The VPI API for string literals does not correctly handle the case where a
null-byte ('\0') appears in the string literal. It uses strlen() to
calculate the length of the literal, which will give the wrong result if
there is a null-byte in the string literal. Instead of using strlen() use
the stored length to fix this.
In addition when formatting a string literal as a string ignore any
null-bytes. The LRM is not entirely clear what should happen to null-bytes
when formatting a value as a string. But the behavior of ignoring the
null-bytes is consistent with the rules of SystemVerilog for converting a
string literal to a SV string.
This problem can occur when a string literal gets null-byte left-padded due
to width of its context of its expression, but then optimization removes
part of the expression and only leaves the padded string literal.
E.g.
```
$display(0 ? "Yes" : "No");
```
will be transformed into
```
$display("\000No");
```
There is also one subtle change in behavior associated with this. The empty
string ("") is supposed to be equivalent to 8'h00. So e.g.
`$display(":%s:", "")` should print ": :" since the width of the empty
string is 1 byte and the %s modifier prints a string with the width of the
value, left-padding with spaces if necessary. The current implementation
will print "::" though. This change requires to update the marco_with_args
gold file.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Clean up warnings that show up on newer compilers. Many of these warnings
are related to obsolete c library features or language features. This does
not clear up warnings in code generated by bison or flex.
Second try cleaning up cast-alignment problems surrounding need_result_buf().
Clang gave a bunch of warnings like
vvp/vpi_const.cc:196:34: warning: cast from 'char *' to 'p_vpi_vecval' (aka 't_vpi_vecval *') increases required alignment from 1 to 4 [-Wcast-align]
This version is verbose and changes the prototype for need_result_buf().
But it is semantically (c++) correct, and makes need_result_buf() feel like malloc().
Currently, when a variable expression is passed to a system task,
the expression value is stored in thread memory. Values stored
in thread memory cannot safely be passed to $strobe or $monitor,
because the thread memory may get reused or deallocated before
the $strobe or $monitor task actually executes. As a temporary
measure, we just trap this case and terminate with a "sorry"
message. A proper fix would require the expression value to be
calculated at the time the $strobe or $monitor executes, not at
the time it is called.
This patch updates the vvp code so it will compile with the valgrind hooks
again. There are still new constructs that need to be cleaned up correctly
and some old constructs were changed enough that the old code no longer
works, but the rest of this can be done as an incremental improvement.
Added: basic vpiPort VPI Objects for vpiModulkes
vpiDirection, vpiPortIndex, vpiName, vpiSize attributes
Since ports do not exist as net-like entities (nets either side
module instance boundaries are in effect connect directly in
the language front-ends internal representation) the port information
is effectively just meta-data passed through t-dll interface and
output as a additional annotation of module scopes in vvp.
Added: vpiLocalParam attribute for vpiParameter VPI objects
Added: support build for 32-bit target on 64-bit host (--with-m32
option to configure.in and minor tweaks to Makefiles and systemc-vpi).
The standard specifies that the size of a vecval should be calculated as
(size - 1)/32 + 1. When size is a PLI_INT32 this is needed to prevent an
overflow, but when the size is unsigned this can be simplified to
(size + 31)/32 since the size must fit into an integer, but we have an
extra significant bit in an unsigned so no overflow can happen.
This patch changes the code to use the correct version of the equation
depending on the context.
The previous patch does this in vvp/vpi_priv.cc
The clang compiler does not like using struct to reference a class object.
This patch removes all the struct keywords for __vpiNamedEvent objects
since they are now a class and can be called without a struct/class
qualifier.
This patch also removes all the extra class qualifiers from the rest of
the source code.
The clang compiler does not like mixing class and struct references. This
patch updates all the struct __vpiHandle, etc. to use class since that is
how they are now defined.
All the methods that this structure supported are now pulled
into the __vpiHandle class as virtual methods. This includes
the vpi_free_object_ method, which required some extra trickery.
Instead of C-like data structures where the __vpiHandle base is a
leading member, make the __vpiHandle a derived class. Give the base
class a virtual destructor so that dynamic_cast works reliably, and
now pretty much all of the junk for testing if an object really is
of the derived class goes away. Also, problems with casting up to
a vpiHandle become trivial non-issues.
In ivl_alloc.h we redefine malloc(), realloc() and calloc() to have
standard error checking. We don't want to do this for anything that
comes from the standard headers. This specifically doesn't work if
a C++ header files does std::malloc, etc.
Also change to -W instead of -Wextra since that is more portable. I
plan to add a check from -Wextra and use it when available since it
is more descriptive.
This patch adds -Wextra to the compilation flags for C++ files in
the vvp and vpi subdirectories. It also fixes all the problems
found while adding -Wextra. This mostly entailed removing some of
the unused arguments, removing the name for others and using the
correct number of initializers.
The functions (malloc, free, etc.) that used to be provided in
malloc.h are now provided in cstdlib for C++ files and stdlib.h for
C files. Since we require a C99 compliant compiler it makes sense
that malloc.h is no longer needed.
This patch also modifies all the C++ files to use the <c...>
version of the standard C header files (e.g. <cstdlib> vs
<stdlib.h>). Some of the files used the C++ version and others did
not. There are still a few other header changes that could be done,
but this takes care of much of it.
The Cygwin compiler is a bit picky. This patch adds some casts
to remove compilation warnings. In the past I have had warnings
off because of problems with the STL, but for this directory we
may as well squash as many warings as we can. It also does not
recognize that an assert(0) or assert(false) ends a routine so
it complains about no return at end of function or variables
not being defined.
This patch modifies the real parameter get_value routine to use
the standard vpip_real_get_value() routine. This routine has
support for an integer and a decimal string value.
This patch adds code to free most of the memory when vvp
finishes. It also adds valgrind hooks to manage the various
memory pools. The functionality is enabled by passing
--with-valgrind to configure. It requires that the
valgrind/memcheck.h header from a recent version of
valgrind be available. It check for the existence of this
file, but not that it is new enough (version 3.1.3 is known
to not work and version 3.4.0 is known to work).
You can still use valgrind when this option is not given,
but you will have memory that is not released and the
memory pools show as a single block.
With this vvp is 100% clean for many of the tests in the
test suite. There are still a few things that need to be
cleaned up, but it should be much easier to find any real
leaks now.
Enabling this causes a negligible increase in run time and
memory. The memory could be a problem for very large
simulations. The increase in run time is only noticeable on
very short simulations where it should not matter.
Most named objects should have a vpiModule handle to get a handle
to the enclosing module. This patch adds code to get this for all
the elements that I could find that needed it.
It also adds a three more names to vpi_get_str(vpiType, ...) and
fixes a problem in the vpiLeftRange for PV signals.
This patch fixes vvp to use the standard static result buffer
when returning the vector value of a constant string. The
previous calloc method was creating a memory leak.
This patch adds a number of compile and run-time checks for illegal
uses of variables declared in automatic tasks and functions. It
also adds a check for event expressions in automatic tasks that use
features not yet supported in VVP.
This patch adds file and line information for parameters and
local parameters. It also adds file/line stubs for signals in
the tgt-* files. It adds the pform code needed to eventually
do genvar checks and passing of genvar file/line information.
It verifies that a genvar does not have the same name as a
parameter/local parameter.
vvp did not have the ability to handle real parameters.
This patch fixes that omission. Parameters are only used
by vpi calls to get compile time information.
Add the vpiFile and vpiLineNo properties to system functions.
Most other objects have stubs that return "N/A"/0. Interactive
functions (called from the debugger) use <interactive> for the
file name.
Gets rid of a few warning: deprecated conversion from string
constant to 'char*', follows IEEE 1364-2001C 27.10 in more cases,
and fixes at least one real bug (look at the previous use of
strdup/strcat in real_var_get_str() and signal_get_str()).
Modified the code that deals with real variables to accept an integer
value when using vpi_put_value(). Also added some type of diagnostic
message for all switch defaults that have an assert(0) to indicate an
error condition, removed CVS comments and removed a small section of
unreachable code.
This patch makes vpiFullName for real variables return the correct
value. A Scope reference was added to the base structure along with
the relevant code to support generating the full name. A couple of
memory leaks were plugged and some formatting fixed as well.
This patch adds the missing vpiFullName property to binary and
string parameters (FYI real parameters are not currently supported
by the VPI interface).
This patch implements the swrite* and sformat system tasks. It also
makes $simtime distinguishable from the other integer time tasks.
This was needed to get the correct time units when $simtime was given
as an argument to $swrite*. The string constant code was also modified
to allow a string to be returned as a vector (0/1 bit pattern).
Here are some more specifics about the swrite* changes.
1. They do not share formatting code with the other display functions,
so they may/will produce different results.
2. All %{alpha} codes allow a width and justification. Others have been
enhanced (%t allows the default width and precision to be overridden,
time functions print with time formatting, better error checking and
messages, etc.).
3. %u and %z formatting codes have been added. It is important to note
that these two formats can produce embedded NULLs, since these
functions are returning a string anything after the first NULL will
not be reachable! memcpy is used instead of regular string processing
where needed so that the original string will contain the total
result. The size returned when the string is created is the true
length. A warning will be printed if a string with embedded NULLs is
produced (strlen() does not match the true length).
4. Real numbers are printed with %g instead of %f.
Once this new formatting code has been evaluated we should incorporate
the changes/fixes into the formatting code for the other functions or
the other functions could be modified to use this new code. The true
string length is available so we should be able to work around the
embedded NULL problem.
Cary R
Lars-Peter Clausen
Stephen Williams
Greg Steuck
Martin Whitaker
Stephen Williams
Christian Taedcke
Larry Doolittle
Arun Persaud
Andrew Stevens
Martin Whitaker