Commit graph

26 commits

Author SHA1 Message Date
Philippe Mathieu-Daudé 296c32a8da decodetree: Open files with encoding='utf-8'
When decodetree.py was added in commit 568ae7efae7, 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)

Backports 4cacecaaa2bbf8af0967bd3eee43297fada475a9
2021-03-04 13:34:08 -05:00
Peter Maydell 51093daf5f decodetree: Fix codegen for non-overlapping group inside overlapping group
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.

Backports 514101c0b931f0a11a40d29d26af1cc40482f951
2021-03-01 20:14:19 -05:00
Peter Maydell 61abec1908 target/arm: Convert Neon VCVT fp size field to MO_* in decode
Convert the insns using the 2reg_vcvt and 2reg_vcvt_f16 formats
to pass the size through to the trans function as a MO_* value
rather than the '0==f32, 1==f16' used in the fp 3-same encodings.

Backports commit 0ae715c658a02af1834b63563c56112a6d8842cb
2021-03-01 18:20:11 -05:00
Richard Henderson b45a02e2f7 decodetree: Multi-cleanup
Includes multiple changes by Richard Henderson as follows:

- Use proper varargs to print the arguments. (2fd51b19c9)
- Rename MultiPattern to IncMultiPattern (040145c4f8)
- Split out MultiPattern from IncMultiPattern (df63044d02)
- Allow group covering the entire insn space (b44b3449a0)
- Move semantic propagation into classes (08561fc128)
- Implement non-overlapping groups (067e8b0f45)
- Drop check for less than 2 patterns in a group (fe079aa13d)
2020-06-15 12:49:02 -04:00
Philippe Mathieu-Daudé c68800aa29 decodetree: Use Python3 floor division operator
This script started using Python2, where the 'classic' division
operator returns the floor result. In commit 3d004a371 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: 3d004a371

Backports commit b412378785c1bd95e3461c1373dd8938bc54fb4e from qemu
2020-04-30 07:16:30 -04:00
Richard Henderson b33a5bd513
decodetree: Suppress redundant declaration warnings
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.

Backports commit c692079597d98337b6f25deff7599afe39b2a468 from qemu
2019-11-18 21:21:30 -05:00
Richard Henderson 6e2358ab60
decodetree: Allow !function with no input bits
Call this form a "parameter", returning a value extracted
from the DisasContext.

Backports commit 94597b6146f30f949f2c454f424082a2b0f55a0e from qemu
2019-11-18 21:21:25 -05:00
Richard Henderson 7c03c8eb04
decodetree: Fix comparison of Field
Typo comparing the sign of the field, twice, instead of also comparing
the mask of the field (which itself encodes both position and length).

Backports commit 2c7d442743854d2c1f5475446e088bd523f4bb20 from qemu
2019-06-13 16:17:56 -04:00
Lioncash a71c027063
decodetree: Add DisasContext argument to !function expanders
This does require adjusting all existing users.

Backports commit 451e4ffdb0003ab5ed0d98bd37b385c076aba183 from qemu
2019-05-09 17:40:45 -04:00
Richard Henderson 9030870a8f
decodetree: Expand a decode_load function
Read the instruction, loading no more bytes than necessary.

Backports commit 70e0711ab18fa48279cd2c8cc570b57f38648598 from qemu
2019-05-09 17:35:20 -04:00
Richard Henderson a98e70e791
decodetree: Initial support for variable-length ISAs
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.

Backports commit 17560e9349ff1fcce814184b37993f92378cf0c4 from qemu
2019-05-09 17:32:38 -04:00
Richard Henderson 4111a3a892
decodetree: Properly diagnose fields overflowing an insn
Previously this would result in an exception for shifting
the field mask by a negative number.

Backports commit 2decfc95583dc28add69810eaca6ada7b4b44d3a from qemu
2019-03-13 11:21:04 -04:00
Richard Henderson fcb49bb6f6
decodetree: Prefix extract function names with decode_function
This makes it easier to name Formats within multiple decode files.

Backports commit 71ecf79bf40db20237a3cfc01cc407cc4cad8817 from qemu
2019-03-13 11:20:26 -04:00
Richard Henderson 1f57e9bedc
decodetree: Allow +- to begin a number initializing a field
Backports commit 263ac638a76a72841e3f513b14c515680703e084 from qemu
2019-03-13 11:19:56 -04:00
Richard Henderson e18e116ce5
decodetree: Produce clean output for an empty input file
This is interesting for bisection, where an output file is plumbed,
but does not yet have patterns.

Backports commit 82bfac1c06cadeb5c7252734dc695d951185916c from qemu
2019-03-13 11:19:22 -04:00
Richard Henderson 190ee1657b
decodetree: Add --static-decode option
Like --decode, but do not drop 'static' qualifier.

Backports commit cd3e7fc18db43b296f413814cd4b72bcd6878bc4 from qemu
2019-03-13 11:18:43 -04:00
Richard Henderson c8514cc538
decodetree: Allow grouping of overlapping patterns
Backports commit 0eff2df4a2ce677230119440f7eb057acffad5eb from qemu
2019-03-13 11:17:48 -04:00
Richard Henderson 0c1b2a5d5a
decodetree: Do not unconditionaly return from Pattern.output_code
As a consequence, the 'return false' gets pushed up one level.

This will allow us to perform some other action when the
translator returns failure.

Backports commit eb6b87fac70dd62e3f1286703db20c012e7a9611 from qemu
2019-03-13 11:13:48 -04:00
Philippe Mathieu-Daudé edb21478b7
decodetree: Ensure build_tree does not include values outside insnmask
Reproduced with "scripts/decodetree.py /dev/null".

Backports commit 9b3186e38f00ae0cba36c096e3654f916699f336 from qemu
2019-03-13 11:12:24 -04:00
Paolo Bonzini 54c93c5198
decodetree: re.fullmatch was added in 3.4
Python 3 versions earlier than 3.4 do not have it, use the
same workaround that is in place for 3.0.

Backports commit 651514df88fd53d537b3b78a7548663cc0816b1b from qemu
2019-01-25 13:47:47 -05:00
Richard Henderson 800c9db9c9
decodetree: Allow multiple input files
While it would be possible to concatenate input files with make,
passing the original input files to decodetree.py allows us to
generate error messages which allows compilation environments
(read: emacs) to next-error to the correct input file.

Backports commit 6699ae6a8e74381583622502db8bd47fac381c9e from qemu
2018-11-11 08:28:55 -05:00
Richard Henderson 4d49c004e4
decodetree: Remove insn argument from trans_* expanders
This allows trans_* expanders to be shared between decoders
for 32 and 16-bit insns, by not tying the expander to the
size of the insn that produced it.

This change requires adjusting the two existing users to match.

Backports commit 3a7be5546506be62d5c6c4b804119cedf9e367d6 from qemu
2018-11-11 08:27:01 -05:00
Richard Henderson 36a718c062
decodetree: Add !extern flag to argument sets
Allow argument sets to be shared between two decoders by avoiding
a re-declaration error. Make sure that anonymous argument sets
and anonymous formats have unique names.

Backports commit abd04f9290094f4eb7f3c07335766bbac3de22bb from qemu
2018-11-11 08:21:20 -05:00
Cleber Rosa 7c94b86d31
scripts/decodetree.py: remove unused imports
Backports commit b25ab557c666ad666c8acbb27fd1b57244505fed from qemu
2018-11-11 07:34:19 -05:00
Cleber Rosa 40a33d2542
scripts/decodetree.py: fix reference to attributes
Backports commit cbcdf1a951aa605c43dc80a98a8cc366299e378c from qemu
2018-11-11 07:33:30 -05:00
Richard Henderson 49def4bbde
target/arm: Add SVE decode skeleton
Including only 4, as-yet unimplemented, instruction patterns
so that the whole thing compiles.

Backports commit 38388f7ee3adc04a7e7246c04352451c4f8d00fb from qemu
2018-05-20 00:48:14 -04:00