --version
output now includes the commit hash if built from a Git checkout.
- The new
--gtkw
run option writes a .gtkw
save file for GtkWave containing all the signals in the design (suggested by @amb5l).
libffi
is now a build-time dependency.
- Negation of the smallest negative value of a type such as
-integer'left
now produces an error.
- Default OSVVM version updated to 2022.11.
case .. generate
statements are now supported in VHDL-2008.
- Coverage implementation was reworked and now collects statement, branch, expression and toggle metrics (from @Blebowski).
- The
--make
command is deprecated and will be repurposed in a later release. Use the new --print-deps
command instead to generate Makefile dependencies.
Version 1.7.2 - 2022-10-16
- Fixed build on FreeBSD/arm (#534).
- Fixed crash with generic package instantiation (#520).
- Now compatible with LLVM 15.0.
- Fixed calculation of longest static prefix with
'RANGE
expression (#542).
MOD
and REM
are now defined for physical types in VHDL-2008 (#540).
- Signal declarations are now allowed in entity declarative part (#547).
- Protected objects are now allowed in concurrent procedure calls (#547).
- Opening a file with
APPEND_MODE
now actually appends to the file instead of truncating (#551).
Version 1.7.1 - 2022-08-31
- Added missing textio
WRITE [LINE, REAL, STRING]
in VHDL-2008.
- Added support for FreeBSD/powerpc (#503, #504, from @pkubaj).
- Fixed “missing vcode unit” error during elaboration (#502).
- Fixed crash with recursive entity instantiation (#502).
- Fixed error with expressions like
X'ELEMENT'LENGTH
(#508).
- Added support for FreeBSD/i386.
- Fixed crash reading resolved value of record signal (#502).
- Improved folding of for-generate expressions (#514).
- Fixed memory leak when forcing signals.
- Fixed crash with type conversion in generic map (#518).
- Fixed crash with expressions like
X'DELAYED'STABLE
(#517).
- External names now work with record signals (#520).
- Xilinx Vivado vendor libraries can now be compiled with
nvc --install vivado
.
- VITAL libraries are now built by default on Windows.
- Fixed build with old versions of Glibc.
- Resolution functions with nested record types now behave correctly (#516).
- Avoid repeated
stat(2)
calls when accessing library.
- Fixed very slow elaboration in some cases with function calls in generic map expressions.
- Fixed intermittent segfault during elaboration (#506).
- Fixed incorrect constant folding of case statements with range choices.
- Fixed crash with constrained array declared in entity.
- Real valued signals can now be dumped in FST files (#524).
- Fixed signal assignment delay with side effects being evaluated twice (#527).
- An error is now reported for duplicate choices in array-type case statements (#528).
Version 1.7.0 - 2022-08-07
- Breaking change: In-tree builds are no longer supported: use a separate build directory instead.
- Breaking change: The
--force-init
command is deprecated and has no effect.
- Added support for VHDL-2008 type generics on packages and entities.
- Diagnostic messages have been enhanced with more contextual information.
- Added support for record element constraints and record fields with unconstrained array types.
- Alias of multidimensional array allowed in VHDL-2008 mode.
- Implemented VHDL-2008 rules for aggregates with slices.
- VHPI is now always enabled at build time and the
--enable-vhpi
configure option has no effect.
- Arithmetic operations that overflow the underlying machine type now produce an error (#101).
- Added support for VHDL-2008 force/release assignments.
- Basic support for external names in VHDL-2008.
- Matching case
case?
statements are supported in VHDL-2008 mode.
- Fixed several bugs in the implementation of guarded signals.
- Implemented VHDL-2008 rules for generic visibility.
- Shared variable declaration permitted in entity declaration.
- Case expression no longer requires a locally static subtype in VHDL-2008 mode (#460).
- The VHDL heap is now garbage collected as required by VHDL-2019 and the
deallocate
operator has no effect other than setting the access to null
.
- A new global option
-H
specifies the size of the simulation heap and defaults to 16 megabytes.
- Concurrent procedure call allowed in entity statement part.
- Added support for
'SUBTYPE
and 'ELEMENT
attributes in VHDL-2008.
- The new top-level
--init
command creates a new empty library directory.
- The
-a
analysis command now reads from the standard input if the file name is -
.
- Added support for array element constraints in VHDL-2008.
- The
--prefer-explicit
analysis option which was deprecated before the 1.0 release has been removed.
- A new
--relaxed
analysis option enables “relaxed rules” mode. This has the same effect as enabling all the existing --relax=
options. However some constructs will still produce warnings.
- The
--relax=
analysis option is deprecated and is now equivalent to passing --relaxed
. The individual options are ignored.
- Added support for generic subprograms in VHDL-2008.
- New command
--install
allows easy installation of common third-party packages such as OSVVM and UVVM.
- Identifiers in waveform dumps are now in lower case instead of upper case.
- The function
CURRENT_DELTA_CYCLE
in NVC.SIM_PKG
can be used to query the current delta cycle number.
Version 1.6.2 - 2022-04-03
- Fix
make -j
with GNU make (#440).
- Subtraction from zero could return the wrong result in some circumstances.
- Fix incorrect code generation for access-to-array.
- Fix assertion failure with nested context.
- Generic declarations are now allowed to hide the entity name.
- Fix spurious error about duplicate declarations when using VHDL-2008 context declarations.
- Fix incorrect default generic value when component and entity specify generics in different order (#448).
- Postponed processes with sensitivity lists now work correctly.
- Unit tests no longer fail when built without debug symbols (#445).
- Simulation now correctly terminates when time reaches
TIME'HIGH
.
- Assertion failure and report messages were not printed during the initialisation phase of the simulation.
Version 1.6.1 - 2022-02-05
- Fix compatibility with BSD make (#440).
- Fix an out-of-memory condition when initialising processes (#441).
- Fix incorrect generic value in binding specification (#442).
- Fix spurious error in overload resolution if required arguments follow optional arguments (#443).
- Fix intermittent crash generating code for enumerated types (#444).
- Minor elaboration performance optimisation.
Version 1.6.0 - 2022-01-25
- 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.
- The
--relax=impure
option 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=off
to 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-arrays
option 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
make -j
.
- 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
$prefix/lib/nvc/
instead of $prefix/share/nvc
.
- New configure option
--disable-vital
disables 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.
- The
fetch-ieee.sh
script which did nothing since the last release has been removed.
- The
--codegen
command, which has been deprecated since 1.3, was removed.
- The
--profile
option now prints internal simulation statistics instead of the top processes by CPU time.
Version 1.5.3 - 2021-11-13
- Handle access(2) returning EPERM in macOS sandbox (#421).
- Fix race when multiple processes concurrently update a library.
- Fix
--syntax
command when file contains multiple design units.
- Allow constant folding of nand/nor/xor/xnor.
- Fix potential out of memory condition when evaluating complex assert expressions.
- Fix incorrect result of
mod
operator with negative operands.
- Fixed intermittent crash when evaluating nested constant records (#425).
- Buffer too small for printing TIME’HIGH (#98).
Version 1.5.2 - 2021-07-28
- Link libexecinfo on FreeBSD.
- Implement textio READ procedure for BIT and TIME (#408).
- Fixed a crash when a long running procedure suspends in a loop (#412).
- Fix static linking with LLVM 12.0.
- Fix crash when assigning to a signal declared in a package.
- Fix incorrect recording of dependencies which caused a failure to load generated DLLs on Windows.
- Fix file locking error when a library is located on NFS (#417).
- Optimise loading large library index from disk.
- Fix a crash when using ’VALUE with enumeration subtypes (#419).
- Fix a crash when a signal with more than 256 elements is declared in a package (#420).
Version 1.5.1 - 2021-04-09
- Fix a compiler warning in vcode.c.
- Disable VHDL backtrace on non-Linux systems as the symbol names cannot be parsed reliably (#385).
- Update to latest
pc_from_uncontext.m4
for Apple M1 support.
- Fix incorrect application of LRM rules for building an equivalent wait statement for concurrent statements.
- Library build is now reproducible when running
make -j
(#409).
- Fix assertion failure with nested record type (#404).
- Use Pandoc to generate the manual page.
Version 1.5 - 2020-07-19
- IEEE library sources are now distributed
- Updated FST library to match GtkWave 3.3.79
- The LXT wave output format is deprecated, use FST instead
- Fix incorrect file name in assertion message
- Fix crash while recovering from parse error
- Add
--dump-json
command to print AST as JSON (from Sebastien Van Cauwenberghe)
- Fix crash when using LLVM 7 and later
- Fix spurious assertion failure in
std.textio.readline
- Reals are now rounded to the nearest integer as specified by the LRM
- Fix crash when constant folding uses too much memory
- Improved memory management in evaluator (thanks to Frank Mori Hess)
- Various other minor fixes and improvements
Version 1.4 - 2018-07-16
- Windows with MSYS2 is now fully supported
- Continuous integration for OS X and Windows using Travis and AppVeyor
- Record resolution functions are now supported
- The
--relax=prefer-explicit
option now works correctly
Version 1.3 - 2017-12-31
- Native code is always generated on platforms that support it
- Initial support for VHDL-2017 conditional compilation blocks
- The TCL shell has been removed
- Various code generation and constant folding fixes
- Fix crash when build IEEE library from non-clean tree
- ORC is used for JIT if LLVM version is 3.9 or later
- LLVM 3.8 or later is now required
- Added
-O0
to -O3
options to control LLVM optimisation level
- The
--disable-opt
option is deprecated, use -O0
instead
- The elaborate
--native
option is now a global option and should be placed before the -e
command
- The
--codegen
command is deprecated, use --native
when analysing to generate native shared libraries for packages
Version 1.2 - 2017-05-04
- Compile time evaluation now uses vcode
- Record aggregates can now be constant folded (#305)
- The TCL shell is deprecated and will be removed in the next release
- Compatible with LLVM 4.0
- Functions returning records can now be constant folded (#315)
- LLVM 3.4 or later is now required
Version 1.1 - 2016-11-05
- Improvements to based literal parsing
- Improved stack traces on Linux when
libdw-dev
installed
- Fixed elaboration of subprograms in entity declarations
- Improved elaboration performance when design contains many signals
- Fixed various bugs involving record signals
- Fixed sensitivity list generation for concurrent procedure calls
- Improvements to simulation performance
- Implemented
vhpi_get_phys
- Added command
--list
to print all units in a library
- Rewrote the
run_regr
program in C so make check
no longer requires Ruby
- The
--relax=generic-static
option is now renamed to --relax=locally-static
and applies in wider range of contexts
Version 1.0 - 2016-05-01