In C, we'll wait until the end of the scope to clean up aggregate
temporaries used for returns from calls. This means in cases like:
{
// Assuming that `Bar` is large enough to warrant indirect returns
struct Bar b = {};
b = foo(&b);
b = foo(&b);
b = foo(&b);
b = foo(&b);
}
...We'll allocate space for 5 Bars on the stack (`b`, and 4
temporaries). This becomes painful in things like large switch
statements.
If cleaning up sooner is trivial, we should do it.
llvm-svn: 327229
Simplify the dispatching for the personality routines. This really had
no test coverage previously, so add test coverage for the various cases.
This turns out to be pretty complicated as the various languages and
models interact to change personalities around.
You really should feel bad for the compiler if you are using exceptions.
There is no reason for this type of cruelty.
llvm-svn: 327105
EmitLifetimeStart returns a non-null `size` pointer if it actually
emits a lifetime.start. Later in this function, we use `tempSize`'s
nullness to determine whether or not we should emit a lifetime.end.
llvm-svn: 326844
Summary:
The _get_ssp intrinsic can be used to retrieve the
shadow stack pointer, independent of the current arch -- in
contract with the rdsspd and the rdsspq intrinsics.
Also, this intrinsic returns zero on CPUs which don't
support CET. The rdssp[d|q] instruction is decoded as nop,
essentially just returning the input operand, which is zero.
Example result of compilation:
```
xorl %eax, %eax
movl %eax, %ecx
rdsspq %rcx # NOP when CET is not supported
movq %rcx, %rax # return zero
```
Reviewers: craig.topper
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D43814
llvm-svn: 326689
Summary:
Currently only calls to mcount were suppressed with
no_instrument_function attribute.
Linux kernel requires that calls to fentry should also not be
generated.
This is an extended fix for PR PR33515.
Reviewers: hfinkel, rengolin, srhines, rnk, rsmith, rjmccall, hans
Reviewed By: rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D43995
llvm-svn: 326639
Make types with sizes that aren't a power of two an error (that can
be disabled) in structs with ms_struct layout, except on mingw where
the situation is quite likely to occur and GCC handles it silently.
Differential Revision: https://reviews.llvm.org/D43908
llvm-svn: 326476
When targeting GNU/MinGW for i386, the size of the "long double" data
type is 12 bytes (while it is 8 bytes in MSVC). When building
with -mms-bitfields to have struct layouts match MSVC, data types
are laid out in a struct with alignment according to their size.
However, this doesn't make sense for the long double type, since
it doesn't match MSVC at all, and aligning to a non-power-of-2
size triggers other asserts later.
This matches what GCC does, aligning a long double to 4 bytes
in structs on i386 even when -mms-bitfields is specified.
This fixes asserts when using the max_align_t data type when
building for MinGW/i386 with the -mms-bitfields flag.
Differential Revision: https://reviews.llvm.org/D43734
llvm-svn: 326173
In DWARF v5 the Line Number Program Header is extensible, allowing values with
new content types. This vendor extension to DWARF v5 allows source text to be
embedded directly in the line tables of the debug line section.
Add new flag (-g[no-]embed-source) to Driver and CC1 which indicates
that source should be passed through to LLVM during CodeGen.
Differential Revision: https://reviews.llvm.org/D42766
llvm-svn: 326102
Summary:
If the flag -fforce-enable-int128 is passed, it will enable support for __int128_t and __uint128_t types.
This flag can then be used to build compiler-rt for RISCV32.
Reviewers: asb, kito-cheng, apazos, efriedma
Reviewed By: asb, efriedma
Subscribers: shiva0217, efriedma, jfb, dschuff, sdardis, sbc100, jgravelle-google, aheejin, rbar, johnrusso, simoncook, jordy.potman.lists, sabuasal, niosHD, cfe-commits
Differential Revision: https://reviews.llvm.org/D43105
llvm-svn: 326045
The tests that failed on a windows host have been fixed.
Original message:
Start setting dso_local for COFF.
With this there are still some GVs where we don't set dso_local
because setGVProperties is never called. I intend to fix that in
followup commits. This is just the bare minimum to teach
shouldAssumeDSOLocal what it should do for COFF.
llvm-svn: 325940
With this there are still some GVs where we don't set dso_local
because setGVProperties is never called. I intend to fix that in
followup commits. This is just the bare minimum to teach
shouldAssumeDSOLocal what it should do for COFF.
llvm-svn: 325915
This test was previously in lldb, and was only checking that clang
was emitting the correct section. So, it belongs here and not
in the debugger.
llvm-svn: 325850
This patch fixes creating TBAA access descriptors for
may_alias-marked access types. Currently, for such types we
generate ordinary descriptors with char as its access type. The
patch changes this to produce proper may-alias descriptors.
Differential Revision: https://reviews.llvm.org/D42366
llvm-svn: 325575
Currently, clang compiles explicit initializers for array
elements into series of store instructions. For large arrays of
built-in types this results in bloated output code and
significant amount of time spent on the instruction selection
phase. This patch fixes the issue by initializing such arrays
with global constants that store the binary image of the
initializer.
Differential Revision: https://reviews.llvm.org/D43181
llvm-svn: 325478
Summary:
Make clang accept `-msahf` (and `-mno-sahf`) flags to activate the
`+sahf` feature for the backend, for bug 36028 (Incorrect use of
pushf/popf enables/disables interrupts on amd64 kernels). This was
originally submitted in bug 36037 by Jonathan Looney
<jonlooney@gmail.com>.
As described there, GCC also uses `-msahf` for this feature, and the
backend already recognizes the `+sahf` feature. All that is needed is to
teach clang to pass this on to the backend.
The mapping of feature support onto CPUs may not be complete; rather, it
was chosen to match LLVM's idea of which CPUs support this feature (see
lib/Target/X86/X86.td).
I also updated the affected test case (CodeGen/attr-target-x86.c) to
match the emitted output.
Reviewers: craig.topper, coby, efriedma, rsmith
Reviewed By: craig.topper
Subscribers: emaste, cfe-commits
Differential Revision: https://reviews.llvm.org/D43394
llvm-svn: 325446
Summary:
Gold plugin does not add pass to ThinLTO modules without useful symbols.
In this case ThinLTO can't create corresponding index file and some features, like CFI,
cannot be processes by backed correctly without index.
Given that we don't need the backed output we can request it to avoid
processing the module. This is implemented by this patch using new
"SkipModuleByDistributedBackend" flag.
Reviewers: pcc, tejohnson
Subscribers: mehdi_amini, inglorion, eraman, cfe-commits
Differential Revision: https://reviews.llvm.org/D42995
llvm-svn: 325411
Summary:
ThinLTO compilation may decide not to split module and keep at as regular LTO.
In this can this module already processed during indexing and already a part of
merged object file. So here we can just skip it.
Reviewers: pcc, tejohnson
Reviewed By: tejohnson
Subscribers: mehdi_amini, inglorion, eraman, cfe-commits
Differential Revision: https://reviews.llvm.org/D42680
llvm-svn: 325410
This adds Sema and Codegen tests for the vcvtr builtins
(because they were missing).
Differential Revision: https://reviews.llvm.org/D43372
llvm-svn: 325351
Summary:
TypeID summaries are used by CFI and need to be serialized by ThinLTO
indexing for later use by LTO Backend.
Reviewers: tejohnson, pcc
Subscribers: mehdi_amini, inglorion, eraman, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D42611
llvm-svn: 325182
Added support in clang for GCC function attribute 'artificial'. This attribute
is used to control stepping behavior of debugger with respect to inline
functions.
Patch By: Elizabeth Andrews (eandrews)
Differential Revision: https://reviews.llvm.org/D43259
llvm-svn: 325081
Summary:
This patch also adds the 'DW_AT_artificial' flag to the generated variable.
Addresses the issues mentioned in http://llvm.org/PR30553.
Reviewers: CarlosAlbertoEnciso, probinson, aprantl
Reviewed By: aprantl
Subscribers: JDevlieghere, cfe-commits
Differential Revision: https://reviews.llvm.org/D43189
llvm-svn: 324988
As reported here: https://bugs.llvm.org/show_bug.cgi?id=36301
The issue is that the 'use' causes the plain declaration to emit
the attributes to LLVM-IR. However, if the definition added it
later, these would silently disappear.
This commit extracts that logic to its own function in CodeGenModule,
and has the attribute-applications done during 'definition' update
the attributes properly.
Differential Revision: https://reviews.llvm.org/D43095
llvm-svn: 324907
Summary:
Right now clang is skipping array cookie poisoning for any operator
new[] which is not part of the set of replaceable global allocation
functions.
This commit adds a flag to tell clang to poison all operator new[]
cookies.
A previous review was poisoning all array cookies unconditionally, but
there is an edge case which would stop working under ASan (a custom
operator new[] saves whatever pointer it returned, and then accesses
it).
This newer revision adds a command line argument to toggle this feature.
Original revision: https://reviews.llvm.org/D41301
Compiler-rt test revision with an explanation of the edge case: https://reviews.llvm.org/D41664
Reviewers: rjmccall, kcc, rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D43013
llvm-svn: 324884
Summary:
This change avoids the overhead of storing, and later crawling,
an initializer list of all zeros for arrays. When LLVM
visits this (llvm/IR/Constants.cpp) ConstantArray::getImpl()
it will scan the list looking for an array of all zero.
We can avoid the store, and short-cut the scan, by detecting
all zeros when clang builds-up the initialization representation.
This was brought to my attention when investigating PR36030
Reviewers: majnemer, rjmccall
Reviewed By: rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D42549
llvm-svn: 324776
Reid Kleckner