r291503, "Lift the 10-type limit for AlignedCharArrayUnion"
r291514, "Fix MSVC build of AlignedCharArrayUnion"
r291515, "Revert the attempt to optimize the constexpr functions. MSVC does not handle this yet"
r291519, "Try once again to fix the MSVC build of AlignedCharArrayUnion"
They has been failing on i686-linux.
llvm-svn: 291875
This patch uses C++11 parameter packs and constexpr functions
to allow AlignedCharArrayUnion to hold an arbitrary number of
types.
Differential Revision: https://reviews.llvm.org/D28429
llvm-svn: 291503
On i386 alignof(double) = 8 is not the same as alignof(struct { double
}) = 4. This used to be not an issue because the old implementation
always measured alignment inside of structs. Wrap a dummy struct around
the test to avoid this issue.
llvm-svn: 284812
Also clean up the legacy hacks for AlignedCharArray. I'm keeping
LLVM_ALIGNAS alive for a bit longer because GCC 4.8.0 (which we still
support apparently) shipped a buggy alignas(). All other supported
compilers have a working alignas.
llvm-svn: 284736
This is necessary to use them as part of pointer traits and is generally
useful. I've added unit test coverage to isolate and ensure this works
correctly.
I'll watch the build bots to try to see if any compilers can't tolerate
this bit of magic (and much credit goes to Richard Smith for coming up
with this magical production!) but give a shout if you see issues.
llvm-svn: 256553
The patch is generated using clang-tidy misc-use-override check.
This command was used:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py \
-checks='-*,misc-use-override' -header-filter='llvm|clang' \
-j=32 -fix -format
http://reviews.llvm.org/D8925
llvm-svn: 234679
We wrap __attribute((aligned)) for GCC 4.7 and __declspec(align) for
MSVC. The latter behaves weird in some contexts so this should be used
carefully.
llvm-svn: 233910
test. Do that after we suppress the warnings for unknown pragmas as this
warning flag is quite new in Clang and so old Clang's would warn all the
time on this file.
llvm-svn: 226444
This adds AlignedCharArray<Alignment, Size>. A templated struct that contains
a member named buffer of type char[Size] that is aligned to Alignment.
llvm-svn: 171319
platforms.
Also, remove one assertion on MSVC because it produces a completely
preposterous result, claiming something needs 12-byte alignment.
llvm-svn: 158599
array of a suitable size and alignment for any of a number of different
types to be stored into the character array.
The mechanisms for producing an explicitly aligned type are fairly
complex because this operation is poorly supported on all compilers.
We've spent a fairly significant amount of time experimenting with
different implementations inside of Google, and the one using explicitly
expanded templates has been the most robust.
Credit goes to Nick Lewycky for writing the first 20 versions or so of
this logic we had inside of Google. I based this on the only one to
actually survive. In case anyone is worried, yes we are both explicitly
re-contributing and re-licensing it for LLVM. =]
Once the issues with actually specifying the alignment are finished, it
turns out that most compilers don't in turn align anything the way they
are instructed. Testing of this logic against both Clang and GCC
indicate that the alignment constraints are largely ignored by both
compilers! I've come up with and used a work-around by wrapping each
alignment-hinted type directly in a struct, and using that struct to
align the character array through a union. This elaborate hackery is
terrifying, but I've included testing that caught a terrifying number of
bugs in every other technique I've tried.
All of this in order to implement a poor C++98 programmers emulation of
C++11 unrestricted unions in classes such as SmallDenseMap.
llvm-svn: 158597
NAKAMURA Takumi