Summary:
This is motivated by D63591, where we realized that there isn't a really
good way of telling whether a DataExtractor is reading actual data, or
is it just returning default values because it reached the end of the
buffer.
This patch resolves that by providing a new "Cursor" class. A Cursor
object encapsulates two things:
- the current position/offset in the DataExtractor
- an error object
Storing the error object inside the Cursor enables one to use the same
pattern as the std::{io}stream API, where one can blindly perform a
sequence of reads and only check for errors once at the end of the
operation. Similarly to the stream API, as soon as we encounter one
error, all of the subsequent operations are skipped (return default
values) too, even if the would suceed with clear error state. Unlike the
std::stream API (but in line with other llvm APIs), we force the error
state to be checked through usage of llvm::Error.
Reviewers: probinson, dblaikie, JDevlieghere, aprantl, echristo
Subscribers: kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63713
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@370042 91177308-0d34-0410-b5e6-96231b3b80d8
Using 64-bit offsets is required to fully implement 64-bit DWARF.
As these classes are used in many different libraries they should
temporarily support both 32- and 64-bit offsets.
Differential Revision: https://reviews.llvm.org/D64006
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368013 91177308-0d34-0410-b5e6-96231b3b80d8
When code relaxation is enabled many RISC-V fixups are not resolved but
instead relocations are emitted. This happens even for DWARF debug
sections. Therefore, to properly support the parsing of DWARF debug info
we need to be able to resolve RISC-V relocations. This patch adds:
* Support for RISC-V relocations in RelocationResolver
* DWARF support for two relocations per object file offset
* DWARF changes to support relocations in more DIE fields
The two relocations per offset change is needed because some RISC-V
relocations (used for label differences) come in pairs.
Relocations can also be emitted for DWARF fields where relocations were
not yet evaluated. Adding relocation support for some of these fields is
essencial. On the other hand, LLVM currently emits RISC-V relocations
for fixups that could be safely evaluated, since they can never be
affected by code relaxations. This patch also adds relocation support
for the fields affected by those extraneous relocations (the DWARF unit
entry Length, and the DWARF debug line entry TotalLength and
PrologueLength), for testing purposes.
Differential Revision: https://reviews.llvm.org/D62062
Patch by Luís Marques.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366402 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
getRelocatedValue may compute incorrect value for SHT_RELA-typed relocation entries.
// DWARFDataExtractor.cpp
uint64_t DWARFDataExtractor::getRelocatedValue(uint32_t Size, uint32_t *Off,
...
// This formula is correct for REL, but may be incorrect for RELA if the value
// stored in the location (getUnsigned(Off, Size)) is not zero.
return getUnsigned(Off, Size) + Rel->Value;
In this patch, we
* refactor these visit* functions to include a new parameter `uint64_t A`.
Since these visit* functions are no longer used as visitors, rename them to resolve*.
+ REL: A is used as the addend. A is the value stored in the location where the
relocation applies: getUnsigned(Off, Size)
+ RELA: The addend encoded in RelocationRef is used, e.g. getELFAddend(R)
* and add another set of supports* functions to check if a given relocation type is handled.
DWARFObjInMemory uses them to fail early.
Reviewers: echristo, dblaikie
Reviewed By: echristo
Subscribers: mgorny, aprantl, aheejin, fedor.sergeev, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57939
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356729 91177308-0d34-0410-b5e6-96231b3b80d8
That patch is the fix for https://bugs.llvm.org/show_bug.cgi?id=40703
"wrong line number info for obj file compiled with -ffunction-sections"
bug. The problem happened with only .o files. If object file contains
several .text sections then line number information showed incorrectly.
The reason for this is that DwarfLineTable could not detect section which
corresponds to specified address(because address is the local to the
section). And as the result it could not select proper sequence in the
line table. The fix is to pass SectionIndex with the address. So that it
would be possible to differentiate addresses from various sections. With
this fix llvm-objdump shows correct line numbers for disassembled code.
Differential review: https://reviews.llvm.org/D58194
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354972 91177308-0d34-0410-b5e6-96231b3b80d8
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Original change was D43313 (r326932) and reverted by r326953 because it
broke an LLD test and a windows build. The LLD test was already fixed in
lld commit r326944 (thanks maskray). This is the original change with
the windows build fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326970 91177308-0d34-0410-b5e6-96231b3b80d8
This patch enhances DWARFDebugFrame with the capability of parsing and
printing DWARF expressions in CFI instructions. It also makes FDEs and
CIEs accessible to lib users, so they can process them in client tools
that rely on LLVM. To make it self-contained with a test case, it
teaches llvm-readobj to be able to dump EH frames and checks they are
correct in a unit test. The llvm-readobj code is Maksim Panchenko's work
(maksfb).
Reviewers: JDevlieghere, espindola
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D43313
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326932 91177308-0d34-0410-b5e6-96231b3b80d8
This changes DwarfContext to delegate to DwarfObject instead of having
pure virtual methods.
With this DwarfContextInMemory is replaced with an implementation of
DwarfObject that is local to a .cpp file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@308543 91177308-0d34-0410-b5e6-96231b3b80d8
Requires callers to directly associate relocations with a DataExtractor
used to read data from a DWARF section, which helps a callee not make
assumptions about which section it is reading.
This is the next step in reducing DWARFFormValue's dependence on DWARFUnit.
Differential Revision: https://reviews.llvm.org/D34704
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306699 91177308-0d34-0410-b5e6-96231b3b80d8
