This reverts commit r209178.
This seems to be asserting in an LTO build on some internal Apple
buildbots. No upstream reproduction (and I don't have an LLVM-aware gold
built right now to reproduce it personally) but it's a small patch & the
failure's semi-plausible so I'm going to revert first while I try to
reproduce this.
llvm-svn: 209251
Undecided whether this should include a test case - SROA produces bad
dbg.value metadata describing a value for a reference that is actually
the value of the thing the reference refers to. For now, loosening the
assert lets this not assert, but it's still bogus/wrong output...
If someone wants to tell me to add a test, I'm willing/able, just
undecided. Hopefully we'll get SROA fixed soon & we can tighten up this
assertion again.
llvm-svn: 209240
This change preserves the original algorithm of generating history
for user variables, but makes it more clear.
High-level description of algorithm:
Scan all the machine basic blocks and machine instructions in the order
they are emitted to the object file. Do the following:
1) If we see a DBG_VALUE instruction, add it to the history of the
corresponding user variable. Keep track of all user variables, whose
locations are described by a register.
2) If we see a regular instruction, look at all the registers it clobbers,
and terminate the location range for all variables described by these registers.
3) At the end of the basic block, terminate location ranges for all
user variables described by some register.
Although this change shouldn't be user-visible (the contents of .debug_loc section
should be the same), it changes some internal assumptions about the set
of instructions used to track the variable locations. Watching the bots.
llvm-svn: 209225
In refactoring DwarfUnit::isUnsignedDIType I restricted it to only work
on values with signedness (unsigned or signed), asserting on anything
else (which did uncover some bugs). But it turns out that we do need to
emit constants of signless data, such as pointer constants - only null
pointer constants are known to need this so far, but it's conceivable
that there might be non-null pointer constants at some point (hardcoded
address offsets for device drivers?).
This patch just uses 'unsigned' for signless data such as pointer
constants. Arguably we could use signless representations
(DW_FORM_dataN) instead, allowing a trinary result from isUnsignedDIType
(signed, unsigned, signless), but this seems reasonable for now.
llvm-svn: 209223
This workaround (presumably for ancient GDB) doesn't appear to be
required (GDB 7.5 seems to tolerate function definition DIEs in
namespace scope just fine).
llvm-svn: 209189
Since we visit the whole list of subprograms for each CU at module
start, this is clearly true - don't test for the case, just assert it.
A few old test cases seemed to have incomplete subprogram lists, but any
attempt to reproduce them shows full subprogram lists that even include
entities that have been completely inlined and the out of line
definition removed.
llvm-svn: 209178
When I refactored this in r208636 I accidentally caused this to be added
multiple times to each abstract subprogram (not accounting for the
deduplicating effect of the InlinedSubprogramDIEs set).
This got better in r208798 when the abstract definitions got the
attribute added to them at construction time, but still had the
redundant copies introduced in r208636.
This commit removes those excess DW_AT_inlines and relies solely on the
insertion in r208798.
llvm-svn: 209166
The check in DwarfDebug::constructScopeDIE was meant to consider inlined
subroutines as any non-top-level scope that was a subprogram. Instead of
checking "not top level scope" it was checking if the /subprogram's/
scope was non-top-level.
Fix this and beef up a test case to demonstrate some of the missing
inlined_subroutines are no longer missing.
In the course of fixing this I also found that r208748 (with this fix)
found one /extra/ inlined_subroutine in concrete_out_of_line.ll due to
two inlined_subroutines having the same inlinedAt location. The previous
implementation was collapsing these into a single inlined subroutine.
I'm not sure what the original code was that created this .ll file so
I'm not sure if this actually happens in practice today. Since we
deliberately include column information to disambiguate two calls on the
same line, that may've addressed this bug in the frontend, but it's good
to know that workaround isn't necessary for this particular case
anymore.
llvm-svn: 209165
This allows us to put dynamic initializers for weak data into the same
comdat group as the data being initialized. This is necessary for MSVC
ABI compatibility. Once we have comdats for guard variables, we can use
the combination to help GlobalOpt fire more often for weak data with
guarded initialization on other platforms.
Reviewers: nlewycky
Differential Revision: http://reviews.llvm.org/D3499
llvm-svn: 209015
I'm not sure this is how it'll be going forward (I'd rather prefer the
definition to be in the main SP mapping, for various reasons) but this
helps me understand how it is today.
llvm-svn: 209009
DIBuilder maintains this invariant and the current DwarfDebug code could
end up doing weird things if it contained declarations (such as putting
the definition DIE inside a CU that contained the declaration - this
doesn't seem like a good idea, so rather than adding logic to handle
this case we'll just ban in for now & cross that bridge if we come to
it later).
llvm-svn: 209004
This reverts commit r208934.
The patch depends on aliases to GEPs with non zero offsets. That is not
supported and fairly broken.
The good news is that GlobalAlias is being redesigned and will have support
for offsets, so this patch should be a nice match for it.
llvm-svn: 208978
This commit implements two command line switches -global-merge-on-external
and -global-merge-aligned, and both of them are false by default, so this
optimization is disabled by default for all targets.
For ARM64, some back-end behaviors need to be tuned to get this optimization
further enabled.
llvm-svn: 208934
Since type units in the dwo file are handled by a debug aware tool, they
don't need to leverage the ELF comdat grouping to implement
deduplication. Avoid creating all the .group sections for these as a
space optimization.
llvm-svn: 208930
Abstract variables should never have/use locations. In this case the
data wasn't used, so no functional change intended here, just
simplification.
llvm-svn: 208820
Many old tests using prior schemas still had some brokenness here (both
indirect arrays and arrays with single bogus elements). Fixed those up
so they don't hit the new assertions.
Also reduced nesting in some places, etc.
llvm-svn: 208817
This is just unneccessary - we only create abstract definitions when
we're inlining anyway, so there's no reason to delay this to see if
we're going to inline anything.
llvm-svn: 208798
If the function has the landingpad instruction, then the
handlerdata should be emitted even if the function has
nouwnind attribute. Otherwise, following code will not
work:
void test1() noexcept {
try {
throw_exception();
} catch (...) {
log_unexpected_exception();
}
}
Since the cantunwind was incorrectly emitted and the
LSDA is not available.
llvm-svn: 208791
This was reverted in r208642 due to regressions surrounding file changes
within lexical scopes causing inlining information to be lost.
The issue was in LexicalScopes::getOrCreateInlinedScope, where I was
previously testing "isLexicalBlock" which is false for
"DILexicalBlockFile" (a scope used to represent changes in the current
file name) and assuming it was then a function (breaking out of the
inlined scope path and reaching for the parent non-inlined scopes). By
inverting the condition and testing for "isSubprogram" the correct
behavior is attained.
(also found some weirdness in Clang, see r208742 when reducing this test
case - the resulting test case doesn't apply with the Clang fix, but
I've added a more realistic test case to inline-scopes.ll which does
reproduce the issue and demonstrate the fix)
llvm-svn: 208748
This allows code to statically accept a Function or a GlobalVariable, but
not an alias. This is already a cleanup by itself IMHO, but the main
reason for it is that it gives a lot more confidence that the refactoring to fix
the design of GlobalAlias is correct. That will be a followup patch.
llvm-svn: 208716
One test case had to be updated as it still had the extra indirection
for the variable list - removing the extra indirection got it back to
passing.
llvm-svn: 208608
Filed as PR19712, LLVM fails to detect the right type of an enum
constant when a frontend does not provide an underlying type for the
enumeration type.
llvm-svn: 208502
And the winner by a nose is isUnsignedDIType, for no particular reason.
These two functions were just complements of each other and used in very
related code, so refactor callers to just use one of them.
llvm-svn: 208500
Doesn't seem a good reason to duplicate this code (it was more literally
duplicated prior to r208494, and while the dataN code /does/ actually
fire in this case, it doesn't seem necessary (and the DWARF standard
recommends using udata/sdata pervasively instead of dataN, so as to
indicate signedness of the values))
llvm-svn: 208495
This code looks to have become dead at some time in the past. I tried to
reproduce cases where LLVM would emit constants with dataN, but could
not. Upon inspection it seems the code doesn't do that anymore - the
only time a size is provided by isTypeSigned is when the type is signed,
and in those cases we use sdata. dataN is only used for unsigned types
and isTypeSigned doesn't provide a value for sizeInBits in that case.
Remove the dead cases/size plumbing.
llvm-svn: 208494
Summary:
Get rid of UserVariables set, and turn DbgValues into MapVector
to get a fixed ordering, as suggested in review for http://reviews.llvm.org/D3573.
Test Plan: llvm regression tests
Reviewers: dblaikie
Reviewed By: dblaikie
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D3579
llvm-svn: 207720
Breaks GDB buildbot
(http://lab.llvm.org:8011/builders/clang-x86_64-ubuntu-gdb-75/builds/14517)
GCC emits DW_AT_object_pointer /everywhere/ (declaration, abstract
definition, inlined subroutine), but it looks like GCC relies on it
being somewhere other than the declaration, at least. I'll experiment
further & can hopefully still remove it from the inlined_subroutine.
This reverts commit r207705.
llvm-svn: 207719
They just don't need to be there - they're inherited from the abstract
definition. In theory I would like them to be inherited from the
declaration, but the DWARF standard doesn't quite say that... we can
probably do it anyway but I'm less confident about that so I'll leave it
for a separate commit.
llvm-svn: 207717
This effectively reverts r164326, but adds some comments and
justification and ensures we /don't/ emit the DW_AT_object_pointer on
the (abstract and concrete) definitions. (while still preserving it on
standalone definitions involving ObjC Blocks)
This does increase the size of member function declarations from 7 to 11
bytes, unfortunately, but still seems like the Right Thing to do so that
callers that see only the declaration still have the information about
the object pointer. That said, I don't know what, if any, DWARF
consumers don't have a heuristic to guess this in the case of normal
C++ member functions - perhaps we can remove it entirely.
llvm-svn: 207705
DwarfDebug.h has a SmallVector member containing a unique_ptr of an
incomplete type. MSVC doesn't have key functions, so the vtable and
dtor are emitted in AsmPrinter.cpp, where DwarfDebug's ctor is called.
AsmPrinter.cpp include DwarfUnit.h and doesn't get a complete definition
of DwarfTypeUnit. We could fix the problem by including DwarfUnit.h in
DwarfDebug.h, but that would increase header bloat. Instead, define
~DwarfDebug out of line.
llvm-svn: 207701
These were called from distinct places and had significant distinct
behavior. No need to make that a dynamic check inside the function
rather than just having two functions (refactoring some common code into
a helper function to be called from the two separate functions).
llvm-svn: 207539
Seems at some point the intent was to emit fission ranges_base as unique
per CU but the code today emits ranges_base as the start of the ranges
section for all CUs being compiled and all the ranges_base relative
addresses are relative to that. So removing this dead code and leaving
the status quo until there's a reason to change it (perhaps something's
faster if it has distinct ranges for each CU).
llvm-svn: 207464
(Clang doesn't warn here because it knows the string is benign - the
assert still checks what it's intended to - though putting the correct
parens does make clang-format format the code a little better)
llvm-svn: 207456
Since all 4 ctor calls in DwarfDebug just pass in a trivially
constructed DIE with the right tag type, sink the tag selection down
into the Dwarf*Unit ctors (removing the argument entirely from callers
in DwarfDebug) and initialize the DIE member in DwarfUnit.
llvm-svn: 207448
Now that the subtle constructScopeDIE has been refactored into two
functions - one returning memory to take ownership of, one returning a
pointer to already owning memory - push unique_ptr through more APIs.
I think this completes most of the unique_ptr ownership of DIEs.
llvm-svn: 207442
While refactoring out constructScopeDIE into two functions I realized we
were emitting DW_AT_object_pointer in the inlined subroutine when we
didn't need to (GCC doesn't, and the abstract subprogram definition has
the information already).
So here's the refactoring and the bug fix. This is one step of
refactoring to remove some subtle memory ownership semantics. It turns
out the original constructScopeDIE returned ownership in its return
value in some cases and not in others. The split into two functions now
separates those two semantics - further cleanup (unique_ptr, etc) will
follow.
llvm-svn: 207441
entry. This is in preparation for generic DW_OP_piece support.
No functional change so far.
http://reviews.llvm.org/D3373
rdar://problem/15928306
llvm-svn: 207368
Since there's no way to ensure the type unit in the .dwo and the type
unit skeleton in the .o are correlated, this cannot work.
This implementation is a bit inefficient for a few reasons, called out
in comments.
llvm-svn: 207323
Sinking addition of the declaration attribute down to where the
signature is added. So that if the signature is not added neither is the
declaration attribute (this will come in handy when aborting type unit
construction to instead emit the type into the CU directly in some
cases)
Pull out type unit identifier hashing just to simplify the function a
little, it'll be getting longer.
llvm-svn: 207321
This also avoids the need for subtly side-effecting calls to manifest
strings in the string table at the point where items are added to the
accelerator tables.
llvm-svn: 207281
Pulls out some more code from some of the rather monolithic DWARF
classes. Unlike the address table, the string table won't move up into
DwarfDebug - each DWARF file has its own string table (but there can be
only one address table).
llvm-svn: 207277
This should reduce the chance of memory leaks like those fixed in
r207240.
There's still some unclear ownership of DIEs happening in DwarfDebug.
Pushing unique_ptr and references through more APIs should help expose
the cases where ownership is a bit fuzzy.
llvm-svn: 207263
Since this doesn't return ownership (the DIE has been added to the
specified parent already) nor return null, just return by reference.
llvm-svn: 207259
This'll make changing to unique_ptr ownership of DIEs easier since the
usages will now have '*' on them making them textually compatible
between unique_ptr and raw pointer.
llvm-svn: 207253
There's only ever one address pool, not one per DWARF output file, so
let's just have one.
(similar refactoring of the string pool to come soon)
llvm-svn: 207026
Some of these types (DwarfDebug in particular) are quite large to begin
with (and I keep forgetting whether DwarfFile is in DwarfDebug or
DwarfUnit... ) so having a few smaller files seems like goodness.
llvm-svn: 207010
For now it contains a single flag, SanitizeAddress, which enables
AddressSanitizer instrumentation of inline assembly.
Patch by Yuri Gorshenin.
llvm-svn: 206971
This prompted me to push references through most of DwarfDebug. Sorry
for the churn.
Honestly it's a bit silly that we're passing around units all over the
place like that anyway and I think it's mostly due to the DIE attribute
adding utility functions being utilities in DwarfUnit. I should have
another go at moving them out of DwarfUnit...
llvm-svn: 206925
This reverts commit r206780.
This commit was regressing gdb.opt/inline-locals.exp in the GDB 7.5 test
suite. Reverting until I can fix the issue.
llvm-svn: 206867
define below all header includes in the lib/CodeGen/... tree. While the
current modules implementation doesn't check for this kind of ODR
violation yet, it is likely to grow support for it in the future. It
also removes one layer of macro pollution across all the included
headers.
Other sub-trees will follow.
llvm-svn: 206837
Requires switching some vectors to lists to maintain pointer validity.
These could be changed to forward_lists (singly linked) with a bit more
work - I've left comments to that effect.
llvm-svn: 206780
Summary:
This prevents the discriminator generation pass from triggering if
the DWARF version being used in the module is prior to 4.
Reviewers: echristo, dblaikie
CC: llvm-commits
Differential Revision: http://reviews.llvm.org/D3413
llvm-svn: 206507
Got bored, removed some manual memory management.
Pushed references (rather than pointers) through a few APIs rather than
replacing *x with x.get().
llvm-svn: 206222
Thanks to dblaikie for updating the testcase!
Debug info: (bugfix) C++ C/Dtors can be compiled to multiple functions,
therefore, their declaration cannot have one DW_AT_linkage_name.
The specific instances however can and should have that attribute.
This patch reorders the code in DwarfUnit::getOrCreateSubprogramDIE()
to emit linkage names for C/Dtors.
rdar://problem/16362674.
llvm-svn: 206210
Nice to be able to just print out the Tag and have the debugger print
dwarf::DW_TAG_subprogram or whatever, rather than an int.
It's a bit finicky (for example DIDescriptor::getTag still returns
unsigned) because some places still handle real dwarf tags + our fake
tags (one day we'll remove the fake tags, hopefully).
llvm-svn: 206098
therefore, their declaration cannot have one DW_AT_linkage_name.
The specific instances however can and should have that attribute.
This patch reorders the code in DwarfUnit::getOrCreateSubprogramDIE()
to emit linkage names for C/Dtors.
rdar://problem/16362674.
llvm-svn: 206096
While we were encoding 64 bit values (data8) in the subrange itself,
using a 32 bit type for the subrange was still confusing the gdb. Oh,
and make it unsigned too.
As the comment points out, this could be pushed into the frontend so
that it would be 32 or 64 bit as appropriate, etc.
llvm-svn: 205512
I'm not sure the comment in the implementation really adds a lot of
value (it's clear that we emit zero when no symbol is provided, but it
doesn't explain why we would do that). Happy to iterate.
llvm-svn: 205386
This removes the magic-number-esque code creating/retrieving the same
label for a debug_loc entry from two places and removes the last small
piece of reusable logic from emitDebugLoc so that there will be less
duplication when refactoring it into two functions (one for debug_loc,
the other for debug_loc.dwo).
llvm-svn: 205382
Seems we didn't have any test coverage for merging... awesome. So I
added some - but hit an llvm-objdump bug while I was there. I'm choosing
not to shave that yak right now.
Code review feedback/bug catch by Adrian Prantl in r205360.
llvm-svn: 205373
No test case (this would invoke UB by examining uninitialized members,
etc, at best - and this code is apparently untested anyway - I'm about
to fix that)
Code review feedback from Adrian Prantl on r205360.
llvm-svn: 205367
This moves one case of raw text checking down into the MCStreamer
interfaces in the form of a virtual function, even if we ultimately end
up consolidating on the one-or-many line tables issue one day, this is
nicer in the interim. This just generally streamlines a bunch of use
cases into a common code path.
llvm-svn: 205287
No other functionality changes, DIBuilder testcase is included in a paired
CFE commit.
This relaxes the assertion in isScopeRef to also accept subclasses of
DIScope.
llvm-svn: 205279
Construct a uniform Windows target triple nomenclature which is congruent to the
Linux counterpart. The old triples are normalised to the new canonical form.
This cleans up the long-standing issue of odd naming for various Windows
environments.
There are four different environments on Windows:
MSVC: The MS ABI, MSVCRT environment as defined by Microsoft
GNU: The MinGW32/MinGW32-W64 environment which uses MSVCRT and auxiliary libraries
Itanium: The MSVCRT environment + libc++ built with Itanium ABI
Cygnus: The Cygwin environment which uses custom libraries for everything
The following spellings are now written as:
i686-pc-win32 => i686-pc-windows-msvc
i686-pc-mingw32 => i686-pc-windows-gnu
i686-pc-cygwin => i686-pc-windows-cygnus
This should be sufficiently flexible to allow us to target other windows
environments in the future as necessary.
llvm-svn: 204977
Implement debug_loc.dwo, as well as llvm-dwarfdump support for dumping
this section.
Outlined in the DWARF5 spec and http://gcc.gnu.org/wiki/DebugFission the
debug_loc.dwo section has more variation than the standard debug_loc,
allowing 3 different forms of entry (plus the end of list entry). GCC
seems to, and Clang certainly, only use one form, so I've just
implemented dumping support for that for now.
It wasn't immediately obvious that there was a good refactoring to share
the implementation of dumping support between debug_loc and
debug_loc.dwo, so they're separate for now - ideas welcome or I may come
back to it at some point.
As per a comment in the code, we could choose different forms that may
reduce the number of debug_addr entries we emit, but that will require
further study.
llvm-svn: 204697
This seems excessive - switching section isn't expensive (or if it is
we're already being wasteful, since we emitted the debug_loc section
symbol earlier anyway) and otherwise there's no work that happens in
this function when the list is empty.
llvm-svn: 204696
No functional change intended.
Merging up-front rather than delaying this task until later. This just
seems simpler and more efficient (avoiding growing the debug loc list
only to have to skip over those post-merged entries, etc).
llvm-svn: 204679
This is used to avoid relocations in the dwo file by allowing
DW_AT_ranges specified in debug_info.dwo to be relative to this base
address. (r204667 implements the base-relative DW_AT_ranges side of
this)
llvm-svn: 204672
This removes the debug_ranges relocations from debug_info.dwo (but
doesn't implement the DW_AT_GNU_ranges_base which is also necessary for
correct functioning)
llvm-svn: 204668
Type units have no addresses, so there's no need for DW_AT_addr_base.
This removes another relocation from every skeletal type unit and brings
LLVM's skeletal type units in line with GCC's (containing only
GNU_dwo_name (strp), comp_dir (strp), and GNU_pubnames (flag_present)).
Cary's got some ideas about using str_index in the .o file to reduce
those last two relocations (well, replace two relocations with one
relocation (pointing to the string index) and two indicies)
llvm-svn: 204506
Use the range machinery for DW_AT_ranges and DW_AT_high/lo_pc.
This commit moves us from a single range per subprogram to extending
ranges if we are:
a) In the same section, and
b) In the same enclosing CU.
This means we have more fine grained ranges for compile units, and fewer
ranges overall when we have multiple functions in the same CU
adjacent to each other in the object file.
Also remove all of the earlier hacks around this functionality for
function sections etc. Also update all of the testcases to take into
account the merging functionality.
with a fix for location entries in the debug_loc section:
Make sure that debug loc entries are relative to the low_pc
of the compile unit. This means that when we only have a single
range that the offset should be just relative to the low_pc
of the unit, for multiple ranges for a CU this means that we'll be
relative to 0 which we emit along with DW_AT_ranges.
This mostly shows up with linked binaries, so add a testcase with
multiple CUs so that our location is going to be offset of a CU
with a non-zero low_pc.
llvm-svn: 204377
This commit moves us from a single range per subprogram to extending
ranges if we are:
a) In the same section, and
b) In the same enclosing CU.
This means we have more fine grained ranges for compile units, and fewer
ranges overall when we have multiple functions in the same CU
adjacent to each other in the object file.
Also remove all of the earlier hacks around this functionality for
function sections etc. Also update all of the testcases to take into
account the merging functionality.
llvm-svn: 204277
This isn't a complete fix - it falls back to non-comp_dir when multiple
compile units are in play. Adding a map of comp_dir to table is part of
the more general solution, but I gave up (in the short term) when I
realized I'd also have to calculate the size of each type unit so as to
produce correct DW_AT_stmt_list attributes.
llvm-svn: 204202
When deployment target version information is available, emit it to the
target streamer for inclusion in the object file.
rdar://11337778
llvm-svn: 204191
This allows us to catch more opportunities for ODR-based type uniquing
during LTO.
Paired commit with CFE which updates some testcases to verify the new
DIBuilder behavior.
llvm-svn: 204106
This removes an attribute (and more importantly, a relocation) from
skeleton type units and removes some unnecessary file names from the
debug_line section that remains in the .o (and linked executable) file.
There's still a few places we could shave off some more space here:
* use compilation dir of the underlying compilation unit (since all the
type units share that compilation dir - though this would be more
complicated in LTO cases where they don't (keep a map of compilation
dir->line table header?))
* Remove some of the unnecessary header fields from the line table since
they're not needed in this situation (about 12 bytes per table).
llvm-svn: 204099
When emitting assembly there's no support for emitting separate line
tables for each compilation unit - so LLVM emits .loc directives
producing a single line table.
Line tables have an implicit directory (index 0) equal to the
compilation directory (DW_AT_comp_dir) of the compilation unit that
references them.
If multiple compilation units (with possibly disparate compilation
directories) reference the same line table, we must avoid relying on
this ambiguous directory.
Achieve this my simply not setting the compilation directory on the line
table when we're in this situation (multiple units while emitting
assembly).
llvm-svn: 204094
We still do a few lookups into the line table mapping in MCContext that
could be factored out into a single lookup (rather than looking it up
once for the table label, once to set the compilation unit, once for
each time we need a file ID, etc... ) but assembly output complicates
that somewhat as we still need a virtual dispatch back to the
MCAsmStreamer in that case.
llvm-svn: 204092
Our handling of compilation directory in DwarfDebug was broken
(incorrectly using the 'last' compilation directory (that of the last
CU in the metadata list) for all function emission in any CU). By moving
this handling down into MCDwarf the issue is fixed as the compilation
dir is tracked correctly per line table.
llvm-svn: 204089
See r204027 for the precursor to this that applied to asm debug info.
This required some non-obvious API changes to handle the case of asm
output (we never go asm->asm so this didn't come up in r204027): the
modification of the file/directory name by MCDwarfLineTableHeader needed
to be reflected in the MCAsmStreamer caller so it could print the
appropriate .file directive, so those StringRef parameters are now
non-const ref (in/out) parameters rather than just const.
llvm-svn: 204069
based on the ODR.
This adds an OdrMemberMap to DwarfDebug which is used to unique C++
member function declarations based on the unique identifier of their
containing class and their mangled name.
We can't use the usual DIRef mechanism here because DIScopes are indexed
using their entire MDNode, including decl_file and decl_line, which need
not be unique (see testcase).
Prior to this change multiple redundant member function declarations would
end up in the same uniqued DW_TAG_class_type.
llvm-svn: 203982
any lexical scopes then go ahead and turn on DW_AT_ranges for the
compile unit since we would be claiming to describe in the CU
a range for which we don't have information in the CU otherwise.
llvm-svn: 203969
These linkages were introduced some time ago, but it was never very
clear what exactly their semantics were or what they should be used
for. Some investigation found these uses:
* utf-16 strings in clang.
* non-unnamed_addr strings produced by the sanitizers.
It turns out they were just working around a more fundamental problem.
For some sections a MachO linker needs a symbol in order to split the
section into atoms, and llvm had no idea that was the case. I fixed
that in r201700 and it is now safe to use the private linkage. When
the object ends up in a section that requires symbols, llvm will use a
'l' prefix instead of a 'L' prefix and things just work.
With that, these linkages were already dead, but there was a potential
future user in the objc metadata information. I am still looking at
CGObjcMac.cpp, but at this point I am convinced that linker_private
and linker_private_weak are not what they need.
The objc uses are currently split in
* Regular symbols (no '\01' prefix). LLVM already directly provides
whatever semantics they need.
* Uses of a private name (start with "\01L" or "\01l") and private
linkage. We can drop the "\01L" and "\01l" prefixes as soon as llvm
agrees with clang on L being ok or not for a given section. I have two
patches in code review for this.
* Uses of private name and weak linkage.
The last case is the one that one could think would fit one of these
linkages. That is not the case. The semantics are
* the linker will merge these symbol by *name*.
* the linker will hide them in the final DSO.
Given that the merging is done by name, any of the private (or
internal) linkages would be a bad match. They allow llvm to rename the
symbols, and that is really not what we want. From the llvm point of
view, these objects should really be (linkonce|weak)(_odr)?.
For now, just keeping the "\01l" prefix is probably the best for these
symbols. If we one day want to have a more direct support in llvm,
IMHO what we should add is not a linkage, it is just a hidden_symbol
attribute. It would be applicable to multiple linkages. For example,
on weak it would produce the current behavior we have for objc
metadata. On internal, it would be equivalent to private (and we
should then remove private).
llvm-svn: 203866
On ELF and COFF an alias is just another name for a position in the file.
There is no way to refer to a position in another file, so an alias to
undefined is meaningless.
MachO currently doesn't support aliases. The spec has a N_INDR, which when
implemented will have a different set of restrictions. Adding support for
it shouldn't be harder than any other IR extension.
For now, having the IR represent what is actually possible with current
tools makes it easier to fix the design of GlobalAlias.
llvm-svn: 203705
I could fold the callers into their one call site, but the indirection
(given how verbose choosing the section is) seemed helpful.
The use of a member function pointer's a bit "tricky", but seems limited
enough, the call sites are simple/clean/clear, and there's only one use.
llvm-svn: 203619
David Blaikie