diff options
| author | Nico Rieck <nico.rieck@gmail.com> | 2013-04-10 23:28:17 +0000 |
|---|---|---|
| committer | Nico Rieck <nico.rieck@gmail.com> | 2013-04-10 23:28:17 +0000 |
| commit | 18d49acdab79d6f0966b47182b6c3a2ba3d9f80f (patch) | |
| tree | 627374fd66e65ec88b6ba4f4cfd81c79cf6be35b /docs/Extensions.rst | |
| parent | bb5cbd86a4add5944c869836c507d419255d98dc (diff) | |
| download | llvm-18d49acdab79d6f0966b47182b6c3a2ba3d9f80f.tar.gz llvm-18d49acdab79d6f0966b47182b6c3a2ba3d9f80f.tar.bz2 llvm-18d49acdab79d6f0966b47182b6c3a2ba3d9f80f.tar.xz | |
MC: Support COFF image-relative MCSymbolRefs
Add support for the COFF relocation types IMAGE_REL_I386_DIR32NB and
IMAGE_REL_AMD64_ADDR32NB for 32- and 64-bit respectively. These are
similar to normal 4-byte relocations except that they do not include
the base address of the image.
Image-relative relocations are used for debug information (32-bit) and
SEH unwind tables (64-bit).
A new MCSymbolRef variant called 'VK_COFF_IMGREL32' is introduced to
specify such relocations. For AT&T assembly, this variant can be accessed
using the symbol suffix '@imgrel'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179240 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/Extensions.rst')
| -rw-r--r-- | docs/Extensions.rst | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/docs/Extensions.rst b/docs/Extensions.rst new file mode 100644 index 0000000000..062804a9fc --- /dev/null +++ b/docs/Extensions.rst @@ -0,0 +1,39 @@ +=============== +LLVM Extensions +=============== + +.. contents:: + :local: + :depth: 1 + +.. toctree:: + :hidden: + +Introduction +============ + +This document describes extensions to tools and formats LLVM seeks compatibility +with. + +Machine-specific Assembly Syntax +================================ + +X86/COFF-Dependent +------------------ + +The following additional relocation type is supported: + +**@IMGREL** (AT&T syntax only) generates an image-relative relocation that +corresponds to the COFF relocation types ``IMAGE_REL_I386_DIR32NB`` (32-bit) or +``IMAGE_REL_AMD64_ADDR32NB`` (64-bit). + +.. code-block:: gas + + .text + fun: + mov foo@IMGREL(%ebx, %ecx, 4), %eax + + .section .pdata + .long fun@IMGREL + .long (fun@imgrel + 0x3F) + .long $unwind$fun@imgrel |