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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204697 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204696 91177308-0d34-0410-b5e6-96231b3b80d8
Rather than using a flat list with "empty" entries (ala the actual
on-disk format), keep separate lists for each variable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204680 91177308-0d34-0410-b5e6-96231b3b80d8
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).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204679 91177308-0d34-0410-b5e6-96231b3b80d8
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)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204672 91177308-0d34-0410-b5e6-96231b3b80d8
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)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204668 91177308-0d34-0410-b5e6-96231b3b80d8
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)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204506 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204377 91177308-0d34-0410-b5e6-96231b3b80d8
This appears to trigger failures with optimization and function arguments somehow.
This reverts commit r204277.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204286 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204277 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204202 91177308-0d34-0410-b5e6-96231b3b80d8
When deployment target version information is available, emit it to the
target streamer for inclusion in the object file.
rdar://11337778
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204191 91177308-0d34-0410-b5e6-96231b3b80d8
This is a follow-up to r203983 based on feedback from dblaikie and mren (Thanks!)
No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204107 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204106 91177308-0d34-0410-b5e6-96231b3b80d8
Introduce a slightly tighter wrapper around the header structure that
handles this use case. (MCDwarfDwoLineTable)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204101 91177308-0d34-0410-b5e6-96231b3b80d8
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).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204099 91177308-0d34-0410-b5e6-96231b3b80d8
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).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204094 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204092 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204089 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204069 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203982 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203969 91177308-0d34-0410-b5e6-96231b3b80d8
Rewrite a couple of testcases to cover areas that would be normally
by turning it on into testcases that will follow the logic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203968 91177308-0d34-0410-b5e6-96231b3b80d8
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).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203866 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203705 91177308-0d34-0410-b5e6-96231b3b80d8
