[lld] r281515 - Add an interesting test.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Wed Sep 14 13:06:02 2016
New Revision: 281515

URL: http://llvm.org/viewvc/llvm-project?rev=281515&view=rev
Log:
Add an interesting test.

Added:
    lld/trunk/test/ELF/linkerscript/alternate-sections.s

Added: lld/trunk/test/ELF/linkerscript/alternate-sections.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/alternate-sections.s?rev=281515&view=auto
==============================================================================
--- lld/trunk/test/ELF/linkerscript/alternate-sections.s (added)
+++ lld/trunk/test/ELF/linkerscript/alternate-sections.s Wed Sep 14 13:06:02 2016
@@ -0,0 +1,34 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+# RUN: echo "SECTIONS { abc : { *(foo) *(bar) *(zed) } }" > %t.script
+# RUN: ld.lld -o %t --script %t.script %t.o -shared
+# RUN: llvm-readobj -s -section-data %t | FileCheck %s
+
+# This test shows an oddity in lld. When a linker script alternates among
+# different types of output section in the same command, the sections are
+# reordered.
+# In this test we go from regular, to merge and back to regular. The reason
+# for the reordering is that we need two create two output sections and
+# one cannot be in the middle of another.
+# If this ever becomes a problem, some options would be:
+# * Adding an extra layer in between input section and output sections (Chunk).
+#   With that this example would have 3 chunks, but only one output section.
+#   This would unfortunately complicate the non-script case too.
+# * Just create three output sections.
+# * If having three output sections causes problem, have linkerscript specific
+#   code to write the section table and section indexes. That way we could
+#   keep 3 sections internally but not expose that.
+
+# CHECK: Name: abc
+# CHECK: 0000: 01000000 00000000 02000000 00000000  |
+# CHECK: Name: abc
+# CHECK: 0000: 61626331 323300                      |abc123.|
+
+        .section foo, "a"
+        .quad 1
+
+        .section bar,"aMS", at progbits,1
+        .asciz  "abc123"
+
+        .section zed, "a"
+        .quad 2