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This patch implements proposal https://lists.llvm.org/pipermail/llvm-dev/2020-August/144579.html llvm-dwarfutil - is a tool that is used for processing debug info(DWARF) located in built binary files to improve debug info quality, reduce debug info size. The patch currently implements smaller set of command-line options(comparing to the proposal): ``` ./llvm-dwarfutil [options] <input file> <output file> --garbage-collection Do garbage collection for debug info(default) -j <value> Alias for --num-threads --no-garbage-collection Don`t do garbage collection for debug info --no-odr-deduplication Don`t do ODR deduplication for debug types --no-odr Alias for --no-odr-deduplication --no-separate-debug-file Create single output file, containing debug tables(default) --num-threads <threads> Number of available threads for multi-threaded execution. Defaults to the number of cores on the current machine --odr-deduplication Do ODR deduplication for debug types(default) --odr Alias for --odr-deduplication --separate-debug-file Create two output files: file w/o debug tables and file with debug tables --tombstone [bfd,maxpc,exec,universal] Tombstone value used as a marker of invalid address(default: universal) =bfd - Zero for all addresses and [1,1] for DWARF v4 (or less) address ranges and exec =maxpc - Minus 1 for all addresses and minus 2 for DWARF v4 (or less) address ranges =exec - Match with address ranges of executable sections =universal - Both: bfd and maxpc ``` Reviewed By: clayborg Differential Revision: https://reviews.llvm.org/D86539
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3.2 KiB
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123 lines
3.2 KiB
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llvm-dwarfutil - A tool to copy and manipulate debug info
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=========================================================
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.. program:: llvm-dwarfutil
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SYNOPSIS
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--------
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:program:`llvm-dwarfutil` [*options*] *input* *output*
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DESCRIPTION
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-----------
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:program:`llvm-dwarfutil` is a tool to copy and manipulate debug info.
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In basic usage, it makes a semantic copy of the input to the output. If any
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options are specified, the output may be modified along the way, e.g.
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by removing unused debug info.
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If "-" is specified for the input file, the input is read from the program's
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standard input stream. If "-" is specified for the output file, the output
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is written to the standard output stream of the program.
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The tool is still in active development.
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COMMAND-LINE OPTIONS
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--------------------
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.. option:: --garbage-collection
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Removes pieces of debug information related to discarded sections.
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When the linker does section garbage collection the abandoned debug info
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is left behind. Such abandoned debug info references address ranges using
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tombstone values. Thus, when this option is specified, the tool removes
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debug info which is marked with the tombstone value.
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That option is enabled by default.
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.. option:: --odr-deduplication
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Remove duplicated types (if "One Definition Rule" is supported by source
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language). Keeps first type definition and removes other definitions,
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potentially significantly reducing the size of output debug info.
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That option is enabled by default.
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.. option:: --help, -h
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Print a summary of command line options.
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.. option:: --no-garbage-collection
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Disable :option:`--garbage-collection`.
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.. option:: --no-odr-deduplication
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Disable :option:`--odr-deduplication`.
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.. option:: --no-separate-debug-file
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Disable :option:`--separate-debug-file`.
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.. option:: --num-threads=<n>, -j
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Specifies the maximum number (`n`) of simultaneous threads to use
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for processing.
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.. option:: --separate-debug-file
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Generate separate file containing output debug info. Using
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:program:`llvm-dwarfutil` with that option equals to the
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following set of commands:
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.. code-block:: console
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:program:`llvm-objcopy` --only-keep-debug in-file out-file.debug
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:program:`llvm-objcopy` --strip-debug in-file out-file
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:program:`llvm-objcopy` --add-gnu-debuglink=out-file.debug out-file
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.. option:: --tombstone=<value>
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<value> can be one of the following values:
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- `bfd`: zero for all addresses and [1,1] for DWARF v4 (or less) address ranges and exec.
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- `maxpc`: -1 for all addresses and -2 for DWARF v4 (or less) address ranges.
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- `universal`: both `bfd` and `maxpc`.
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- `exec`: match with address ranges of executable sections.
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The value `universal` is used by default.
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.. option:: --verbose
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Enable verbose logging. This option disables multi-thread mode.
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.. option:: --verify
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Run the DWARF verifier on the output DWARF debug info.
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.. option:: --version
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Print the version of this program.
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SUPPORTED FORMATS
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-----------------
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The following formats are currently supported by :program:`llvm-dwarfutil`:
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ELF
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EXIT STATUS
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-----------
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:program:`llvm-dwarfutil` exits with a non-zero exit code if there is an error.
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Otherwise, it exits with code 0.
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BUGS
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----
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To report bugs, please visit <https://github.com/llvm/llvm-project/labels/tools:llvm-dwarfutil/>.
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