Skip to content

Name the RISC-V ISA alongside the ABI #33

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
colemancda merged 1 commit into from
Aug 1, 2026
Merged

Name the RISC-V ISA alongside the ABI #33

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
38 changes: 34 additions & 4 deletions package/swift/swift.mk
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -63,6 +63,29 @@ ifeq ($(SWIFT_TARGET_ARCH),i686)
SWIFT_GCC_MULTIARCH_TRIPLE = i386-linux-$(SWIFT_LIBC_NAME)
endif

# RISC-V names its ISA and its calling convention separately, and clang derives
# neither from the target triple: riscv64-unknown-linux-gnu defaults to
# -march=rv64gc -mabi=lp64d whatever buildroot configured. Both have to be
# spelled out, or the stdlib is built for a machine other than the one the rest
# of the system was built for - the default BR2_riscv_g is IMAFD with no
# compressed instructions, so even the shipped defconfig disagrees with clang's
# rv64gc, and a soft-float configuration (-mabi=lp64) would still get F and D
# instructions the core need not implement.
#
# The ABI comes from BR2_GCC_TARGET_ABI, but the ISA string does not have a
# config symbol on RISC-V: buildroot assembles it in arch/arch.mk.riscv as the
# make variable GCC_TARGET_ARCH, leaving BR2_GCC_TARGET_ARCH empty. arch.mk is
# included before the packages, so the value is in scope here. Clang spells both
# exactly as gcc does, down to the _zicsr_zifencei suffix.
#
# These reach swiftc's own code generation, not just the clang importer: swift
# builds its llvm module through clang's CodeGenerator, so -Xcc -march/-mabi
# land in the module's target-abi flag and the target-features of every function
# swiftc emits.
SWIFT_RISCV_ABI_FLAGS = -mno-relax \
$(if $(GCC_TARGET_ARCH),-march=$(GCC_TARGET_ARCH)) \
$(if $(call qstrip,$(BR2_GCC_TARGET_ABI)),-mabi=$(call qstrip,$(BR2_GCC_TARGET_ABI)))

ifeq ($(SWIFT_TARGET_ARCH),armv7)
SWIFT_EXTRA_FLAGS = -mfloat-abi=$(call qstrip,$(BR2_GCC_TARGET_FLOAT_ABI))
SWIFTC_EXTRA_FLAGS = -Xcc -mfloat-abi=$(call qstrip,$(BR2_GCC_TARGET_FLOAT_ABI))
Expand All @@ -73,8 +96,8 @@ else ifeq ($(SWIFT_TARGET_ARCH),armv5)
SWIFT_EXTRA_FLAGS = -march=armv5te
SWIFTC_EXTRA_FLAGS = -Xcc -march=armv5te
else ifeq ($(SWIFT_TARGET_ARCH),riscv64)
SWIFT_EXTRA_FLAGS = -mno-relax -mabi=$(call qstrip,$(BR2_GCC_TARGET_ABI))
SWIFTC_EXTRA_FLAGS = -Xcc -mno-relax -Xcc -mabi=$(call qstrip,$(BR2_GCC_TARGET_ABI))
SWIFT_EXTRA_FLAGS = $(SWIFT_RISCV_ABI_FLAGS)
SWIFTC_EXTRA_FLAGS = $(addprefix -Xcc ,$(SWIFT_RISCV_ABI_FLAGS))
else ifneq ($(filter $(SWIFT_TARGET_ARCH),mips mipsel mips64 mips64el),)
SWIFT_EXTRA_FLAGS = -msoft-float
SWIFTC_EXTRA_FLAGS = -Xcc -msoft-float
Expand Down Expand Up @@ -408,6 +431,12 @@ define HOST_SWIFT_INSTALL_CMDS
echo ' "-msoft-float",' >> $(SWIFT_DESTINATION_FILE);;\
esac

@if [ "$(SWIFT_TARGET_ARCH)" = "riscv64" ]; then\
for flag in $(SWIFT_RISCV_ABI_FLAGS); do\
echo " \"$$flag\"," >> $(SWIFT_DESTINATION_FILE);\
done;\
fi

echo ' ],' >> $(SWIFT_DESTINATION_FILE)
echo ' "extra-swiftc-flags":[' >> $(SWIFT_DESTINATION_FILE)
echo ' "-target", "$(SWIFT_TARGET_NAME)",' >> $(SWIFT_DESTINATION_FILE)
Expand Down Expand Up @@ -444,8 +473,9 @@ define HOST_SWIFT_INSTALL_CMDS
fi

@if [ "$(SWIFT_TARGET_ARCH)" = "riscv64" ]; then\
echo ' "-Xcc", "-mno-relax",' >> $(SWIFT_DESTINATION_FILE);\
echo ' "-Xcc", "-mabi=$(call qstrip,$(BR2_GCC_TARGET_ABI))",' >> $(SWIFT_DESTINATION_FILE);\
for flag in $(SWIFT_RISCV_ABI_FLAGS); do\
echo " \"-Xcc\", \"$$flag\"," >> $(SWIFT_DESTINATION_FILE);\
done;\
fi

@case "$(SWIFT_TARGET_ARCH)" in mips|mipsel|mips64|mips64el)\
Expand Down
Loading