While we have successfully implemented a funclet-oriented EH scheme on
top of LLVM IR, our scheme has some notable deficiencies:
- catchendpad and cleanupendpad are necessary in the current design
but they are difficult to explain to others, even to seasoned LLVM
experts.
- catchendpad and cleanupendpad are optimization barriers. They cannot
be split and force all potentially throwing call-sites to be invokes.
This has a noticable effect on the quality of our code generation.
- catchpad, while similar in some aspects to invoke, is fairly awkward.
It is unsplittable, starts a funclet, and has control flow to other
funclets.
- The nesting relationship between funclets is currently a property of
control flow edges. Because of this, we are forced to carefully
analyze the flow graph to see if there might potentially exist illegal
nesting among funclets. While we have logic to clone funclets when
they are illegally nested, it would be nicer if we had a
representation which forbade them upfront.
Let's clean this up a bit by doing the following:
- Instead, make catchpad more like cleanuppad and landingpad: no control
flow, just a bunch of simple operands; catchpad would be splittable.
- Introduce catchswitch, a control flow instruction designed to model
the constraints of funclet oriented EH.
- Make funclet scoping explicit by having funclet instructions consume
the token produced by the funclet which contains them.
- Remove catchendpad and cleanupendpad. Their presence can be inferred
implicitly using coloring information.
N.B. The state numbering code for the CLR has been updated but the
veracity of it's output cannot be spoken for. An expert should take a
look to make sure the results are reasonable.
Reviewers: rnk, JosephTremoulet, andrew.w.kaylor
Differential Revision: http://reviews.llvm.org/D15139
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255422 91177308-0d34-0410-b5e6-96231b3b80d8
It's strange to duplicate the logic for emitting FP values into
emitGlobalConstantDataSequential, and it's even stranger that we end
up printing the verbose assembly comments differently between the two
paths. Just call into emitGlobalConstantFP rather than crudely
duplicating its logic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254988 91177308-0d34-0410-b5e6-96231b3b80d8
CFI emits jump slots for indirect functions as a byte array
constant, and declares function-typed aliases to these constants.
This change fixes AsmPrinter to emit these aliases as function
symbols and not data symbols.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254674 91177308-0d34-0410-b5e6-96231b3b80d8
If a section is rw, it is irrelevant if the dynamic linker will write to
it or not.
It looks like llvm implemented this because gcc was doing it. It looks
like gcc implemented this in the hope that it would put all the
relocated items close together and speed up the dynamic linker.
There are two problem with this:
* It doesn't work. Both bfd and gold will map .data.rel to .data and
concatenate the input sections in the order they are seen.
* If we want a feature like that, it can be implemented directly in the
linker since it knowns where the dynamic relocations are.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253436 91177308-0d34-0410-b5e6-96231b3b80d8
While still allowing CodeGen/AsmPrinter in llvm to own them using a bump
ptr allocator. (might be nice to replace the pointers there with
something that at least automatically calls their dtors, if that's
necessary/useful, rather than having it done explicitly (I think a typed
BumpPtrAllocator already does this, or maybe a unique_ptr with a custom
deleter, etc))
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253409 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Now that there is a one-to-one mapping from MachineFunction to
WinEHFuncInfo, we don't need to use a DenseMap to select the right
WinEHFuncInfo for the current funclet.
The main challenge here is that X86WinEHStatePass is an IR pass that
doesn't have access to the MachineFunction. I gave it its own
WinEHFuncInfo object that it uses to calculate state numbers, which it
then throws away. As long as nobody creates or removes EH pads between
this pass and SDAG construction, we will get the same state numbers.
The other thing X86WinEHStatePass does is to mark the EH registration
node. Instead of communicating which alloca was the registration through
WinEHFuncInfo, I added the llvm.x86.seh.ehregnode intrinsic. This
intrinsic generates no code and simply marks the alloca in use.
Reviewers: JCTremoulet
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14668
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253378 91177308-0d34-0410-b5e6-96231b3b80d8
Several places in AsmPrinter.cpp print comments describing MachineOperand
registers using MCRegisterInfo, which uses MCOperand-oriented names. This
doesn't work for targets that use virtual registers exclusively, as
WebAssembly does, since virtual registers are represented and printed
differently.
This patch preserves what seems to be the spirit of r229978, avoiding the
use of TM.getSubtargetImpl(), while still using MachineOperand-oriented
printing for MachineOperands.
Differential Revision: http://reviews.llvm.org/D14709
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253338 91177308-0d34-0410-b5e6-96231b3b80d8
The way prelink used to work was
* The compiler decides if a given section only has relocations that
are know to point to the same DSO. If so, it names it
.data.rel.ro.local<something>.
* The static linker puts all of these together.
* The prelinker program assigns addresses to each library and resolves
the local relocations.
There are many problems with this:
* It is incompatible with address space randomization.
* The information passed by the compiler is redundant. The linker
knows if a given relocation is in the same DSO or not. If could sort
by that if so desired.
* There are newer ways of speeding up DSO (gnu hash for example).
* Even if we want to implement this again in the compiler, the previous
implementation is pretty broken. It talks about relocations that are
"resolved by the static linker". If they are resolved, there are none
left for the prelinker. What one needs to track is if an expression
will require only dynamic relocations that point to the same DSO.
At this point it looks like the prelinker is an historical curiosity.
For example, fedora has retired it because it failed to build for two
releases
(http://pkgs.fedoraproject.org/cgit/prelink.git/commit/?id=eb43100a8331d91c801ee3dcdb0a0bb9babfdc1f)
This patch removes support for it. That is, it stops printing the
".local" sections.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253280 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Since we're passing references to dbg.value as pointers,
we need to have the frontend properly declare their sizes and
alignments (as it already does for regular pointers) in preparation
for my upcoming patch to have the verifer check that the sizes agree.
Also augment the backend logic that skips actually emitting this
information into DWARF such that it also handles reference types.
Reviewers: aprantl, dexonsmith, dblaikie
Subscribers: dblaikie, llvm-commits
Differential Revision: http://reviews.llvm.org/D14275
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253186 91177308-0d34-0410-b5e6-96231b3b80d8
MCRelaxableFragment previously kept a copy of MCSubtargetInfo and
MCInst to enable re-encoding the MCInst later during relaxation. A copy
of MCSubtargetInfo (instead of a reference or pointer) was needed
because the feature bits could be modified by the parser.
This commit replaces the MCSubtargetInfo copy in MCRelaxableFragment
with a constant reference to MCSubtargetInfo. The copies of
MCSubtargetInfo are kept in MCContext, and the target parsers are now
responsible for asking MCContext to provide a copy whenever the feature
bits of MCSubtargetInfo have to be toggled.
With this patch, I saw a 4% reduction in peak memory usage when I
compiled verify-uselistorder.lto.bc using llc.
rdar://problem/21736951
Differential Revision: http://reviews.llvm.org/D14346
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253127 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Inlined callsites need to be emitted in debug info so that sample profile can be annotated to the correct inlined instance.
Reviewers: dnovillo, dblaikie
Subscribers: dblaikie, llvm-commits
Differential Revision: http://reviews.llvm.org/D14511
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252768 91177308-0d34-0410-b5e6-96231b3b80d8
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.
For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.
This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.
Since this is an IR change, a bitcode upgrade has been provided.
Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.
Differential Revision: http://reviews.llvm.org/D14265
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252219 91177308-0d34-0410-b5e6-96231b3b80d8
We already had a test for this for 32-bit SEH catchpads, but those don't
actually create funclets. We had a bug that only appeared in funclet
prologues, where we would establish EBP and ESI as our FP and BP, and
then downstream prologue code would overwrite them.
While I was at it, I fixed Win64+funclets+stackrealign. This issue
doesn't come up as often there due to the ABI requring 16 byte stack
alignment, but now we can rest easy that AVX and WinEH will work well
together =P.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252210 91177308-0d34-0410-b5e6-96231b3b80d8
When push instructions are being used to pass function arguments on
the stack, and either EH or debugging are enabled, we need to generate
.cfi_adjust_cfa_offset directives appropriately. For (synch) EH, it is
enough for the CFA offset to be correct at every call site, while
for debugging we want to be correct after every push.
Darwin does not support this well, so don't use pushes whenever it
would be required.
Differential Revision: http://reviews.llvm.org/D13767
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251904 91177308-0d34-0410-b5e6-96231b3b80d8
These MachO file directives are used by linkers and other tools to provide
compatibility information, much like the existing .ios_version_min and
.macosx_version_min.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251569 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This ensures that BranchFolding (and similar) won't remove these blocks.
Also allow AsmPrinter::EmitBasicBlockStart to process MBBs which are
address-taken but do not have BBs that are address-taken, since otherwise
its call to getAddrLabelSymbolTableToEmit would fail an assertion on such
blocks. I audited the other callers of getAddrLabelSymbolTableToEmit
(and getAddrLabelSymbol); they all have BBs known to be address-taken
except for the call through getAddrLabelSymbol from
WinException::create32bitRef; that call is actually now unreachable, so
I've removed it and updated the signature of create32bitRef.
This fixes PR25168.
Reviewers: majnemer, andrew.w.kaylor, rnk
Subscribers: pgavlin, llvm-commits
Differential Revision: http://reviews.llvm.org/D13774
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251113 91177308-0d34-0410-b5e6-96231b3b80d8
Our previous value of "16 + 8 + MaxCallFrameSize" for ParentFrameOffset
is incorrect when CSRs are involved. We were supposed to have a test
case to catch this, but it wasn't very rigorous.
The main effect here is that calling _CxxThrowException inside a
catchpad doesn't immediately crash on MOVAPS when you have an odd number
of CSRs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250583 91177308-0d34-0410-b5e6-96231b3b80d8
When building with modules the forward-declared inner class
DebugLocStream::ListBuilder causes clang to fall over.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250459 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Emit the handler and clause locations immediately after the standard
xdata.
Clauses are emitted in the same order and format used to communiate them
to the CLR Execution Engine.
Add a lit test to verify correct table generation on a small but
interesting example function.
Reviewers: majnemer, andrew.w.kaylor, rnk
Subscribers: pgavlin, AndyAyers, llvm-commits
Differential Revision: http://reviews.llvm.org/D13451
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250219 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Add an iterator that can walk across blocks and which visits the state
transitions rather than state ranges, with explicit transitions to -1
indicating the presence of top-level calls that may throw and cause the
current function to unwind to caller. This will simplify code that needs
to identify nested try regions.
Refactor SEH and C++EH table generation to use the new
InvokeStateChangeIterator, and remove the InvokeLabelIterator they were
using.
Reviewers: majnemer, andrew.w.kaylor, rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13623
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250179 91177308-0d34-0410-b5e6-96231b3b80d8
The new implementation works at least as well as the old implementation
did.
Also delete the associated preparation tests. They don't exercise
interesting corner cases of the new implementation. All the codegen
tests of the EH tables have already been ported.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249918 91177308-0d34-0410-b5e6-96231b3b80d8
Also Fix a buglet where SEH tables had ranges that spanned funclets.
The remaining tests using the old landingpad IR are preparation tests,
and will be deleted along with the old preparation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249917 91177308-0d34-0410-b5e6-96231b3b80d8
We got them right for the old IR, but not with funclets. Port the old
test to the new IR and fix the code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249906 91177308-0d34-0410-b5e6-96231b3b80d8
This wasn't very observable in execution tests, because usually there is
an invoke in the catchpad that unwinds the the catchendpad but never
actually throws.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249898 91177308-0d34-0410-b5e6-96231b3b80d8
The relocation for the filter funclet will be against a symbol table
entry for a function instead of the section, making it easier to
understand what is going on.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249621 91177308-0d34-0410-b5e6-96231b3b80d8
The __CxxFrameHandler3 tables for 32-bit are supposed to hold stack
offsets relative to EBP, not ESP. I blindly updated the win-catchpad.ll
test case, and immediately noticed that 32-bit catching stopped working.
While I'm at it, move the frame index to frame offset WinEH table logic
out of PEI. PEI shouldn't have to know about WinEHFuncInfo. I realized
we can calculate frame index offsets just fine from the table printer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249618 91177308-0d34-0410-b5e6-96231b3b80d8
There was an off-by-one bug in ip2state tables which manifested when one
call immediately preceded the try-range of the next. The return address
of the previous call would appear to be within the try range of the next
scope, resulting in extra destructors or catches running.
We also computed the wrong offset for catch parameter stack objects. The
offset should be from RSP, not from RBP.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249578 91177308-0d34-0410-b5e6-96231b3b80d8
When outgoing function arguments are passed using push instructions, and EH
is enabled, we may need to indicate to the stack unwinder that the stack
pointer was adjusted before the call.
This should fix the exception handling issues in PR24792.
Differential Revision: http://reviews.llvm.org/D13132
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249522 91177308-0d34-0410-b5e6-96231b3b80d8
This is handy for some AutoFDO stuff, and seems like a minor improvement
to correctness (otherwise a debug info consumer might think the decl
line/file of the def was the same as that of the declaration - though
what a consumer might use that for, I'm not sure - maybe "list <func>"
would've misbehaved with the old behavior?) and at a minor cost (in my
experiment, with fission, without type units, without compression, 0.01%
growth in debug info in the executable/objects, 0.02% growth in the .dwo
files).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249487 91177308-0d34-0410-b5e6-96231b3b80d8
Call the correct overload so a string literal does not get converted to a bool.
Also fix the test case to match the names given.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249183 91177308-0d34-0410-b5e6-96231b3b80d8
We emit denormalized tables, where every range of invokes in the same
state gets a complete list of EH action entries. This is significantly
simpler than trying to infer the correct nested scoping structure from
the MI. Fortunately, for SEH, the nesting structure is really just a
size optimization.
With this, some basic __try / __except examples work.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249078 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Funclets have been turned into functions by the time they hit the object
file. Make sure that they have decent names for the symbol table and
CFI directives explaining how to reason about their prologues.
Differential Revision: http://reviews.llvm.org/D13261
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248824 91177308-0d34-0410-b5e6-96231b3b80d8
