Remove inline-asm feature and update MSRV to 1.59

Author: taiki-e

.github/bors.toml

@@ -3,7 +3,7 @@ delete_merged_branches = true
 required_approvals = 1
 status = [
     "ci-linux (stable)",
-    "ci-linux (1.42.0)",
+    "ci-linux (1.59.0)",
     "build-other (macOS-latest)",
     "build-other (windows-latest)",
     "Rustfmt"

.github/workflows/ci.yaml

@@ -11,8 +11,8 @@ jobs:
     continue-on-error: ${{ matrix.experimental || false }}
     strategy:
       matrix:
-        # All generated code should be running on stable now, MRSV is 1.42.0
-        rust: [nightly, stable, 1.42.0]
+        # All generated code should be running on stable now, MRSV is 1.59.0
+        rust: [nightly, stable, 1.59.0]
 
         include:
           # Nightly is only for reference and allowed to fail
@@ -34,12 +34,6 @@ jobs:
         run: cargo check --target x86_64-unknown-linux-gnu
       - name: Run CI script for riscv32imac-unknown-none-elf under ${{ matrix.rust }}
         run: cargo check --target riscv32imac-unknown-none-elf
-      - name: Run CI script for riscv32imac-unknown-none-elf (inline-asm) under ${{ matrix.rust }}
-        run: |
-          # asm! requires Rust 1.59
-          if [ "${{ matrix.rust }}" != "1.42.0" ]; then
-            cargo check --target riscv32imac-unknown-none-elf --features inline-asm
-          fi
       - name: Run CI script for riscv64imac-unknown-none-elf under ${{ matrix.rust }}
         run: cargo check --target riscv64imac-unknown-none-elf
       - name: Run CI script for riscv64gc-unknown-none-elf under ${{ matrix.rust }}

CHANGELOG.md

@@ -19,7 +19,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Changed
 
 - Use new `asm!` instead of `llvm_asm!`
-- Change `pmpcfgx::read()` macro to `read_csr_as!()` from `read_csr_as_usize!()` 
+- Change `pmpcfgx::read()` macro to `read_csr_as!()` from `read_csr_as_usize!()`
+- Inline assembly is now always used
+- Update Minimum Supported Rust Version to 1.59
+
+### Removed
+
+- Remove `inline-asm` feature which is now always enabled
 
 ## [v0.7.0] - 2020-07-29
 

Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "riscv"
 version = "0.7.0"
+rust-version = "1.59"
 repository = "https://github.com/rust-embedded/riscv"
 authors = ["The RISC-V Team <[email protected]>"]
 categories = ["embedded", "hardware-support", "no-std"]
@@ -19,9 +20,3 @@ targets = [
 bare-metal = "1.0.0"
 bit_field = "0.10.0"
 embedded-hal = "0.2.6"
-
-[build-dependencies]
-riscv-target = "0.1.2"
-
-[features]
-inline-asm = []

README.md

@@ -12,7 +12,7 @@ This project is developed and maintained by the [RISC-V team][team].
 
 ## Minimum Supported Rust Version (MSRV)
 
-This crate is guaranteed to compile on stable Rust 1.42.0 and up. It *might*
+This crate is guaranteed to compile on stable Rust 1.59 and up. It *might*
 compile with older versions but that may change in any new patch release.
 
 ## License

build.rs

@@ -1,31 +1,7 @@
-extern crate riscv_target;
-
-use riscv_target::Target;
-use std::path::PathBuf;
-use std::{env, fs};
+use std::env;
 
 fn main() {
     let target = env::var("TARGET").unwrap();
-    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
-    let name = env::var("CARGO_PKG_NAME").unwrap();
-
-    if target.starts_with("riscv") && env::var_os("CARGO_FEATURE_INLINE_ASM").is_none() {
-        let mut target = Target::from_target_str(&target);
-        target.retain_extensions("ifdc");
-
-        let target = target.to_string();
-        // capture riscvNNxxxxx only
-        let target = target.split("-").next().unwrap();
-
-        fs::copy(
-            format!("bin/{}.a", target),
-            out_dir.join(format!("lib{}.a", name)),
-        )
-        .unwrap();
-
-        println!("cargo:rustc-link-lib=static={}", name);
-        println!("cargo:rustc-link-search={}", out_dir.display());
-    }
 
     if target.starts_with("riscv32") {
         println!("cargo:rustc-cfg=riscv");

src/asm.rs

@@ -6,18 +6,9 @@ macro_rules! instruction {
         #[inline]
         pub unsafe fn $fnname() {
             match () {
-                #[cfg(all(riscv, feature = "inline-asm"))]
+                #[cfg(riscv)]
                 () => core::arch::asm!($asm),
 
-                #[cfg(all(riscv, not(feature = "inline-asm")))]
-                () => {
-                    extern "C" {
-                        fn $asm_fn();
-                    }
-
-                    $asm_fn();
-                }
-
                 #[cfg(not(riscv))]
                 () => unimplemented!(),
             }
@@ -62,18 +53,9 @@ instruction!(
 #[allow(unused_variables)]
 pub unsafe fn sfence_vma(asid: usize, addr: usize) {
     match () {
-        #[cfg(all(riscv, feature = "inline-asm"))]
+        #[cfg(riscv)]
         () => core::arch::asm!("sfence.vma {0}, {1}", in(reg) addr, in(reg) asid),
 
-        #[cfg(all(riscv, not(feature = "inline-asm")))]
-        () => {
-            extern "C" {
-                fn __sfence_vma(addr: usize, asid: usize);
-            }
-
-            __sfence_vma(addr, asid);
-        }
-
         #[cfg(not(riscv))]
         () => unimplemented!(),
     }
@@ -92,7 +74,7 @@ pub unsafe fn sfence_vma(asid: usize, addr: usize) {
 #[allow(unused_variables)]
 pub unsafe fn delay(cycles: u32) {
     match () {
-        #[cfg(all(riscv, feature = "inline-asm"))]
+        #[cfg(riscv)]
         () => {
             let real_cyc = 1 + cycles / 2;
             core::arch::asm!(
@@ -103,15 +85,6 @@ pub unsafe fn delay(cycles: u32) {
             )
         }
 
-        #[cfg(all(riscv, not(feature = "inline-asm")))]
-        () => {
-            extern "C" {
-                fn __delay(cycles: u32);
-            }
-
-            __delay(cycles);
-        }
-
         #[cfg(not(riscv))]
         () => unimplemented!(),
     }

src/lib.rs

@@ -2,7 +2,7 @@
 //!
 //! # Minimum Supported Rust Version (MSRV)
 //!
-//! This crate is guaranteed to compile on stable Rust 1.42 and up. It *might*
+//! This crate is guaranteed to compile on stable Rust 1.59 and up. It *might*
 //! compile with older versions but that may change in any new patch release.
 //!
 //! # Features

src/register/macros.rs

@@ -4,22 +4,13 @@ macro_rules! read_csr {
         #[inline]
         unsafe fn _read() -> usize {
             match () {
-                #[cfg(all(riscv, feature = "inline-asm"))]
+                #[cfg(riscv)]
                 () => {
                     let r: usize;
                     core::arch::asm!(concat!("csrrs {0}, ", stringify!($csr_number), ", x0"), out(reg) r);
                     r
                 }
 
-                #[cfg(all(riscv, not(feature = "inline-asm")))]
-                () => {
-                    extern "C" {
-                        fn $asm_fn() -> usize;
-                    }
-
-                    $asm_fn()
-                }
-
                 #[cfg(not(riscv))]
                 () => unimplemented!(),
             }
@@ -33,22 +24,13 @@ macro_rules! read_csr_rv32 {
         #[inline]
         unsafe fn _read() -> usize {
             match () {
-                #[cfg(all(riscv32, feature = "inline-asm"))]
+                #[cfg(riscv32)]
                 () => {
                     let r: usize;
                     core::arch::asm!(concat!("csrrs {0}, ", stringify!($csr_number), ", x0"), out(reg) r);
                     r
                 }
 
-                #[cfg(all(riscv32, not(feature = "inline-asm")))]
-                () => {
-                    extern "C" {
-                        fn $asm_fn() -> usize;
-                    }
-
-                    $asm_fn()
-                }
-
                 #[cfg(not(riscv32))]
                 () => unimplemented!(),
             }
@@ -101,18 +83,9 @@ macro_rules! write_csr {
         #[allow(unused_variables)]
         unsafe fn _write(bits: usize) {
             match () {
-                #[cfg(all(riscv, feature = "inline-asm"))]
+                #[cfg(riscv)]
                 () => core::arch::asm!(concat!("csrrw x0, ", stringify!($csr_number), ", {0}"), in(reg) bits),
 
-                #[cfg(all(riscv, not(feature = "inline-asm")))]
-                () => {
-                    extern "C" {
-                        fn $asm_fn(bits: usize);
-                    }
-
-                    $asm_fn(bits);
-                }
-
                 #[cfg(not(riscv))]
                 () => unimplemented!(),
             }
@@ -127,18 +100,9 @@ macro_rules! write_csr_rv32 {
         #[allow(unused_variables)]
         unsafe fn _write(bits: usize) {
             match () {
-                #[cfg(all(riscv32, feature = "inline-asm"))]
+                #[cfg(riscv32)]
                 () => core::arch::asm!(concat!("csrrw x0, ", stringify!($csr_number), ", {0}"), in(reg) bits),
 
-                #[cfg(all(riscv32, not(feature = "inline-asm")))]
-                () => {
-                    extern "C" {
-                        fn $asm_fn(bits: usize);
-                    }
-
-                    $asm_fn(bits);
-                }
-
                 #[cfg(not(riscv32))]
                 () => unimplemented!(),
             }
@@ -177,18 +141,9 @@ macro_rules! set {
         #[allow(unused_variables)]
         unsafe fn _set(bits: usize) {
             match () {
-                #[cfg(all(riscv, feature = "inline-asm"))]
+                #[cfg(riscv)]
                 () => core::arch::asm!(concat!("csrrs x0, ", stringify!($csr_number), ", {0}"), in(reg) bits),
 
-                #[cfg(all(riscv, not(feature = "inline-asm")))]
-                () => {
-                    extern "C" {
-                        fn $asm_fn(bits: usize);
-                    }
-
-                    $asm_fn(bits);
-                }
-
                 #[cfg(not(riscv))]
                 () => unimplemented!(),
             }
@@ -203,18 +158,9 @@ macro_rules! clear {
         #[allow(unused_variables)]
         unsafe fn _clear(bits: usize) {
             match () {
-                #[cfg(all(riscv, feature = "inline-asm"))]
+                #[cfg(riscv)]
                 () => core::arch::asm!(concat!("csrrc x0, ", stringify!($csr_number), ", {0}"), in(reg) bits),
 
-                #[cfg(all(riscv, not(feature = "inline-asm")))]
-                () => {
-                    extern "C" {
-                        fn $asm_fn(bits: usize);
-                    }
-
-                    $asm_fn(bits);
-                }
-
                 #[cfg(not(riscv))]
                 () => unimplemented!(),
             }