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Diffstat (limited to 'llvm/docs')
| -rw-r--r-- | llvm/docs/Extensions.rst | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/llvm/docs/Extensions.rst b/llvm/docs/Extensions.rst index 32eeadd78ba..46189a3b1ec 100644 --- a/llvm/docs/Extensions.rst +++ b/llvm/docs/Extensions.rst @@ -221,6 +221,44 @@ which is equivalent to just .section .foo,"a",@progbits .section .bar,"ao",@progbits,.foo +``.linker-options`` Section (linker options) +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +In order to support passing linker options from the frontend to the linker, a +special section of type ``SHT_LLVM_LINKER_OPTIONS`` (usually named +``.linker-options`` though the name is not significant as it is identified by +the type). The contents of this section is a simple pair-wise encoding of +options for consideration by the linker. The strings are encoded as standard +null-terminated UTF-8 strings. They are emitted inline to avoid having the +linker to traverse the object file for retrieving the value. The linker is +permitted to not honour the option and instead provide a warning/error to the +user that the requested option was not honoured. + +The section is marked as ``SHT_LLVM_LINKER_OPTIONS`` and has the ``SHF_EXCLUDE`` +flag to ensure that the section is treated as opaque by linkers which do not +support the feature and will not be emitted into the final linked binary. + +This would be equivalent to the follow raw assembly: + +.. code-block:: gas + + .section ".linker-options","e",@llvm_linker_options + .asciz "option 1" + .asciz "value 1" + .asciz "option 2" + .asciz "value 2" + +LLVM emits the following options: + - lib + + The parameter identifies a library to be linked against. The library will + be looked up in the default and any specified library search paths + (specified to this point). + + - path + + The paramter identifies an additional library search path to be considered + when looking up libraries after the inclusion of this option. Target Specific Behaviour ========================= |
