ld: Support input section description keyword: REVERSE

  PR 27565
  * ldlex.l: Add REVERSE.
  * ldgram.y: Allow REVERSE to be used wherever a sorting command can be used.
  * ld.h (struct wildcard_spec): Add 'reversed' field.
  * ldlang.h (lang_wild_statement_struct): Add 'filenames_reversed' field.
  * ldlang.c (compare_sections): Add reversed parameter. (wild_sort): Reverse the comparison if requested. (print_wild_statement): Handle the reversed field.
  * ld.texi: Document the new feature.
  * NEWS: Mention the new feature.
  * testsuite/ld-scripts/sort-file-reversed-1.d: New test driver.
  * testsuite/ld-scripts/sort-file-reversed-1.t: New test source.
  * testsuite/ld-scripts/sort-file-reversed-2.t: New test source.
  * testsuite/ld-scripts/sort-file-reversed-2.d: New test driver.
  * testsuite/ld-scripts/sort-sections-reversed-1.d: New test driver.
  * testsuite/ld-scripts/sort-sections-reversed-1.t: New test source.
  * testsuite/ld-scripts/sort-sections-reversed-2.t: New test source.
  * testsuite/ld-scripts/sort-sections-reversed-2.d: New test driver.
  * testsuite/ld-scripts/sort-sections-reversed-3.d: New test driver.
  * testsuite/ld-scripts/sort-sections-reversed-3.t: New test source.

1 files changed, 38 insertions, 0 deletions

diff --git a/ld/ld.texi b/ld/ld.texi
index 1f56ded..7ae01b1 100644
--- a/ld/ld.texi
+++ b/ld/ld.texi
@@ -5263,6 +5263,35 @@ the init_priority.  In @code{.ctors.NNNNN} and @code{.dtors.NNNNN},
 @cindex SORT
 @code{SORT} is an alias for @code{SORT_BY_NAME}.
 
+@cindex REVERSE
+@code{REVERSE} indicates that the sorting should be reversed.  If used
+on its own then @code{REVERSE} implies @code{SORT_BY_NAME}, otherwise
+it reverses the enclosed @code{SORT..} command.  Note - reverse
+sorting of alignment is not currently supported.
+
+Note - the sorting commands only accept a single wildcard pattern.  So
+for example the following will not work:
+@smallexample
+  *(REVERSE(.text* .init*))
+@end smallexample
+To resolve this problem list the patterns individually, like this:
+@smallexample
+  *(REVERSE(.text*))
+  *(REVERSE(.init*))
+@end smallexample
+
+Note - you can put the @code{EXCLUDE_FILE} command inside a sorting
+command, but not the other way around.  So for example:
+@smallexample
+  *(SORT_BY_NAME(EXCLUDE_FILE(foo) .text*))
+@end smallexample
+will work, but:
+@smallexample
+  *(EXCLUDE_FILE(foo) SORT_BY_NAME(.text*))
+@end smallexample
+will not.
+
+
 When there are nested section sorting commands in linker script, there
 can be at most 1 level of nesting for section sorting commands.
 
@@ -5282,6 +5311,15 @@ treated the same as @code{SORT_BY_NAME} (wildcard section pattern).
 @code{SORT_BY_ALIGNMENT} (@code{SORT_BY_ALIGNMENT} (wildcard section pattern))
 is treated the same as @code{SORT_BY_ALIGNMENT} (wildcard section pattern).
 @item
+@code{SORT_BY_NAME} (@code{REVERSE} (wildcard section pattern))
+reverse sorts by name.
+@item
+@code{REVERSE} (@code{SORT_BY_NAME} (wildcard section pattern))
+reverse sorts by name.
+@item
+@code{SORT_BY_INIT_PRIORITY} (@code{REVERSE} (wildcard section pattern))
+reverse sorts by init priority.
+@item
 All other nested section sorting commands are invalid.
 @end enumerate