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authorNick Clifton <nickc@redhat.com>2016-02-15 11:11:46 +0000
committerNick Clifton <nickc@redhat.com>2016-02-15 11:11:46 +0000
commit9fb71ee49fc37163697e4f34e16097928eb83d66 (patch)
tree059842e2b43a163ceae1867632b98dc00014d133 /gas/doc
parent2b63aca39c2b0abbb410f7a5a60124ac5abf7438 (diff)
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Enhance GAS's .section directive so that it can take numeric values for the flags and type fields. (ELF only)
gas * doc/as.texinfo (.section): Document that numeric values can now be used for the flags and type fields of the ELF target's .section directive. Add notes about the restrictions on setting flags and types. * config/obj-elf.c (obj_elf_change_section): Allow known sections to be given processor specific section types. Allow processor and application specific flags of a section to be set after definition. (obj_elf_parse_section_letters): Handle parsing numeric values. (obj_elf_section_type): Handle parsing numeric values. (obj_elf_section): Allow numeric type values. * config/obj-elf.h (obj_elf_change_section): Update prototype. * testsuite/gas/elf/section10.d: New test. * testsuite/gas/elf/section10.s: Source file for new test. * testsuite/gas/elf/elf.exp: Run the new test. * testsuite/gas/i386/ilp32/x86-64-unwind.d: Remove dependency upon the description of the flags produced by readelf. * testsuite/gas/tic6x/scomm-directive-4.d: Likewise. * NEWS: Mention the new feature. bfd * elf-bfd.h (struct bfd_elf_special_section): Use unsigned values for length and type fields. Use a signed value for the suffix_length field. binutils* readelf.c (get_section_type_name): Add hex prefix to offsets printed for LOPROC and LOOS values. Ensure that a result is always returned for the V850 target, even when an unrecognised processor specific value is encountered. (process_section_headers): Display key values in the order in which they appear to the user. Add the "C (compressed)" value to the list. ld * testsuite/ld-i386/pr12718.d: Remove dependency upon the description of the flags produced by readelf. * testsuite/ld-i386/pr12921.d: Likewise. * testsuite/ld-i386/tlsbin-nacl.rd: Likewise. * testsuite/ld-i386/tlsbin.rd: Likewise. * testsuite/ld-i386/tlsbindesc-nacl.rd: Likewise. * testsuite/ld-i386/tlsbindesc.rd: Likewise. * testsuite/ld-i386/tlsdesc-nacl.rd: Likewise. * testsuite/ld-i386/tlsdesc.rd: Likewise. * testsuite/ld-i386/tlsgdesc-nacl.rd: Likewise. * testsuite/ld-i386/tlsgdesc.rd: Likewise. * testsuite/ld-i386/tlsnopic-nacl.rd: Likewise. * testsuite/ld-i386/tlsnopic.rd: Likewise. * testsuite/ld-i386/tlspic-nacl.rd: Likewise. * testsuite/ld-i386/tlspic.rd: Likewise. * testsuite/ld-s390/tlsbin.rd: Likewise. * testsuite/ld-s390/tlsbin_64.rd: Likewise. * testsuite/ld-s390/tlspic.rd: Likewise. * testsuite/ld-s390/tlspic_64.rd: Likewise. * testsuite/ld-sh/tlsbin-2.d: Likewise. * testsuite/ld-sh/tlspic-2.d: Likewise. * testsuite/ld-tic6x/common.d: Likewise. * testsuite/ld-tic6x/shlib-1.rd: Likewise. * testsuite/ld-tic6x/shlib-1b.rd: Likewise. * testsuite/ld-tic6x/shlib-1r.rd: Likewise. * testsuite/ld-tic6x/shlib-1rb.rd: Likewise. * testsuite/ld-tic6x/shlib-app-1.rd: Likewise. * testsuite/ld-tic6x/shlib-app-1b.rd: Likewise. * testsuite/ld-tic6x/shlib-app-1r.rd: Likewise. * testsuite/ld-tic6x/shlib-app-1rb.rd: Likewise. * testsuite/ld-tic6x/shlib-noindex.rd: Likewise. * testsuite/ld-tic6x/static-app-1.rd: Likewise. * testsuite/ld-tic6x/static-app-1b.rd: Likewise. * testsuite/ld-tic6x/static-app-1r.rd: Likewise. * testsuite/ld-tic6x/static-app-1rb.rd: Likewise. * testsuite/ld-x86-64/ilp32-4-nacl.d: Likewise. * testsuite/ld-x86-64/ilp32-4.d: Likewise. * testsuite/ld-x86-64/pr12718.d: Likewise. * testsuite/ld-x86-64/pr12921.d: Likewise. * testsuite/ld-x86-64/split-by-file-nacl.rd: Likewise. * testsuite/ld-x86-64/split-by-file.rd: Likewise. * testsuite/ld-x86-64/tlsbin-nacl.rd: Likewise. * testsuite/ld-x86-64/tlsbin.rd: Likewise. * testsuite/ld-x86-64/tlsbindesc-nacl.rd: Likewise. * testsuite/ld-x86-64/tlsbindesc.rd: Likewise. * testsuite/ld-x86-64/tlsdesc-nacl.rd: Likewise. * testsuite/ld-x86-64/tlsdesc.rd: Likewise. * testsuite/ld-x86-64/tlsgdesc-nacl.rd: Likewise. * testsuite/ld-x86-64/tlsgdesc.rd: Likewise. * testsuite/ld-x86-64/tlspic-nacl.rd: Likewise. * testsuite/ld-x86-64/tlspic.rd: Likewise. * testsuite/ld-xtensa/tlsbin.rd: Likewise. * testsuite/ld-xtensa/tlspic.rd: Likewise.
Diffstat (limited to 'gas/doc')
-rw-r--r--gas/doc/as.texinfo25
1 files changed, 24 insertions, 1 deletions
diff --git a/gas/doc/as.texinfo b/gas/doc/as.texinfo
index 917781b..86b09fc 100644
--- a/gas/doc/as.texinfo
+++ b/gas/doc/as.texinfo
@@ -6375,8 +6375,22 @@ section is a member of a section group
section is used for thread-local-storage
@item ?
section is a member of the previously-current section's group, if any
+@item @var{number}
+a numeric value indicating the bits to be set in the ELF section header's flags
+field. Note - if one or more of the alphabetic characters described above is
+also included in the flags field, their bit values will be ORed into the
+resulting value.
+@item @{target specific}
+some targets extend this list with their own types
@end table
+Note - once a section's flags have been set they cannot be changed. There are
+a few exceptions to this rule however. Processor and application specific
+flags can be added to an already defined section. The @code{.interp},
+@code{.strtab} and @code{.symtab} sections can have the allocate flag
+(@code{a}) set after they are initially defined, and the @code{.note-GNU-stack}
+section may have the executable (@code(x)) flag added.
+
The optional @var{type} argument may contain one of the following constants:
@table @code
@item @@progbits
@@ -6391,14 +6405,23 @@ section contains an array of pointers to init functions
section contains an array of pointers to finish functions
@item @@preinit_array
section contains an array of pointers to pre-init functions
+@item @@@var{number}
+a numeric value to be set as the ELF section header's type field.
+@item @@@{target specific}
+some targets extend this list with their own types
@end table
-Many targets only support the first three section types.
+Many targets only support the first three section types. The type may be
+enclosed in double quotes if necessary.
Note on targets where the @code{@@} character is the start of a comment (eg
ARM) then another character is used instead. For example the ARM port uses the
@code{%} character.
+Note - some sections, eg @code{.text} and @code{.data} are considered to be
+special and have fixed types. Any attempt to declare them with a different
+type will generate an error from the assembler.
+
If @var{flags} contains the @code{M} symbol then the @var{type} argument must
be specified as well as an extra argument---@var{entsize}---like this: