casa-mp-base

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=a985e9b9deabd81e16754584f4397a638e9d3f36

​

From: Nick Clifton <nickc@redhat.com>

Date: Mon, 5 Feb 2018 09:12:42 +0000

Subject: [PATCH] Import patch from mainline to remove PROVODE qualifiers

 around definitions of __CTOR_LIST__ and __DTOR_LIST__ in PE linker scripts.

​

    PR 22762

    * scripttempl/pe.sc: Remove PROVIDE()s from __CTOR_LIST__ and

    __DTOR_LIST__ symbols.  Add a comment explaining why this is

    necessary.

    * scripttemp/pep.sc: Likewise.

    * ld.texinfo (PROVIDE): Add a note about the effect of common

    symbols.

---

--- ld/ld.texinfo.orig

+++ ld/ld.texinfo

@@ -4001,6 +4001,12 @@ 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.

+Note - the @code{PROVIDE} directive considers a common symbol to be

+defined, even though such a symbol could be combined with the symbol

+that the @code{PROVIDE} would create.  This is particularly important

+when considering constructor and destructor list symbols such as

+@samp{__CTOR_LIST__} as these are often defined as common symbols.

+

 @node PROVIDE_HIDDEN

 @subsection PROVIDE_HIDDEN

 @cindex PROVIDE_HIDDEN

--- ld/scripttempl/pe.sc.orig

+++ ld/scripttempl/pe.sc

@@ -98,8 +98,22 @@ SECTIONS

     ${RELOCATING+*(.glue_7t)}

     ${RELOCATING+*(.glue_7)}

     ${CONSTRUCTING+

-       PROVIDE(___CTOR_LIST__ = .);

-       PROVIDE(__CTOR_LIST__ = .);

+       /* Note: we always define __CTOR_LIST__ and ___CTOR_LIST__ here,

+          we do not PROVIDE them.  This is because the ctors.o startup

+     code in libgcc defines them as common symbols, with the 

+          expectation that they will be overridden by the definitions

+     here.  If we PROVIDE the symbols then they will not be

+     overridden and global constructors will not be run.

+     

+     This does mean that it is not possible for a user to define

+     their own __CTOR_LIST__ and __DTOR_LIST__ symbols.  If that

+     ability is needed a custom linker script will have to be

+     used.  (The custom script can just be a copy of this script

+     with the PROVIDE() qualifiers added).

+

+     See PR 22762 for more details.  */

+       ___CTOR_LIST__ = .;

+       __CTOR_LIST__ = .;

        LONG (-1);

        KEEP(*(.ctors));

        KEEP(*(.ctor));

@@ -107,8 +121,10 @@ SECTIONS

        LONG (0);

      }

     ${CONSTRUCTING+

-       PROVIDE(___DTOR_LIST__ = .);

-       PROVIDE(__DTOR_LIST__ = .);