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When linker relaxation converts CALL (auipc+jalr, 8 bytes) to JAL (4 bytes), further relaxation to C.J or C.JAL (2 bytes) may become possible as code shrinks and jump distances decrease. This patch adds _bfd_riscv_relax_jal to perform this second-pass relaxation. To enable this, we introduce R_RISCV_DELETE_AND_RELAX, a new internal relocation that combines piecewise deletion with preservation of relaxation capability. When _bfd_riscv_relax_call relaxes CALL to JAL, it marks the deletion as R_RISCV_DELETE_AND_RELAX instead of R_RISCV_DELETE. After the piecewise deletion is resolved, R_RISCV_DELETE_AND_RELAX is converted back to R_RISCV_RELAX at the JAL instruction offset, allowing _bfd_riscv_relax_jal to further relax JAL to C.J/C.JAL. C.JAL is only available on RV32 (rd=ra), while C.J is available on both RV32 and RV64 (rd=x0). Changes since v1: - Use R_RISCV_DELETE_AND_RELAX with piecewise deletion instead of calling _riscv_relax_delete_immediate directly, to maintain relaxation performance. - Add preserve_relax parameter to riscv_relax_delete_bytes to simplify the logic in _bfd_riscv_relax_call.
README for LD
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.
* 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 supports a control language.
* There is a user manual (ld.texi), as well as the
beginnings of an internals manual (ldint.texi).
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
or using the --with-lib-path configure switch.
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
=======================
See the ldint.texi 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.
Copyright (C) 2012-2026 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.