Implement unique sections with an unique ID.

This allows the compiler/assembly programmer to switch back to a
section. This in turn fixes the bootstrap failure on powerpc (tested
on gcc110) without changing the ppc codegen at all.

I will try to cleanup the various getELFSection overloads in a  followup patch.
Just using a default argument now would lead to ambiguities.

llvm-svn: 234099

1 files changed, 23 insertions, 0 deletions

diff --git a/llvm/docs/Extensions.rst b/llvm/docs/Extensions.rst
index 271c08598b3..12eac5e0ed8 100644
--- a/llvm/docs/Extensions.rst
+++ b/llvm/docs/Extensions.rst
@@ -165,6 +165,29 @@ and ``.bar`` is associated to ``.foo``.
 	.section	.foo,"bw",discard, "sym"
 	.section	.bar,"rd",associative, "sym"
 
+
+ELF-Dependent
+-------------
+
+``.section`` Directive
+^^^^^^^^^^^^^^^^^^^^^^
+
+In order to support creating multiple sections with the same name and comdat,
+it is possible to add an unique number at the end of the ``.seciton`` directive.
+For example, the following code creates two sections named ``.text``.
+
+.. code-block:: gas
+
+	.section	.text,"ax",@progbits,unique 1
+        nop
+
+	.section	.text,"ax",@progbits,unique 2
+        nop
+
+
+The unique number is not present in the resulting object at all. It is just used
+in the assembler to differentiate the sections.
+
 Target Specific Behaviour
 =========================