Summary:
MASM can produce type streams that are not topologically sorted. It can
even produce type streams with circular references, but those are not
common in practice.
Reviewers: inglorion, ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31629
llvm-svn: 299403
This is helpful when extracting objects from archives produced by MSVC's
lib.exe, which users absolute paths to describe the archive members.
llvm-svn: 299264
Summary:
Assertions assuming that function calls may not have zero durations do
not seem to hold in the wild. There are valid cases where the conversion
of the tsc counters end up becoming zero-length durations. These
assertions don't really hold and the algorithms don't need those to be
true for them to work.
Reviewers: dblaikie, echristo
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31519
llvm-svn: 299150
BIND_OPCODE_DONE/REBASE_OPCODE_DONE may appear at the end of the opcode array,
but they are not required to. The linker only adds them as padding to align the
opcodes to pointer size.
This fixes rdar://problem/31285560.
llvm-svn: 299104
Mostly this change adds support converting to and from
YAML which will allow us to write more test cases for
the WebAssembly MC and lld ports.
Better support for objdump, readelf, and nm will be in
followup CLs.
I had to update the two wasm test binaries because they
used the old style 'name' section which is no longer
supported.
Differential Revision: https://reviews.llvm.org/D31099
Patch by Sam Clegg
llvm-svn: 299101
Summary:
These tests were not being run because the yaml extension
wasn't be picked up by lit.
This change also fixes the tests which themselves were broken.
Patch By: Sam Clegg
Reviewers: beanz
Reviewed By: beanz
Subscribers: fhahn
Differential Revision: https://reviews.llvm.org/D31436
llvm-svn: 299088
This assert is just trying to test that processing each record adds
exactly one entry to the index map. The assert logic was wrong when the
first record in the type stream was a field list.
I've simplified the code by moving the LF_FIELDLIST-specific logic into
the callback for that record type.
llvm-svn: 299035
Summary:
It is problematic for this reader that it expects to read data from
several threads, but the header or message format does not define
framing. Since the buffers are reused, we can't rely on skipping
zeroed out data as a synchronization method either.
There is an argument that this is not version compatible with the format
the reader expected previously. I argue that since the writer wrote garbage
past the end of buffer record, there is no currently working reader to
compromise.
The corresponding writer change is posted to D31384.
Reviewers: dberris, pelikan
Reviewed By: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31385
llvm-svn: 298983
Summary:
Currently the llvm-xray commandline tool fails to handle the case for
when no subcommand is provided in a graceful manner. This fixes that to
print the help message explaining the subcommands and the available
options.
Reviewers: pcc, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31409
llvm-svn: 298975
rebase entry errors and test cases for each of the error checks.
Also verified with Nick Kledzik that a BIND_OPCODE_SET_ADDEND_SLEB
opcode is legal in a lazy bind table, so code that had that as an error
check was removed.
With MachORebaseEntry and MachOBindEntry classes now returning
an llvm::Error in all cases for malformed input the variables Malformed
and logic to set use them is no longer needed and has been removed
from those classes.
Also in a few places, removed the redundant Done assignment to true
when also calling moveToEnd() as it does that assignment.
This only leaves the dyld compact export entries left to have
error handling yet to be added for the dyld compact info.
llvm-svn: 298883
Summary: MSVC does this when producing a PDB.
Reviewers: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31316
llvm-svn: 298717
Summary:
The cumulative size of the bitcode files for a very large application
can be huge, particularly with -g. In a distributed build environment,
all of these files must be sent to the remote build node that performs
the thin link step, and this can exceed size limits.
The thin link actually only needs the summary along with a bitcode
symbol table. Until we have a proper bitcode symbol table, simply
stripping the debug metadata results in significant size reduction.
Add support for an option to additionally emit minimized bitcode
modules, just for use in the thin link step, which for now just strips
all debug metadata. I plan to add a cc1 option so this can be invoked
easily during the compile step.
However, care must be taken to ensure that these minimized thin link
bitcode files produce the same index as with the original bitcode files,
as these original bitcode files will be used in the backends.
Specifically:
1) The module hash used for caching is typically produced by hashing the
written bitcode, and we want to include the hash that would correspond
to the original bitcode file. This is because we want to ensure that
changes in the stripped portions affect caching. Added plumbing to emit
the same module hash in the minimized thin link bitcode file.
2) The module paths in the index are constructed from the module ID of
each thin linked bitcode, and typically is automatically generated from
the input file path. This is the path used for finding the modules to
import from, and obviously we need this to point to the original bitcode
files. Added gold-plugin support to take a suffix replacement during the
thin link that is used to override the identifier on the MemoryBufferRef
constructed from the loaded thin link bitcode file. The assumption is
that the build system can specify that the minimized bitcode file has a
name that is similar but uses a different suffix (e.g. out.thinlink.bc
instead of out.o).
Added various tests to ensure that we get identical index files out of
the thin link step.
Reviewers: mehdi_amini, pcc
Subscribers: Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D31027
llvm-svn: 298638
and test cases for each of the error checks.
To do this more plumbing was needed so that the segment indexes and
segment offsets can be checked. Basically what was done was the SegInfo
from llvm-objdump’s MachODump.cpp was moved into libObject for Mach-O
objects as BindRebaseSegInfo and it is only created when an iterator for
bind or rebase entries are created.
This commit really only adds the error checking and test cases for the
bind table entires and the checking for the lazy bind and weak bind entries
are still to be fully done as well as the rebase entires. Though some of
the plumbing for those are added with this commit. Those other error
checks and test cases will be added in follow on commits.
Note, the two llvm_unreachable() calls should now actually be unreachable
with the error checks in place and would take a logic bug in the error
checking code to be reached if the segment indexes and segment
offsets are used from a checked bind entry. Comments have been added
to the methods that require the arguments to have been checked
prior to calling.
llvm-svn: 298292
Refactor the dumping function so that we can add other value profile kind easily.
Differential Revision: https://reviews.llvm.org/D30752
llvm-svn: 297399
Summary:
This test was missing the target triple.
Once I fixed that, the case with the invalid character error stopped
returning 1 from llvm-lto2 and the test reported a failure. Fixed by
adding the missing return from llvm-lto2. Apparently we were failing
when we eventually tried to get the target.
Reviewers: pcc
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D30585
llvm-svn: 297173
Summary:
Reset the ValueData for each function to avoid using the ones in
the previous function.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: llvm-commits, xur
Differential Revision: https://reviews.llvm.org/D30479
llvm-svn: 296916
other tables. Providing a helpful error message to what the error is and
where the error occurred based on which opcode it was associated with.
There have been handful of bug fixes dealing with bad bind info in
object files, r294021 and r249845, which only put a band aid on the
problem after a bad bind table was created after unpacking from
its compact info. In these cases a bind table should have never been
created and an error should have simply been generated.
This change puts in place the plumbing to allow checking and returning
of an error when the compact info is unpacked. This follows the model
of iterators that can fail that Lang Hanes designed when fixing the problem
for bad archives r275316 (or r275361).
This change uses one of the existing test cases that now causes an
error instead of printing <<bad library ordinal>> after a bad bind table
is created. The error uses the offset into the opcode table as shown with
the macOS dyldinfo(1) tool to indicate where the error is and which
opcode and which parameter is in error.
For example the exiting test case has this lazy binding opcode table:
% dyldinfo -opcodes test/tools/llvm-objdump/Inputs/bad-ordinal.macho-x86_64
…
lazy binding opcodes:
0x0000 BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB(0x02, 0x00000010)
0x0002 BIND_OPCODE_SET_DYLIB_ORDINAL_IMM(2)
In the test case the binary only has one library so setting the library
ordinal to the value of 2 in the BIND_OPCODE_SET_DYLIB_ORDINAL_IMM
opcode at 0x0002 above is an error. This now produces this error message:
% llvm-objdump -lazy-bind bad-ordinal.macho-x86_64
…
llvm-objdump: 'bad-ordinal.macho-x86_64': truncated or malformed object (for BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB bad library ordinal: 2 (max 1) for opcode at: 0x2)
This change provides the plumbing for the error handling and one example
of an error message. Other error checks and test cases will be added in follow
on commits.
llvm-svn: 296527
Summary:
In Preparation for graph comparison, this patch breaks out the color
choice code from xray-graph into a library and adds polynomials for
the Sequential and Difference sets from ColorBrewer.
Depends on D29005
Reviewers: dblaikie, chandlerc, dberris
Reviewed By: dberris
Subscribers: chandlerc, llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D29363
llvm-svn: 296210
Instead of stripping the longest common prefix off of the filenames in a
report, strip out the longest chain of redundant path components. This
fixes the case in PR31982, where there are two files with the same
prefix, and stripping out the LCP makes things less intelligible.
llvm-svn: 296029
Summary:
The file type packs function trace data onto disk from potentially multiple
threads that are aggregated and flushed during the course of an instrumented
program's runtime.
It is named FDR mode or Flight Data recorder as an analogy to plane
blackboxes, which instrument a running system without access to IO.
The writer code is defined in compiler-rt in xray_fdr_logging.h/cc
Reviewers: rSerge, kcc, dberris
Reviewed By: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29697
llvm-svn: 295397
Summary:
The YAML output produced by llvm-xray is supposed to be wrapped at the
arbitrary default of 70 columns set by `yaml:Output`. Unfortunately,
the wrapping is rather unpredictable, and can easily go past the set
number of columns, depending on the execution environment.
To make the YAML output environment-independent, disable wrapping
instead.
Reviewers: dberris
Reviewed By: dberris
Subscribers: fhahn, llvm-commits
Differential Revision: https://reviews.llvm.org/D29962
llvm-svn: 295116
in this case for CPU_SUBTYPE_ARM64_ALL.
For this cpusubtype it should default to a cyclone CPU
to give proper disassembly without a -mcpu= flag.
rdar://27767188
llvm-svn: 294771
until we can get better TargetMachine::isCompatibleDataLayout to compare - otherwise
we can't code generate existing bitcode without a string equality data layout.
This reverts commit r294702.
llvm-svn: 294709
For other platforms we should find out what they need and likely
make the same change, however, a smaller additional change is easier
for platforms we know have it specified in the ABI. As part of this
rewrite some of the handling in the backends for data layout and update
a bunch of testcases.
Based on a patch by Simonas Kazlauskas!
llvm-svn: 294702
r288399 introduced the DIEUnit class, and in the process broke
the corner case where dsymutil generates an empty CU during an
LTO link. This restores the logic and adds a test for the corner
case.
llvm-svn: 294618
Disassembly currently begins from addresses obtained from the objects
symbol table. For ELF, add the dynamic symbols to the list if no
static symbols are available so that we can more successfully
disassemble stripped binaries.
Differential Revision: https://reviews.llvm.org/D29632
llvm-svn: 294430
DWARF info contains info about the line number at which a function starts (DW_AT_decl_line).
This patch creates a function to look up the start line number for a function, and returns it in
DILineInfo when looking up debug info for a particular address.
Patch by Simon Que!
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D27962
llvm-svn: 294231
which caused it to not disassemble the bytes a the start of the section if
the section had symbols and the first symbol was not at the start of the
section.
rdar://30143243
llvm-svn: 294212
Summary:
This is necessary to get stats from the ThinLink printed before the
early exit when compiling in a distributed build.
Reviewers: mehdi_amini
Subscribers: Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D29461
llvm-svn: 293908
Summary:
This change implements the instrumentation map loading library which can
understand both YAML-defined instrumentation maps, and ELF 64-bit object
files that have the XRay instrumentation map section. We break it out
into a library on its own to allow for other applications to deal with
the XRay instrumentation map defined in XRay-instrumented binaries.
This type provides both raw access to the logical representation of the
instrumentation map entries as well as higher level functions for
converting a function ID into a function address.
At this point we only support ELF64 binaries and YAML-defined XRay
instrumentation maps. Future changes should extend this to support
32-bit ELF binaries, as well as other binary formats (like MachO).
As part of this change we also migrate all uses of the extraction logic
that used to be defined in tools/llvm-xray/ to use this new type and
interface for loading from files. We also remove the flag from the
`llvm-xray` tool that required users to specify the type of the
instrumentation map file being provided to instead make the library
auto-detect the file type.
Reviewers: dblaikie
Subscribers: mgorny, varno, llvm-commits
Differential Revision: https://reviews.llvm.org/D29319
llvm-svn: 293721
without symbols that makes calls through a symbol stub which were not
correctly being annotated with “## symbol stub for: _foo”.
Just adds the same parameters for getting the annotations from
DisAsm->getInstruction() and passing them to IP->printInst() from the
code above when boolean variable symbolTableWorked was true.
rdar://29791952
llvm-svn: 293662
Create a WasmDumper subclass of ObjDumper to support Webassembly binary
files.
Patch by Sam Clegg
Differential Revision: https://reviews.llvm.org/D27355
llvm-svn: 293569
To better match the old darwin otool(1) behavior, when llvm-obdump(1) is used
with the -macho option and the input file is not an object file simply print
the file name and this message:
foo: is not an object file
and continue on to process other input files. Also in this case don’t exit
non-zero. This should help in some OSS projects' with autoconf scripts
that are expecting the old darwin otool(1) behavior.
rdar://26828015
llvm-svn: 293547
Mach-O files don’t have size information about the symbols in the object file
format unlike ELF.
Also add the part of the fix to llvm-nm that was missed with r290001 so
-arch armv7m works.
rdar://25681018
llvm-svn: 293099
Summary:
A patch to enable the llvm-xray graph subcommand to color edges and
vertices based on statistics and to annotate vertices with statistics.
Depends on D27243
Reviewers: dblaikie, dberris
Reviewed By: dberris
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D28225
llvm-svn: 293031
for CPU_SUBTYPE_ARM_V7S and CPU_SUBTYPE_ARM_V7K.
For these two cpusubtypes they should default to a cortex-a7 CPU
to give proper disassembly without a -mcpu= flag.
rdar://27431703
llvm-svn: 292993
in llvm-objdump for Mach-O files add the printing of the
x86_thread_state32_t in the same format as
otool-classic(1) on darwin.
To do this the 32-bit x86 general tread state
needed to be defined in include/llvm/Support/MachO.h .
rdar://30110111
llvm-svn: 292829
Summary:
Add a new load command LC_BUILD_VERSION. It is a generic version of
LC_*_VERSION_MIN load_command used on Apple platforms. Instead of having
a seperate load command for each platform, LC_BUILD_VERSION is recording
platform info as an enum. It also records SDK version, min_os, and tools
that used to build the binary.
rdar://problem/29781291
Reviewers: enderby
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29044
llvm-svn: 292824
Add the `--strip-underscore` option to llvm-cxxfilt to strip the leading
underscore. This is useful for when dealing with targets which add a
leading underscore.
llvm-svn: 292759
Summary:
Allow non-ODR weak/linkonce non-prevailing copies to be marked
as available_externally in the index. Add support for dropping these to
declarations in the backend.
Reviewers: mehdi_amini, pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28806
llvm-svn: 292656
By default c++filt demangles functions, though you can optionally pass
`-t` to have it decode types as well, behaving nearly identical to
`__cxa_demangle`. Add support for this mode.
llvm-svn: 292576
It describes a region of arbitrary data included in a Mach-O file.
Its initial use is to record extra data in MH_CORE files.
rdar://30001545
rdar://30001731
llvm-svn: 292500
c++filt does not attempt to demangle symbols which do not match its
expected format. This means that the symbol must start with _Z or ___Z
(block invocation function extension). Any other symbols are returned
as is. Note that this is different from the behaviour of __cxa_demangle
which will demangle fragments.
llvm-svn: 292467
An ELFObjectFile can now create SubtargetFeatures from the available
ARM build attributes, in a similar manner to MIPS. I've moved the
MIPS code into its own function and the ARM handler also has a
separate function.
Differential Revision: https://reviews.llvm.org/D28291
llvm-svn: 292403
Enable an ELFObjectFile to read the its arm build attributes to
produce a target triple with a specific ARM architecture.
llvm-objdump now uses this functionality to automatically produce
a more accurate target.
Differential Revision: https://reviews.llvm.org/D28769
llvm-svn: 292366
Summary:
Tests under tools/llvm-objdump should not use inputs from Object. Copied the
required inputs and aligned the new tests to be more consistent with the existing
tests in this respect.
Reviewers: ioeric
Reviewed By: ioeric
Subscribers: davide, djasper, cfe-commits
Differential Revision: https://reviews.llvm.org/D28799
llvm-svn: 292222
Here we define the `graph` subcommand which generates a graph from the function
call information and uses it to present the call information graphically with
additional annotations.
Reviewers: dblaikie, dberris
Differential Revision: https://reviews.llvm.org/D27243
llvm-svn: 292156
Summary:
Revert [ARM] Fix ubig32_t read in ARMAttributeParser
Now using support functions to read data instead of trying to
perform casts.
===========================================================
Revert [ARM] Enable objdump to construct triple for ARM
Now that The ARMAttributeParser has been moved into the library,
it has been modified so that it can parse the attributes without
printing them and stores them in a map. ELFObjectFile now queries
the attributes to fill out the architecture details of a provided
triple for 'arm' and 'thumb' targets. llvm-objdump uses this new
functionality.
Subscribers: llvm-commits, samparker, aemerson, mgorny
Differential Revision: https://reviews.llvm.org/D28683
llvm-svn: 291911
Now that The ARMAttributeParser has been moved into the library,
it has been modified so that it can parse the attributes without
printing them and stores them in a map. ELFObjectFile now queries
the attributes to fill out the architecture details of a provided
triple for 'arm' and 'thumb' targets. llvm-objdump uses this new
functionality.
Differential Revision: https://reviews.llvm.org/D28281
llvm-svn: 291898
Summary:
This is the third of a multi-part change to implement subcommands for
the `llvm-xray` tool.
Here we define the `account` subcommand which does simple function call
accounting, generating basic statistics on function calls we find in an
XRay log/trace. We support text output and csv output for this
subcommand.
This change also supports sorting, summing, and filtering the top N
results.
Part of this tool will later be turned into a library that could be used
for basic function call accounting.
Depends on D24376.
Reviewers: dblaikie, echristo
Subscribers: mehdi_amini, dberris, beanz, llvm-commits
Differential Revision: https://reviews.llvm.org/D24377
llvm-svn: 291749
Summary:
In this change we move the definition of the log reading routines from
the tools directory in LLVM to {include/llvm,lib}/XRay. We improve the
documentation a little bit for the publicly accessible headers, and
adjust the top-matter. This also leads to some refactoring and cleanup
in the tooling code.
In particular, we do the following:
- Rename the class from LogReader to Trace, as it better represents
the logical set of records as opposed to a log.
- Use file type detection instead of asking the user to say what
format the input file is. This allows us to keep the interface
simple and encapsulate the logic of loading the data appropriately.
In future changes we increase the API surface and write dedicated unit
tests for the XRay library.
Depends on D24376.
Reviewers: dblaikie, echristo
Subscribers: mehdi_amini, mgorny, llvm-commits, varno
Differential Revision: https://reviews.llvm.org/D28345
llvm-svn: 291652
Following the similar change to lit configuration, ensure that all CMake
booleans are canonicalized to 0/1 when being passed to llvm-config. This
fixes the incorrect interpretation of values when user passes another
value than the ON/OFF, and simplifies the code by removing unnecessary
string matching.
Furthermore, the code for --has-rtti and --has-global-isel has been
modified to print consistent values indepdently of the boolean used by
passed by the user to CMake. Sadly, the code already implicitly used
different values for the two (YES/NO for --has-rtti, ON/OFF for
--has-global-isel).
Include tests for all booleans and multi-value options in llvm-config.
Differential Revision: https://reviews.llvm.org/D28366
llvm-svn: 291593
This is the second part of a multi-part change to define additional
subcommands to the `llvm-xray` tool.
This change defines a conversion subcommand to take XRay log files, and
turns them from one format to another (binary or YAML). This currently
only supports the first version of the log file format, defined in the
compiler-rt runtime.
Depends on D21987.
Reviewers: dblaikie, echristo
Subscribers: mehdi_amini, dberris, beanz, llvm-commits
Differential Revision: https://reviews.llvm.org/D24376
llvm-svn: 291529
Don't print a line multiple times, each for different inlining contexts, if
nothing happened in any context. This prevents situations like this:
[[
> main:
65 | if ((i * ni + j) % 20 == 0) fprintf
> print_array:
65 | if ((i * ni + j) % 20 == 0) fprintf
]]
which could happen if different optimizations were missed in different inlining
contexts.
llvm-svn: 291361
Modify the --system-libs option in llvm-config to print system libs only
when using static linking. The system libraries are irrelevant when
linking to a shared library since the library has appropriate library
dependencies embedded.
Modify the --system-libs test appropriately to force static linking, and
disable it if static libs are not available (i.e. BUILD_SHARED_LIBS is
enabled).
Differential Revision: https://reviews.llvm.org/D27805
llvm-svn: 291285
These tests are missing a target triple and the -m elf_x86_64 gold option,
which makes them fail on non-x86 targets.
Differential revision: https://reviews.llvm.org/D28285
Reviewers: tejohnson
llvm-svn: 290965
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
llvm-svn: 290153
The Mach-O command line flag like "-arch armv7m" does not match the
arch name part of its llvm Triple which is "thumbv7m-apple-darwin”.
I think the best way to fix this is to have
llvm::object::MachOObjectFile::getArchTriple() optionally return the
name of the Mach-O arch flag that would be used with -arch that
matches the CPUType and CPUSubType. Then change
llvm::object::MachOUniversalBinary::ObjectForArch::getArchTypeName()
to use that and change it to getArchFlagName() as the type name is
really part of the Triple and the -arch flag name is a Mach-O thing
for a specific Triple with a specific Mcpu value.
rdar://29663637
llvm-svn: 290001
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!
llvm-svn: 289982
Summary: ThinLTO needs to invoke SampleProfileLoader pass during link time in order to annotate profile correctly after module importing.
Reviewers: davidxl, mehdi_amini, tejohnson
Subscribers: pcc, davide, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D27790
llvm-svn: 289957
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
llvm-svn: 289920
Reid Kleckner