std.os.linux: Add riscv32 support.

lib/std/os/linux.zig

@@ -38,6 +38,7 @@ const arch_bits = switch (native_arch) {
     .x86_64 => @import("linux/x86_64.zig"),
     .aarch64, .aarch64_be => @import("linux/arm64.zig"),
     .arm, .thumb => @import("linux/arm-eabi.zig"),
+    .riscv32 => @import("linux/riscv32.zig"),
     .riscv64 => @import("linux/riscv64.zig"),
     .sparc64 => @import("linux/sparc64.zig"),
     .mips, .mipsel => @import("linux/mips.zig"),
@@ -101,6 +102,7 @@ pub const SYS = switch (@import("builtin").cpu.arch) {
     .x86_64 => syscalls.X64,
     .aarch64, .aarch64_be => syscalls.Arm64,
     .arm, .thumb => syscalls.Arm,
+    .riscv32 => syscalls.RiscV32,
     .riscv64 => syscalls.RiscV64,
     .sparc64 => syscalls.Sparc64,
     .mips, .mipsel => syscalls.Mips,
@@ -160,7 +162,7 @@ pub const MAP = switch (native_arch) {
         UNINITIALIZED: bool = false,
         _: u5 = 0,
     },
-    .riscv64 => packed struct(u32) {
+    .riscv32, .riscv64 => packed struct(u32) {
         TYPE: MAP_TYPE,
         FIXED: bool = false,
         ANONYMOUS: bool = false,
@@ -265,7 +267,7 @@ pub const O = switch (native_arch) {
         TMPFILE: bool = false,
         _: u9 = 0,
     },
-    .x86, .riscv64 => packed struct(u32) {
+    .x86, .riscv32, .riscv64 => packed struct(u32) {
         ACCMODE: ACCMODE = .RDONLY,
         _2: u4 = 0,
         CREAT: bool = false,
@@ -1787,31 +1789,47 @@ pub fn accept4(fd: i32, noalias addr: ?*sockaddr, noalias len: ?*socklen_t, flag
 }
 
 pub fn fstat(fd: i32, stat_buf: *Stat) usize {
-    if (@hasField(SYS, "fstat64")) {
+    if (native_arch == .riscv32) {
+        // riscv32 has made the interesting decision to not implement some of
+        // the older stat syscalls, including this one.
+        @compileError("No fstat syscall on this architecture.");
+    } else if (@hasField(SYS, "fstat64")) {
         return syscall2(.fstat64, @as(usize, @bitCast(@as(isize, fd))), @intFromPtr(stat_buf));
     } else {
         return syscall2(.fstat, @as(usize, @bitCast(@as(isize, fd))), @intFromPtr(stat_buf));
     }
 }
 
 pub fn stat(pathname: [*:0]const u8, statbuf: *Stat) usize {
-    if (@hasField(SYS, "stat64")) {
+    if (native_arch == .riscv32) {
+        // riscv32 has made the interesting decision to not implement some of
+        // the older stat syscalls, including this one.
+        @compileError("No stat syscall on this architecture.");
+    } else if (@hasField(SYS, "stat64")) {
         return syscall2(.stat64, @intFromPtr(pathname), @intFromPtr(statbuf));
     } else {
         return syscall2(.stat, @intFromPtr(pathname), @intFromPtr(statbuf));
     }
 }
 
 pub fn lstat(pathname: [*:0]const u8, statbuf: *Stat) usize {
-    if (@hasField(SYS, "lstat64")) {
+    if (native_arch == .riscv32) {
+        // riscv32 has made the interesting decision to not implement some of
+        // the older stat syscalls, including this one.
+        @compileError("No lstat syscall on this architecture.");
+    } else if (@hasField(SYS, "lstat64")) {
         return syscall2(.lstat64, @intFromPtr(pathname), @intFromPtr(statbuf));
     } else {
         return syscall2(.lstat, @intFromPtr(pathname), @intFromPtr(statbuf));
     }
 }
 
 pub fn fstatat(dirfd: i32, path: [*:0]const u8, stat_buf: *Stat, flags: u32) usize {
-    if (@hasField(SYS, "fstatat64")) {
+    if (native_arch == .riscv32) {
+        // riscv32 has made the interesting decision to not implement some of
+        // the older stat syscalls, including this one.
+        @compileError("No fstatat syscall on this architecture.");
+    } else if (@hasField(SYS, "fstatat64")) {
         return syscall4(.fstatat64, @as(usize, @bitCast(@as(isize, dirfd))), @intFromPtr(path), @intFromPtr(stat_buf), flags);
     } else {
         return syscall4(.fstatat, @as(usize, @bitCast(@as(isize, dirfd))), @intFromPtr(path), @intFromPtr(stat_buf), flags);
@@ -7135,6 +7153,7 @@ pub const AUDIT = struct {
             .x86_64 => .X86_64,
             .aarch64 => .AARCH64,
             .arm, .thumb => .ARM,
+            .riscv32 => .RISCV32,
             .riscv64 => .RISCV64,
             .sparc64 => .SPARC64,
             .mips => .MIPS,

lib/std/os/linux/riscv32.zig

@@ -0,0 +1,227 @@
+const std = @import("../../std.zig");
+const iovec = std.posix.iovec;
+const iovec_const = std.posix.iovec_const;
+const linux = std.os.linux;
+const SYS = linux.SYS;
+const uid_t = std.os.linux.uid_t;
+const gid_t = std.os.linux.gid_t;
+const pid_t = std.os.linux.pid_t;
+const sockaddr = linux.sockaddr;
+const socklen_t = linux.socklen_t;
+const timespec = std.os.linux.timespec;
+
+pub fn syscall0(number: SYS) usize {
+    return asm volatile ("ecall"
+        : [ret] "={x10}" (-> usize),
+        : [number] "{x17}" (@intFromEnum(number)),
+        : "memory"
+    );
+}
+
+pub fn syscall1(number: SYS, arg1: usize) usize {
+    return asm volatile ("ecall"
+        : [ret] "={x10}" (-> usize),
+        : [number] "{x17}" (@intFromEnum(number)),
+          [arg1] "{x10}" (arg1),
+        : "memory"
+    );
+}
+
+pub fn syscall2(number: SYS, arg1: usize, arg2: usize) usize {
+    return asm volatile ("ecall"
+        : [ret] "={x10}" (-> usize),
+        : [number] "{x17}" (@intFromEnum(number)),
+          [arg1] "{x10}" (arg1),
+          [arg2] "{x11}" (arg2),
+        : "memory"
+    );
+}
+
+pub fn syscall3(number: SYS, arg1: usize, arg2: usize, arg3: usize) usize {
+    return asm volatile ("ecall"
+        : [ret] "={x10}" (-> usize),
+        : [number] "{x17}" (@intFromEnum(number)),
+          [arg1] "{x10}" (arg1),
+          [arg2] "{x11}" (arg2),
+          [arg3] "{x12}" (arg3),
+        : "memory"
+    );
+}
+
+pub fn syscall4(number: SYS, arg1: usize, arg2: usize, arg3: usize, arg4: usize) usize {
+    return asm volatile ("ecall"
+        : [ret] "={x10}" (-> usize),
+        : [number] "{x17}" (@intFromEnum(number)),
+          [arg1] "{x10}" (arg1),
+          [arg2] "{x11}" (arg2),
+          [arg3] "{x12}" (arg3),
+          [arg4] "{x13}" (arg4),
+        : "memory"
+    );
+}
+
+pub fn syscall5(number: SYS, arg1: usize, arg2: usize, arg3: usize, arg4: usize, arg5: usize) usize {
+    return asm volatile ("ecall"
+        : [ret] "={x10}" (-> usize),
+        : [number] "{x17}" (@intFromEnum(number)),
+          [arg1] "{x10}" (arg1),
+          [arg2] "{x11}" (arg2),
+          [arg3] "{x12}" (arg3),
+          [arg4] "{x13}" (arg4),
+          [arg5] "{x14}" (arg5),
+        : "memory"
+    );
+}
+
+pub fn syscall6(
+    number: SYS,
+    arg1: usize,
+    arg2: usize,
+    arg3: usize,
+    arg4: usize,
+    arg5: usize,
+    arg6: usize,
+) usize {
+    return asm volatile ("ecall"
+        : [ret] "={x10}" (-> usize),
+        : [number] "{x17}" (@intFromEnum(number)),
+          [arg1] "{x10}" (arg1),
+          [arg2] "{x11}" (arg2),
+          [arg3] "{x12}" (arg3),
+          [arg4] "{x13}" (arg4),
+          [arg5] "{x14}" (arg5),
+          [arg6] "{x15}" (arg6),
+        : "memory"
+    );
+}
+
+const CloneFn = *const fn (arg: usize) callconv(.C) u8;
+
+pub extern fn clone(func: CloneFn, stack: usize, flags: u32, arg: usize, ptid: *i32, tls: usize, ctid: *i32) usize;
+
+pub const restore = restore_rt;
+
+pub fn restore_rt() callconv(.Naked) noreturn {
+    asm volatile (
+        \\ ecall
+        :
+        : [number] "{x17}" (@intFromEnum(SYS.rt_sigreturn)),
+        : "memory"
+    );
+}
+
+pub const MMAP2_UNIT = 4096;
+
+pub const F = struct {
+    pub const DUPFD = 0;
+    pub const GETFD = 1;
+    pub const SETFD = 2;
+    pub const GETFL = 3;
+    pub const SETFL = 4;
+    pub const GETLK = 5;
+    pub const SETLK = 6;
+    pub const SETLKW = 7;
+    pub const SETOWN = 8;
+    pub const GETOWN = 9;
+    pub const SETSIG = 10;
+    pub const GETSIG = 11;
+
+    pub const RDLCK = 0;
+    pub const WRLCK = 1;
+    pub const UNLCK = 2;
+
+    pub const SETOWN_EX = 15;
+    pub const GETOWN_EX = 16;
+
+    pub const GETOWNER_UIDS = 17;
+};
+
+pub const LOCK = struct {
+    pub const SH = 1;
+    pub const EX = 2;
+    pub const UN = 8;
+    pub const NB = 4;
+};
+
+pub const blksize_t = i32;
+pub const nlink_t = u32;
+pub const time_t = i64;
+pub const mode_t = u32;
+pub const off_t = i64;
+pub const ino_t = u64;
+pub const dev_t = u64;
+pub const blkcnt_t = i64;
+
+pub const timeval = extern struct {
+    tv_sec: time_t,
+    tv_usec: i64,
+};
+
+pub const Flock = extern struct {
+    type: i16,
+    whence: i16,
+    start: off_t,
+    len: off_t,
+    pid: pid_t,
+    __unused: [4]u8,
+};
+
+pub const msghdr = extern struct {
+    name: ?*sockaddr,
+    namelen: socklen_t,
+    iov: [*]iovec,
+    iovlen: i32,
+    __pad1: i32 = 0,
+    control: ?*anyopaque,
+    controllen: socklen_t,
+    __pad2: socklen_t = 0,
+    flags: i32,
+};
+
+pub const msghdr_const = extern struct {
+    name: ?*const sockaddr,
+    namelen: socklen_t,
+    iov: [*]const iovec_const,
+    iovlen: i32,
+    __pad1: i32 = 0,
+    control: ?*const anyopaque,
+    controllen: socklen_t,
+    __pad2: socklen_t = 0,
+    flags: i32,
+};
+
+// The `stat` definition used by the Linux kernel.
+pub const Stat = extern struct {
+    dev: dev_t,
+    ino: ino_t,
+    mode: mode_t,
+    nlink: nlink_t,
+    uid: uid_t,
+    gid: gid_t,
+    rdev: dev_t,
+    __pad: usize,
+    size: off_t,
+    blksize: blksize_t,
+    __pad2: i32,
+    blocks: blkcnt_t,
+    atim: timespec,
+    mtim: timespec,
+    ctim: timespec,
+    __unused: [2]u32,
+
+    pub fn atime(self: @This()) timespec {
+        return self.atim;
+    }
+
+    pub fn mtime(self: @This()) timespec {
+        return self.mtim;
+    }
+
+    pub fn ctime(self: @This()) timespec {
+        return self.ctim;
+    }
+};
+
+pub const Elf_Symndx = u32;
+
+pub const VDSO = struct {};

lib/std/os/linux/riscv64.zig

@@ -143,12 +143,12 @@ pub const LOCK = struct {
 
 pub const blksize_t = i32;
 pub const nlink_t = u32;
-pub const time_t = isize;
+pub const time_t = i64;
 pub const mode_t = u32;
-pub const off_t = isize;
-pub const ino_t = usize;
-pub const dev_t = usize;
-pub const blkcnt_t = isize;
+pub const off_t = i64;
+pub const ino_t = u64;
+pub const dev_t = u64;
+pub const blkcnt_t = i64;
 
 pub const timeval = extern struct {
     tv_sec: time_t,