This patch eliminates the gen-py-const.awk variant of gen-as-const,
switching to use of gnu-as-const.py (with a new --python option) to
process .pysym files (i.e., to generate nptl_lock_constants.py), as
the syntax of those files is identical to that of .sym files.
Note that the generated nptl_lock_constants.py is *not* identical to
the version generated by the awk script. Apart from the trivial
changes (comment referencing the new script, and output being sorted),
the constant FUTEX_WAITERS, PTHREAD_MUTEXATTR_FLAG_BITS,
PTHREAD_MUTEXATTR_FLAG_PSHARED and PTHREAD_MUTEX_PRIO_CEILING_MASK are
now output as positive rather than negative constants (on x86_64
anyway; maybe not necessarily on 32-bit systems):
< FUTEX_WAITERS = -2147483648
---
> FUTEX_WAITERS = 2147483648
< PTHREAD_MUTEXATTR_FLAG_BITS = -251662336
< PTHREAD_MUTEXATTR_FLAG_PSHARED = -2147483648
---
> PTHREAD_MUTEXATTR_FLAG_BITS = 4043304960
> PTHREAD_MUTEXATTR_FLAG_PSHARED = 2147483648
< PTHREAD_MUTEX_PRIO_CEILING_MASK = -524288
---
> PTHREAD_MUTEX_PRIO_CEILING_MASK = 4294443008
This is because gen-as-const has a cast of the constant value to long
int, which gen-py-const lacks.
I think the positive values are more logically correct, since the
constants in question are in fact unsigned in C. But to reliably
produce gen-as-const.py output for constants that always (in C and
Python) reflects the signedness of values with the high bit of "long
int" set would mean more complicated logic needs to be used in
computing values.
The more correct positive values by themselves produce a failure of
nptl/test-mutexattr-printers, because masking with
~PTHREAD_MUTEXATTR_FLAG_BITS & ~PTHREAD_MUTEX_NO_ELISION_NP now leaves
a bit -1 << 32 in the Python value, resulting in a KeyError exception.
To avoid that, places masking with ~ of one of the constants in
question are changed to mask with 0xffffffff as well (this reflects
how ~ in Python applies to an infinite-precision integer whereas ~ in
C does not do any promotions beyond the width of int).
Tested for x86_64.
* scripts/gen-as-const.py (main): Handle --python option.
* scripts/gen-py-const.awk: Remove.
* Makerules (py-const-script): Use gen-as-const.py.
($(py-const)): Likewise.
* nptl/nptl-printers.py (MutexPrinter.read_status_no_robust): Mask
with 0xffffffff together with ~(PTHREAD_MUTEX_PRIO_CEILING_MASK).
(MutexAttributesPrinter.read_values): Mask with 0xffffffff
together with ~PTHREAD_MUTEXATTR_FLAG_BITS and
~PTHREAD_MUTEX_NO_ELISION_NP.
* manual/README.pretty-printers: Update reference to
gen-py-const.awk.
Joseph Myers
Zack Weinberg