Weak symbols were a nice idea, but they turned out not to be a good one.
Toolchain support is just too sparse, in particular llvm-gcc is totally
broken.
This patch uses a surprisingly low-tech approach: a static library.
Symbols in a static library are always overridden by symbols in an
object file. Furthermore, if you place each function in a separate
source file, object files for unused functions will not be taken in.
This means that each function can use all the dependencies that it needs
(especially QAPI stuff such as error_setg).
Thus, all stubs are placed in separate object files and put together in
a static library. The library then is linked to all programs.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Weakrefs only tell you if the symbol was defined elsewhere, so you
need a further check at runtime to pick the default definition
when needed.
This could be automated by the compiler, but it does not do it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
GLib 2.0 include files use __printf__ for the format attribute
which resolves to native format strings on w32 hosts.
QEMU wants standard format strings instead of native format
strings, so we simply change any declaration with __printf__
to use __gnu_printf__.
This works because all basic printf functions support both
kinds of format strings.
This fixes a compiler warning:
qapi/string-output-visitor.c: In function ‘print_type_int’:
qapi/string-output-visitor.c:34:5: warning: unknown conversion type character ‘l’ in format [-Wformat]
qapi/string-output-visitor.c:34:5: warning: too many arguments for format [-Wformat-extra-args]
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
mingw32 seems to want the declaration to also carry the weak attribute.
Strangely, gcc on Linux absolutely does not want the declaration to be marked
as weak. This may not be the right fix, but it seems to do the trick.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This lets us provide a default implementation of a symbol which targets can
override.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
On some platforms, __LINE__ will not expand to real number in QEMU_BUILD_BUG_ON,
so if using QEMU_BUILD_BUG_ON twice, compiler will report errors. This patch will
fix it.
BTW, I got error message on RHEL 6.1/gcc 4.4.5.
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The code which tests whether gcc supports warn_unused_result was wrong.
Remove the wrong test from configure and replace it by code using
macro QEMU_GNUC_PREREQ in compiler.h.
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
The macro is compiler specific and does not depend on the operating system.
Move macro QEMU_GNUC_PREREQ from osdep.h to compiler.h
and use it to simplify existing code.
host-utils.h uses this macro, so it now needs compiler.h
instead of osdep.h.
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
A packed struct needs different gcc attributes for compilations
with MinGW compilers because glib-2.0 adds compiler flag
-mms-bitfields which modifies the packing algorithm.
Attribute gcc_struct reverses the negative effects of -mms-bitfields.
QEMU_PACKED sets this attribute and must be used for any packed
struct which is affected by -mms-bitfields.
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This moves compiler related macros from qemu-common.h to compiler.h.
The reason for this change is that there are simple header files that
depend only on the compiler macros, so including qemu-common.h is overkill.
Besides, qemu-common.h is bloated and will benefit from some splitting.
Please, also note that the QEMU_BUILD_BUG_ON() macro is being fixed to
not use double underscores as a prefix and the license text was added
by Vassili Karpov (malc), who is one of the authors of the new file.
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
