| Message ID | 20190809154153.31763-2-richard.henderson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | decodetree improvements | expand |
On Fri, 9 Aug 2019 at 16:41, Richard Henderson <richard.henderson@linaro.org> wrote: > > Call this form a "parameter", returning a value extracted > from the DisasContext. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > docs/devel/decodetree.rst | 8 ++++- > scripts/decodetree.py | 54 ++++++++++++++++++++++++------- > tests/decode/err_field6.decode | 5 +++ > tests/decode/succ_function.decode | 6 ++++ > 4 files changed, 60 insertions(+), 13 deletions(-) > create mode 100644 tests/decode/err_field6.decode > create mode 100644 tests/decode/succ_function.decode > > diff --git a/docs/devel/decodetree.rst b/docs/devel/decodetree.rst > index 44ac621ea8..ce7f52308f 100644 > --- a/docs/devel/decodetree.rst > +++ b/docs/devel/decodetree.rst > @@ -23,7 +23,7 @@ Fields > > Syntax:: > > - field_def := '%' identifier ( unnamed_field )+ ( !function=identifier )? > + field_def := '%' identifier ( unnamed_field )* ( !function=identifier )? > unnamed_field := number ':' ( 's' ) number > > For *unnamed_field*, the first number is the least-significant bit position > @@ -34,6 +34,12 @@ present, they are concatenated. In this way one can define disjoint fields. > If ``!function`` is specified, the concatenated result is passed through the > named function, taking and returning an integral value. > > +One may use ``!function`` with zero ``unnamed_fields``. This case is called > +a *parameter*, and the named function is only passed the ``DisasContext`` > +and returns an integral value extracted from there. > + > +A field with no ``unnamed_fields`` and no ``!function`` is in error. > + > FIXME: the fields of the structure into which this result will be stored > is restricted to ``int``. Which means that we cannot expand 64-bit items. > > diff --git a/scripts/decodetree.py b/scripts/decodetree.py > index d7a59d63ac..a2490aeb74 100755 > --- a/scripts/decodetree.py > +++ b/scripts/decodetree.py > @@ -195,7 +195,10 @@ class MultiField: > """Class representing a compound instruction field""" > def __init__(self, subs, mask): > self.subs = subs > - self.sign = subs[0].sign > + if len(subs): > + self.sign = subs[0].sign > + else: > + self.sign = 0 > self.mask = mask > > def __str__(self): Is this change to MultiField left over from the previous implementation ? I was expecting a zero-length MultiField to now be a bug in this python script (ie we should never try to create one). > @@ -245,7 +248,7 @@ class ConstField: > > > class FunctionField: > - """Class representing a field passed through an expander""" > + """Class representing a field passed through a function""" > def __init__(self, func, base): > self.mask = base.mask > self.sign = base.sign > @@ -266,6 +269,27 @@ class FunctionField: > # end FunctionField > > > +class ParameterField: > + """Class representing a psuedo-field read from a function""" "pseudo" > + def __init__(self, func): > + self.mask = 0 > + self.sign = 0 > + self.func = func > + > + def __str__(self): > + return self.func > + > + def str_extract(self): > + return self.func + '(ctx)' > + > + def __eq__(self, other): > + return self.func == other.func > + > + def __ne__(self, other): > + return not self.__eq__(other) > +# end FunctionField > thanks -- PMM
On 8/9/19 8:52 AM, Peter Maydell wrote: >> @@ -195,7 +195,10 @@ class MultiField: >> """Class representing a compound instruction field""" >> def __init__(self, subs, mask): >> self.subs = subs >> - self.sign = subs[0].sign >> + if len(subs): >> + self.sign = subs[0].sign >> + else: >> + self.sign = 0 >> self.mask = mask >> >> def __str__(self): > Is this change to MultiField left over from the previous > implementation ? I was expecting a zero-length MultiField > to now be a bug in this python script (ie we should never > try to create one). > Oops, yes. The error is emitted here: > + if len(subs) == 0: > + if func: > + f = ParameterField(func) > + else: > + error(lineno, 'field with no value') and tested: > +++ b/tests/decode/err_field6.decode > @@ -0,0 +1,5 @@ > +# This work is licensed under the terms of the GNU LGPL, version 2 or later. > +# See the COPYING.LIB file in the top-level directory. > + > +# Diagnose no bits in field > +%field
diff --git a/docs/devel/decodetree.rst b/docs/devel/decodetree.rst index 44ac621ea8..ce7f52308f 100644 --- a/docs/devel/decodetree.rst +++ b/docs/devel/decodetree.rst @@ -23,7 +23,7 @@ Fields Syntax:: - field_def := '%' identifier ( unnamed_field )+ ( !function=identifier )? + field_def := '%' identifier ( unnamed_field )* ( !function=identifier )? unnamed_field := number ':' ( 's' ) number For *unnamed_field*, the first number is the least-significant bit position @@ -34,6 +34,12 @@ present, they are concatenated. In this way one can define disjoint fields. If ``!function`` is specified, the concatenated result is passed through the named function, taking and returning an integral value. +One may use ``!function`` with zero ``unnamed_fields``. This case is called +a *parameter*, and the named function is only passed the ``DisasContext`` +and returns an integral value extracted from there. + +A field with no ``unnamed_fields`` and no ``!function`` is in error. + FIXME: the fields of the structure into which this result will be stored is restricted to ``int``. Which means that we cannot expand 64-bit items. diff --git a/scripts/decodetree.py b/scripts/decodetree.py index d7a59d63ac..a2490aeb74 100755 --- a/scripts/decodetree.py +++ b/scripts/decodetree.py @@ -195,7 +195,10 @@ class MultiField: """Class representing a compound instruction field""" def __init__(self, subs, mask): self.subs = subs - self.sign = subs[0].sign + if len(subs): + self.sign = subs[0].sign + else: + self.sign = 0 self.mask = mask def __str__(self): @@ -245,7 +248,7 @@ class ConstField: class FunctionField: - """Class representing a field passed through an expander""" + """Class representing a field passed through a function""" def __init__(self, func, base): self.mask = base.mask self.sign = base.sign @@ -266,6 +269,27 @@ class FunctionField: # end FunctionField +class ParameterField: + """Class representing a psuedo-field read from a function""" + def __init__(self, func): + self.mask = 0 + self.sign = 0 + self.func = func + + def __str__(self): + return self.func + + def str_extract(self): + return self.func + '(ctx)' + + def __eq__(self, other): + return self.func == other.func + + def __ne__(self, other): + return not self.__eq__(other) +# end FunctionField + + class Arguments: """Class representing the extracted fields of a format""" def __init__(self, nm, flds, extern): @@ -433,17 +457,23 @@ def parse_field(lineno, name, toks): if width > insnwidth: error(lineno, 'field too large') - if len(subs) == 1: - f = subs[0] + if len(subs) == 0: + if func: + f = ParameterField(func) + else: + error(lineno, 'field with no value') else: - mask = 0 - for s in subs: - if mask & s.mask: - error(lineno, 'field components overlap') - mask |= s.mask - f = MultiField(subs, mask) - if func: - f = FunctionField(func, f) + if len(subs) == 1: + f = subs[0] + else: + mask = 0 + for s in subs: + if mask & s.mask: + error(lineno, 'field components overlap') + mask |= s.mask + f = MultiField(subs, mask) + if func: + f = FunctionField(func, f) if name in fields: error(lineno, 'duplicate field', name) diff --git a/tests/decode/err_field6.decode b/tests/decode/err_field6.decode new file mode 100644 index 0000000000..a719884572 --- /dev/null +++ b/tests/decode/err_field6.decode @@ -0,0 +1,5 @@ +# This work is licensed under the terms of the GNU LGPL, version 2 or later. +# See the COPYING.LIB file in the top-level directory. + +# Diagnose no bits in field +%field diff --git a/tests/decode/succ_function.decode b/tests/decode/succ_function.decode new file mode 100644 index 0000000000..7751b1784e --- /dev/null +++ b/tests/decode/succ_function.decode @@ -0,0 +1,6 @@ +# This work is licensed under the terms of the GNU LGPL, version 2 or later. +# See the COPYING.LIB file in the top-level directory. + +# "Field" as parameter pulled from DisasContext. +%foo !function=foo +foo 00000000000000000000000000000000 %foo
Call this form a "parameter", returning a value extracted from the DisasContext. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- docs/devel/decodetree.rst | 8 ++++- scripts/decodetree.py | 54 ++++++++++++++++++++++++------- tests/decode/err_field6.decode | 5 +++ tests/decode/succ_function.decode | 6 ++++ 4 files changed, 60 insertions(+), 13 deletions(-) create mode 100644 tests/decode/err_field6.decode create mode 100644 tests/decode/succ_function.decode -- 2.17.1