[docs][llvm-objcopy] Update --output-target text with right defaults

The --output-target documentation has slightly rotted, as the default is
no longer purely based on the input file format, but also the value of
--input-target. This patch updates the documentation to make this
explicit.

Reviewed by: MaskRay, alexshap

Differential Revision: https://reviews.llvm.org/D79318

diff --git a/llvm/docs/CommandGuide/llvm-objcopy.rst b/llvm/docs/CommandGuide/llvm-objcopy.rst
index 14e08d7..c5cff2e 100644 (file)
--- a/llvm/docs/CommandGuide/llvm-objcopy.rst
+++ b/llvm/docs/CommandGuide/llvm-objcopy.rst
@@ -417,7 +417,8 @@ them.
 
  Write the output as the specified format. See `SUPPORTED FORMATS`_ for a list
  of valid ``<format>`` values. If unspecified, the output format is assumed to
- be the same as the input file's format.
+ be the same as the value specified for :option:`--input-target` or the input
+ file's format if that option is also unspecified.
 
 .. option:: --prefix-alloc-sections <prefix>