The "expected failure" tests for decodetree result in the
error messages from decodetree ending up in logs and in
V=1 output:

>>> MALLOC_PERTURB_=226 /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/x86/pyvenv/bin/python3 /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/scripts/decodetree.py --output-null --test-for-error /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/x86/../../tests/decode/err_argset1.decode
――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――― ✀  ――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――
/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/x86/../../tests/decode/err_argset1.decode:5: error: duplicate argument "a"
―――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――
 1/44 qemu:decodetree / err_argset1                OK              0.05s

This then produces false positives when scanning the
logfiles for strings like "error: ".

For the expected-failure tests, make decodetree print
"detected:" instead of "error:".

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230720131521.1325905-1-peter.maydell@linaro.org

Using "-o /dev/null" fails on Windows.  Rather that working
around this in meson, add a separate command-line option so
that we can use python's os.devnull.

Reported-by: Thomas Huth <thuth@redhat.com>
Fixes: 656666dc ("tests/decode: Convert tests to meson")
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20230531232510.66985-1-richard.henderson@linaro.org>

Implement support for named fields, i.e.  where one field is defined
in terms of another, rather than directly in terms of bits extracted
from the instruction.

The new method referenced_fields() on all the Field classes returns a
list of fields that this field references.  This just passes through,
except for the new NamedField class.

We can then use referenced_fields() to:
 * construct a list of 'dangling references' for a format or
   pattern, which is the fields that the format/pattern uses but
   doesn't define itself
 * do a topological sort, so that we output "field = value"
   assignments in an order that means that we assign a field before
   we reference it in a subsequent assignment
 * check when we output the code for a pattern whether we need to
   fill in the format fields before or after the pattern fields, and
   do other error checking

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230523120447.728365-6-peter.maydell@linaro.org>

To support named fields, we will need to be able to do a topological
sort (so that we ensure that we output the assignment to field A
before the assignment to field B if field B refers to field A by
name). The good news is that there is a tsort in the python standard
library; the bad news is that it was only added in Python 3.9.

To bridge the gap between our current minimum supported Python
version and 3.9, provide a local implementation that has the
same API as the stdlib version for the parts we care about.
In future when QEMU's minimum Python version requirement reaches
3.9 we can delete this code and replace it with an 'import' line.

The core of this implementation is based on
https://code.activestate.com/recipes/578272-topological-sort/


which is MIT-licensed.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230523120447.728365-5-peter.maydell@linaro.org>

To support referring to other named fields in field definitions, we
need to pass the str_extract() method a function which tells it how
to emit the code for a previously initialized named field.  (In
Pattern::output_code() the other field will be "u.f_foo.field", and
in Format::output_extract() it is "a->field".)

Refactor the two callsites that currently do "output code to
initialize each field", and have them pass a lambda that defines how
to format the lvalue in each case.  This is then used both in
emitting the LHS of the assignment and also passed down to
str_extract() as a new argument (unused at the moment, but will be
used in the following patch).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230523120447.728365-4-peter.maydell@linaro.org>

Nor report any PermissionError on remove.
The primary purpose is testing with -o /dev/null.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Test err_pattern_group_empty.decode failed with exception:

Traceback (most recent call last):
  File "./scripts/decodetree.py", line 1424, in <module> main()
  File "./scripts/decodetree.py", line 1342, in main toppat.build_tree()
  File "./scripts/decodetree.py", line 627, in build_tree
    self.tree = self.__build_tree(self.pats, self.fixedbits,
  File "./scripts/decodetree.py", line 607, in __build_tree
    fb = i.fixedbits & innermask
TypeError: unsupported operand type(s) for &: 'NoneType' and 'int'

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Two copy-paste errors walking the parse tree.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Invert the exit code, for use with the testsuite.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Rather than force all structure members to be 'int',
allow the type of the member to be specified.

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Allow '64' to be specified for the instruction width command line params
and use the appropriate extract and deposit functions in that case.

This will be used to implement the new 64-bit Power ISA 3.1 instructions.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Luis Pires <luis.pires@eldorado.org.br>
Message-Id: <CP2PR80MB3668E123E2EFDB0ACD3A46F1DA759@CP2PR80MB3668.lamprd80.prod.outlook.com>
[rth: Drop the change to the field type; use bitop_width instead of separate
variables for extract/deposit; use "ull" for 64-bit constants.]
Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Form a hex constant of the appropriate insnwidth.
Begin using f-strings on changed lines.

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

When decodetree.py was added in commit 568ae7ef, QEMU was
using Python 2 which happily reads UTF-8 files in text mode.
Python 3 requires either UTF-8 locale or an explicit encoding
passed to open(). Now that Python 3 is required, explicit
UTF-8 encoding for decodetree source files.

To avoid further problems with the user locale, also explicit
UTF-8 encoding for the generated C files.

Explicit both input/output are plain text by using the 't' mode.

This fixes:

  $ /usr/bin/python3 scripts/decodetree.py test.decode
  Traceback (most recent call last):
    File "scripts/decodetree.py", line 1397, in <module>
      main()
    File "scripts/decodetree.py", line 1308, in main
      parse_file(f, toppat)
    File "scripts/decodetree.py", line 994, in parse_file
      for line in f:
    File "/usr/lib/python3.6/encodings/ascii.py", line 26, in decode
      return codecs.ascii_decode(input, self.errors)[0]
  UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 80:
  ordinal not in range(128)

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Suggested-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210110000240.761122-1-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.

Signed-off-by: Chetan Pant <chetan4windows@gmail.com>
Message-Id: <20201023123353.19796-1-chetan4windows@gmail.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

For nested groups like:

  {
    [
      pattern 1
      pattern 2
    ]
    pattern 3
  }

the intended behaviour is that patterns 1 and 2 must not
overlap with each other; if the insn matches neither then
we fall through to pattern 3 as the next thing in the
outer overlapping group.

Currently we generate incorrect code for this situation,
because in the code path for a failed match inside the
inner non-overlapping group we generate a "return" statement,
which causes decode to stop entirely rather than continuing
to the next thing in the outer group.

Generate a "break" instead, so that decode flow behaves
as required for this nested group case.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20201019151301.2046-2-peter.maydell@linaro.org

I found that there are many spelling errors in the comments of qemu,
so I used the spellcheck tool to check the spelling errors
and finally found some spelling errors in the scripts folder.

Signed-off-by: zhaolichang <zhaolichang@huawei.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200917075029.313-5-zhaolichang@huawei.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

Only argument set members have to be C identifiers, everything
else gets prefixed during conversion to C.  Some places just
checked the leading character, and some places matched a leading
character plus a C identifier.

Convert everything to match full identifiers, including the
[&%@&] prefix, and drop the full C identifier requirement.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20200903192334.1603773-1-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Similar to hw_arch, each architecture defines two sourceset which are placed in
dictionaries target_arch and target_softmmu_arch.  These are then picked up
from there when building the per-emulator static_library.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

GCC supports "#pragma GCC diagnostic" since version 4.6, and
Clang seems to support it, too, since its early versions 3.x.
That means that our minimum required compiler versions all support
this pragma already and we can remove the test from configure and
all the related #ifdefs in the code.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200710045515.25986-1-thuth@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

While it makes little sense for the end product to have a group
containing only a single pattern, avoiding this case within an
incremental patch set is troublesome.

Because this is expected to be a transient condition, do not
bother "optimizing" this case, e.g. by folding away the group.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Intended to be nested within overlapping groups.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Create ExcMultiPattern to hold an set of non-overlapping patterns.
The body of build_tree, prop_format become member functions on this
class.  Add minimal member functions to Pattern and MultiPattern
to allow recusion through the tree.

Move the bulk of build_incmulti_pattern to prop_masks and prop_width
in MultiPattern, since we will need this for both kinds of containers.
Only perform prop_width for variablewidth.

Remove global patterns variable, and pass down container object into
parse_file from main.

No functional change in all of this.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

This is an edge case for sure, but the logic that disallowed
this case was faulty.  Further, a few fixes scattered about
can allow this to work.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Name the current node for "inclusive" multi-pattern, in
preparation for adding a node for "exclusive" multi-pattern.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Use proper varargs to print the arguments.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

We guarantee 3.5+ everywhere; remove more dead checks. In general, try
to avoid using version checks and instead prefer to attempt behavior
when possible.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200514035230.25756-1-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

This script started using Python2, where the 'classic' division
operator returns the floor result. In commit 3d004a37 we started
to use Python3, where the division operator returns the float
result ('true division').
To keep the same behavior, use the 'floor division' operator "//"
which returns the floor result.

Fixes: 3d004a37
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200330121345.14665-1-f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Use the program search path to find the Python 3 interpreter.

Patch created mechanically by running:

  $ sed -i "s,^#\!/usr/bin/\(env\ \)\?python$,#\!/usr/bin/env python3," \
       $(git grep -l 'if __name__.*__main__')

Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200130163232.10446-6-philmd@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

We can tell that a decodetree input file is "secondary" when it
uses an argument set marked "!extern".  This indicates that at
least one of the insn translation functions will have already
been declared by the "primary" input file, but given only the
secondary we cannot tell which.

Avoid redundant declaration warnings by suppressing them with pragmas.

Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Suggested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Call this form a "parameter", returning a value extracted
from the DisasContext.

Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Typo comparing the sign of the field, twice, instead of also comparing
the mask of the field (which itself encodes both position and length).

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190604154225.26992-1-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

This does require adjusting all existing users.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Read the instruction, loading no more bytes than necessary.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Assuming that the ISA clearly describes how to determine
the length of the instruction, and the ISA has a reasonable
maximum instruction length, the input to the decoder can be
right-justified in an appropriate insn word.

This is not 100% convenient, as out-of-line %fields are
numbered relative to the maximum instruction length, but
this appears to still be usable.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Previously this would result in an exception for shifting
the field mask by a negative number.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

This makes it easier to name Formats within multiple decode files.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

This is interesting for bisection, where an output file is plumbed,
but does not yet have patterns.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>