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Unreleased changes

  • --load is now a global option and should be placed before the -r command. This allows VHPI foreign subprograms to be called during elaboration (#988).
  • The --per-file coverage report option outputs code coverage reports for each source file instead of each instance (#823).
  • The new --check-synthesis analysis option warns when signals are missing from process sensitivity lists.
  • Fixed a crash when a generic subprogram is associated with open (#1025).
  • Added a functional coverage API in nvc.cover_pkg that can be used by external frameworks such as OSVVM to define cover points.
  • Added threshold-<value> option for coverage to set minimal count a coverage bin must reach to be reported as covered.
  • Added a warning for potential infinite loops in processes without sensitivity and lacking any wait statements (from @NikLeberg).
  • Selected names can now be to register value change callbacks with vhpi_register_cb (#1045).
  • Removed the limit on the maximum number of parameters that can be passed to a VHDL subprogram (#1036).
  • The new --no-save analysis option parses and checks the input files but does not save the working library to disk. This is a replacement for the --syntax top-level command which is now deprecated.
  • The coverage database file name has changed to <toplevel>.ncdb in the current working directory and this can now be customised with the new --cover-file= elaboration option. Attempts to access the old file name inside the library directory will be redirected to the new location, with a warning.
  • Partial association of ports with interface views now works correctly (#1074).
  • Added support for PSL suffix implication, SERE repetition, and SERE fusion.
  • Nested arrays more than two levels deep can now be dumped in FST format (#1071).
  • Added support for package external names (#1072).
  • Fixed parser hang for bit string literals (from @NikLeberg).
  • Fixed a crash on an illegal package definition inside an interface.
  • Comping the Vivado vendor libraries with nvc --install vivado is now around 2x faster and analysing files with many dependencies is up to an order of magnitude faster (#1098).
  • The --jit elaboration mode now works on Windows-on-Arm systems.
  • vhpi_assert now behaves the same as VHDL assert for the purposes of determining the simulation exit code and early termination (#1060).
  • The 'driving_value attribute now works correctly with record types.
  • Added basic support for 'instance_name, 'path_name and 'simple_name attributes of generate block labels (from @NikLeberg) (#1125).
  • Several other minor bugs were resolved (#1038, #1057, #1067).

Version 1.14.2 - 2024-11-23

  • Fixed a crash when 'last_value is used with record types (#1043).
  • Fixed a crash when a process sensitivity list contains an external name and the process is elaborated before the object referenced by the name (#1062).
  • Fixed parser hang for integers in scientific notation (from @NikLeberg).
  • Fixed a platform detection issue that caused JIT code loading to fail on Apple silicon macOS (#1069).
  • The STD_INPUT and STD_OUTPUT files can now be opened and closed multiple times (#1079).
  • Fixed a crash when a subtype is used for an aggregate element association range choice which associates an array slice (#1080).
  • Several other minor bugs were resolved (#1038, #1055).

Version 1.14.1 - 2024-10-26

  • Fixed an error when using the work library alias and the working library has the same name as design unit being analysed (#991).
  • Added a check for illegal references to signal or variable external names inside pure functions (#1010).
  • Added a check that the parameter of 'stable and other implicit signal attributes is a static expression (#1018).
  • Fixed an elaboration crash when an external name is passed to a procedure (#1029).
  • Record subtype constraints can now be accessed over VHPI (#1035).
  • Several other minor bugs were resolved (#1017, #1020, #1030, #1040).

Version 1.14.0 - 2024-09-22

  • Waiting on implicit 'stable and 'quiet signals now works correctly.
  • Updated to OSVVM 2024.07 and UVVM 2024.07.03b for nvc --install.
  • Added a warning when an inner declaration hides an outer declaration in a way that is likely to be unintentional (#905).
  • The -c sub-command for coverage is deprecated and replaced with separate --cover-report and --cover-merge commands. See the manual for details.
  • The argument to the --cover-export command is now the path to a coverage database file instead of a top-level unit name.
  • The --force-init command which was deprecated in the 1.7 release has been removed.
  • Coverage exclude files now support fold command to merge coverage data from independent sub-hierarchies (from @Blebowski).
  • FSM state coverage bin renamed from STATE to BIN_STATE.
  • A signature is now allowed in the formal part of generic map associations in VHDL-2019 mode.
  • use lib.pack.all no longer makes the bare package name pack potentially visible.
  • Very limited initial Verilog support has been added, including the ability to instantiate vendor-supplied UDPs from VHDL.
  • Fixed a regression which caused parse errors for some concurrent assertion statements (#956).
  • Arrays-of-arrays with downto direction are now dumped in the correct order (#957).
  • Fixed incorrect result of 'event and 'active where the prefix is an array of records.
  • Fixed a crash when the 'stable attribute is used with a record type (#960).
  • Conversion functions applied to individual record elements in a port map now work correctly (#963).
  • External name elaboration order checks were overly strict (#964).
  • Associating a signal with an out or inout parameter in a procedure that is not within a process now produces an analysis error rather than crashing at runtime (#965).
  • The --dump-arrays option now takes an optional argument to specify an upper limit on the length of nested arrays to dump (#959).
  • Matching case? statements are now checked for duplicate and missing choices at analysis time (#966).
  • Limited maximum instantiation depth to prevent crashes due to stack overflow when elaborating a design that has unbounded recursive entity instantiation (#969).
  • Physical subtype ranges and 64-bit integer types are now handled correctly by VHPI (#978).
  • Added support for generic map on subprogram call in VHDL-2019 and improved support for array type generics.
  • Optimised emission of FST initial signal values which also fixes a potential crash (#979).
  • Added checks for duplicate attribute specification (#977).
  • Several other minor bugs were resolved (#961, #962, #971, #975, #985).

Version 1.13.3 - 2024-08-24

  • Type checking was not performed correctly for conversion function actuals in port maps (#945).
  • Fixed a crash with signal aliases inside an instantiated generic package (#946).
  • Fixed random crashes when the simulation heap size is eight gigabytes or larger (#949).
  • Fixed a crash when a constant array with unconstrained element type is initialised with an aggregate (#954).
  • External names in concurrent assertion statements and PSL assertions are now parsed correctly (#952).
  • Several other minor bugs were resolved (#942, #943, #950, #951, #953).

Version 1.13.2 - 2024-08-11

  • Fixed an incorrect bounds check error when a constant declaration has a partially constrained type (#932).
  • Elaboration of large designs on Windows no longer fail with linker errors due to excessive command line length.
  • Fixed a bug which prevented VCD files from being generated on Windows systems using the UCRT runtime library (#637).
  • Fixed a crash when the type of a qualified expression is an unconstrained array-of-array (#934).
  • Fixed random segmentation fault when the simulation heap size is larger than four gigabytes (#935).
  • Fixed an incorrect ambiguous subprogram error when using the 1993 standard and calling a subprogram via a selected name such as ieee.numeric_std."=".

Version 1.13.1 - 2024-07-25

  • Windows installer was missing some standard library files.
  • Fixed a regression where generics and ports could not be referenced in external names (#921).
  • Fixed a crash when an unconstrained port with a default value is associated with open.
  • Fixed a duplicate symbol linker error with some uses of the 'delayed attribute.
  • Fixed a crash when an aliased subprogram is matched by a generic subprogram <> (#924)
  • Fixed a crash when a generic package containing a subprogram is passed to an entity package generic (#925).
  • Fixed an intermittent "failed to suspend thread" fatal error on macOS (#922).
  • Fixed a crash when a shared variable is declared inside an instantiated generic package in 2019 mode (#923).
  • Fixed a crash when a port with unconstrained array-of-record type is associated with a signal that has a static subtype.
  • Fixed incorrect longest static prefix calculation for array slices containing 'length, 'left, 'right and similar attributes (#930).
  • Fixed wrong result when slicing a generic that has an unconstrained array type (#931).

Version 1.13.0 - 2024-07-13

  • Type and package generics now work correctly with components and configurations (#883).
  • Fixed a crash when a matching case? alternative contains multiple choices (#890).
  • Implemented VHPI support for package declarations and vhpiPackInsts iterators (#891).
  • Signatures in attribute names are now parsed correctly (#892).
  • Attribute specifications for all are now parsed correctly (#889).
  • Predefined "=" and "/=" operators are no longer declared for file types.
  • Alias of packages now work correctly (#893).
  • Stricter checking of identifiers to reject those with multiple consecutive underscores or trailing underscores (from @typingArtist).
  • Stricter checking for subprograms, deferred constants, and protected types referenced before their corresponding body or full declaration.
  • Decimal physical literals like 8.2 ms are now correctly rounded (to 8200 us in this case) when they are converted to the base unit (#899).
  • External names can now be passed as signal actuals to subprograms (#900).
  • Fixed a crash when branch coverage is enabled and an if-statement contains a return (#903).
  • The NVC_CONCURRENT_JOBS environment variable can be used to scale the number of worker threads NVC creates based on the number of concurrently executing simulations.
  • Fixed a crash when certain attributes such as 'val are used in the target of a signal assignment statement (#908).
  • Signals in packages are now dumped to the FST file (#901).
  • Function interface declarations can now be pure or impure (#917).

Version 1.12.2 - 2024-05-15

  • Fixed a crash when 'transaction is used with a record type.
  • Fixed a compatibility issue with LLVM 18 that could cause an illegal instruction exception when the --jit elaboration option is used (#887).

Version 1.12.1 - 2024-05-09

  • Fixed a crash when a process contains a force or release assignment inside a process (all) statement (#877).
  • Fixed a crash creating a waveform dump with --dump-arrays and the design contains an array-of-array-of-records (#878).
  • Fixed a spurious error when a type declaration from a package generic is used in a port list (#881).
  • Fixed an assertion failure when a procedure declared within a process (all) assigns to a signal (#882).
  • Added a missing check for illegal assignment to external signal name outside a process (#884).
  • Fixed a crash while printing diagnostic information when the simulation delta cycle limit is reached (#885).
  • Generic actuals no longer need to be globally static, which was never required by the LRM (#886).

Version 1.12.0 - 2024-04-07

  • The --jit elaboration option no longer requires --no-save.
  • Fixed a crash when subtype bounds depend on a package instance generic (#815).
  • Fixed various issues in the implementation of guarded blocks and disconnection specifications (#829).
  • The --std option now controls which VHDL standard the --install command uses to compile third-party libraries (#836).
  • The prefix of an indexed or slice name now must be another name or function call, as required by the LRM (#835).
  • The implementation of conversions in port maps has been reworked and fixes a number of long-standing issues (#843).
  • Added support for inertial keyword in port maps (#843).
  • Fixed a bug where 'last_value could give the wrong result if the signal has multiple sources.
  • Updated to OSVVM 2023.09a and UVVM 2023.09.16 for nvc --install.
  • The --exit-severity= option now also controls which severity level results in a non-zero exit code (#850).
  • Improvements to waveform dumping for signals with record types or types with non-locally-static bounds (#851, #852).
  • The parameter for attributes with dimensions such as 'length(N) may be any integer type when --relaxed is passed (#862).
  • Resolved several other minor issues (#654, #854, #855, #859, #863).
  • The default standard version was changed to VHDL-2008.
  • The --vhpi-trace option now implies --vhpi-debug.
  • The bounds of array aggregates are now calculated correctly in several corner cases (#873).
  • Added supported for VHPI foreign subprograms.

Version 1.11.3 - 2024-02-04

  • Fixed incorrect effective value when a signal has multiple sources due to port-collapsing optimisation (#824).
  • Signals that appear in aggregate choice expressions like (S downto 0 => '0') are now included in the sensitivity list for concurrent statement equivalent processes, and in process (all) (#825).
  • The direction of aggregates with range choices is now calculated correctly in VHDL-2008 mode (#826).
  • Fixed a memory corruption bug when evaluating certain aggregates that contain a range association (#827).
  • Resolved several other minor issues (#837, #839, #840).

Version 1.11.2 - 2024-01-04

  • Fixed an incorrect length check in the equivalent process for non-static port map actuals (#817).
  • Library file names for design units that contain extended identifiers such as /Foo/ are now encoded in a way that avoids illegal characters and case sensitivity issues on Windows and macOS (#816).
  • Implemented vhpiIsNullP and vhpiIsDiscreteP for ranges.
  • Fixed a crash when an aliased enumeration literal appears in a case choice expression (#819).
  • Fixed calculation of longest static prefix with indexes and slices of a constant array (#820).
  • Fixed a crash during elaboration when simplifying an if-statement that depends on a generate parameter (#821).
  • Increased the limit on the number of subprogram arguments to allow compiling some Lattice IPs (from @sean-anderson-seco).

Version 1.11.1 - 2023-12-16

  • Fix crash during elaboration when an if-statement branch is always taken (#812).
  • VHPI plugins can now access types in instantiated packages (from @sean-anderson-seco).
  • The --version output now includes the bare Git commit SHA if the program is built from a shallow clone with no tags (#813).

Version 1.11.0 - 2023-12-06

  • New command --cover-export exports coverage data in the Cobertura XML format which is supported by most CI environments such as GitLab.
  • Generics on internal instances can now be overridden with the -g elaboration option. For example -g uut.value=42.
  • Implemented the 'reflect attribute and associated protected types from VHDL-2019.
  • Added support for VHDL-2019 sequential block statements.
  • Implemented the VHDL-2019 directory I/O functions in std.env.
  • Added VHDL-2019 assert API (with @Blebowski).
  • Implemented 'image, 'value and to_string for composite types in VHDL-2019.
  • Implemented the "closely related record types" feature from VHDL-2019.
  • Implemented the "composition with protected types" feature from VHDL-2019.
  • The new --shuffle option runs processes in a random order which can help to identify code that depends on a particular execution order.
  • Updated to OSVVM 2023.07 for nvc --install.
  • Various enhancements and fixes to the VHPI implementation.
  • Implemented the VHDL-2019 changes to instance_name and path_name for protected type variables.
  • VHPI error messages are no longer reported as diagnostic messages on the console. The new --vhpi-debug option restores the old behaviour.
  • Support for type conversions between arrays with closely related element types.
  • Added support for FSM state coverage collection (from @Blebowski).
  • An alias of a type now correctly creates implicit aliases for each predefined operator of that type (#776).
  • Improve overload resolution where a partial named association implies the formal parameter must be an array (#793).
  • Handling of implicit conversion for universal types has been reworked to better comply with the LRM.
  • Fixed a crash when string literal characters have a type which is an alias to another type (#801).
  • Added a warning when calling the predefined "=" and "/=" operators on arrays and the left and right hand sides have different lengths.
  • Expressions like abs(x)**2.0 are now parsed correctly (#805).

Version 1.10.4 - 2023-10-16

  • Fixed compatibility with LLVM 17.
  • Fixed an intermittent crash when using the --jit elaboration option.
  • Improved overload resolution when subprogram argument is known to have character type.
  • Improved bounds checking for port map actuals.
  • Fixed a crash with aggregates for record types that contain an unconstrained field (#768).
  • Fix spurious "checksum 00000000" error when analysing multiple design units and one contains use work.all (#769).
  • Fix crash when using the --relaxed analysis option and multiple warnings are printed (#770).

Version 1.10.3 - 2023-09-17

  • Fixed memory corruption in rare circumstances with functions declared in process declarative regions (#751).
  • Fixed a race condition when creating library directories that occasionally led to build failures with make -j (#746).
  • Aliases of protected type methods are now allowed.
  • Fixed a crash when a pragma appears outside of a design unit (#752).
  • Fixed a crash analysing an alias of an alias of a subprogram (#755).
  • Fixed an elaboration failure when an allocator expression has an array type with an unconstrained element (#756).
  • Fixed a memory leak in the --print-deps command.
  • Fixed a crash when evaluating globally static expressions during elaboration with coverage enabled (#759).
  • Fixed an analysis crash where a predefined function for a type declared in a package is overridden in the package body only (#760).

Version 1.10.2 - 2023-08-20

  • Fixed a crash due to an array bounds check being incorrectly optimised out (#747).
  • The type of string literals and aggregates in generic map associations such as G => X"00" where G has a generic type can now be determined correctly (#750).
  • Fixed a spurious "duplicate declaration" error if a use clause for an instantiated packages appears in the same declarative region that instantiated the package (#750).
  • Improved checking for configuration specifications.
  • Empty bit string literals are now parsed correctly.
  • Fixed stack corruption when a function returns an alias of one of its array arguments.

Version 1.10.1 - 2023-07-28

  • Fixed incorrect sensitivity list generation with concurrent statements such as x <= C(y) where C is a constant array.
  • Fixed an incorrect optimisation which caused 'event to return the wrong value in rare circumstances.
  • Decimal bit string literals more than 64 bits wide are now supported (#731).
  • The format of fractional time values returned by the standard to_string function was changed to match other simulators.
  • Fixed a crash when constant folding a locally static expression in a package body (#742).
  • Added support for reading command line arguments in VHPI (from @Forty-Bot).
  • Fixed a compilation error when using the predefined minimum/maximum functions with arrays of physical types.
  • Overloaded protected procedure calls could read the wrong value of protected type variables in rare circumstances.

Version 1.10.0 - 2023-07-14

  • The Zstandard compression library 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 2023.05 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 signal and variable sequential assignment statements.
  • 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.
  • Accesses to protected types and files are now allowed in VHDL-2019.
  • Fixed a crash when indexing a null array (#734).
  • Named and range choices are now supported in aggregate targets of variable and signal assignments (#712).
  • The synopsys.attributes package is no longer distributed or built as part of the standard libraries.

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

  • First stable release