Commit graph

169 commits

Author SHA1 Message Date
Andreas Hansson
12eb034378 scons: Enable -Wextra by default
Make best use of the compiler, and enable -Wextra as well as
-Wall. There are a few issues that had to be resolved, but they are
all trivial.
2016-01-11 05:52:20 -05:00
Curtis Dunham
87b9da2df4 sim: tag-based checkpoint versioning
This commit addresses gem5 checkpoints' linear versioning bottleneck.
Since development is distributed across many private trees, there exists
a sort of 'race' for checkpoint version numbers: internally a checkpoint
version may be used but then resynchronizing with the external tree causes
a conflict on that version.  This change replaces the linear version number
with a set of unique strings called tags.  Now the only conflicts that can
arise are of tag names, where collisions are much easier to avoid.

The checkpoint upgrader (util/cpt_upgrader.py) upgrades the version
representation, as one would expect. Each tag version implements its
upgrader code in a python file in the util/cpt_upgraders directory
rather than adding a function to the upgrader script itself.

The version tags are stored in the 'Globals' section rather than 'root'
(as the version was previously) because 'Globals' gets unserialized
first and can provide a warning before any other unserialization errors
can occur.
2015-09-02 15:23:30 -05:00
Andreas Hansson
c466d55a26 scons: Bump compiler requirement to gcc >= 4.7 and clang >= 3.1
This patch updates the compiler minimum requirement to gcc 4.7 and
clang 3.1, thus allowing:

1. Explicit virtual overrides (no need for M5_ATTR_OVERRIDE)
2. Non-static data member initializers
3. Template aliases
4. Delegating constructors

This patch also enables a transition from --std=c++0x to --std=c++11.
2015-07-03 10:14:15 -04:00
Andreas Sandberg
9e6f803254 base: Add compiler macros to add deprecation warnings
Gcc and clang both provide an attribute that can be used to flag a
function as deprecated at compile time. This changeset adds a gem5
compiler macro for that compiler feature. The macro can be used to
indicate that a legacy API within gem5 has been deprecated and provide
a graceful migration to the new API.
2015-02-11 10:23:24 -05:00
Andreas Hansson
c9b8616c51 base: Do not dereference NULL in CompoundFlag creation
This patch fixes the CompoundFlag constructor, ensuring that it does
not dereference NULL. Doing so has undefined behaviuor, and both clang
and gcc's undefined-behaviour sanitiser was rather unhappy.
2015-02-11 10:23:23 -05:00
Andreas Hansson
966c3f4bc5 scons: Ensure dictionary iteration is sorted by key
This patch adds sorting based on the SimObject name or parameter name
for all situations where we iterate over dictionaries. This should
ensure a deterministic and consistent order across the host systems
and hopefully avoid regression results differing across python
versions.
2014-12-02 06:08:22 -05:00
Andreas Hansson
2475862747 arch,x86,mem: Dynamically determine the ISA for Ruby store check
This patch makes the memory system ISA-agnostic by enabling the Ruby
Sequencer to dynamically determine if it has to do a store check. To
enable this check, the ISA is encoded as an enum, and the system
is able to provide the ISA to the Sequencer at run time.

--HG--
rename : src/arch/x86/insts/microldstop.hh => src/arch/x86/ldstflags.hh
2014-10-16 05:49:44 -04:00
Andreas Hansson
66df7b7fd4 config: Add the ability to read a config file using C++ and Python
This patch adds the ability to load in config.ini files generated from
gem5 into another instance of gem5 built without Python configuration
support. The intended use case is for configuring gem5 when it is a
library embedded in another simulation system.

A parallel config file reader is also provided purely in Python to
demonstrate the approach taken and to provided similar functionality
for as-yet-unknown use models. The Python configuration file reader
can read both .ini and .json files.

C++ configuration file reading:

A command line option has been added for scons to enable C++ configuration
file reading: --with-cxx-config

There is an example in util/cxx_config that shows C++ configuration in action.
util/cxx_config/README explains how to build the example.

Configuration is achieved by the object CxxConfigManager. It handles
reading object descriptions from a CxxConfigFileBase object which
wraps a config file reader. The wrapper class CxxIniFile is provided
which wraps an IniFile for reading .ini files. Reading .json files
from C++ would be possible with a similar wrapper and a JSON parser.

After reading object descriptions, CxxConfigManager creates
SimObjectParam-derived objects from the classes in the (generated with this
patch) directory build/ARCH/cxx_config

CxxConfigManager can then build SimObjects from those SimObjectParams (in an
order dictated by the SimObject-value parameters on other objects) and bind
ports of the produced SimObjects.

A minimal set of instantiate-replacing member functions are provided by
CxxConfigManager and few of the member functions of SimObject (such as drain)
are extended onto CxxConfigManager.

Python configuration file reading (configs/example/read_config.py):

A Python version of the reader is also supplied with a similar interface to
CxxConfigFileBase (In Python: ConfigFile) to config file readers.

The Python config file reading will handle both .ini and .json files.

The object construction strategy is slightly different in Python from the C++
reader as you need to avoid objects prematurely becoming the children of other
objects when setting parameters.

Port binding also needs to be strictly in the same port-index order as the
original instantiation.
2014-10-16 05:49:37 -04:00
Andreas Hansson
b14f521e5f scons: Add Undefined Behavior Sanitizer (UBSan) option
This patch adds the Undefined Behavior Sanitizer (UBSan) for clang and
gcc >= 4.9. Due to the performance impact, the usage is guarded by a
command-line option.
2014-10-16 05:49:36 -04:00
Curtis Dunham
f7c6a2cbed scons: Generate a single debug flag C++ file
Reduces target count/compiler invocations by ~180.
2014-08-12 17:35:28 -05:00
Curtis Dunham
f780e85dc3 scons: create dummy target to have SWIG generate C++ classes
scons build/<arch>/swig
2014-10-16 05:49:33 -04:00
Andrew Bardsley
d8502ee46d config: Add a --without-python option to build process
Add the ability to build libgem5 without embedded Python or the
ability to configure with Python.

This is a prelude to a patch to allow config.ini files to be loaded
into libgem5 using only C++ which would make embedding gem5 within
other simulation systems easier.

This adds a few registration interfaces to things which cross
between Python and C++.  Namely: stats dumping and SimObject resolving
2014-10-16 05:49:32 -04:00
Andreas Sandberg
6b908211e6 scons: Silence clang 3.4 warnings on Ubuntu 12.04
This changeset fixes three types of warnings that occur in clang 3.4
on Ubuntu 12.04:

 * Certain versions of libstdc++ (primarily 4.8) use struct and class
   interchangeably. This triggers a warning in clang.

 * Swig has a tendency to generate code with the register class which
   was deprecated in C++11. This triggers a deprecation warning in
   clang.

 * Swig sometimes generates Python wrapper code which returns
   uninitialized values. It's unclear if this is actually a problem
   (the cases might be limited to failure paths). We'll silence these
   warnings for now since there is little we can do about the
   generated code.
2014-08-13 06:57:28 -04:00
Andreas Hansson
fdb965f5c1 scons: Bump the compiler version to gcc 4.6 and clang 3.0
This patch bumps the supported version of gcc from 4.4 to 4.6, and
clang from 2.9 to 3.0. This enables, amongst other things, range-based
for loops, lambda expressions, etc. The STL implementation shipping
with 4.6 also has a full functional implementation of unique_ptr and
shared_ptr.
2014-06-10 17:44:39 -04:00
Curtis Dunham
fe27f937aa arch: teach ISA parser how to split code across files
This patch encompasses several interrelated and interdependent changes
to the ISA generation step.  The end goal is to reduce the size of the
generated compilation units for instruction execution and decoding so
that batch compilation can proceed with all CPUs active without
exhausting physical memory.

The ISA parser (src/arch/isa_parser.py) has been improved so that it can
accept 'split [output_type];' directives at the top level of the grammar
and 'split(output_type)' python calls within 'exec {{ ... }}' blocks.
This has the effect of "splitting" the files into smaller compilation
units.  I use air-quotes around "splitting" because the files themselves
are not split, but preprocessing directives are inserted to have the same
effect.

Architecturally, the ISA parser has had some changes in how it works.
In general, it emits code sooner.  It doesn't generate per-CPU files,
and instead defers to the C preprocessor to create the duplicate copies
for each CPU type.  Likewise there are more files emitted and the C
preprocessor does more substitution that used to be done by the ISA parser.

Finally, the build system (SCons) needs to be able to cope with a
dynamic list of source files coming out of the ISA parser. The changes
to the SCons{cript,truct} files support this. In broad strokes, the
targets requested on the command line are hidden from SCons until all
the build dependencies are determined, otherwise it would try, realize
it can't reach the goal, and terminate in failure. Since build steps
(i.e. running the ISA parser) must be taken to determine the file list,
several new build stages have been inserted at the very start of the
build. First, the build dependencies from the ISA parser will be emitted
to arch/$ISA/generated/inc.d, which is then read by a new SCons builder
to finalize the dependencies. (Once inc.d exists, the ISA parser will not
need to be run to complete this step.) Once the dependencies are known,
the 'Environments' are made by the makeEnv() function. This function used
to be called before the build began but now happens during the build.
It is easy to see that this step is quite slow; this is a known issue
and it's important to realize that it was already slow, but there was
no obvious cause to attribute it to since nothing was displayed to the
terminal. Since new steps that used to be performed serially are now in a
potentially-parallel build phase, the pathname handling in the SCons scripts
has been tightened up to deal with chdir() race conditions. In general,
pathnames are computed earlier and more likely to be stored, passed around,
and processed as absolute paths rather than relative paths.  In the end,
some of these issues had to be fixed by inserting serializing dependencies
in the build.

Minor note:
For the null ISA, we just provide a dummy inc.d so SCons is never
compelled to try to generate it. While it seems slightly wrong to have
anything in src/arch/*/generated (i.e. a non-generated 'generated' file),
it's by far the simplest solution.
2014-05-09 18:58:47 -04:00
Anthony Gutierrez
8a53da22c2 cpu: allow the fetch buffer to be smaller than a cache line
the current implementation of the fetch buffer in the o3 cpu
is only allowed to be the size of a cache line. some
architectures, e.g., ARM, have fetch buffers smaller than a cache
line, see slide 22 at:
http://www.arm.com/files/pdf/at-exploring_the_design_of_the_cortex-a15.pdf

this patch allows the fetch buffer to be set to values smaller
than a cache line.
2013-11-15 13:21:15 -05:00
Andreas Hansson
8a8e5cdc7e build: Place proto output in the same directory, also for EXTRAS
This patch changes the ProtoBuf builder such that the generated source
and header is placed in the build directory of the proto file. This
was previously not the case for the directories included as EXTRAS. To
make this work, we also ensure that the build directory for the EXTRAS
are added to the include path (which does not seem to automatically be
the case).
2013-10-17 10:20:45 -05:00
Steve Reinhardt
f0b745d556 scons: don't die on warnings in swig-generated code
There's not much to do about it other than disable the offending
warning anyway, so it's not worth terminating the build over.

Also suppress uninitialized variable warnings on gcc (happens
at least with gcc 4.4 and swig 1.3.40).
2013-03-27 10:03:02 -07:00
Andreas Hansson
08a5fd328b scons: Unify the flags shared by gcc and clang
This patch restructures and unifies the flags used by gcc and clang as
they are largely the same. The common parts are now dealt with in a
shared block of code, and the few bits and pieces that are
specifically affecting either gcc or clang are done separately.
2013-02-19 05:56:07 -05:00
Andreas Hansson
5eddb63877 scons: Add warning delete with non-virtual destructor
This patch enables a warning for deleting derived classes that do not
have a virtual destructor. The patch merely adds additional checks,
and there are currently no cases that had to be fixed.
2013-02-19 05:56:07 -05:00
Andreas Hansson
319443d42d scons: Add warning for missing declarations
This patch enables warnings for missing declarations. To avoid issues
with SWIG-generated code, the warning is only applied to non-SWIG
code.
2013-02-19 05:56:07 -05:00
Andreas Hansson
221302335b scons: Remove stale compiler options
This patch simply prunes the SUNCC and ICC compiler options as they
are both sufficiently stale that they would have to be re-written from
scratch anyhow. The patch serves to clean things up before shifting to
a build environment that enforces basic c++11 compliance as done in
the following patch.
2013-01-07 13:05:39 -05:00
Andreas Hansson
41f228c2ea scons: Add support for google protobuf building
This patch enables the use of protobuf input files in the build
process, thus allowing .proto files to be added to input. Each .proto
file is compiled using the protoc tool and the newly created C++
source is added to the list of sources.

The first location where the protobufs will be used is in the
capturing and replay of memory traces, involving the communication
monitor and the trace-generator state of the traffic generator. This
will follow in the next patch.

This patch does add a dependency on the availability of the BSD
licensed protobuf library (and headers), and the protobuf compiler,
protoc. These dependencies are checked in the SConstruct, similar to
e.g. swig. The user can override the use of protoc from the PATH by
specifying the PROTOC environment variable.

Although the dependency on libprotobuf and protoc might seem like a
big step, they add significant value to the project going
forward. Execution traces and other types of traces could easily be
added and parsers for C++ and Python are automatically generated. We
could also envision using protobufs for the checkpoints, description
of the traffic-generator behaviour etc. The sky is the limit. We could
also use the GzipOutputStream from the protobuf library instead of the
current GPL gzstream.

Currently, only the C++ source and header is generated. Going forward
we might want to add the Python output to support simple command-line
tools for displaying and editing the traces.
2013-01-07 13:05:37 -05:00
Andreas Sandberg
c0ab52799c sim: Include object header files in SWIG interfaces
When casting objects in the generated SWIG interfaces, SWIG uses
classical C-style casts ( (Foo *)bar; ). In some cases, this can
degenerate into the equivalent of a reinterpret_cast (mainly if only a
forward declaration of the type is available). This usually works for
most compilers, but it is known to break if multiple inheritance is
used anywhere in the object hierarchy.

This patch introduces the cxx_header attribute to Python SimObject
definitions, which should be used to specify a header to include in
the SWIG interface. The header should include the declaration of the
wrapped object. We currently don't enforce header the use of the
header attribute, but a warning will be generated for objects that do
not use it.
2012-11-02 11:32:01 -05:00
Andreas Sandberg
1b29352dd5 build: Add missing dependencies when building param SWIG interfaces
This patch adds an explicit dependency between param_%s.i and the
Python source file defining the object. Previously, the build system
didn't rebuild SWIG interfaces correctly when an object's Python
sources were updated.
2012-09-25 11:49:40 -05:00
Andreas Hansson
d1f3a3b91a gcc: Enable Link-Time Optimization for gcc >= 4.6
This patch adds Link-Time Optimization when building the fast target
using gcc >= 4.6, and adds a scons flag to disable it (-no-lto). No
check is performed to guarantee that the linker supports LTO and use
of the linker plugin, so the user has to ensure that binutils GNU ld
>= 2.21 or the gold linker is available. Typically, if gcc >= 4.6 is
available, the latter should not be a problem. Currently the LTO
option is only useful for gcc >= 4.6, due to the limited support on
clang and earlier versions of gcc. The intention is to also add
support for clang once the LTO integration matures.

The same number of jobs is used for the parallel phase of LTO as the
jobs specified on the scons command line, using the -flto=n flag that
was introduced with gcc 4.6. The gold linker also supports concurrent
and incremental linking, but this is not used at this point.

The compilation and linking time is increased by almost 50% on
average, although ARM seems to be particularly demanding with an
increase of almost 100%. Also beware when using this as gcc uses a
tremendous amount of memory and temp space in the process. You have
been warned.

After some careful consideration, and plenty discussions, the flag is
only added to the fast target, and the warning that was issued in an
earlier version of this patch is now removed. Similarly, the flag used
to enable LTO, now the default is to use it, and the flag has been
modified to disable LTO. The rationale behind this decision is that
opt is used for development, whereas fast is only used for long runs,
e.g. regressions or more elaborate experiments where the additional
compile and link time is amortized by a much larger run time.

When it comes to the return on investment, the regression seems to be
roughly 15% faster with LTO. For a bit more detail, I ran twolf on
ARM.fast, with three repeated runs, and they all finish within 42
minutes (+- 25 seconds) without LTO and 31 minutes (+- 25 seconds)
with LTO, i.e. LTO gives an impressive >25% speed-up for this case.

Without LTO (ARM.fast twolf)

real	42m37.632s
user	42m34.448s
sys	0m0.390s

real	41m51.793s
user	41m50.384s
sys	0m0.131s

real	41m45.491s
user	41m39.791s
sys	0m0.139s

With LTO (ARM.fast twolf)

real	30m33.588s
user	30m5.701s
sys	0m0.141s

real	31m27.791s
user	31m24.674s
sys	0m0.111s

real	31m25.500s
user	31m16.731s
sys	0m0.106s
2012-09-14 12:13:22 -04:00
Andreas Hansson
a57eda0843 scons: Add a target for google-perftools profiling
This patch adds a new target called 'perf' that facilitates profiling
using google perftools rather than gprof. The perftools CPU profiler
offers plenty useful information in addition to gprof, and the latter
is kept mostly to offer profiling also on non-Linux hosts.
2012-09-14 12:13:21 -04:00
Andreas Hansson
224ea5fba6 scons: Restructure ccflags and ldflags
This patch restructures the ccflags such that the common parts are
defined in a single location, also capturing all the target types in a
single place.

The patch also adds a corresponding ldflags in preparation for
google-perf profiling support and the addition of Link-Time
Optimization.
2012-09-14 12:13:20 -04:00
Andreas Hansson
d090f4d930 swig: Disable unused value warning with llvm 3.1 compilers
This patch disables a warning for unused values which causes problems
when compiling the swig-generated sources using recent llvm-based
compilers like llvm-gcc and clang.
2012-08-28 14:30:22 -04:00
Ali Saidi
70d7d6cc7f sim: Provide a framework for detecting out of data checkpoints and migrating them. 2012-06-05 01:23:10 -04:00
Ali Saidi
331696582f stats: fix compilation of unit test. 2012-05-10 18:04:28 -05:00
Andreas Hansson
b6aa6d55eb clang/gcc: Fix compilation issues with clang 3.0 and gcc 4.6
This patch addresses a number of minor issues that cause problems when
compiling with clang >= 3.0 and gcc >= 4.6. Most importantly, it
avoids using the deprecated ext/hash_map and instead uses
unordered_map (and similarly so for the hash_set). To make use of the
new STL containers, g++ and clang has to be invoked with "-std=c++0x",
and this is now added for all gcc versions >= 4.6, and for clang >=
3.0. For gcc >= 4.3 and <= 4.5 and clang <= 3.0 we use the tr1
unordered_map to avoid the deprecation warning.

The addition of c++0x in turn causes a few problems, as the
compiler is more stringent and adds a number of new warnings. Below,
the most important issues are enumerated:

1) the use of namespaces is more strict, e.g. for isnan, and all
   headers opening the entire namespace std are now fixed.

2) another other issue caused by the more stringent compiler is the
   narrowing of the embedded python, which used to be a char array,
   and is now unsigned char since there were values larger than 128.

3) a particularly odd issue that arose with the new c++0x behaviour is
   found in range.hh, where the operator< causes gcc to complain about
   the template type parsing (the "<" is interpreted as the beginning
   of a template argument), and the problem seems to be related to the
   begin/end members introduced for the range-type iteration, which is
   a new feature in c++11.

As a minor update, this patch also fixes the build flags for the clang
debug target that used to be shared with gcc and incorrectly use
"-ggdb".
2012-04-14 05:43:31 -04:00
Steve Reinhardt
29482e90ba SCons: restore Werror option in src/SConscript
Partial backout of cset 8b223e308b08.

Although it's great that there's currently no need
for Werror=false in the current tree, some of us
have uncommitted code that still needs this option.
2012-04-13 08:13:04 -07:00
Gabe Black
15ca4f2fc7 tests: Fix building unit tests.
Unit tests shouldn't build in gem5's main function because they have thier
own.
2012-04-09 23:20:30 -07:00
Andreas Hansson
fb395b56dd Scons: Remove Werror=False in SConscript files
This patch removes the overriding of "-Werror" in a handful of
cases. The code compiles with gcc 4.6.3 and clang 3.0 without any
warnings, and thus without any errors. There are no functional changes
introduced by this patch. In the future, rather than ypassing
"-Werror", address the warnings.
2012-03-22 06:34:50 -04:00
Marc Orr
eb43883bef build scripts: Made minor modifications to reduce build overhead time.
1. --implicit-cache behavior is default.
2. makeEnv in src/SConscript is conditionally called.
3. decider set to MD5-timestamp
4. NO_HTML build option changed to SLICC_HTML (defaults to False)
2012-03-06 19:07:41 -08:00
Koan-Sin Tan
7d4f187700 clang: Enable compiling gem5 using clang 2.9 and 3.0
This patch adds the necessary flags to the SConstruct and SConscript
files for compiling using clang 2.9 and later (on Ubuntu et al and OSX
XCode 4.2), and also cleans up a bunch of compiler warnings found by
clang. Most of the warnings are related to hidden virtual functions,
comparisons with unsigneds >= 0, and if-statements with empty
bodies. A number of mismatches between struct and class are also
fixed. clang 2.8 is not working as it has problems with class names
that occur in multiple namespaces (e.g. Statistics in
kernel_stats.hh).

clang has a bug (http://llvm.org/bugs/show_bug.cgi?id=7247) which
causes confusion between the container std::set and the function
Packet::set, and this is currently addressed by not including the
entire namespace std, but rather selecting e.g. "using std::vector" in
the appropriate places.
2012-01-31 12:05:52 -05:00
Andreas Hansson
59b7cad3ec SWIG: Make gem5 compile and link with swig 2.0.4
To make gem5 compile and run with swig 2.0.4 a few minor fixes are
necessary, the fail label issues by swig must not be treated as an
error by gcc (tested with gcc 4.2.1), and the vector wrappers must
have SWIGPY_SLICE_ARG defined which happens in pycontainer.swg,
included through std_container.i. By adding the aforementioned include
to the vector wrappers everything seems to work.
2012-01-09 18:08:20 -06:00
Gabe Black
2ee59cee1b GCC: Guard some gcc flags so they're used when available and needed. 2011-11-09 21:48:28 -08:00
Gabe Black
d735abe5da GCC: Get everything working with gcc 4.6.1.
And by "everything" I mean all the quick regressions.
2011-10-31 01:09:44 -07:00
Steve Reinhardt
45d14e02c4 scons/swig: refactor some of the scons/SWIG code
- Move the random bits of SWIG code generation out of src/SConscript
  file and into methods on the objects being wrapped.
- Cleaned up some variable naming and added some comments to make
  the process a little clearer.
- Did a little generated file/module renaming:
   - vptype_Foo now Foo_vector
   - init_Foo is now Foo_init
  This makes it easier to see all the Foo-related files in a
  sorted directory listing.
- Made cxx_predecls and swig_predecls normal SimObject classmethods.
- Got rid of swig_objdecls hook, even though this breaks the System
  objects get/setMemoryMode method exports.  Will be fixing this in
  a future changeset.
2011-10-20 13:08:49 -07:00
Nathan Binkert
d8cc8d3ab8 scons: fix building of shared objects 2011-10-17 17:06:40 -07:00
Nathan Binkert
2b1aa35e20 scons: rename TraceFlags to DebugFlags 2011-06-02 17:36:21 -07:00
Nathan Binkert
f49f384fe4 scons: rename some things from m5 to gem5
The default generated binary is now gem5.<type> instead of m5.<type>.
The latter does still work but gem5.<type> will be generated first and
then m5.<type> will be hard linked to it.
2011-06-02 17:36:18 -07:00
Nathan Binkert
0c424344fa copyright: Add code for finding all copyright blocks and create a COPYING file
The end of the COPYING file was generated with:
% python ./util/find_copyrights.py configs src system tests util

Update -C command line option to spit out COPYING file
2011-06-02 17:36:07 -07:00
Brad Danofsky
dd38b4b83e scons: Allow the build directory live under an EXTRAS directory 2011-04-20 11:14:51 -07:00
Nathan Binkert
915f49ae92 unittest: Make unit tests capable of using swig and python, convert stattest 2011-04-15 10:45:11 -07:00
Nathan Binkert
3182913e94 scons: make a flexible system for guarding source files
This is similar to guards on mercurial queues and they're used for selecting
which files are compiled into some given object.  We already do something
similar, but it's mostly hard coded for the m5 binary and the m5 library
and I'd like to make it more flexible to better support the unittests
2011-04-15 10:44:44 -07:00
Nathan Binkert
eddac53ff6 trace: reimplement the DTRACE function so it doesn't use a vector
At the same time, rename the trace flags to debug flags since they
have broader usage than simply tracing.  This means that
--trace-flags is now --debug-flags and --trace-help is now --debug-help
2011-04-15 10:44:32 -07:00
Gabe Black
02f10fbdc8 SCons: Stop embedding the mercurial revision into the binary.
This causes a lot of rebuilds that could have otherwise possibly been
avoided, and, more annoyingly, a lot of unnecessary rerunning of the
regressions. The benefits of having the revision in the output haven't
materialized, so this change removes it.
2011-03-11 11:27:36 -08:00