UVM/uvm-1.2/docs/html/src/overviews/relnotes.txt

Section: UVM 1.2 Release Notes

Topic: General Overview

This is release 1.2 of the Universal Verification Methodology (UVM)
reference implementation from Accellera. This distribution includes a
SystemVerilog based class library, examples, UVM Stardard Reference
(PDF and HTML), and a User's Guide.

The class library is a reference implementation of the standard. It,
the examples, and User Guide provide guidance to users of the
standard. For additional information on the Accellera standard, see

     <http://www.accellera.org/activities/vip>

A good source for information, answers, and resources is
<http://www.accellera.org/community/uvm>. It contains forums on
methodology, tool specific issues, and commercial announcements. It
also has links to additional resources, Accellera sponsored events,
and other UVM events.


Topic: What's Changed

Release 1.2 contains enhancements and fixes to errata.

UVM 1.2 fixes the following enhancements and issues reported under the
Mantis bug-tracking system. Issues affecting the reference
documentation (API changes or semantic changes) are follwed with a
plus sign (+). Issues affecting backward compatibility are folled with
an asterisk (*)

For detailed information on a specific issue, refer to the Mantis
database at http://www.eda.org/svdb/view.php?id=<id>, where <id> is
the Mantis id.

Topic: 1.1 to 1.2 Migration Script

Many of the backwards compatibility concerns caused when transitioning
from UVM version 1.1 to 1.2 can be addressed with a reasonably simple
search-and-replace in user code.  To that end, the ~uvm11-to-uvm12.pl~
is provided.

The following command will update all SystemVerilog source files
located in the current working directory and any sub-directory:

| % uvm11-to-uvm12.pl --write

See the ~--help~ command-line option for additional details.

The script may not be able to automatically identify all cases of
backwards incompatibility, and the user may need to fix some
manually.  Because most of these issues will result in a compile-time
error, they should be easy to identify.

Group: Mantis 3407 (+)
uvm_event should be a parameterized class

The ~uvm_event~ class was split into two classes, an abstract
<uvm_event_base>, and a parameterized <uvm_event#(T)>.

This should have minimal backwards compatibility concerns, as any code
using ~uvm_event~ without explicitly declaring a ~#(T)~ will default
to ~uvm_event#(uvm_object)~.

Group: Mantis 3472 (*)
Deprecate get_config/set_config interface for configuration

The methods ~set_config_int~, ~set_config_string~ and
~set_config_object~ (and their ~get~ counterparts) are now deprecated
in favor of <uvm_config_int>, <uvm_config_string> and
<uvm_config_object>.

Topic: Backwards Compatibility
Care must be taken when switching from ~set_config_object~ and
~get_config_object~ to <uvm_config_object>, as the ~clone~
functionality of the old API no longer exists.

Group: Mantis 3557
ref guide doesn't show names of UVM runtime phases

The documentation for <UVM Common Phases> and <UVM Run-Time Phases>
has been updated to include a definition of how phases are named.

Group: Mantis 3586 (+)
UVM_DISABLE_AUTO_ITEM_RECORDING should be a run_time option

<uvm_sqr_if_base#(REQ,RSP)::disable_auto_item_recording> and 
<uvm_sqr_if_base#(REQ,RSP)::is_auto_item_recording_enabled> have been
added to the <uvm_sqr_if_base#(REQ,RSP)> class, allowing the driver
runtime control over whether or not a sequencer should automatically
record the items which flow through the sequence item port.

Group: Mantis 3693 (+)
Setting enum values by name from command line doesn't work

The <uvm_enum_wrapper#(T)> utility class has been added, which provides the
ability to retrieve an enum value when provided with a string matching
the ~enum.name()~ for that value.

This class is used by the <`uvm_field_enum> macro when performing
auto-configuration, such that values can be set using
~uvm_config_db#(string)~ (or the <uvm_cmdline_processor::+uvm_set_config_string> plusarg).

Group: Mantis 3741 (+)
Phase's default sequence should also have get_config string support

A new plusarg has been added (<uvm_cmdline_processor::+uvm_set_default_sequence>) which allows
for the ~default_sequence~ a sequencer executes in
<uvm_sequencer_base::start_phase_sequence> to be set directly from the command line.

General support for setting ~default_sequence~ as a string was not
provided, as during runtime the ~default_sequence~ should always be set using
either <uvm_sequence_base> or <uvm_object_wrapper>.  

Group: Mantis 3783
Remove all $display calls from BCL, except report_server

All messaging is now routed via <uvm_report_server>.

Group: Mantis 3887 (*)
request facility to identify unused factory overrides

The ~uvm_factory~ class was split into two classes, an abstract
<uvm_factory>, a default implementation of <uvm_default_factory>.
This allows for alternate factories (including those with additional
debug functionality) to be created.

Control over the global factory was
migrated to the new <uvm_coreservice_t> class.  

Topic: Backwards Compatibility:
The undocumented ~uvm_pkg::factory~ variable has been removed, as it
was unsafe during static initialization, and incompatible with the
<uvm_coreservice_t> class.  References to this variable need to be
upgraded to retrieve the factory via <uvm_factory::get>.

Group: Mantis 3893 (+)
Feature request to create a non-hierarchical objection

<uvm_objection::set_propagate_mode> has been added to provide control
over whether or not objections propagate.

Group: Mantis 3901
Feature request to prevent objection from throwing
decrement-below-zero error if the count is 0

An error is no longer produced if <uvm_objection::drop_objection> is
called with a count of ~0~, when the current object count is ~0~.

Group: Mantis 4032 (+)
Not possible to undo a factory override.

A factory override can now be "undone" by supplying a type
as an override for itself.

i.e.
| // Perform an override
| set_type_override_by_type(old_type::get_type(), new_type::get_type());
| // Undo the override
| set_type_override_by_type(old_type::get_type(), old_type::get_type());

Group: Mantis 4091
bug in the ~get_full_name~ method of <uvm_reg_file>.

The ~get_full_name~ method of <uvm_reg_file> now includes the top-level block name.

Group: Mantis 4160
uvm_comparer not using verbosity setting for print_msg()

The <uvm_comparer::print_msg> method now obeys the
<uvm_comparer::verbosity> setting.

Group: Mantis 4181 (+)
transaction order unclear and cant be changed when bus/reg size differ

The ordering of transactions generated when the size of a
register/field is different than the size of the bus can now be
controlled via the new <uvm_reg_transaction_order_policy> class.

Group: Mantis 4253
Volatile fields should always need updating

Volatile register fields will always cause a write(), even if mirrored
and desired values are the same.

Group: Mantis 4269 (*)
Add UVM_ prefix to enumerated values

Various top-level enumeration values (such as those declared in
<uvm_sequence_state_enum>) did not have the ~UVM_~ prefix.  This would
cause compilation errors when the ~uvm_pkg~ was wildcard imported into
a scope which had already declared the same names.  These enumerations
have been corrected to include the proper ~UVM_~ prefix.

Topic: Backawards Compatibility
References to the values within <uvm_sequence_state_enum> and
 <uvm_sequencer_arb_mode> must now be prefixed with ~UVM_~.

Group: Mantis 4306
Bad reference to "record_field_int" in reference guide

A bad reference to ~record_field_int~ has been corrected to
~record_field~ inside of <uvm_recorder>.

Group: Mantis 4307
Bad reference to "DEC" in reference guide

Bad references to "DEC" have been corrected to <UVM_DEC> within
<uvm_object::do_print> and <uvm_object::do_record>.

Group: Mantis 4366 (+)
uvm_sequence_library documentation missing from html documentation

The <uvm_sequence_library> class has been updated from "beta" to
"official" status.  As such, it is now documented in the reference
guide.

Group: Mantis 4378
Documentation of uvm_component::set_inst_override_by_type()
incorrectly documents uvm_factory::set_inst_override_by_type()

The documentation of <uvm_component::set_inst_override_by_type> as
been updated to reflect the proper ordering of the parameters to
<uvm_factory::set_inst_override_by_type>.

Group: Mantis 4382 (+)
some symbols in uvm_radix_enum undocumented

Documentation was added for <UVM_UNFORMAT2>, <UVM_UNFORMAT4>,
<UVM_REAL>, <UVM_REAL_DEC>, and <UVM_REAL_EXP> within the
<uvm_radix_enum>.

Group: Mantis 4389 (+)
Deprecate hierarchical propagation of objections; add mode bit in
interim

<Mantis 3893 (+)> provides the mode bit for controlling propagation of
objections.  Hierarchical propagation was not outright deprecated in
this release.

Group: Mantis 4391
Redundant code in uvm_port_base

Some redundant code in the <uvm_port_base#(IF)> was removed.

Group: Mantis 4416 (*)
Remove the confusing uvm_severity type 

The confusing ~uvm_severity_type~ was deprecated, and replaced
internally using <uvm_severity>.

Topic: Backwards Compatibility
This change should have minimal effect on user code, as the old type
was simply deprecated, as opposed to removed.  The <1.1 to 1.2 Migration Script> 
can be used to replace any occurances of the old
type in user code.

Group: Mantis 4418
set_report_verbosity doc unclear about setting value or threshold 

The documentation of
<uvm_report_object::set_report_verbosity_level>,
<uvm_report_object::set_report_id_verbosity>, and 
<uvm_report_object::set_report_severity_id_verbosity> were updated to
provide a clearer definition of exactly what the ~verbosity~ values
implied.

Group: Mantis 4425
BUSY flag not cleared when register model is reset 

The register model was updated to clear the BUSY flag when reset.

Group: Mantis 4430 (+)
Refactor start_phase_sequence logic to be able to kill sequence on
phase ending 

The method <uvm_sequencer_base::stop_phase_sequence> was added which
acts as the bookend to <uvm_sequencer_base::start_phase_sequence>.  It
will call <uvm_sequence_base::kill> on the ~default_sequence~ if the
sequence is still executing when the phase ends.

Topic: Backwards Compatibility
While technically acting different than the previous implementation,
it is unlikely that this will result in any backwards incompatibility
challenges, as the old mechanism simply terminated the process which
launched the ~default_sequence~, resulting in a "zombie" sequence.

Group: Mantis 4431 (*)(+)
Enhance uvm_sequence::starting_phase 

The ~uvm_sequence_base::starting_phase~ variable was publicly accessible
and not protected from writes-after-reads.  This would result in
strange behavior (including FATALS and HANGS) if the value was changed
between a ~raise~ and ~drop~ of the objection within the phase.

The variable was removed, and is now only accessible via the
<uvm_sequence_base::set_starting_phase> and
<uvm_sequence_base::get_starting_phase> accessors.  An error will be
thrown if there are any attempts to 'set' the starting phase after it
has been retrieved via a 'get'.

Topic: Backwards Compatibility
This change could potentially effect users, as references to the
~uvm_sequence_base::starting_phase~ variable will now miscompile.
The <1.1 to 1.2 Migration Script> can be used to search-and-replace
within the user code, updating it to the new methods.

Group: Mantis 4432 (+)
Provide auto-object-to-phase in uvm_sequence_base 

The <uvm_sequence_base::set_automatic_phase_objection> method was
added, simplifying the code required to object to the ~starting_phase~
inside of a phase.

Group: Mantis 4433 (*)
Clean up the number of objections created by phasing 

Objections only make sense in <uvm_task_phase>s which are of the
<UVM_PHASE_IMP> type.  For all other phases and types, the objections
have been removed, and any attempt to access the objection will result
in an error.

Topic: Backwards Compatibility
While technically acting different than the previous implementation,
it is unlikely that this will result in any backwards incompatibility
challenges.  Any user code which would cause the error to occur would
have been silently ignored by the library in the past, which meant
that whatever the user was ~trying~ to do wouldn't have worked.

Group: Mantis 4434 (+)
Provide get_objection_count in uvm_phase 

The method <uvm_phase::get_objection_count> was added, providing the
user with a cleaner mechanism for dropping all raised objections.

| // Old Code:
| uvm_objection phase_done;
| phase_done = phase.get_objection();
| phase_done.drop_objection(this, 
|                           "dropping all objections",
|                           phase_done.get_objection_count(this));
|
| // New Code:
| phase.drop_objection(this,
|                      "dropping all objections",
|                      phase.get_objection_count(this));
|

Group: Mantis 4439 (+)
seq_item_port.put_response is not documented 

The previously undocumented <uvm_sqr_if_base#(REQ,RSP)::put_response> 
was added to the standard, providing a non-blocking mechanism for
sending response information from a driver.

Group: Mantis 4440 
jump logic too early in phase state pipeline 

The previous implementation of the ~jump~ logic <uvm_phase> caused
jumps during the ~phase_ended~ callback to be ignored.  This has been
corrected.

Group: Mantis 4469 (+)
Provide schedule introspection via get_predecessor/successor_nodes 

The <uvm_phase::get_adjacent_predecessor_nodes> and
<uvm_phase::get_adjacent_successor_nodes> methods were adding the
<uvm_phase> api.  This provides the user with the ability to
programmatically traverse the entire phase graph.

Group: Mantis 4476 (+)
uvm_sequence fields req/rsp are not documented 

The previously undocumented <uvm_sequence#(REQ,RSP)::req> and
<uvm_sequence#(REQ,RSP)::rsp> fields were added to the standard.

Group: Mantis 4488 (+)
sequencer_base should throw error if user allows wait_for_relevant to
return while is_relevant=0 

An error will now be thrown if the sequencer exceeds the allowable
number of returns from <uvm_sequence_base::wait_for_relevant> without
<uvm_sequence_base::is_relevant> returning true.  The allowable
maximum number can be controlled via the
<uvm_sequencer_base::set_max_zero_time_wait_relevant_count> method.

Group: Mantis 4513 (+)
Add uvm_mem_mam_policy allocator to uvm_vreg::allocate() 

The <uvm_vreg::allocate> API was expanded to include an optional third
~alloc~ argument.

Group: Mantis 4516 (*)
Remove the unnecessary over-prioritization of uvm_sequence_base in
default_sequence 

The previous implementation of <uvm_sequencer_base> over-prioritized
~default_sequence~ configurations which were of type
<uvm_sequence_base>, such that they would override configurations of
type <uvm_object_wrapper>, even if the wrapper configurations were
done with higher precedence.

Topic: Backwards Compatibility
While technically acting different than the previous implementation,
it is unlikely that this will result in any backwards incompatibility
challenges.  The previous implementation would have resulted in
unexpected behavior at best.

Group: Mantis 4517 (+)
Add phase-transition callbacks 

The <uvm_phase_cb> and <uvm_phase_cb_pool> were added to provide
additional hooks into the phasing API.

Group: Mantis 4518 (*)(+)
Make UVM_OBJECT_MUST_HAVE_CONSTRUCTOR the default behavior 

~Mantis 3770~ provided the ability to optionally enforce an explicit
constructor with a string-type ~name~ argument in the UVM 1.1a, via
the ~`UVM_OBJECT_MUST_HAVE_CONSTRUCTOR~ symbol.  This functionality is
now the ~*default*~ behavior for the UVM.  

Topic: Why uvm_object constructors are now mandatory

The UVM recommends that the following constructor be specified for any class
extended from <uvm_object>:

| class my_obj extends uvm_object;
|     ...
|     `uvm_object_utils(my_obj)
|
|     function new(string name = "my_obj")
|       super.new(name);
|       ...
|     endfunction
|     ...
| endclass

However, in UVM 1.0 and UVM 1.1, the presence of such a constructor were not enforced
by the library and they were technically optional.
If no constructor was specified, a default constructor was provided by SystemVerilog:

| class my_obj extends uvm_object;
|     ...
|     `uvm_object_utils(my_obj)
|
|     function new();
|     endfunction
|     ...
| endclass

Note the important difference: in the default constructor, there is no ~name~ argument.
Because the factory could not rely on the presence of that argument,
<uvm_object> instances were created by calling ~new()~ without any arguments
and subsequently setting the object instance name using <uvm_object::set_name>.

| obj = new();
| if (name != "") obj.set_name(name);

In most cases, this difference was not significant.
However, for any class that makes use of the value of the ~name~ argument
in the constructor,

| class my_obj extends uvm_object;
|     your_obj sub;
|
|     `uvm_object_utils(my_obj)
|
|     function new(string name = "my_obj")
|       super.new(name);
|       sub = your_obj::type_id::create({name,".sub"});
|     endfunction
|     ...
| endclass

a difference in behavior was observed between
instantiating an object directly:

| my_obj o = new("o");

and instantiating an object via the
factory:

| my_obj o = my_obj::type_id::create("o");

The difference could have been worked around by
overriding the <uvm_object::set_name> method to
percolate the effect of the name change.
However, that work-around was often impossible or too late.
In the examples above, the former creates an instance of ~your_obj~ named "o.sub"
whereas the latter creates an instance named "my_obj.sub".
It made it impossible to control the sub-object factory based on the
parent object name.

Instantiating coverage group is another example where the work-around did not work.
Coverage groups cannot be renamed and
must be instantiated in the encapsulating object's constructor.
The following example would create coverage groups that are always named "my_obj"
when using the object factory.

| class my_obj extends uvm_object;
|     covergroup my_cg(string name);
|        option.name = name;
|        ...
|     endgroup
|
|     `uvm_object_utils(my_obj)
|
|     function new(string name = "my_obj")
|       super.new(name);
|       my_cg = new(name);
|     endfunction
|     ...
| endclass

Because the object factory is such a fundamental element of UVM,
it is important that it be able to rely on the presence of a ~name~ argument
in object constructors.

Topic: Backwards Compatibility
In UVM 1.2, the UVM object factory now requires that uvm_object have a
constructor with a name argument.  Should this constructor be missing,
a syntax error will be issued. 
However, because much of the factory code is hidden in the utility macros,
the syntax error may not point to the ultimate cause of the problem
and may be confusing the diagnose.

For example, this simple file

| `include "uvm_macros.svh"
| program test;
| 
| import uvm_pkg::*;
| 
| class my_obj extends uvm_object;
|    `uvm_object_utils(my_obj)
| endclass
|
| endprogram

will produce the following error
messages:

Questa:

| TBD

IUS:

|file: test.sv
|`uvm_object_utils(my_obj)
|                        |
|ncvlog: *E,TOOMAC (test.sv,8|24): too many actual arguments [10.2.2][10.3(IEEE)].


VCS:

| Error-[TMAFTC] Too many arguments to function/task call
| $UVM_HOME/src/base/uvm_registry.svh, 197
| "my_obj::new(name)"
|   The above function/task call is done with more arguments than needed.
| 
| 
| Error-[TMAFTC] Too many arguments to function/task call
| test.sv, 6
| "my_obj::new(name)"
|   The above function/task call is done with more arguments than needed.

When using VCS, ignore the first message reported in uvm_registry.svh
and focus on the subsequent one identifying the invalid constructor being called.
The reported line number will be on the ~endclass~ token of the class
that is missing the required constructor.

Topic: Code migration script

Suitable constructors may be automatically added to classes that are missing them
by using the ~add_uvm_object_new.pl~ script.
The following command will update all SystemVerilog source files
located in the current working directory and any sub-directory:

| % add_uvm_object_new.pl --write

See the ~--help~ command-line option for more details.

The script may not be able to automatically identify all classes
with missing constructors,
or users may prefer to manually modify their source files.
The script is also unable to fix unsuitable constructors;
those will need to be fixed manually.
Because the error is a compile-time error, it will be easy to identify
any remaining changes that are required.


Topic: Migrating code using UVM 1.2

To ease the process of migrating code to UVM 1.2,
the old (incorrect) behavior remain available.
To restore the old behavior, it is necessary to define
the `UVM_OBJECT_DO_NOT_NEED_CONSTRUCTOR symbol when compiling the UVM library:

| % ... +define+UVM_OBJECT_DO_NOT_NEED_CONSTRUCTOR uvm_pkg.sv

Users must be aware that this may result in difference in behavior in code that
now relies on the correct implementation of the UVM object factory.

Topic: What will happen in UVM 1.3?

In UVM 1.3, the UVM object factory will have the corrected behavior *ONLY*.
The old (incorrect) behavior will no longer remain available.

This is to encourage users to migrate their code forward
and enable VIP providers to eventually rely on the correct
behavior of the UVM object factory.

Group: Mantis 4519 (+)
Enable all flavors of phase jumping 

The <uvm_phase>'s ~jump~ API was extended to include
<uvm_phase::set_jump_phase> and <uvm_phase::end_prematurely>.  These
methods allow for a "softer" ~jump~ wherein the phase's execution is
not immediately terminated.

Group: Mantis 4532
uvm_reg_access_seq ignoring regs with one RO field 

The <uvm_reg_access_seq> implementation was incorrectly skipping
registers which contained ~any~ 'RO' fields, as opposed to registers
which had ~only~ 'RO' fields.  This behavior has been corrected.

Group: Mantis 4533
initialized memory on DPI side may survive reset and will cause bad
behaviour

The C-side of the UVM's internal DPI calls was not safe during a
simulation reset, and could potentially cause memory leaks and bad
behavior.  This has been corrected.

Group: Mantis 4542
uvm_test_done should be made "const" 

The undocumented and deprecated ~uvm_pkg::uvm_test_done~ reference was
made ~const~ to prevent users from accidently changing it.

Topic: Backwards Compatibility
The ~uvm_test_done~ variable is not part of the UVM
standard, but may have been used by users coming from the OVM.  As
such, this change does not have any backward compatibility concerns
for the UVM standard.

Group: Mantis 4550
are uvm tlm connections with non-uvm_object a legal/supported use
model? 

The ~TLM~ documentation was expanded to explicitly allow
non-<uvm_object>-based types within their parameterization.

Group: Mantis 4553 (+)
Infinite recursion in uvm_reg_field::get_access 

An error message within the <uvm_reg_field::get_access> method was
recursively calling <uvm_reg_field::get_access>, resulting in an
infinite recursion.  This behavior was corrected.

Additionally, while fixing this mantis is was determined that the map
of field accesses defined in <uvm_reg_field::set_access> was lacking a
name for the scenario caused when a 'RO' field was added to a 'WO'
map.  The "NOACCESS" policy was added to handle this scenario.

Group: Mantis 4548
cleanup static dpi issues 

This mantis wrapped various fixes within the C-side of DPI used within
the UVM.  

Group: Mantis 4566
comparer.show_max can cause check to pass when length mismatches 

A bug in the <uvm_comparer> class caused queues of different sizes to
false-pass when the <uvm_comparer::show_max> value was not equal to
'1'.  This behavior has been corrected.

Group: Mantis 4567
uvm_reg::do_predict ignoring UVM_NOT_OK 

The ~uvm_reg::do_predict~ method was overwriting <UVM_NOT_OK> status
under certain circumstances, and replacing it with <UVM_IS_OK>.  This
behavior has been corrected.

Group: Mantis 4570 (*)(+)
Messaging System Revamp

The reporting system was overhauled to use an object-based approach to
passing information (as opposed to passing many fields multiple
times).  This simultaneously expanded the functionality of the
messaging API while providing an easier path for adding functionality
to this section of the standard in the future.

Topic: Backwards Compatibility
The ~uvm_report_server::process_report~ and
~uvm_report_server::compose_message~ methods have been replaced by the
object-based <uvm_report_server::execute_report_message> and
<uvm_report_server::compose_report_message> methods.  User code which
used the old methods will not behave as expected with the new
implementation.

Topic: Migrating code using UVM 1.2

To ease the process of migrating code to UVM 1.2, the old behavior
remains available to the user.  To restore the old behavior, it is
necessary to define the `UVM_DEPRECATED_REPORTING symbol when
compiling the UVM library:

| % ... +define+UVM_DEPRECATED_REPORTING uvm_pkg.sv

Users must be aware that this will result in different behavior in
code that now relies on the new implementation of <uvm_report_server>.

Group: Mantis 4572
packing/unpacking issues 

The ~uvm_packer::pack_int~ method (which has been renamed to
<uvm_packer::pack_field>) was incorrectly implemented, causing big
endian packs of 64+ bits to be preocessed incorrectly.  Additionally,
the <`uvm_unpack_array> implementation did not work properly when
<uvm_packer::use_metadata> was set to '0'.  These behaviors have been
corrected.

Group: Mantis 4587
Bugs in UVM 1.1-c: uvm_reg_tlm_adapter::reg2bus() 

Various fixes we provided for <uvm_reg_tlm_adapter::reg2bus> such that
iw would properly adhere to <uvm_tlm_gp> rules for ~length~,
~byte_enable~, and ~byte_enable_length~.

Group: Mantis 4588
in-built sequence is not equipped to exclude a block from the test
sequence 

The <uvm_reg_hw_reset_seq> was updated to ensure sub-blocks were
properly excluded when relevant ~NO_REG_TEST~ attributes were set.

Group: Mantis 4590
update uvm_hdl.c to allow VCS/IUS to perform backdoor access to VHDL 

The capability to allow VHDL UVM_REG backdoor access using VCS and IUS
were added.

Group: Mantis 4606
uvm_report_server is not really extendable/chainable 

In a fix similar to <Mantis 3887 (*)>,  ~uvm_report_server~
was also split into two classes, an abstract <uvm_report_server> and a
default implementation of <uvm_default_report_server>.  This allows
<uvm_report_server> to be fully extended, and multiple report servers
can be chained together using a "delegate" pattern.

Control over the global report server was
migrated to the new <uvm_coreservice_t> class.  

Topic: Backwards Compatibility
If users had previously extended <uvm_report_server>, then their code
will likely no longer compile because they are not fully implementing
the ~pure virtual~ interface which the report server now provides.
The fix to reinstate the previous functionality is to extend the
<uvm_default_report_server> instead of the <uvm_report_server>.

The <1.1 to 1.2 Migration Script> can be used to replace any
occurances of the old type in user code.

Group: Mantis 4617
uvm_report_cb::add_by_name example needs review 

A bad example in the documentation of ~uvm_report_cb::add_by_name~ has
been fixed.

Group: Mantis 4618 (*)
resource lookup broken/undefined when fieldname has wildcards 

Meta characters (globs or regular expressions) within the ~fieldname~
of a resource are no longer interpretted by the resource pool.

Topic: Backwards Compatibility
The previous behavior for meta characters within the field name was
not fully defined.

Group: Mantis 4621
printing of int fields will mask Z values with X 

The <uvm_printer::print_field> and <uvm_printer::print_field_int>
methods were incorrectly implemented, causing 'Z' values to appear as
'X' when printed.  This behavior has been corrected.

Group: Mantis 4622
uvm_phase::unsync() does not work 

The implementation of <uvm_phase::unsync> was updated to properly remove
the sync relationship.

Group: Mantis 4643
uvm_dpi_get_next_arg_c doesnt fully adhere to -1800-lrm 

The internal method ~uvm_dpi_get_next_arg_c~ was updated to completely
adhere to the 1800 lrm.

Group: Mantis 4649 (+)(*)
Improve memory performance of 'bitstream' interfaces for
report/record/etc. 

The new <uvm_integral_t> was standardized, which is a less
memory-expensive packed vector than the <uvm_bitstream_t>.  Support
for this new type was added to the <uvm_printer>, <uvm_packer>,
<uvm_recorder> and <uvm_comparer>, as well as the auto-configuration
provided by the <`uvm_field_*macros>.

Topic: Backwards Compatibility
In order to provide a consistent API, the ~uvm_printer::print_int~
method was deprecated and replaced by <uvm_printer::print_field_int>.

Group: Mantis 4666
uvm_config_db::set expects to be invoked in process context 

The implementation of <uvm_config_db::set> was improperly assuming
that the method would be invoked within a process context
(i.e. process.self() != null).  This behavior has been corrected.

Group: Mantis 4677
remove uvm_global_copy_map 

The internal and undocumented ~uvm_global_copy_map~ was removed and
replaced by a simple associative array.

Group: Mantis 4686 (+)
predict updated not just the mirrored field 

The documentation of the <uvm_reg::predict> and <uvm_reg_field::predict>
methods was clarified to indicate that the methods update ~both~ the
mirrored and desired values. 

Group: Mantis 4690
Typo in uvm_sequence_base.vh (mehod should be method) 

A typo in the documentation of <uvm_sequence_base> was corrected.

Group: Mantis 4711
uvm macros violate 1800lrm iterator requirements 

The <`uvm_field_*macros> were updated to obey 1800 LRM requirements
for the iterators of arrays.

Group: Mantis 4731
Static initialization races 

The fix to <Mantis 4606> accidently included a static race condition
which was fixed.

Group: Mantis 4732 (+)
uvm_phase_state initializes to incorrect value 

The new phase state <UVM_PHASE_UNINITIALIZED> was added to the
<uvm_phase_state>.  This new state is the default state for all
phases after construction.

Group: Mantis 4734
Bug in uvm_reg_map::get_size(); 

The implementation of ~uvm_reg_map::get_size~ had a typo which
resulted in the value of the last offset added being used instead of
the value of the largest offset.  This behavior has been corrected.

Group: Mantis 4738
DPI Code does not use UVM Messaging 

Similar to <Mantis 3783>, the messages generated from the C-side
implementation of the UVM dpi code have been refactored to route
through standard UVM messaging.

Group: Mantis 4743 (+)
Promote get_next_item, try_next_item, item_done, get, peek, and put to
be a part of the standard

The documentation of the <uvm_sequencer#(REQ,RSP)::Sequencer Interface> 
was expanded to include the implementations of the various methods.

Group: Mantis 4744 (*)(+)
Recording System Revamp 

Similar to <Mantis 4570 (*)(+)>, the recording system was overhauled
to use an object-based approach to connecting to transaction
databases.  This resulted in two new classes <uvm_tr_stream> and
<uvm_tr_database>, which provided an object-based implementation of
the undocumented implementation API for the ~uvm_recorder~.

Additionally, a new data policy <uvm_link_base> was added for
expressing arbitrary relationships in a compile-safe manner.

Topic: Backwards Compatibility
The changes made to the <uvm_recorder> API were primarily isolated to
undocumented and non-standardized methods within <uvm_recorder>
class.  New examples are provided via <uvm_text_recorder>,
<uvm_text_tr_stream> and <uvm_text_tr_database> to illustrate to
developers how the new system works.

Group: Mantis 4766 (*)
Fix broken `uvm_record_field + `uvm_record_attribute interaction 

The fix for this mantis involved creating a new method
<uvm_recorder::use_record_attribute>.  The new method allows for a
conditional usage of the <`uvm_record_attribute> macro, allowing users
to create their own recorders without interfering with
vendor-specific recorders

Topic: Backwards Compatibility
Vendors which had provided an implementation of the
<`uvm_record_attribute> macro need to add an implementation of
<uvm_recorder::use_record_attribute> in their recorders to allow
compatibility with the new macro implementation.

Group: Mantis 4767 (+)
`uvm_pack_int and `uvm_unpack_int bypass the uvm_packer policy methods 

The previous implementation of the ~`uvm_pack_*~ macros bypassed the
<uvm_packer> policy methods, and directly accessed an undocumented
member variable of the <uvm_packer> class.  This implementation was
refactored to use the policy methods without accessing any
undocumented functionality.

Additionally, a new API was added to the <uvm_packer> to provide the
ability to pack/unpack an arbrary number of bits from an array of
bits, bytes or ints.  This new API provides easier compatibility with
the SystemVerilog stream operator.

Group: Mantis 4772
separate uvm_hdl* source into files-by-vendor 

Related to <Mantis 4588>, the fix for this mantis separated the hdl
vendor dpi implementations into vendor-specific files.

Group: Mantis 4783 (*)
`uvm_record_* macros bypass uvm_recorder policy class 

The previously undocumented ~`uvm_record_*~ macros bypassed the
<uvm_recorder> policy methods, and called undocumented and
non-standard methods.  Their implementation has been refactored to use the
<uvm_recorder> policy methods by default.

Topic: Backwards Compatibility
The changes to the macros should be transparent to most end users,
however developers which were supporting the old undocumented macros
may need to update their implementations.

Group: Mantis 4786 (+)
print_real is undocumented 

A typo in the documentation of <uvm_printer::print_real> resulted in
the method being absent from the standard.  This has been corrected.

Group: Mantis 4784 (+)
`uvm_record_int/string/time/real are undocumented 

After fixing <Mantis 4783 (*)>, the previously undocumented
<`uvm_record_int>, <`uvm_record_field>, <`uvm_record_real>,
<`uvm_record_string> and <`uvm_record_time> have been officially added
to the standard.

Group: Mantis 4861
Adding a uvm_reg_map to an existing regmap instance required both maps 
to have the same parent.  The behavior was fixed and the bad error
message corrected.

Group: Mantis 4871
Fixed a problem wherein multiple ~+uvm_set_*~ commands were ignored
after a format error.

Group: Mantis 4882
The instance name of the phase objection was changed to reflect the
name of the phase.

Group: Mantis 4884
A performance fix was implemented which avoided the copy of large QDA
within the spell checker.

Group: Mantis 4893
Fixed a bug within uvm_leaf_scope which could lead to stall of
simulation.

Group: Mantis 4920
Fixed random stability bug in ~lookup_name~ which caused instability
when the config database was queried.

Group: Mantis 4923
A check was added for an out-of-bound queue access in uvm_misc.svh.
This check caused no functional change, but prevents certain tools
from throwing a warning when processing the code.

Group: Mantis 4925
The macros <`UVM_MAX_STREAMBITS>, <`UVM_PACKER_MAX_BYTES> and 
<`UVM_DEFAULT_TIMEOUT> were relocated to
src/macros/uvm_global_defines.svh, which is included via
uvm_macros.svh.  These changes will make the UVM 1.2 Reference HTML
out of sync with the UVM 1.2 Reference PDF, however this change is
strictly contained to the formatting/location of documentation, not a
functional difference.

Group: Mantis 4931
Various typos and bad links within the reference guide were corrected.