For a very long time we have used 'uname -s' as our fallback if
we don't identify the target OS using a compiler #define. This
obviously doesn't work for cross-compilation, and we've had
a comment suggesting we fix this in configure for a long time.
Since we now have an exhaustive list of which OSes we can run
on (thanks to commit 898be3e0415 making an unrecognized OS
be a fatal error), we know which ones we're missing.
Add check_define tests for the remaining OSes we support. The
defines checked are based on ones we already use in the codebase for
identifying the host OS (with the exception of GNU/kFreeBSD).
We can now set bogus_os immediately rather than doing it later.
We leave the comment about uname being bad untouched, since
there is still a use of it for the fallback for unrecognized
host CPU type.
Backports commit 951fedfceeda1b09ac8aa1f5263288b65e13caca from qemu
Currently if the user's compiler works for creating .o files but
their linker is broken such that compiling an executable from a
C file does not work, we will report a misleading error message
about the compiler not supporting __thread (since that happens
to be the first test we run which requires a working linker).
Explicitly check that compile_prog works as well as compile_object,
so that people whose toolchain setup is broken get a more helpful
error message.
Backports commit 0ef74c7496fd3c526b2259f86326eca4b3a03b78 from qemu
The change in commit 898be3e0415c6d which made completely
unrecognized OSes cause an error_exit "Unsupported host OS"
has some unfortunate unintended effects:
* if you run 'configure --help' on an unsupported host OS
(eg if intending to use it as a build machine for a
cross compile to a supported host) then the message
is printed instead of --help
* if the C compiler doesn't work or is missing (eg if
you passed an incorrect --cross-prefix by mistake)
the message is printed instead of the more useful
'compiler does not exist or does not work' message
Fix this by postponing the error_exit in this situation
until later, when we have already identified the more
useful cases for this.
The long term fix for this would be to move handling
of --help much further up in the configure script,
and make its output not dependent on checks that configure
runs. However for 2.9 this would be too invasive.
Backports commit fb59dabd4fa7e6586824ac3012073b943fc8dc79 from qemu
We plan to drop support in a future QEMU release for host OSes
and host architectures for which we have no test machine where
we can build and run tests. For the 2.9 release, make configure
print a warning if it is run on such a host, so that the user
has some warning of the plans and can volunteer to help us
maintain the port if they need it to continue to function.
This commit flags up as deprecated the CPU architectures:
* ia64
* sparc
* anything which we don't have a TCG port for
(and which was presumably using TCI)
and the OSes:
* GNU/kFreeBSD
* DragonFly BSD
* NetBSD
* OpenBSD
* Solaris
* AIX
* Haiku
It also makes entirely unrecognized host OS strings be
rejected rather than treated as if they were Linux (which
likely never worked).
Backports commit 898be3e0415c6d614395c087ef1e91210797cda7 from qemu
Solaris 9 was released in 2002, its successor Solaris 10 was
released in 2005, and Solaris 9 was end-of-lifed in 2014.
Nobody has stepped forward to express interest in supporting
Solaris of any flavour, so removing support for the ancient
versions seems uncontroversial.
In particular, this allows us to remove a use of 'uname'
in configure that won't work if you're cross-compiling.
Backports commit 91939262ffcd3c85ea6a4793d3029326eea1d649 from qemu
Clang 3.9 passes the CONFIG_AVX2_OPT configure test. However, the
supplied <cpuid.h> does not contain the bit_AVX2 define that we use
when detecting whether the routine can be enabled.
Introduce a qemu-specific header that uses the compiler's definition
of __cpuid et al, but supplies any missing bit_* definitions needed.
This avoids introducing any extra ifdefs to util/bufferiszero.c, and
allows quite a few to be removed from tcg/i386/tcg-target.inc.c.
Backports commit 5dd8990841a9e331d9d4838a116291698208cbb6 from qemu
We dropped support for ia64 host CPUs in the 2.11 release (removing
the TCG backend for it, and advertising the support as being
completely removed in the changelog). However there are a few bits
and pieces of code still floating about. Remove those, too.
We can drop the check in configure for "ia64 or hppa host?"
entirely, because we don't support hppa hosts either any more.
Backports commit b1cef6d02f84bd842fb94a6109ad4e2ad873e8e5 from qemu
Since 218bb57dd79d6843e0592c30a82ea8c1fddc74a5, the -fsanitize=address
check fails with:
config-temp/qemu-conf.c:3:20: error: integer overflow in expression [-Werror=overflow]
return INT32_MIN / -1;
Interestingly, UBSAN check doesn't produce a compile time warning.
Use a test that doesn't have compile time warnings, and make it
specific to UBSAN check.
Backports commit b9f44da2f2cdc1a1a1be5aed0c46bd7fcc69cf4a from qemu
Check for the presence of posix_memalign() in the configure script,
not using "defined(_POSIX_C_SOURCE) && !defined(__sun__)". This
lets qemu use posix_memalign() on NetBSD versions that have it,
instead of falling back to valloc() which is wasteful when the
required alignment is smaller than a page.
Backports commit 9bc5a7193fb422ee53187601eba577ee5d195522 from qemu
Typical slowdown introduced by AddressSanitizer is 2x.
UBSan shouldn't have much impact on runtime cost.
Enable it by default when --enable-debug, unless --disable-sanitizers.
Backports commit 247724cb302af5d70c8853154b640dfabf2bbb56 from qemu
GCC 4.9 and newer stopped warning for missing braces around the
"universal" C zero initializer {0}. One such initializer sneaked
into scsi/qemu-pr-helper.c and is breaking the build with such
older GCC versions.
Detect the lack of support for the idiom, and disable the warning
in that case.
Backports commit 20bc94a2b8449b7700b6bfa25a87ce2320a1c649 from qemu
Nobody has mentioned AIX host support on the mailing list for years,
and we have no test systems for it so it is most likely broken.
We've advertised in configure for two releases now that we plan
to drop support for this host OS, and have had no complaints.
Drop the AIX host support code.
We can also drop the now-unused AIX version of sys_cache_info().
Note that the _CALL_AIX define used in the PPC tcg backend is
also used for Linux PPC64, and so that code should not be removed.
Backports commit 7872375219c03682bda3f6191fa5f6a58238ed36 from qemu
This warning is included in -Wall by clang, but not by GCC (which only
enables it for -Wextra). Include it in the list of warnings we enable
to minimize the differences between the compilers:
Backports commit b98fcfd8840f290c406c32301340e96f00238a93 from qemu
This lets you build without TCG (hardware accelerationor qtest only). When
this flag is passed to configure, it will automatically filter out the target
list to only those that support KVM or Xen or HAX.
Backports commit b3f6ea7e55e8228d6f84d5cee7cb11cae917ba95 from qemu
The Cygwin target is really compiling for native Win32 with -mno-cygwin.
Except, GCC 4.7.0 has finally removed the long deprecated -mno-cygwin
option, and that happened about five years ago.
Let it rest in peace.
Backports commit c8645752ce31cc044ecc5f969a986fdcb6aab590 from qemu
This enables the multi-threaded system emulation by default for ARMv7
and ARMv8 guests using the x86_64 TCG backend. This is because on the
guest side:
- The ARM translate.c/translate-64.c have been converted to
- use MTTCG safe atomic primitives
- emit the appropriate barrier ops
- The ARM machine has been updated to
- hold the BQL when modifying shared cross-vCPU state
- defer powerctl changes to async safe work
All the host backends support the barrier and atomic primitives but
need to provide same-or-better support for normal load/store
operations.
Backports commit ca759f9e387db87e1719911f019bc60c74be9ed8 from qemu
Allow qemu to build on 32-bit hosts without 64-bit atomic ops.
Even if we only allow 32-bit hosts to multi-thread emulate 32-bit
guests, we still need some way to handle the 32-bit guest using a
64-bit atomic operation. Do so by dropping back to single-step.
Backports commit df79b996a7b21c6ea7847f7927a2e1a294b86c72 from qemu
Force the use of cmpxchg16b on x86_64.
Wikipedia suggests that only very old AMD64 (circa 2004) did not have
this instruction. Further, it's required by Windows 8 so no new cpus
will ever omit it.
If we truely care about these, then we could check this at startup time
and then avoid executing paths that use it.
Backports commit 7ebee43ee3e2fcd7b5063058b7ef74bc43216733 from qemu
QEMU's code relies on left shifts of signed integers always
being defined behaviour with the obvious 2s-complement
semantics. The only way to tell the compiler (and any
associated undefined-behaviour sanitizer) that we require a
C dialect with these semantics is to use the -fwrapv option.
This is a bit of a heavy hammer for the job as it also gives
us guaranteed semantics on integer arithmetic overflow which
in theory we don't require.
In an ideal world this would allow us to drop the warning
flag -Wno-shift-negative-value, but we must retain this to
avoid spurious warnings on clang versions predating the
fix to https://llvm.org/bugs/show_bug.cgi?id=25552.
Backports commit 2d31515bc0880a1cea86ce638d2a109f4f4e6f7d from qemu
MinGW seems to compile currently without warnings, so it should
be safe to enable -Werror now for this environment, too.
Backports commit e4650c81b3d15ba67236815defbb475c4bdf8690 from qemu
This fixes these warnings from shellcheck:
^-- SC2006: Use $(..) instead of deprecated `..`
Backports commit 89138857619b2a023c32200e9af780792ccaa8c3 from qemu
