Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.
Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.
Motivation
----------
Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.
We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.
Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.
http://reviews.llvm.org/D19034
<rdar://problem/25256815>
llvm-svn: 266446
Although it seems like clang will never emit scattered relocations in
the debug information (at least I couldn't find a way), we have too
support them for the benefit of other compilers.
As clang doesn't generate them, the included testcase was produced
from hacked up assembly.
llvm-svn: 259339
llvm-dsymutil was misinterpreting the value of common symbols as their
address when it actually contains their size. This didn't impact
llvm-dsymutil's ability to link the debug information for common symbols
because these are always found by name and not by address. Things could
however go wrong when the size of a common object matched the object
file address of another symbol. Depending on the link order of the symbols
the common object might incorrectly evict this other object from the
address to symbol mapping, and then link the evicted symbol with a wrong
binary address.
Use the new ability to have symbols without an object file address to fix
this.
llvm-svn: 259318
This replicates the logic of Darwin dwarfdump for manually opening up
.dSYM bundles without introducing any new dependencies.
<rdar://problem/20491670>
llvm-svn: 256350
Quoting from the comment added to the code:
// Objective-C on i386 uses artificial absolute symbols to
// perform some link time checks. Those symbols have a fixed 0
// address that might conflict with real symbols in the object
// file. As I cannot see a way for absolute symbols to find
// their way into the debug information, let's just ignore those.
llvm-svn: 255350
already emitted and fix a latent bug in DIECloner where the DW_CHILDREN_yes
flag is set based on the number of children in the input DIE rather than
the number of children that are actually being cloned.
rdar://problem/23439845
llvm-svn: 252649
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
llvm-svn: 252219
if there exists not definition for the type.
For this to work, we need to clone the imported modules before building
the decl context chains of the DIEs in the non-skeleton CUs.
llvm-svn: 249362
so the lookup works as expected after prepending the oso-prepend-path.
This manifested only on Windows, because "/" is not a relative path there.
llvm-svn: 248423
This patch extends llvm-dsymutil's ODR type uniquing machinery to also
resolve forward decls for types defined in clang modules.
http://reviews.llvm.org/D13038
llvm-svn: 248398
When cloning the debug info for a function that hasn't been linked,
strip the DIEs from all location attributes that wouldn't contain any
meaningful information anyway.
This kind of situation can happen when a function got discarded by the
linker, but its debug information is still wanted in the final link
because it was marked as required as some other DIE dependency. The easiest
way to get into that situation is to have using directives. They get
linked unconditionally, but their targets might not always be present.
llvm-svn: 247386
With a fix for big endian machines. Thanks to Daniel Sanders for the debugging!
Original commit message:
The binaries containing the linked DWARF generated by dsymutil are not
standard relocatable object files like emitted did previsously. They should be
dSYM companion files, which means they have a different file type in the
header, but also a couple other peculiarities:
- they contain the segments and sections from the original binary in their
load commands, but not the actual contents. This means they get an address
and a size, but their offset is always 0 (but these are not virtual sections)
- they also conatin all the defined symbols from the original binary
This makes MC a really bad fit to emit these kind of binaries. The approach
that was used in this patch is to leverage MC's section layout for the
debug sections, but to use a replacement for MachObjectWriter that lives
in MachOUtils.cpp. Some of the low-level helpers from MachObjectWriter
were reused too.
llvm-svn: 246673
This testcase required 2 copies of the same file, and the second
copy was missing. It was currently working because of a bug I'm
about to fix.
llvm-svn: 246411
The fix is trivial (The actual patch is 2 lines, but as it changes
indentation it looks like more).
clang does not produce this kind of (slightly bogus) debug info
anymore, thus I had to rely on a hand-crafted assembly test to trigger
that case.
llvm-svn: 246410
The value of an inlined subprogram low_pc attribute should not
get relocated, but it can happen that it matches the enclosing
function's start address and thus gets the generic treatment.
Special case it to avoid applying the PC offset twice.
llvm-svn: 246406
As a follow-up to r246098, require `DISubprogram` definitions
(`isDefinition: true`) to be 'distinct'. Specifically, add an assembler
check, a verifier check, and bitcode upgrading logic to combat testcase
bitrot after the `DIBuilder` change.
While working on the testcases, I realized that
test/Linker/subprogram-linkonce-weak-odr.ll isn't relevant anymore. Its
purpose was to check for a corner case in PR22792 where two subprogram
definitions match exactly and share the same metadata node. The new
verifier check, requiring that subprogram definitions are 'distinct',
precludes that possibility.
I updated almost all the IR with the following script:
git grep -l -E -e '= !DISubprogram\(.* isDefinition: true' |
grep -v test/Bitcode |
xargs sed -i '' -e 's/= \(!DISubprogram(.*, isDefinition: true\)/= distinct \1/'
Likely some variant of would work for out-of-tree testcases.
llvm-svn: 246327
The binaries containing the linked DWARF generated by dsymutil are not
standard relocatable object files like emitted did previsously. They should be
dSYM companion files, which means they have a different file type in the
header, but also a couple other peculiarities:
- they contain the segments and sections from the original binary in their
load commands, but not the actual contents. This means they get an address
and a size, but their offset is always 0 (but these are not virtual sections)
- they also conatin all the defined symbols from the original binary
This makes MC a really bad fit to emit these kind of binaries. The approach
that was used in this patch is to leverage MC's section layout for the
debug sections, but to use a replacement for MachObjectWriter that lives
in MachOUtils.cpp. Some of the low-level helpers from MachObjectWriter
were reused too.
llvm-svn: 246012
llvm-dsymutil needs to emit dSYM companion bundles. These are binary files
that replicate some of the orignal binary file properties (sections and
symbols). To get acces to these properties, pass the binary path in the
debug map.
llvm-svn: 246011
There was an issue in the test setup because the test requires an arch that
wasn't filtered by the lit.local.cfg, but given the set of bots that failed,
I'm not confident this is the (only) issue. So this commit also adds more
output to the test to help me track down the failure if it happens again.
Original commit message:
[dsymutil] Rewrite thumb triple names in user visible messages.
We autodetect triples from the input file(s) while reading the mach-o debug map.
As we need to create a Target from those triples, we always chose the thumb
variant (because the arm variant might not be 'instantiable' eg armv7m). The
user visible architecture names should still be 'arm' and not 'thumb' variants
though.
llvm-svn: 245988
This reverts commit r245960.
Multiple bots are failing on the new test. It seemd like llvm-dsymutil exits with an error. Investigating.
llvm-svn: 245964
We autodetect triples from the input file(s) while reading the mach-o debug map.
As we need to create a Target from those triples, we always chose the thumb
variant (because the arm variant might not be 'instantiable' eg armv7m). The
user visible architecture names should still be 'arm' and not 'thumb' variants
though.
llvm-svn: 245960
This patch adds all the refactored tests in new files, the old
tests will be removed by a followup commit.
Thanks to D. Blaikie for all the feedback.
llvm-svn: 245803
I looked into adding a warning / error for this to FileCheck, but there doesn't
seem to be a good way to avoid it triggering on the instances of it in RUN lines.
llvm-svn: 244481
llvm-dsymutil has to be able to process debug info produced by other compilers
which use different line table settings. The testcase wasn't generated by
another compiler, but by a modified clang.
llvm-svn: 244319
A dSYM bundle is a file hierarchy that looks slike this:
<bundle name>.dSYM/
Contents/
Info.plist
Resources/
DWARF/
<DWARF file(s)>
This is the default output mode of dsymutil.
llvm-svn: 244270
dsymutil should by default generate dSYM bundles which are filesystem
hierarchies containing the debug info and an additional Info.plist.
Currently llvm-dsymutil emits raw binaries containing the debug info.
This is what we call the 'flat mode'. Add a -f/-flat option that is
supposed to enable that flat mode, but don't wire it for now, only
pass it to the tests that will need it to stay functional once we
do bundle generation by default.
This basically makes this commit NFC and removes the noise from the
actual commit that adds support for bundle generation.
llvm-svn: 244269
This reverts commit r244163. The workaround shouldn't be necessary
after r244172, and moreover the commit was slightly buggy as it
dis a simple mkdir without removing the directory first, which could
cause 'File exists' errors.
llvm-svn: 244182
