be in wholly disjoint pages from any other data. Don't create separate
code @code{PT_LOAD} segment if @samp{noseparate-code} is used.
-@item unique-symbol
-@itemx nounique-symbol
-Avoid duplicated local symbol names in the symbol string table. Append
-".@code{number}" to duplicated local symbol names if @samp{unique-symbol}
-is used. @option{nounique-symbol} is the default.
-
@item shstk
Generate GNU_PROPERTY_X86_FEATURE_1_SHSTK in .note.gnu.property section
to indicate compatibility with Intel Shadow Stack. Supported for
Specifying zero will override any default non-zero sized
@code{PT_GNU_STACK} segment creation.
+@item start-stop-gc
+@itemx nostart-stop-gc
+@cindex start-stop-gc
+When @samp{--gc-sections} is in effect, a reference from a retained
+section to @code{__start_SECNAME} or @code{__stop_SECNAME} causes all
+input sections named @code{SECNAME} to also be retained, if
+@code{SECNAME} is representable as a C identifier and either
+@code{__start_SECNAME} or @code{__stop_SECNAME} is synthesized by the
+linker. @samp{-z start-stop-gc} disables this effect, allowing
+sections to be garbage collected as if the special synthesized symbols
+were not defined. @samp{-z start-stop-gc} has no effect on a
+definition of @code{__start_SECNAME} or @code{__stop_SECNAME} in an
+object file or linker script. Such a definition will prevent the
+linker providing a synthesized @code{__start_SECNAME} or
+@code{__stop_SECNAME} respectively, and therefore the special
+treatment by garbage collection for those references.
+
@item start-stop-visibility=@var{value}
@cindex visibility
@cindex ELF symbol visibility
either when creating an executable, or when creating a shared library.
This option is the inverse of @samp{-z defs}.
+@item unique-symbol
+@itemx nounique-symbol
+Avoid duplicated local symbol names in the symbol string table. Append
+".@code{number}" to duplicated local symbol names if @samp{unique-symbol}
+is used. @option{nounique-symbol} is the default.
+
@item x86-64-baseline
@item x86-64-v2
@item x86-64-v3
needed. This is similar to the rules for extraction of object files
from archives. @option{--no-as-needed} restores the default behaviour.
+Note: On Linux based systems the @option{--as-needed} option also has
+an affect on the behaviour of the @option{--rpath} and
+@option{--rpath-link} options. See the description of
+@option{--rpath-link} for more details.
+
@kindex --add-needed
@kindex --no-add-needed
@item --add-needed
This option is only meaningful on ELF platforms which support shared
libraries.
+@kindex -Bno-symbolic
+@item -Bno-symbolic
+This option can cancel previously specified @samp{-Bsymbolic} and
+@samp{-Bsymbolic-functions}.
+
@kindex --dynamic-list=@var{dynamic-list-file}
@item --dynamic-list=@var{dynamic-list-file}
Specify the name of a dynamic list file to the linker. This is
normal dynamically linked executables they can be executed and symbols
defined in the executable cannot be overridden by shared libraries.
+@kindex -no-pie
+@item -no-pie
+@cindex position dependent executables
+Create a position dependent executable. This is the default.
+
@kindex -qmagic
@item -qmagic
This option is ignored for Linux compatibility.
libraries needed by it. The @code{DT_RPATH} entries are ignored if
@code{DT_RUNPATH} entries exist.
@item
-The default directories, normally @file{/lib} and @file{/usr/lib}.
-@item
For a linker for a Linux system, if the file @file{/etc/ld.so.conf}
exists, the list of directories found in that file. Note: the path
to this file is prefixed with the @code{sysroot} value, if that is
the @code{_PATH_ELF_HINTS} macro defined in the @file{elf-hints.h}
header file.
@item
-Any directories specifed by a @code{SEARCH_DIR} command in the
-linker script being used.
+Any directories specified by a @code{SEARCH_DIR} command in a
+linker script given on the command line, including scripts specified
+by @option{-T} (but not @option{-dT}).
+@item
+The default directories, normally @file{/lib} and @file{/usr/lib}.
+@item
+Any directories specified by a plugin LDPT_SET_EXTRA_LIBRARY_PATH.
+@item
+Any directories specified by a @code{SEARCH_DIR} command in a default
+linker script.
@end enumerate
+Note however on Linux based systems there is an additional caveat: If
+the @option{--as-needed} option is active @emph{and} a shared library
+is located which would normally satisfy the search @emph{and} this
+library does not have DT_NEEDED tag for @file{libc.so}
+@emph{and} there is a shared library later on in the set of search
+directories which also satisfies the search @emph{and}
+this second shared library does have a DT_NEEDED tag for
+@file{libc.so} @emph{then} the second library will be selected instead
+of the first.
+
If the required shared library is not found, the linker will issue a
warning and continue with the link.
+
@end ifset
@kindex -shared
@end smallexample
In this example, if the program defines @samp{_etext} (with a leading
-underscore), the linker will give a multiple definition error. If, on
-the other hand, the program defines @samp{etext} (with no leading
+underscore), the linker will give a multiple definition diagnostic. If,
+on the other hand, the program defines @samp{etext} (with no leading
underscore), the linker will silently use the definition in the program.
If the program references @samp{etext} but does not define it, the
linker will use the definition in the linker script.
projects / deliverable / binutils-gdb.git / blobdiff