This change also removes the preprocessor-based function renaming.
It also applied to tests in resolv/, which ended up running against
the historic functions.
_endhtent was not part of the ABI because it is not listed in the
resolv/Versions file.
TS 18661-1 defines *fromfp* functions, which are declared in math.h
and whose return types are intmax_t and uintmax_t, without allowing
math.h to define those typedefs. (This is similar to e.g. ISO C
declaring vprintf in stdio.h without allowing that header to define
va_list.) Thus, math.h needs to access those typedefs under internal
names.
This patch accordingly arranges for bits/types.h (which defines only
internal names, not public *_t typedefs) to define __intmax_t and
__uintmax_t. stdint.h is made to use bits/types.h and define intmax_t
and uintmax_t using __intmax_t and __uintmax_t, to avoid duplication
of information. (It would be reasonable to define more of the types
in stdint.h - and in sys/types.h, where it duplicates such types -
using information already available in bits/types.h.) The idea is
that the subsequent addition of fromfp functions would then make
math.h include bits/types.h and use __intmax_t and __uintmax_t as the
return types of those functions.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* bits/types.h (__intmax_t): New typedef.
(__uintmax_t): Likewise.
* sysdeps/generic/stdint.h: Include <bits/types.h>.
(intmax_t): Define using __intmax_t.
(uintmax_t): Define using __uintmax_t.
The support/tst-support_record_failure-2.out test attempts to run
built code even if run-built-tests = no, so failing with
build-many-glibcs.py for all architectures whose code cannot be run on
the system running the script. This patch disables the test in that
case.
Tested for x86_64 (native), and for aarch64 with build-many-glibcs.py.
* support/Makefile (tests-special): Make definition conditional on
[$(run-built-tests) = yes].
($(objpfx)tst-support_record_failure-2.out): Make rule conditional
on [$(run-built-tests) = yes].
Both regexes end with a "*." which means the previous match can be
omitted, and then the . allows them to match any input at all.
This means tools like coreutils' `rm -i` will always delete things
when prompted because the yesexpr regex matches all inputs (even
the negative ones).
In my change to add configure tests for python I had a brainfart where
I tried to filter out unsupported tests from tests-printers-programs
instead of tests-printers to select tests to build. I realize now
that all of that is completely unnecessary and it would be safe to
just build the tests as long as we don't try to run it.
This patch reverts that bit of the change. Tested with
run-built-tests = no in config.make.
* Rules (tests): Add tests-printers-programs to tests to be
built.
This patch adds a simple SYSV shared memory test to check for correct
argument passing on kernel. The idea is neither to be an extensive
testing nor to check for any specific Linux test.
* sysvipc/Makefile (tests): Add test-sysvshm.
* sysvipc/test-sysvshm.c: New file.
this patch add a direct call to shmget syscall if it is supported by
kernel features.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (shmget): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (shmget): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (shmget): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (shmget): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (shmget): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (shmget): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (shmget):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (shmget):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (shmget): Likewise.
* sysdeps/unix/sysv/linux/shmget.c (shmget): Use shmget syscall if it
is defined.
this patch add a direct call to shmdt syscall if it is supported by
kernel features.
hecked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (shmdt): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (shmdt): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (shmdt): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (shmdt): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (shmdt): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (shmdt): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (shmdt):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (shmdt):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (shmdt): Likewise.
* sysdeps/unix/sysv/linux/shmdt.c (shmdt): Use shmdt syscall if it is
defined.
This patch consolidates the shmctl Linux implementation in only
one default file, sysdeps/unix/sysv/linux/shmctl.c. If tries to use
the direct syscall if it is supported, otherwise will use the old ipc
multiplex mechanism.
The patch also simplify header inclusion and reorganize internal
compat symbol to be built only if old ipc is defined.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/Makefile (sysdeps_routines): Remove
oldshmctl.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (shmctl): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (shmctl): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (shmctl): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (shmctl): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (shmctl): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (shmctl): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (shmctl):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (shmctl):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (shmctl): Likewise.
* sysdeps/unix/sysv/linux/alpha/shmctl.c: Remove file.
* sysdeps/unix/sysv/linux/arm/shmctl.c: Likewise.
* sysdeps/unix/sysv/linux/microblaze/shmctl.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/shmctl.c: Use default
implementation.
* sysdeps/unix/sysv/linux/shmctl.c (__new_shmctl): Use shmctl syscall
if it is defined.
This patch adds a simple SYSV semaphore test to check for correct
argument passing on kernel. The idea is neither to be an extensive
testing nor to check for any specific Linux test.
* sysvipc/Makefile (tests): Add test-sysvsem.
* sysvipc/test-sysvsem.c: New file.
This patch consolidates the semtimedop Linux implementation in only
one default file, sysdeps/unix/sysv/linux/semtimedop.c. If tries to use
the direct syscall if it is supported, otherwise will use the old ipc
multiplex mechanism.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (semtimedop): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (semtimedop): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (semtimedop):
Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (semtimedop): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (semtimedop): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (semtimedop):
Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (semtimedop):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (semtimedop): Likewise.
* sysdeps/unix/sysv/linux/m68k/semtimedop.S: Remove file.
* sysdeps/unix/sysv/linux/s390/semtimedop.c: Reorganize headers and
add a comment about s390 syscall difference from default one.
* sysdeps/unix/sysv/linux/semtimedop.c (semtimedop): Use semtimedop
syscall if it is defined.
This patch add a direct call to semop syscall if it is supported by
kernel headers.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (semop): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (semop): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (semop): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (semop): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (semop): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (semop): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (semop):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (semop):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (semop): Likewise.
* sysdeps/unix/sysv/linux/semop.c (semop): Use semop syscall if it is
defined.
This patch add a direct call to semget syscall if it is supported by
kernel features.
hecked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (semget): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (semget): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (semget): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (semget): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (semget): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (semget): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (semget):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (semget):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (semget): Likewise.
* sysdeps/unix/sysv/linux/semget.c (semget): Use semget syscall
if it is defined.
This patch consolidates the semctl Linux implementation in only
one default file, sysdeps/unix/sysv/linux/semctl.c. If tries to use
the direct syscall if it is supported, otherwise will use the old ipc
multiplex mechanism.
The patch also simplify header inclusion and reorganize internal
compat symbol to be built only if old ipc is defined.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/Makefile (sysdeps_routines): Remove
oldsemctl.
* sysdeps/unix/sysv/linux/alpha/semctl.c: Remove file.
* sysdeps/unix/sysv/linux/arm/semctl.c: Likewise.
* sysdeps/unix/sysv/linux/microblaze/semctl.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/semctl.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/semctl.c: Use defaulf
implementation.
* sysdeps/unix/sysv/linux/semctl.c (__new_semctl): Use semctl
syscall if it is defined.
* sysdeps/unix/sysv/linux/generic/syscalls.list (semctl): Remove.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (semctl): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (semctl): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (semctl): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (semctl):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (semctl): Likewise.
This patch adds a simple SYSV message queue test to check for correct
argument passing on kernel. The idea is neither to be an extensive
testing nor to check for any specific Linux test.
* sysvipc/Makefile (tests): Add test-sysvmsg.
* sysvipc/test-sysvmsg.c: New file.
* test-skeleton.c (FAIL_UNSUPPORTED): New define.
This patch consolidates the msgrcv Linux implementation in only
one default file, sysdeps/unix/sysv/linux/msgrcv.c. If tries to use
the direct syscall if it is supported, otherwise will use the old ipc
multiplex mechanism.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (msgctl): Remove.
* sysdeps/unix/sysv/linux/arm/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/generic/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (msgctl):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (msgctl): Likewise,
* sysdeps/unix/sysv/linux/mips/mips64/syscalls.list (msgctl):
Likewise.
* sysdeps/unix/sysv/linux/msgrcv.c (__libc_msgrcv): Use msgrcv syscall
if defined.
* sysdeps/unix/sysv/linux/sparc/sparc64/msgrcv.c: Remove file.
This patch consolidates the msgctl Linux implementation in only
one default file, sysdeps/unix/sysv/linux/msgctl.c. If tries to use
the direct syscall if it is supported, otherwise will use the old ipc
multiplex mechanism.
The patch also simplify header inclusion and reorganize internal
compat symbol to be built only if old ipc is defined.
Checked on x86_64, i686, powerpc64le, aarch64, and armhf.
* sysdeps/unix/sysv/linux/alpha/Makefile (sysdeps_routines): Remove
oldmsgctl.
* sysdeps/unix/sysv/linux/alpha/msgctl.c: Remove file.
* sysdeps/unix/sysv/linux/arm/msgctl.c: Likewise.
* sysdeps/unix/sysv/linux/microblaze/msgctl.c: Likewise.
* sysdeps/unix/sysv/linux/alpha/syscalls.list (oldmsgctl): Remove.
* sysdeps/unix/sysv/linux/generic/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/ia64/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list (msgctl):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/syscalls.list (msgctl): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/msgctl.c: Use default
implementation.
* sysdeps/unix/sysv/linux/msgctl.c (__new_msgctl): Use msgctl syscall
if defined.
Some architectures support the old-style IPC and require IPC_64 equal to
0x100 to be passed along SysV IPC syscalls, while new architectures should
default to new IPC version (without the flags being set).
This patch refactor current ipc_priv.h Linux headers in two directions:
- Remove cross platform references (for instance alpha including powerpc
definition) and add required definition for each required port. The
idea is to avoid tie one architecture definition with another and make
platform change independent.
- Move all common definitions (the ipc syscall commands) on a common
header, ipc_ops.h.
* sysdeps/unix/sysv/linux/aarch64/ipc_priv.h: New file.
* sysdeps/unix/sysv/linux/alpha/ipc_priv.h: Avoid included other arch
definition and define its own.
* sysdeps/unix/sysv/linux/ipc_ops.h: New file.
* sysdeps/unix/sysv/linux/x86_64/ipc_priv.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/ipc_priv.h: Likewise.
* sysdeps/unix/sysv/linux/mips/ipc_priv.h: Remove file.
* sysdeps/unix/sysv/linux/mips/mips64/ipc_priv.h: New file.
* sysdeps/unix/sysv/linux/ipc_priv.h: Move ipc syscall operation
definitions to common header.
* sysdeps/unix/sysv/linux/powerpc/ipc_priv.h: Use common syscall
operation from ipc_ops.h.
On current minimum supported kernels, the SysV IPC on Linux is provided
by either the ipc syscalls or correspondent wire syscalls. Also, for
architectures that supports wire syscalls all syscalls are supported
in a set (msgct, msgrcv, msgsnd, msgget, semctl, semget, semop, semtimedop,
shmctl, shmat, shmget, shmdt).
The architectures that only supports ipc syscall are:
- i386, m68k, microblaze, mips32, powerpc (powerpc32, powerpc64, and
powerpc64le), s390 (32 and 64 bits), sh, sparc32, and sparc64.
And the architectures that only supports wired syscalls are:
- aarch64, alpha, hppa, ia64, mips64, mips64n32, nios2, tile
(tilepro, tilegx, and tilegx64), and x86_64
Also arm is the only one that supports both wire syscalls and the
ipc, although the ipc one is deprecated.
This patch adds a new define, __ASSUME_DIRECT_SYSVIPC_SYSCALL, that wired
syscalls are supported on the system and the general idea is to use
it where possible.
I also checked the syscall table for all architectures on Linux 4.9
and there is no change on described support for Linux 2.6.32/3.2.
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): New define.
* sysdeps/unix/sysv/linux/i386/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Undef.
* sysdeps/unix/sysv/linux/m68k/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/mips/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/powerpc/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/s390/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/sh/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Likewise.
* sysdeps/unix/sysv/linux/sparc/kernel-features.h
(__ASSUME_DIRECT_SYSVIPC_SYSCALL): Likewise.
The same error fixed in commit b224637928
happens in the 32-bit implementation of memchr for power7.
This patch adopts the same solution, with a minimal change: it
implements a saturated addition where overflows sets the maximum pointer
size to UINTPTR_MAX.
The P7 code is used for <=32B strings and for > 32B vectorized loops are used.
This shows as an average 25% improvement depending on the position of search
character. The performance is same for shorter strings.
Tested on ppc64 and ppc64le.
The new functions support_record_failure records a test failure,
but does not terminate the process. The macros TEST_VERIFY
and TEST_VERIFY_EXIT check that a condition is true.
Current optimized memchr for x86_64 does for input arguments pointers
module 64 in range of [49,63] if there is no searchr char in the rest
of 64-byte block a pointer addition which might overflow:
* sysdeps/x86_64/memchr.S
77 .p2align 4
78 L(unaligned_no_match):
79 add %rcx, %rdx
Add (uintptr_t)s % 16 to n in %rdx.
80 sub $16, %rdx
81 jbe L(return_null)
This patch fixes by adding a saturated math that sets a maximum pointer
value if it overflows (UINTPTR_MAX).
Checked on x86_64-linux-gnu and powerpc64-linux-gnu.
[BZ# 19387]
* sysdeps/x86_64/memchr.S (memchr): Avoid overflow in pointer
addition.
* string/test-memchr.c (do_test): Remove alignment limitation.
(test_main): Add test that trigger BZ# 19387.
These are called from the kernel with the stack at a carefully-
chosen location so that the stack frame can be restored: they must not
move the stack pointer lest garbage be restored into the registers.
We explicitly inhibit protection for SPARC and for signal/sigreturn.c:
other arches either define their sigreturn stubs in .S files, or (i386,
x86_64, mips) use macros expanding to top-level asm blocks and explicit
labels in the text section to mock up a "function" without telling the
compiler that one is there at all.
Add a hidden __stack_chk_fail_local alias to libc.so,
and make sure that on targets which use __stack_chk_fail,
this does not introduce a local PLT reference into libc.so.
With all the machinery we just added, we can easily arrange to work even
when the compiler passes in -fstack-protector automatically: all the
necessary bits of glibc are always compiled with -fno-stack-protector
now.
So tear out the check in configure, and add appropriate calls to
-fno-stack-protector in tests that need them (largely those that use
-nostdlib), since we don't yet have a __stack_chk_fail that those
tests can rely upon. (GCC often provides one, but we cannot rely on
this, especially not when bootstrapping.)
When stack protection is disabled, explicitly pass -fno-stack-protector
to everything, to stop a compiler hacked to enable it from inserting
calls to __stack_chk_fail via the PLT in every object file.
The previous commit prevented rtld itself from being built with
-fstack-protector, but this is not quite enough. We identify which
objects belong in rtld via a test link and analysis of the resulting
mapfile. That link is necessarily done against objects that are
stack-protected, so drags in __stack_chk_fail_local, __stack_chk_fail,
and all the libc and libio code they use.
To stop this happening, use --defsym in the test librtld.map-production
link to force the linker to predefine these two symbols (to 0, but it
could be to anything). (In a real link, this would of course be
catastrophic, but these object files are never used for anything else.)
The startup code in csu/, and the brk and sbrk functions are
needed very early in initialization of a statically-linked program,
before the stack guard is initialized; TLS initialization also uses
memcpy, which cannot overrun its own stack. Mark all of these as
-fno-stack-protector.
We also finally introduce @libc_cv_ssp@ and @no_stack_protector@, both
substituted by the configury changes made earlier, to detect the case
when -fno-stack-protector is supported by the compiler, and
unconditionally pass it in when this is the case, whether or not
--enable-stack-protector is passed to configure. (This means that
it'll even work when the compiler's been hacked to pass
-fstack-protector by default, unless the hackage is so broken that
it does so in a way that is impossible to override.)
When dynamically linking, ifunc resolvers are called before TLS is
initialized, so they cannot be safely stack-protected.
We avoid disabling stack-protection on large numbers of files by
using __attribute__ ((__optimize__ ("-fno-stack-protector")))
to turn it off just for the resolvers themselves. (We provide
the attribute even when statically linking, because we will later
use it elsewhere too.)
The address of the stack canary is stored in a per-thread variable,
which means that we must ensure that the TLS area is intialized before
calling any -fstack-protector'ed functions. For dynamically linked
applications, we ensure this (in a later patch) by disabling
-fstack-protector for the whole dynamic linker, but for static
applications, the AT_ENTRY address is called directly by the kernel, so
we must deal with the problem differently.
In static appliations, __libc_setup_tls performs the TCB setup and TLS
initialization, so this commit arranges for it to be called early and
unconditionally. The call (and the stack guard initialization) is
before the DL_SYSDEP_OSCHECK hook, which if set will probably call
functions which are stack-protected (it does on Linux and NaCL too). We
also move apply_irel up, so that we can still safely call functions that
require ifuncs while in __libc_setup_tls (though if stack-protection is
enabled we still have to avoid calling functions that are not
stack-protected at this stage).
This adds =all and =strong, with obvious semantics, defaulting to off.
We don't validate the value of the option yet: that's in a later patch.
Nor do we use it for anything at this stage.
We differentiate between 'the compiler understands -fstack-protector'
and 'the user wanted -fstack-protector' so that we can pass
-fno-stack-protector in appropriate places even if the user didn't want
to turn on -fstack-protector for other parts. (This helps us overcome
another existing limitation, that glibc doesn't work with GCCs hacked
to pass in -fstack-protector by default.)
We also arrange to set the STACK_PROTECTOR_LEVEL #define to a value
appropriate for the stack-protection level in use for each file in
particular.
The value of CPPFLAGS provided by the environment may have optimizations
that interfere with the pretty printer test requirements. To override
such optimizations the pretty printer tests must also specify CPPFLAGS.
The existing pretty printer tests are fixed and the
README.pretty-printers is updated with the new requirement.