ld: Support customized output section type

bfd/
    PR ld/28841
    * bfd-in2.h (struct bfd_section): Add type.
    (discarded_section): Add field.
    * elf.c (elf_fake_sections): Handle bfd_section::type.
    * section.c (BFD_FAKE_SECTION): Add field.
    * mri.c (mri_draw_tree): Update function call.

ld/
    PR ld/28841
    * ld.texi: Document new output section type.
    * ldlex.l: Add new token TYPE.
    * ldgram.y: Handle TYPE=exp.
    * ldlang.h: Add type_section to list of section types.
    * ldlang.c (lang_add_section): Handle type_section.
    (map_input_to_output_sections): Handle type_section.
    * testsuite/ld-scripts/output-section-types.t: Add tests.
    * testsuite/ld-scripts/output-section-types.d: Update.

1 files changed, 13 insertions, 3 deletions

diff --git a/ld/ld.texi b/ld/ld.texi
index fc75e9b..d57e922 100644
--- a/ld/ld.texi
+++ b/ld/ld.texi
@@ -5483,13 +5483,23 @@ loaded into memory when the program is run.
 @item READONLY
 The section should be marked as read-only.
 @item DSECT
-@itemx COPY
-@itemx INFO
-@itemx OVERLAY
+@item COPY
+@item INFO
+@item OVERLAY
 These type names are supported for backward compatibility, and are
 rarely used.  They all have the same effect: the section should be
 marked as not allocatable, so that no memory is allocated for the
 section when the program is run.
+@item TYPE = @var{type}
+Set the section type to the integer @var{type}. When generating an ELF
+output file, type names @code{SHT_PROGBITS}, @code{SHT_STRTAB},
+@code{SHT_NOTE}, @code {SHT_NOBITS}, @code{SHT_INIT_ARRAY},
+@code{SHT_FINI_ARRAY}, and @code{SHT_PREINIT_ARRAY} are also allowed
+for @var{type}.  It is the user's responsibility to ensure that any
+special requirements of the section type are met.
+@item READONLY ( TYPE = @var{type} )
+This form of the syntax combines the @var{READONLY} type with the
+type specified by @var{type}.
 @end table
 
 @kindex NOLOAD