14 Commits

Author SHA1 Message Date
Greg Clayton
75aaaf95b6 Add a llvm-gsymutil tool that can convert object files to GSYM and perform lookups.
Summary:
This patch creates the llvm-gsymutil binary that can convert object files to GSYM using the --convert <path> option. It can also dump and lookup addresses within GSYM files that have been saved to disk.

To dump a file:

llvm-gsymutil /path/to/a.gsym

To perform address lookups, like with atos, on GSYM files:

llvm-gsymutil --address 0x1000 --address 0x1100 /path/to/a.gsym

To convert a mach-o or ELF file, including any DWARF debug info contained within the object files:

llvm-gsymutil --convert /path/to/a.out --out-file /path/to/a.out.gsym

Conversion highlights:
- convert DWARF debug info in mach-o or ELF files to GSYM
- convert symbols in symbol table to GSYM and don't convert symbols that overlap with DWARF debug info
- extract UUID from object files
- extract .text (read + execute) section address ranges and filter out any DWARF or symbols that don't fall in those ranges.
- if .text sections are extracted, and if the last gsym::FunctionInfo object has no size, cap the size to the end of the section the function was contained in

Dumping GSYM files will dump all sections of the GSYM file in textual format.

Reviewers: labath, aadsm, serhiy.redko, jankratochvil, xiaobai, wallace, aprantl, JDevlieghere, jdoerfert

Subscribers: mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74883
2020-02-25 21:11:05 -08:00
Greg Clayton
76f7457508 Add an Offset field to the SourceLocation for LookupResult objects.
Summary:
The Offset provides the offset within the function in a SourceLocation struct. This allows us to show the byte offset within a function. We also track offsets within inline functions as well. Updated the lookup tests to verify the offset for functions and inline functions.

0x1000: main + 32 @ /tmp/main.cpp:45

Reviewers: labath, aadsm, serhiy.redko, jankratochvil, xiaobai, wallace, aprantl, JDevlieghere

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74680
2020-02-19 16:12:32 -08:00
Greg Clayton
ccea019faf Add a DWARF transformer class that converts DWARF to GSYM.
Summary:
The DWARF transformer is added as a class so it can be unit tested fully.

The DWARF is converted to GSYM format and handles many special cases for functions:
- omit functions in compile units with 4 byte addresses whose address is UINT32_MAX (dead stripped)
- omit functions in compile units with 8 byte addresses whose address is UINT64_MAX (dead stripped)
- omit any functions whose high PC is <= low PC (dead stripped)
- StringTable builder doesn't copy strings, so we need to make backing copies of strings but only when needed. Many strings come from sections in object files and won't need to have backing copies, but some do.
- When a function doesn't have a mangled name, store the fully qualified name by creating a string by traversing the parent decl context DIEs and then. If we don't do this, we end up having cases where some function might appear in the GSYM as "erase" instead of "std::vector<int>::erase".
- omit any functions whose address isn't in the optional TextRanges member variable of DwarfTransformer. This allows object file to register address ranges that are known valid code ranges and can help omit functions that should have been dead stripped, but just had their low PC values set to zero. In this case we have many functions that all appear at address zero and can omit these functions by making sure they fall into good address ranges on the object file. Many compilers do this when the DWARF has a DW_AT_low_pc with a DW_FORM_addr, and a DW_AT_high_pc with a DW_FORM_data4 as the offset from the low PC. In this case the linker can't write the same address to both the high and low PC since there is only a relocation for the DW_AT_low_pc, so many linkers tend to just zero it out.

Reviewers: aprantl, dblaikie, probinson

Subscribers: mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74450
2020-02-13 10:48:37 -08:00
Bill Wendling
0816222e8f Revert "Remove redundant "std::move"s in return statements"
The build failed with

  error: call to deleted constructor of 'llvm::Error'

errors.

This reverts commit 1c2241a7936bf85aa68aef94bd40c3ba77d8ddf2.
2020-02-10 07:07:40 -08:00
Bill Wendling
e45b5f33f3 Remove redundant "std::move"s in return statements 2020-02-10 06:39:44 -08:00
Reid Kleckner
633e639e60 Avoid naming variable after type to fix GCC 5.3 build
GCC says:
.../llvm/lib/DebugInfo/GSYM/FunctionInfo.cpp:195:12:
error: ‘InfoType’ is not a class, namespace, or enumeration
       case InfoType::EndOfList:
                   ^

Presumably, GCC thinks InfoType is a variable here. Work around it by
using the name IT as is done above.
2019-12-06 11:25:28 -08:00
Greg Clayton
2bf4a40cf4 Add lookup functions for efficient lookups of addresses when using GsymReader classes.
Summary:
Lookup functions are designed to not fully decode a FunctionInfo, LineTable or InlineInfo, they decode only what is needed into a LookupResult object. This allows lookups to avoid costly memory allocations and avoid parsing large amounts of information one a suitable match is found.

LookupResult objects contain the address that was looked up, the concrete function address range, the name of the concrete function, and a list of source locations. One for each inline function, and one for the concrete function. This allows one address to turn into multiple frames and improves the signal you get when symbolicating addresses in GSYM files.

Reviewers: labath, aprantl

Subscribers: mgorny, hiraditya, llvm-commits, lldb-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70993
2019-12-05 16:49:53 -08:00
Reid Kleckner
8bdbb2386f Fix -Wsign-compare warning with clang-cl
off_t apparently is just "long" on Win64, which is 32-bits, and
therefore not long enough to compare with UINT32_MAX. Use auto to follow
the surrounding code. uint64_t would also be fine.
2019-10-30 15:20:43 -07:00
Greg Clayton
14bc9870e9 Add GsymCreator and GsymReader.
This patch adds the ability to create GSYM files with GsymCreator, and read them with GsymReader. Full testing has been added for both new classes.

This patch differs from the original patch https://reviews.llvm.org/D53379 in that is uses a StringTableBuilder class from llvm instead of a custom version. Support for big and little endian files has been added. If the endianness matches the current host, we use efficient extraction for the header, address table and address info offset tables.

Differential Revision: https://reviews.llvm.org/D68744

llvm-svn: 374381
2019-10-10 17:10:11 +00:00
Greg Clayton
d428cdddb3 GSYM: add encoding and decoding to FunctionInfo
This patch adds encoding and decoding of the FunctionInfo objects along with full error handling and tests. Full details of the FunctionInfo encoding format appear in the FunctionInfo.h header file.

Differential Revision: https://reviews.llvm.org/D67506

llvm-svn: 372135
2019-09-17 16:15:49 +00:00
David Blaikie
4e82e0a032 Add some missing changes to GSYM that was addressing a gcc compilation error due to a type and variable with the same name
llvm-svn: 371681
2019-09-11 22:24:45 +00:00
Greg Clayton
4cef2f62de Add a LineTable class to GSYM and test it.
This patch adds the ability to create a gsym::LineTable object, populate it, encode and decode it and test all functionality.

The full format of the LineTable encoding is specified in the header file LineTable.h.

Differential Revision: https://reviews.llvm.org/D66602

llvm-svn: 371657
2019-09-11 20:51:03 +00:00
Fangrui Song
3c005f1680 [DebugInfo] Simplify GSYM::AddressRange and GSYM::AddressRanges
Delete unnecessary getters of AddressRange.
Simplify AddressRange::size(): Start <= End check should be checked in an upper layer.
Delete isContiguousWith() that doesn't make sense.
Simplify AddressRanges::insert. Delete commented code. Fix it when more than 1 ranges are to be deleted.
Delete trailing newline.

llvm-svn: 364637
2019-06-28 10:06:11 +00:00
Greg Clayton
4e92f3ef15 Add GSYM utility files along with unit tests.
The full GSYM patch started with: https://reviews.llvm.org/D53379

In that patch we wanted to split up getting GSYM into the LLVM code base so we are not committing too much code at once.

This is a first in a series of patches where I only add the foundation classes along with complete unit tests. They provide the foundation for encoding and decoding a GSYM file.

File entries are defined in llvm::gsym::FileEntry. This class splits the file up into a directory and filename represented by uniqued string table offsets. This allows all files that are referred to in a GSYM file to be encoded as 1 based indexes into a global file table in the GSYM file.

Function information in stored in llvm::gsym::FunctionInfo. This object represents a contiguous address range that has a name and range with an optional line table and inline call stack information.

Line table entries are defined in llvm::gsym::LineEntry. They store only address, file and line information to keep the line tables simple and allows the information to be efficiently encoded in a subsequent patch.

Inline information is defined in llvm::gsym::InlineInfo. These structs store the name of the inline function, along with one or more address ranges, and the file and line that called this function. They also contain any child inline information.

There are also utility classes for address ranges in llvm::gsym::AddressRange, and string table support in llvm::gsym::StringTable which are simple classes.

The unit tests test all the APIs on these simple classes so they will be ready for the next patches where we will create GSYM files and parse GSYM files.

Differential Revision: https://reviews.llvm.org/D63104

llvm-svn: 364427
2019-06-26 14:09:09 +00:00