-This is a BETA release of a completely rewritten GNU linker.
-It is distributed with other "binary utilities" which should
-be in ../binutils. See ../binutils/README for more general notes,
-including where to send bug reports.
+ README for LD
-There are many new features of the linker:
+This is the GNU linker. It is distributed with other "binary
+utilities" which should be in ../binutils. See ../binutils/README for
+more general notes, including where to send bug reports.
+
+There are many features of the linker:
* The linker uses a Binary File Descriptor library (../bfd)
-that it uses to read and write object files. This helps
-insulate the linker itself from the format of object files.
+ that it uses to read and write object files. This helps
+ insulate the linker itself from the format of object files.
-* The linker support a number of different object file
-formats. It can even handle multiple formats at once:
-Read two input formats and write a third.
+* The linker supports a number of different object file
+ formats. It can even handle multiple formats at once:
+ Read two input formats and write a third.
* The linker can be configured for cross-linking.
-* The linker contains a control language.
+* The linker supports a control language.
-* There is a manual.
+* There is a user manual (ld.texinfo), as well as the
+ beginnings of an internals manual (ldint.texinfo).
Installation
============
See ../binutils/README.
+
If you want to make a cross-linker, you may want to specify
a different search path of -lfoo libraries than the default.
You can do this by setting the LIB_PATH variable in ./Makefile.
+To build just the linker, make the target all-ld from the top level
+directory (one directory above this one).
+
Porting to a new target
=======================
-A new target configuration may need a new linker script (.sc file)
-to specify linker actions (such as the layout of the output).
-See if one of the existing ones are suitable.
-Note that the Makefile generates variants of the standard script
-that are used when ld is passed -r -Ur -N or -n options.
-These variant default scripts are generated from the "master"
-script using sed scripts that may not work in all cases.
-Look at the rules and comments in ld/Makefile.in to make sure
-you stay with the rules.
-
-Otherwise, you may need to add a new "emulation" (a sample of a
-recently added target and emulation is for the SOny 68k News
-family - look for files named *news*).
-
-Also see the notes in ../binutils/README.
+See the ldint.texinfo manual.
Reporting bugs etc
===========================
+
See ../binutils/README.
+
+Known problems
+==============
+
+The Solaris linker normally exports all dynamic symbols from an
+executable. The GNU linker does not do this by default. This is
+because the GNU linker tries to present the same interface for all
+similar targets (in this case, all native ELF targets). This does not
+matter for normal programs, but it can make a difference for programs
+which try to dlopen an executable, such as PERL or Tcl. You can make
+the GNU linker export all dynamic symbols with the -E or
+--export-dynamic command line option.
+
+HP/UX 9.01 has a shell bug that causes the linker scripts to be
+generated incorrectly. The symptom of this appears to be "fatal error
+- scanner input buffer overflow" error messages. There are various
+workarounds to this:
+ * Build and install bash, and build with "make SHELL=bash".
+ * Update to a version of HP/UX with a working shell (e.g., 9.05).
+ * Replace "(. ${srcdir}/scripttempl/${SCRIPT_NAME}.sc)" in
+ genscripts.sh with "sh ${srcdir}..." (no parens) and make sure the
+ emulparams script used exports any shell variables it sets.
projects / binutils.git / blobdiff