This allows proper disambiguation of unbounded arrays and arrays of zero
bound ("struct foo { int x[]; };" and "struct foo { int x[0]; }"). GCC
instead produces an upper bound of -1 in the latter situation, but count
seems tidier. This way lower_bound is provided if it's not the language
default and count is provided if the count is known, otherwise it's
omitted. Simple.
If someone wants to look at rdar://problem/12566646 and see if this
change is acceptable to that bug/fix, that might be helpful (see the
empty-and-one-elem-array.ll test case which cites that radar).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218726 91177308-0d34-0410-b5e6-96231b3b80d8
No functional change. Pre-emptive refactoring before I start pushing
some of this subprogram creation down into DWARFCompileUnit so I can
build different subprograms in the skeleton unit from the dwo unit for
adding -gmlt-like data to the skeleton.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218713 91177308-0d34-0410-b5e6-96231b3b80d8
r218129 omits DW_TAG_subprograms which have no inlined subroutines when
emitting -gmlt data. This makes -gmlt very low cost for -O0 builds.
Darwin's dsymutil reasonably considers a CU empty if it has no
subprograms (which occurs with the above optimization in -O0 programs
without any force_inline function calls) and drops the line table, CU,
and everything in this situation, making backtraces impossible.
Until dsymutil is modified to account for this, disable this
optimization on Darwin to preserve the desired functionality.
(see r218545, which should be reverted after this patch, for other
discussion/details)
Footnote:
In the long term, it doesn't look like this scheme (of simplified debug
info to describe inlining to enable backtracing) is tenable, it is far
too size inefficient for optimized code (the DW_TAG_inlined_subprograms,
even once compressed, are nearly twice as large as the line table
itself (also compressed)) and we'll be considering things like Cary's
two level line table proposal to encode all this information directly in
the line table.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218702 91177308-0d34-0410-b5e6-96231b3b80d8
To reduce the size of -gmlt data, skip the subprograms without any
inlined subroutines. Since we've now got the ability to make these
determinations in the backend (funnily enough - we added the flag so we
wouldn't produce ranges under -gmlt, but with this change we use the
flag, but go back to producing ranges under -gmlt).
Instead, just produce CU ranges to inform the consumer which parts of
the code are described by this CU's line table. Tools could inspect the
line table directly to compute the range, but the CU ranges only seem to
be about 0.5% of object/executable size, so I'm not too worried about
teaching llvm-symbolizer that trick just yet - it's certainly a possible
piece of future work.
Update an llvm-symbolizer test just to demonstrate that this schema is
acceptable there (if it wasn't, the compiler-rt tests would catch this,
but good to have an in-llvm-tree test for llvm-symbolizer's behavior
here)
Building the clang binary with -gmlt with this patch reduces the total
size of object files by 5.1% (5.56% without ranges) without compression
and the executable by 4.37% (4.75% without ranges).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218129 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This will allow to request the creation of a forward delacred variable
at is point of use (for imported declarations, this will be
DwarfDebug::constructImportedEntityDIE) rather than having to put the
forward decl in a retention list.
Note that getOrCreateGlobalVariable returns the actual definition DIE when the
routine creates a declaration and a definition DIE. If you agree this is the
right behavior, then I'll have a followup patch that registers the definition
in the DIE map instead of the declaration as it is today (this 'breaks' only
one test, where we test that the imported entity is the declaration). I'm
not sure what's best here, but it's easy enough for a consumer to follow the
DW_AT_specification link to get to the declaration, whereas it takes more
work to find the actual definition from a declaration DIE.
Reviewers: echristo, dblaikie, aprantl
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5381
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218126 91177308-0d34-0410-b5e6-96231b3b80d8
This omission will be done in a fancier manner once we're dealing with
"put gmlt in the skeleton CUs under fission" - it'll have to be
conditional on the kind of CU we're emitting into (skeleton or gmlt).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218098 91177308-0d34-0410-b5e6-96231b3b80d8
The patch moved some logic around in an attempt to generate potentially more
DW_AT_declaration attributes. The patch was flawed though and it stopped
generating the attribute in some cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218060 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This doesn't show up today as we don't emit decalration only variables. This
will be tested when the followup patches implementing import of forward
declared entities lands in clang.
Reviewers: echristo, dblaikie, aprantl
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5382
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218041 91177308-0d34-0410-b5e6-96231b3b80d8
On MachO, and MachO only, we cannot have a truly empty function since that
breaks the linker logic for atomizing the section.
When we are emitting a frame pointer, the presence of an unreachable will
create a cfi instruction pointing past the last instruction. This is perfectly
fine. The FDE information encodes the pc range it applies to. If some tool
cannot handle this, we should explicitly say which bug we are working around
and only work around it when it is actually relevant (not for ELF for example).
Given the unreachable we could omit the .cfi_def_cfa_register, but then
again, we could also omit the entire function prologue if we wanted to.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217801 91177308-0d34-0410-b5e6-96231b3b80d8
And since it /looked/ like the DwarfStrSectionSym was unused, I tried
removing it - but then it turned out that DwarfStringPool was
reconstructing the same label (and expecting it to have already been
emitted) and uses that.
So I kept it around, but wanted to pass it in to users - since it seemed
a bit silly for DwarfStringPool to have it passed in and returned but
itself have no use for it. The only two users don't handle strings in
both .dwo and .o files so they only ever need the one symbol - no need
to keep it (and have an unused symbol) in the DwarfStringPool used for
fission/.dwo.
Refactor a bunch of accelerator table usage to remove duplication so I
didn't have to touch 4-5 callers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217628 91177308-0d34-0410-b5e6-96231b3b80d8
So that the two operations in DwarfDebug couldn't get separated (because
I accidentally separated them in some work in progress), put them
together. While we're here, move DwarfUnit::addRange to
DwarfCompileUnit, since it's not relevant to type units.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217468 91177308-0d34-0410-b5e6-96231b3b80d8
PrevSection/PrevCU are used to detect holes in the address range of a CU
to ensure the DW_AT_ranges does not include those holes. When we see a
function with no debug info, though it may be in the same range as the
prior and subsequent functions, there should be a gap in the CU's
ranges. By setting PrevCU to null in that case, the range would not be
extended to cover the gap.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217466 91177308-0d34-0410-b5e6-96231b3b80d8
It's probably not a huge deal to not do this - if we could, maybe the
address could be reused by a subprogram low_pc and avoid an extra
relocation, but it's just one per CU at best.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217338 91177308-0d34-0410-b5e6-96231b3b80d8
The structures for Windows unwinding are shared across multiple platforms.
Indicate the encoding to be used for the particular target. Use this to switch
the unwind emitter instantiated by the AsmPrinter.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216895 91177308-0d34-0410-b5e6-96231b3b80d8
Move the Windows unwind information emitter into a separate header. This is not
related to DWARF based emission. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216894 91177308-0d34-0410-b5e6-96231b3b80d8
DW_TAG_lexical_scopes inform debuggers about the instruction range for
which a given variable (or imported declaration/module/etc) is valid. If
the scope doesn't itself contain any such entities, it's a waste of
space and should be omitted.
We were correctly doing this for entirely empty leaves, but not for
intermediate nodes.
Reduces total (not just debug sections) .o file size for a bootstrap
-gmlt LLVM by 22% and bootstrap -gmlt clang executable by 13%. The wins
for a full -g build will be less as a % (and in absolute terms), but
should still be substantial - with some of that win being fewer
relocations, thus more substantiall reducing link times than fewer bytes
alone would have.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216861 91177308-0d34-0410-b5e6-96231b3b80d8
This makes the emptiness of the scope with regards to variables and
nested scopes is the same as with regards to imported entities. Just
check if we had nothing at all before we build the node.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216840 91177308-0d34-0410-b5e6-96231b3b80d8
First of many steps to improve lexical scope construction (to omit
trivial lexical scopes - those without any direct variables). To that
end it's easier not to create imported entities directly into the
lexical scope node, but to build them, then add them if necessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216838 91177308-0d34-0410-b5e6-96231b3b80d8
specifier and change the default behavior to only emit the
DW_AT_accessibility(public) attribute when the isPublic() is explicitly
set.
rdar://problem/18154959
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216799 91177308-0d34-0410-b5e6-96231b3b80d8
Rushed when I realized I hadn't committed the FreeDeleter for a clang
change I'd committed, and didn't check that I had things lying around in
my client.
Apologies for the noise.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216792 91177308-0d34-0410-b5e6-96231b3b80d8
Somewhat unnoticed in the original implementation of discriminators, but
it could cause instructions to end up in new, small,
DW_TAG_lexical_blocks due to the use of DILexicalBlock to track
discriminator changes.
Instead, use DILexicalBlockFile which we already use to track file
changes without introducing new scopes, so it works well to track
discriminator changes in the same way.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216239 91177308-0d34-0410-b5e6-96231b3b80d8
Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)
Changes made by clang-tidy with minor tweaks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215558 91177308-0d34-0410-b5e6-96231b3b80d8
refactoring in 215384. This way it can unique multiple entries describing
the same piece even if they don't have the exact same location.
(The same piece may get merged in and be added from OpenRanges).
There ought to be a more elegant solution for this, though.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215418 91177308-0d34-0410-b5e6-96231b3b80d8
I believe this was addressed by r215157 and r215227, so let's have
another go at the bots, etc.
This reverts commit r214880.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215412 91177308-0d34-0410-b5e6-96231b3b80d8
