Create a new hook to let target could override the multi-lib-os result.
The motivation for this change arises from the fact that using
TARGET_COMPUTE_MULTILIB to override the original multilib_dir can lead
to unexpected behavior with multilib_os_dir.
In our build scripts, we establish a connection between multilib_os_dir
and multilib_dir. For example, in gcc/config/riscv/t-linux, we set
multilib_os_dir to be the parent directory of multilib_dir. However,
when TARGET_COMPUTE_MULTILIB overrides multilib_dir and returns a reused
result for multilib_dir, multilib_os_dir ends up being identical to
multilib_dir. This discrepancy is clearly inconsistent with our
expectations.
gcc/ChangeLog:
* common/common-target.def (compute_multilib_os): New.
* common/common-targhooks.cc (default_compute_multilib_os): New.
* common/common-targhooks.h (default_compute_multilib_os): New.
* doc/tm.texi (TARGET_COMPUTE_MULTILIB_OS): New.
* doc/tm.texi.in: Regen.
* gcc.cc (set_multilib_dir): Call targetm_common.compute_multilib_os.
---
gcc/common/common-target.def | 14 ++++++++++++++
gcc/common/common-targhooks.cc | 9 +++++++++
gcc/common/common-targhooks.h | 5 +++++
gcc/doc/tm.texi | 10 ++++++++++
gcc/doc/tm.texi.in | 1 +
gcc/gcc.cc | 4 ++++
6 files changed, 43 insertions(+)
diff --git a/gcc/common/common-target.def b/gcc/common/common-target.def
index 08d8a6aeb85..a582320b3a2 100644
--- a/gcc/common/common-target.def
+++ b/gcc/common/common-target.def
@@ -109,6 +109,20 @@ The default definition does nothing but return
@var{multilib_dir} directly.",
const char *multilib_reuse),
default_compute_multilib)
+ DEFHOOK
+(compute_multilib_os,
+ "Some targets like RISC-V might have complicated multilib os dir which\n\
+needs to change it according to the value of multilib_dir. This hook allows\n\
+targets to override the result from the built-in multilib mechanism.\n\
+@var{multilib_os_dir} is the os dirnames for multi-lib, which will override\n\
+the result of MULTILIB_OSDIRNAMES.\n\
+@var{multilib_dir} is the multi-lib result which is computed by the built-in\n\
+multi-lib mechanism.\n\
+The default definition does nothing but return @var{multilib_os_dir}
directly.",
+ const char *, (const char *multilib_os_dir,
+ const char *multilib_dir),
+ default_compute_multilib_os)
+
/* Leave the boolean fields at the end. */
/* True if unwinding tables should be generated by default. */
diff --git a/gcc/common/common-targhooks.cc b/gcc/common/common-targhooks.cc
index 91a788d6927..343daccb398 100644
--- a/gcc/common/common-targhooks.cc
+++ b/gcc/common/common-targhooks.cc
@@ -105,3 +105,12 @@ default_compute_multilib(
{
return multilib;
}
+
+/* Default version of TARGET_COMPUTE_MULTILIB_OS. */
+const char *
+default_compute_multilib_os (
+ const char *multilib_os,
+ const char *)
+{
+ return multilib_os;
+}
\ No newline at end of file
diff --git a/gcc/common/common-targhooks.h b/gcc/common/common-targhooks.h
index 1366d1c4ef6..c645035e999 100644
--- a/gcc/common/common-targhooks.h
+++ b/gcc/common/common-targhooks.h
@@ -43,4 +43,9 @@ default_compute_multilib(
const char *,
const char *);
+const char *
+default_compute_multilib_os (
+ const char *multilib_os,
+ const char *);
+
#endif
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 9f42913a4ef..04462055212 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -803,6 +803,16 @@ and @var{MULTILIB_REUSE}.
The default definition does nothing but return @var{multilib_dir} directly.
@end deftypefn
+@deftypefn {Common Target Hook} {const char *} TARGET_COMPUTE_MULTILIB_OS
(const char *@var{multilib_os_dir}, const char *@var{multilib_dir})
+Some targets like RISC-V might have complicated multilib os dir which
+needs to change it according to the value of multilib_dir. This hook allows
+targets to override the result from the built-in multilib mechanism.
+@var{multilib_os_dir} is the os dirnames for multi-lib, which will override
+the result of MULTILIB_OSDIRNAMES.
+@var{multilib_dir} is the multi-lib result which is computed by the built-in
+multi-lib mechanism.
+The default definition does nothing but return @var{multilib_os_dir} directly.
+@end deftypefn
@defmac SWITCHABLE_TARGET
Some targets need to switch between substantially different subtargets
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 6dbe22581ca..8d95a71a6c8 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -747,6 +747,7 @@ options are changed via @code{#pragma GCC optimize} or by
using the
@hook TARGET_COMPUTE_MULTILIB
+@hook TARGET_COMPUTE_MULTILIB_OS
@defmac SWITCHABLE_TARGET
Some targets need to switch between substantially different subtargets
diff --git a/gcc/gcc.cc b/gcc/gcc.cc
index 04b3736a5da..645a1e34cbc 100644
--- a/gcc/gcc.cc
+++ b/gcc/gcc.cc
@@ -10007,6 +10007,10 @@ set_multilib_dir (void)
multilib_exclusions,
multilib_reuse);
+ multilib_os_dir = targetm_common.compute_multilib_os (
+ multilib_os_dir,
+ multilib_dir);
+
if (multilib_dir == NULL && multilib_os_dir != NULL
&& strcmp (multilib_os_dir, ".") == 0)
{
--
2.25.1
