[PATCH] arm: Support -mfdpic for more targets

Fangrui Song maskray@google.com
Sat Feb 24 03:33:54 GMT 2024


From: Fangrui Song <maskray@gcc.gnu.org>

Targets that are not arm*-*-uclinuxfdpiceabi can use -S -mfdpic, but -c
-mfdpic does not pass --fdpic to gas.  This is an unnecessary
restriction.  Just define the ASM_SPEC in bpabi.h.

Additionally, use armelf[b]_linux_fdpiceabi emulations for -mfdpic in
linux-eabi.h.  This will allow a future musl fdpic port to use the
desired BFD emulation.

gcc/ChangeLog:

	* config/arm/bpabi.h (TARGET_FDPIC_ASM_SPEC): Transform -mfdpic.
	* config/arm/linux-eabi.h (TARGET_FDPIC_LINKER_EMULATION): Define.
	(SUBTARGET_EXTRA_LINK_SPEC): Use TARGET_FDPIC_LINKER_EMULATION
	if -mfdpic.
---
 gcc/config/arm/bpabi.h      | 2 +-
 gcc/config/arm/linux-eabi.h | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/gcc/config/arm/bpabi.h b/gcc/config/arm/bpabi.h
index 7a279f3ed3c..6778be1a8bf 100644
--- a/gcc/config/arm/bpabi.h
+++ b/gcc/config/arm/bpabi.h
@@ -55,7 +55,7 @@
 #define TARGET_FIX_V4BX_SPEC " %{mcpu=arm8|mcpu=arm810|mcpu=strongarm*"\
   "|march=armv4|mcpu=fa526|mcpu=fa626:--fix-v4bx}"
 
-#define TARGET_FDPIC_ASM_SPEC ""
+#define TARGET_FDPIC_ASM_SPEC "%{mfdpic: --fdpic}"
 
 #define BE8_LINK_SPEC							\
   "%{!r:%{!mbe32:%:be8_linkopt(%{mlittle-endian:little}"		\
diff --git a/gcc/config/arm/linux-eabi.h b/gcc/config/arm/linux-eabi.h
index eef791f6a02..0c5c58e4928 100644
--- a/gcc/config/arm/linux-eabi.h
+++ b/gcc/config/arm/linux-eabi.h
@@ -46,12 +46,15 @@
 #undef  TARGET_LINKER_EMULATION
 #if TARGET_BIG_ENDIAN_DEFAULT
 #define TARGET_LINKER_EMULATION "armelfb_linux_eabi"
+#define TARGET_FDPIC_LINKER_EMULATION "armelfb_linux_fdpiceabi"
 #else
 #define TARGET_LINKER_EMULATION "armelf_linux_eabi"
+#define TARGET_FDPIC_LINKER_EMULATION "armelf_linux_fdpiceabi"
 #endif
 
 #undef  SUBTARGET_EXTRA_LINK_SPEC
-#define SUBTARGET_EXTRA_LINK_SPEC " -m " TARGET_LINKER_EMULATION
+#define SUBTARGET_EXTRA_LINK_SPEC " -m %{mfdpic: " \
+  TARGET_FDPIC_LINKER_EMULATION ";:" TARGET_LINKER_EMULATION "}"
 
 /* GNU/Linux on ARM currently supports three dynamic linkers:
    - ld-linux.so.2 - for the legacy ABI
-- 
2.44.0.rc1.240.g4c46232300-goog



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