build_tools/cmake/linux_riscv32.cmake

# Copyright 2025 The IREE Authors
#
# Licensed under the Apache License v2.0 with LLVM Exceptions.
# See https://llvm.org/LICENSE.txt for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

cmake_minimum_required(VERSION 3.26)

# CMake invokes the toolchain file twice during the first build, but only once
# during subsequent rebuilds. This was causing the various flags to be added
# twice on the first build, and on a rebuild ninja would see only one set of the
# flags and rebuild the world.
# https://github.com/android-ndk/ndk/issues/323
if(RISCV_TOOLCHAIN_INCLUDED)
  return()
endif()
set(RISCV_TOOLCHAIN_INCLUDED true)

set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_PROCESSOR riscv32)

if(NOT "${RISCV_TOOLCHAIN_ROOT}" STREQUAL "")
  set(CMAKE_AR           "${RISCV_TOOLCHAIN_ROOT}/bin/${RISCV_TOOLCHAIN_PREFIX}llvm-ar")
  set(CMAKE_C_COMPILER   "${RISCV_TOOLCHAIN_ROOT}/bin/${RISCV_TOOLCHAIN_PREFIX}clang")
  set(CMAKE_CXX_COMPILER "${RISCV_TOOLCHAIN_ROOT}/bin/${RISCV_TOOLCHAIN_PREFIX}clang++")
  set(CMAKE_RANLIB       "${RISCV_TOOLCHAIN_ROOT}/bin/${RISCV_TOOLCHAIN_PREFIX}llvm-ranlib")
  set(CMAKE_STRIP        "${RISCV_TOOLCHAIN_ROOT}/bin/${RISCV_TOOLCHAIN_PREFIX}llvm-strip")
  set(CMAKE_SYSROOT "${RISCV_TOOLCHAIN_ROOT}/sysroot")
  list(APPEND CMAKE_FIND_ROOT_PATH "${RISCV_TOOLCHAIN_ROOT}")
  list(APPEND CMAKE_PREFIX_PATH "${RISCV_TOOLCHAIN_ROOT}")
  list(APPEND CMAKE_SYSTEM_LIBRARY_PATH
    "${RISCV_TOOLCHAIN_ROOT}/sysroot/usr/lib32"
    "${RISCV_TOOLCHAIN_ROOT}/sysroot/usr/lib32/ilp32d"
  )
endif()

# Specify ISA spec for march=rv32gc. This is to resolve the mismatch between
# llvm and binutil ISA version.
set(RISCV_COMPILER_FLAGS "\
    -march=rv32i2p1ma2p1f2p2d2p2c2p0 -mabi=ilp32d \
    -Wno-atomic-alignment")
set(RISCV_LINKER_FLAGS "-lstdc++ -lpthread -lm -ldl -latomic")
set(RISCV_QEMU_CPU_FLAGS "rv32,Zve32f=true,vlen=512,elen=32,vext_spec=v1.0")
set(RISCV32_TEST_DEFAULT_LLVM_FLAGS
  "--iree-llvmcpu-target-triple=riscv32"
  "--iree-llvmcpu-target-abi=ilp32d"
  "--iree-llvmcpu-target-cpu-features=+m,+a,+f,+d,+zvl512b,+zve32f"
  CACHE INTERNAL "Default llvm codegen flags for testing purposes")

set(CMAKE_C_FLAGS             "${RISCV_COMPILER_FLAGS} ${CMAKE_C_FLAGS}")
set(CMAKE_CXX_FLAGS           "${RISCV_COMPILER_FLAGS} ${CMAKE_CXX_FLAGS}")
set(CMAKE_ASM_FLAGS           "${RISCV_COMPILER_FLAGS} ${CMAKE_ASM_FLAGS}")
set(CMAKE_SHARED_LINKER_FLAGS "${RISCV_LINKER_FLAGS} ${CMAKE_SHARED_LINKER_FLAGS}")
set(CMAKE_MODULE_LINKER_FLAGS "${RISCV_LINKER_FLAGS} ${CMAKE_MODULE_LINKER_FLAGS}")
set(CMAKE_EXE_LINKER_FLAGS    "${RISCV_LINKER_FLAGS} ${CMAKE_EXE_LINKER_FLAGS}")