ld: optionally emit _etext last, before .data

So, here's my suggestion for making _init .. __etext cover .text +
.rodata (including things like the read-only exception tables) for
elf64mmix.  A quick web search gives that __etext (and friends) isn't
well defined, so each target can interpret the "end of text segment"
to their own liking.  It seems likely this change is also a better fit
than the default for other ports, at least those with .rodata after
.text in the same segment.

The presence of a separate rodata-segment is optional (and not true
for elf64mmix).  This is reflected in the name as SEPARATE_TEXT /
SEPARATE_CODE isn't considered, to keep it simple; each target has to
make sure their settings of variables make sense.

ld:
	* scripttempl/elf.sc (ETEXT_LAST_IN_RODATA_SEGMENT): New variable.
	* emulparams/elf64mmix.sh (ETEXT_LAST_IN_RODATA_SEGMENT): Define.
	* testsuite/ld-mmix/sec-1.d: Adjust.

1 files changed, 4 insertions, 0 deletions

diff --git a/ld/emulparams/elf64mmix.sh b/ld/emulparams/elf64mmix.sh
index dffc6cc..75e24be 100644
--- a/ld/emulparams/elf64mmix.sh
+++ b/ld/emulparams/elf64mmix.sh
@@ -44,6 +44,10 @@ ${RELOCATING+
  PROVIDE (Main = DEFINED (Main) ? Main : (DEFINED (_start) ? _start : _start.));
 }"
 
+# We need a symbol at the end of the read-only data, which is
+# colocated with the code.  We make __etext fit.
+ETEXT_LAST_IN_RODATA_SEGMENT=" "
+
 OTHER_SECTIONS='
  .MMIX.reg_contents :
  {