Turns out that the Fission/Split DWARF package format (DWP) is currently
insufficient to handle cross-CU (ref_addr) references. So for now,
duplicate any debug info needed in these situations:
* inlined_subroutine's abstract_origin
* inlined variable's abstract_origin
* types
Keep the ref_addr behavior in general, including in the split DWARF
inline debug info that can be emitted into the object files for online
symbolication.
Keep a flag to use the old (ref_addr) behavior for testing ways of
addressing this limitation in the DWP tool (& for those not using DWP
packaging).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302858 91177308-0d34-0410-b5e6-96231b3b80d8
Since Split DWARF needs to name the actual .dwo file that is generated,
it can't be known at the time the llvm::Module is produced as it may be
merged with other Modules before the object is generated and that object
may be generated with any name.
By passing the Split DWARF file name when LLVM is producing object code
the .dwo file name in the object file can match correctly.
The support for Split DWARF for implicit modules remains the same -
using metadata to store the dwo name and dwo id so that potentially
multiple skeleton CUs referring to different dwo files can be generated
from one llvm::Module.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301062 91177308-0d34-0410-b5e6-96231b3b80d8
- introduced in r300522 and found via the Swift LLDB testsuite.
The fix is to set the location kind to memory whenever an FrameIndex
location is emitted.
rdar://problem/31707602
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300793 91177308-0d34-0410-b5e6-96231b3b80d8
- introduced in r300522 and found via the Swift LLDB testsuite.
The fix is to set the location kind to memory whenever an FrameIndex
location is emitted.
rdar://problem/31707602
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300790 91177308-0d34-0410-b5e6-96231b3b80d8
The DWARF specification knows 3 kinds of non-empty simple location
descriptions:
1. Register location descriptions
- describe a variable in a register
- consist of only a DW_OP_reg
2. Memory location descriptions
- describe the address of a variable
3. Implicit location descriptions
- describe the value of a variable
- end with DW_OP_stack_value & friends
The existing DwarfExpression code is pretty much ignorant of these
restrictions. This used to not matter because we only emitted very
short expressions that we happened to get right by accident. This
patch makes DwarfExpression aware of the rules defined by the DWARF
standard and now chooses the right kind of location description for
each expression being emitted.
This would have been an NFC commit (for the existing testsuite) if not
for the way that clang describes captured block variables. Based on
how the previous code in LLVM emitted locations, DW_OP_deref
operations that should have come at the end of the expression are put
at its beginning. Fixing this means changing the semantics of
DIExpression, so this patch bumps the version number of DIExpression
and implements a bitcode upgrade.
There are two major changes in this patch:
I had to fix the semantics of dbg.declare for describing function
arguments. After this patch a dbg.declare always takes the *address*
of a variable as the first argument, even if the argument is not an
alloca.
When lowering a DBG_VALUE, the decision of whether to emit a register
location description or a memory location description depends on the
MachineLocation — register machine locations may get promoted to
memory locations based on their DIExpression. (Future) optimization
passes that want to salvage implicit debug location for variables may
do so by appending a DW_OP_stack_value. For example:
DBG_VALUE, [RBP-8] --> DW_OP_fbreg -8
DBG_VALUE, RAX --> DW_OP_reg0 +0
DBG_VALUE, RAX, DIExpression(DW_OP_deref) --> DW_OP_reg0 +0
All testcases that were modified were regenerated from clang. I also
added source-based testcases for each of these to the debuginfo-tests
repository over the last week to make sure that no synchronized bugs
slip in. The debuginfo-tests compile from source and run the debugger.
https://bugs.llvm.org/show_bug.cgi?id=32382
<rdar://problem/31205000>
Differential Revision: https://reviews.llvm.org/D31439
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300522 91177308-0d34-0410-b5e6-96231b3b80d8
Also add an assertion for the case that there are multiple FI
expressions with a DW_OP_LLVM_fragment; which should violate internal
constraints in DbgVariable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298518 91177308-0d34-0410-b5e6-96231b3b80d8
In doing so, clean up the MD5 interface a little. Most
existing users only care about the lower 8 bytes of an MD5,
but for some users that care about the upper and lower,
there wasn't a good interface. Furthermore, consumers
of the MD5 checksum were required to handle endianness
details on their own, so it seems reasonable to abstract
this into a nicer interface that just gives you the right
value.
Differential Revision: https://reviews.llvm.org/D31105
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298322 91177308-0d34-0410-b5e6-96231b3b80d8
and mark the methods as protected.
Besides reducing the surface area of DwarfExpression, this is in
preparation for an upcoming bugfix in the DwarfExpression
implementation, for which it will be necessary to defer emitting
register operations until the rest of the expression is known.
NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298309 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r242302. External type refs of this form were
never used by any LLVM frontend so this is effectively dead code.
(They were introduced to support clang module debug info, but in the
end we came up with a better design that doesn't use this feature at
all.)
rdar://problem/25897929
Differential Revision: https://reviews.llvm.org/D30917
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297684 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes PR31381, which caused an assertion and/or invalid debug info.
This affects debug variables that have multiple fragments in the MMI
side (i.e.: in the stack frame) table.
rdar://problem/30571676
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295486 91177308-0d34-0410-b5e6-96231b3b80d8
While looking to add support for placing singular types (types that will
only be emitted in one place (such as attached to a strong vtable or
explicit template instantiation definition)) not in type units (since
type units have overhead) I stumbled across that change causing an
increase in pubtypes.
Turns out we were missing some types from type units if they were only
referenced from other type units and not from the debug_info section.
This fixes that, following GCC's line of describing the offset of such
entities as the CU die (since there's no compile unit-relative offset
that would describe such an entity - they aren't in the CU). Also like
GCC, this change prefers to describe the type stub within the CU rather
than the "just use the CU offset" fallback where possible. This may give
the DWARF consumer some opportunity to find the extra info in the type
stub - though I'm not sure GDB does anything with this currently.
The size of the pubnames/pubtypes sections now match exactly with or
without type units enabled.
This nearly triples (+189%) the pubtypes section for a clang self-host
and grows pubnames by 0.07% (without compression). For a total of 8%
increase in debug info sections of the objects of a Split DWARF build
when using type units.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293971 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.
Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:
(1) The DIGlobalVariable should describe the source level variable,
not how to get to its location.
(2) It makes it unsafe/hard to update the expressions when we call
replaceExpression on the DIGLobalVariable.
(3) It makes it impossible to represent a global variable that is in
more than one location (e.g., a variable with multiple
DW_OP_LLVM_fragment-s). We also moved away from attaching the
DIExpression to DILocalVariable for the same reasons.
This reapplies r289902 with additional testcase upgrades and a change
to the Bitcode record for DIGlobalVariable, that makes upgrading the
old format unambiguous also for variables without DIExpressions.
<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290153 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit 289920 (again).
I forgot to implement a Bitcode upgrade for the case where a DIGlobalVariable
has not DIExpression. Unfortunately it is not possible to safely upgrade
these variables without adding a flag to the bitcode record indicating which
version they are.
My plan of record is to roll the planned follow-up patch that adds a
unit: field to DIGlobalVariable into this patch before recomitting.
This way we only need one Bitcode upgrade for both changes (with a
version flag in the bitcode record to safely distinguish the record
formats).
Sorry for the churn!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289982 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.
Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:
(1) The DIGlobalVariable should describe the source level variable,
not how to get to its location.
(2) It makes it unsafe/hard to update the expressions when we call
replaceExpression on the DIGLobalVariable.
(3) It makes it impossible to represent a global variable that is in
more than one location (e.g., a variable with multiple
DW_OP_LLVM_fragment-s). We also moved away from attaching the
DIExpression to DILocalVariable for the same reasons.
This reapplies r289902 with additional testcase upgrades.
<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289920 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.
Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:
(1) The DIGlobalVariable should describe the source level variable,
not how to get to its location.
(2) It makes it unsafe/hard to update the expressions when we call
replaceExpression on the DIGLobalVariable.
(3) It makes it impossible to represent a global variable that is in
more than one location (e.g., a variable with multiple
DW_OP_LLVM_fragment-s). We also moved away from attaching the
DIExpression to DILocalVariable for the same reasons.
<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289902 91177308-0d34-0410-b5e6-96231b3b80d8
This probably ended up this way aften the subprogram<>function link
inversion and debug info metadata schema changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289697 91177308-0d34-0410-b5e6-96231b3b80d8
Follow-up to r289256, address a FIXME to avoid resetting the column
number. This reduced .debug_line by 2.6% in a RelWithDebInfo
self-build of clang.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289620 91177308-0d34-0410-b5e6-96231b3b80d8
DWARF specifies that "line 0" really means "no appropriate source
location" in the line table. By default, use this for branch targets
and some other cases that have no specified source location, to
prevent inheriting unfortunate line numbers from physically preceding
instructions (which might be from completely unrelated source).
Updated patch allows enabling or suppressing this behavior for all
unspecified source locations.
Differential Revision: http://reviews.llvm.org/D24180
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289468 91177308-0d34-0410-b5e6-96231b3b80d8
LLVM's use of DW_OP_bit_piece is incorrect and a based on a
misunderstanding of the wording in the DWARF specification. The offset
argument of DW_OP_bit_piece refers to the offset into the location
that is on the top of the DWARF expression stack, and not an offset
into the source variable. This has since also been clarified in the
DWARF specification.
This patch fixes all uses of DW_OP_bit_piece to emit the correct
offset and simplifies the DwarfExpression class to semi-automaticaly
emit empty DW_OP_pieces to adjust the offset of the source variable,
thus simplifying the code using DwarfExpression.
While this is an incompatible bugfix, in practice I don't expect this
to be much of a problem since LLVM's old interpretation and the
correct interpretation of DW_OP_bit_piece differ only when there are
gaps in the fragmented locations of the described variables or if
individual fragments are smaller than a byte. LLDB at least won't
interpret locations with gaps in them because is has no way to present
undefined bits in a variable, and there is a high probability that an
old-form expression will be malformed when interpreted correctly,
because the DW_OP_bit_piece offset will be outside of the location at
the top of the stack.
As a nice side-effect, this patch enables us to use a more efficient
encoding for subregisters: In order to express a sub-register at a
non-zero offset we now use a DW_OP_bit_piece instead of shifting the
value into place manually.
This patch also adds missing test coverage for code paths that weren't
exercised before.
<rdar://problem/29335809>
Differential Revision: https://reviews.llvm.org/D27550
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289266 91177308-0d34-0410-b5e6-96231b3b80d8
so we can stop using DW_OP_bit_piece with the wrong semantics.
The entire back story can be found here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20161114/405934.html
The gist is that in LLVM we've been misinterpreting DW_OP_bit_piece's
offset field to mean the offset into the source variable rather than
the offset into the location at the top the DWARF expression stack. In
order to be able to fix this in a subsequent patch, this patch
introduces a dedicated DW_OP_LLVM_fragment operation with the
semantics that we used to apply to DW_OP_bit_piece, which is what we
actually need while inside of LLVM. This patch is complete with a
bitcode upgrade for expressions using the old format. It does not yet
fix the DWARF backend to use DW_OP_bit_piece correctly.
Implementation note: We discussed several options for implementing
this, including reserving a dedicated field in DIExpression for the
fragment size and offset, but using an custom operator at the end of
the expression works just fine and is more efficient because we then
only pay for it when we need it.
Differential Revision: https://reviews.llvm.org/D27361
rdar://problem/29335809
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288683 91177308-0d34-0410-b5e6-96231b3b80d8
The DIEUnit class represents a compile or type unit and it owns the unit DIE as an instance variable. This allows anyone with a DIE, to get the unit DIE, and then get back to its DIEUnit without adding any new ivars to the DIE class. Why was this needed? The DIE class has an Offset that is always the CU relative DIE offset, not the "offset in debug info section" as was commented in the header file (the comment has been corrected). This is great for performance because most DIE references are compile unit relative and this means most code that accessed the DIE's offset didn't need to make it into a compile unit relative offset because it already was. When we needed to emit a DW_FORM_ref_addr though, we needed to find the absolute offset of the DIE by finding the DIE's compile/type unit. This class did have the absolute debug info/type offset and could be added to the CU relative offset to compute the absolute offset. With this change we can easily get back to a DIE's DIEUnit which will have this needed offset. Prior to this is required having a DwarfDebug and required calling:
DwarfCompileUnit *DwarfDebug::lookupUnit(const DIE *CU) const;
Now we can use the DIEUnit class to do so without needing DwarfDebug. All clients now use DIEUnit objects (the DwarfDebug stack and the DwarfLinker). A follow on patch for the DWARF generator will also take advantage of this.
Differential Revision: https://reviews.llvm.org/D27170
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288399 91177308-0d34-0410-b5e6-96231b3b80d8
VariableDbgInfo is per function data, so it makes sense to have it with
the function instead of the module.
This is a necessary step to have machine module passes work properly.
Differential Revision: https://reviews.llvm.org/D27186
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288292 91177308-0d34-0410-b5e6-96231b3b80d8
The LLDB tests are now ready for this patch.
DWARF specifies that "line 0" really means "no appropriate source
location" in the line table. Use this for branch targets and some
other cases that have no specified source location, to prevent
inheriting unfortunate line numbers from physically preceding
instructions (which might be from completely unrelated source).
Differential Revision: http://reviews.llvm.org/D24180
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288283 91177308-0d34-0410-b5e6-96231b3b80d8
DWARF specifies that "line 0" really means "no appropriate source
location" in the line table. Use this for branch targets and some
other cases that have no specified source location, to prevent
inheriting unfortunate line numbers from physically preceding
instructions (which might be from completely unrelated source).
Differential Revision: http://reviews.llvm.org/D24180
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288212 91177308-0d34-0410-b5e6-96231b3b80d8
This patch makes AsmPrinter less reliant on DwarfDebug by relying on the DWARF version in the AsmPrinter's MCStreamer's MCContext. This allows us to remove the redundant DWARF version from DwarfDebug. It also lets us change code that used to access the AsmPrinter's DwarfDebug just to get to the DWARF version by changing the DWARF version accessor on AsmPrinter so that it grabs the version from its MCStreamer's MCContext.
Differential Revision: https://reviews.llvm.org/D27032
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287839 91177308-0d34-0410-b5e6-96231b3b80d8
The previously used "names" are rather descriptions (they use multiple
words and contain spaces), use short programming language identifier
like strings for the "names" which should be used when exporting to
machine parseable formats.
Also removed a unused TimerGroup from Hexxagon.
Differential Revision: https://reviews.llvm.org/D25583
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287369 91177308-0d34-0410-b5e6-96231b3b80d8
The core of the change is supposed to be NFC, however it also fixes
what I believe was an undefined behavior when calling:
va_start(ValueArgs, Desc);
with Desc being a StringRef.
Differential Revision: https://reviews.llvm.org/D25342
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283671 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: -fsample-profile needs discriminator, which will not be added if built with -g0. This patch makes sure the discriminator is added for sample-profile at -g0. A followup patch will be send out to update clang tests.
Reviewers: davidxl, dblaikie, echristo, dnovillo
Subscribers: mehdi_amini, probinson, llvm-commits
Differential Revision: https://reviews.llvm.org/D25132
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283565 91177308-0d34-0410-b5e6-96231b3b80d8
