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d1a1d841db
I'm about to add fields to virStorageFileMetadata, which means
also adding fields to the testFileData struct in virstoragetest.
Alas, adding even one pointer on an x86_64 machine gave me a
dreaded compiler error:
virstoragetest.c:712:1: error: the frame size of 4208 bytes is larger than 4096 bytes [-Werror=frame-larger-than=]
After some experimentation, I realized that each test was creating
yet another testChainData (which contains testFileData) on the stack;
forcing the reuse of one of these structures instead of creating a
fresh one each time drastically reduces the size requirements. While
at it, I also got rid of a lot of intermediate structs, with some
macro magic that lets me directly build up the destination chains
inline.
For a bit more insight into what this patch does:
The old code uses an intermediate variable as a fixed-size array
of structs:
testFileData chain[] = { a, b };
data.files = chain;
In the new code, the use of VIR_FLATTEN_* allows the TEST_CHAIN()
macro to still take a single argument for each chain, but now of
the form '(a, b)', where it is turned into the var-args 'a, b'
multiple arguments understood by TEST_ONE_CHAIN(). Thus, the
new code avoids an intermediate variable, and directly provides
the list of pointers to be assigned into array elements:
data.files = { &a, &b };
* tests/virstoragetest.c (mymain): Rewrite TEST_ONE_CHAIN to
reuse the same struct for each test, and to take the data
inline rather than via intermediate variables.
(testChainData): Use bounded array of pointers instead of
unlimited array of struct.
(testStorageChain): Reflect struct change.
Signed-off-by: Eric Blake <eblake@redhat.com>
LibVirt : simple API for virtualization
Libvirt is a C toolkit to interact with the virtualization capabilities
of recent versions of Linux (and other OSes). It is free software
available under the GNU Lesser General Public License. Virtualization of
the Linux Operating System means the ability to run multiple instances of
Operating Systems concurrently on a single hardware system where the basic
resources are driven by a Linux instance. The library aim at providing
long term stable C API initially for the Xen paravirtualization but
should be able to integrate other virtualization mechanisms if needed.
Daniel Veillard <veillard@redhat.com>