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authorVeikka Tuominen <git@vexu.eu>2021-06-12 21:30:36 +0300
committerVeikka Tuominen <git@vexu.eu>2021-06-14 20:13:34 +0300
commit699b6cdf01babd86d56206667a35491d2c4d00f1 (patch)
treeddf70f0d6282034497707a579197428740cb3b30 /lib/std/meta.zig
parentec36b82d058b7e20101a2f55a7ec123077ce9b70 (diff)
downloadzig-699b6cdf01babd86d56206667a35491d2c4d00f1.tar.gz
zig-699b6cdf01babd86d56206667a35491d2c4d00f1.zip
translate-c: move utility functions to a separate namespace
Diffstat (limited to 'lib/std/meta.zig')
-rw-r--r--lib/std/meta.zig376
1 files changed, 0 insertions, 376 deletions
diff --git a/lib/std/meta.zig b/lib/std/meta.zig
index e738ad6efb..e19208cd84 100644
--- a/lib/std/meta.zig
+++ b/lib/std/meta.zig
@@ -884,319 +884,6 @@ pub fn Vector(comptime len: u32, comptime child: type) type {
});
}
-/// Given a type and value, cast the value to the type as c would.
-/// This is for translate-c and is not intended for general use.
-pub fn cast(comptime DestType: type, target: anytype) DestType {
- // this function should behave like transCCast in translate-c, except it's for macros and enums
- const SourceType = @TypeOf(target);
- switch (@typeInfo(DestType)) {
- .Pointer => return castToPtr(DestType, SourceType, target),
- .Optional => |dest_opt| {
- if (@typeInfo(dest_opt.child) == .Pointer) {
- return castToPtr(DestType, SourceType, target);
- }
- },
- .Enum => |enum_type| {
- if (@typeInfo(SourceType) == .Int or @typeInfo(SourceType) == .ComptimeInt) {
- const intermediate = cast(enum_type.tag_type, target);
- return @intToEnum(DestType, intermediate);
- }
- },
- .Int => {
- switch (@typeInfo(SourceType)) {
- .Pointer => {
- return castInt(DestType, @ptrToInt(target));
- },
- .Optional => |opt| {
- if (@typeInfo(opt.child) == .Pointer) {
- return castInt(DestType, @ptrToInt(target));
- }
- },
- .Enum => {
- return castInt(DestType, @enumToInt(target));
- },
- .Int => {
- return castInt(DestType, target);
- },
- else => {},
- }
- },
- else => {},
- }
- return @as(DestType, target);
-}
-
-fn castInt(comptime DestType: type, target: anytype) DestType {
- const dest = @typeInfo(DestType).Int;
- const source = @typeInfo(@TypeOf(target)).Int;
-
- if (dest.bits < source.bits)
- return @bitCast(DestType, @truncate(Int(source.signedness, dest.bits), target))
- else
- return @bitCast(DestType, @as(Int(source.signedness, dest.bits), target));
-}
-
-fn castPtr(comptime DestType: type, target: anytype) DestType {
- const dest = ptrInfo(DestType);
- const source = ptrInfo(@TypeOf(target));
-
- if (source.is_const and !dest.is_const or source.is_volatile and !dest.is_volatile)
- return @intToPtr(DestType, @ptrToInt(target))
- else if (@typeInfo(dest.child) == .Opaque)
- // dest.alignment would error out
- return @ptrCast(DestType, target)
- else
- return @ptrCast(DestType, @alignCast(dest.alignment, target));
-}
-
-fn castToPtr(comptime DestType: type, comptime SourceType: type, target: anytype) DestType {
- switch (@typeInfo(SourceType)) {
- .Int => {
- return @intToPtr(DestType, castInt(usize, target));
- },
- .ComptimeInt => {
- if (target < 0)
- return @intToPtr(DestType, @bitCast(usize, @intCast(isize, target)))
- else
- return @intToPtr(DestType, @intCast(usize, target));
- },
- .Pointer => {
- return castPtr(DestType, target);
- },
- .Optional => |target_opt| {
- if (@typeInfo(target_opt.child) == .Pointer) {
- return castPtr(DestType, target);
- }
- },
- else => {},
- }
- return @as(DestType, target);
-}
-
-fn ptrInfo(comptime PtrType: type) TypeInfo.Pointer {
- return switch (@typeInfo(PtrType)) {
- .Optional => |opt_info| @typeInfo(opt_info.child).Pointer,
- .Pointer => |ptr_info| ptr_info,
- else => unreachable,
- };
-}
-
-test "std.meta.cast" {
- const E = enum(u2) {
- Zero,
- One,
- Two,
- };
-
- var i = @as(i64, 10);
-
- try testing.expect(cast(*u8, 16) == @intToPtr(*u8, 16));
- try testing.expect(cast(*u64, &i).* == @as(u64, 10));
- try testing.expect(cast(*i64, @as(?*align(1) i64, &i)) == &i);
-
- try testing.expect(cast(?*u8, 2) == @intToPtr(*u8, 2));
- try testing.expect(cast(?*i64, @as(*align(1) i64, &i)) == &i);
- try testing.expect(cast(?*i64, @as(?*align(1) i64, &i)) == &i);
-
- try testing.expect(cast(E, 1) == .One);
-
- try testing.expectEqual(@as(u32, 4), cast(u32, @intToPtr(*u32, 4)));
- try testing.expectEqual(@as(u32, 4), cast(u32, @intToPtr(?*u32, 4)));
- try testing.expectEqual(@as(u32, 10), cast(u32, @as(u64, 10)));
- try testing.expectEqual(@as(u8, 2), cast(u8, E.Two));
-
- try testing.expectEqual(@bitCast(i32, @as(u32, 0x8000_0000)), cast(i32, @as(u32, 0x8000_0000)));
-
- try testing.expectEqual(@intToPtr(*u8, 2), cast(*u8, @intToPtr(*const u8, 2)));
- try testing.expectEqual(@intToPtr(*u8, 2), cast(*u8, @intToPtr(*volatile u8, 2)));
-
- try testing.expectEqual(@intToPtr(?*c_void, 2), cast(?*c_void, @intToPtr(*u8, 2)));
-
- const C_ENUM = enum(c_int) {
- A = 0,
- B,
- C,
- _,
- };
- try testing.expectEqual(cast(C_ENUM, @as(i64, -1)), @intToEnum(C_ENUM, -1));
- try testing.expectEqual(cast(C_ENUM, @as(i8, 1)), .B);
- try testing.expectEqual(cast(C_ENUM, @as(u64, 1)), .B);
- try testing.expectEqual(cast(C_ENUM, @as(u64, 42)), @intToEnum(C_ENUM, 42));
-
- var foo: c_int = -1;
- try testing.expect(cast(*c_void, -1) == @intToPtr(*c_void, @bitCast(usize, @as(isize, -1))));
- try testing.expect(cast(*c_void, foo) == @intToPtr(*c_void, @bitCast(usize, @as(isize, -1))));
- try testing.expect(cast(?*c_void, -1) == @intToPtr(?*c_void, @bitCast(usize, @as(isize, -1))));
- try testing.expect(cast(?*c_void, foo) == @intToPtr(?*c_void, @bitCast(usize, @as(isize, -1))));
-}
-
-/// Given a value returns its size as C's sizeof operator would.
-/// This is for translate-c and is not intended for general use.
-pub fn sizeof(target: anytype) usize {
- const T: type = if (@TypeOf(target) == type) target else @TypeOf(target);
- switch (@typeInfo(T)) {
- .Float, .Int, .Struct, .Union, .Enum, .Array, .Bool, .Vector => return @sizeOf(T),
- .Fn => {
- // sizeof(main) returns 1, sizeof(&main) returns pointer size.
- // We cannot distinguish those types in Zig, so use pointer size.
- return @sizeOf(T);
- },
- .Null => return @sizeOf(*c_void),
- .Void => {
- // Note: sizeof(void) is 1 on clang/gcc and 0 on MSVC.
- return 1;
- },
- .Opaque => {
- if (T == c_void) {
- // Note: sizeof(void) is 1 on clang/gcc and 0 on MSVC.
- return 1;
- } else {
- @compileError("Cannot use C sizeof on opaque type " ++ @typeName(T));
- }
- },
- .Optional => |opt| {
- if (@typeInfo(opt.child) == .Pointer) {
- return sizeof(opt.child);
- } else {
- @compileError("Cannot use C sizeof on non-pointer optional " ++ @typeName(T));
- }
- },
- .Pointer => |ptr| {
- if (ptr.size == .Slice) {
- @compileError("Cannot use C sizeof on slice type " ++ @typeName(T));
- }
- // for strings, sizeof("a") returns 2.
- // normal pointer decay scenarios from C are handled
- // in the .Array case above, but strings remain literals
- // and are therefore always pointers, so they need to be
- // specially handled here.
- if (ptr.size == .One and ptr.is_const and @typeInfo(ptr.child) == .Array) {
- const array_info = @typeInfo(ptr.child).Array;
- if ((array_info.child == u8 or array_info.child == u16) and
- array_info.sentinel != null and
- array_info.sentinel.? == 0)
- {
- // length of the string plus one for the null terminator.
- return (array_info.len + 1) * @sizeOf(array_info.child);
- }
- }
- // When zero sized pointers are removed, this case will no
- // longer be reachable and can be deleted.
- if (@sizeOf(T) == 0) {
- return @sizeOf(*c_void);
- }
- return @sizeOf(T);
- },
- .ComptimeFloat => return @sizeOf(f64), // TODO c_double #3999
- .ComptimeInt => {
- // TODO to get the correct result we have to translate
- // `1073741824 * 4` as `int(1073741824) *% int(4)` since
- // sizeof(1073741824 * 4) != sizeof(4294967296).
-
- // TODO test if target fits in int, long or long long
- return @sizeOf(c_int);
- },
- else => @compileError("std.meta.sizeof does not support type " ++ @typeName(T)),
- }
-}
-
-test "sizeof" {
- const E = enum(c_int) { One, _ };
- const S = extern struct { a: u32 };
-
- const ptr_size = @sizeOf(*c_void);
-
- try testing.expect(sizeof(u32) == 4);
- try testing.expect(sizeof(@as(u32, 2)) == 4);
- try testing.expect(sizeof(2) == @sizeOf(c_int));
-
- try testing.expect(sizeof(2.0) == @sizeOf(f64));
-
- try testing.expect(sizeof(E) == @sizeOf(c_int));
- try testing.expect(sizeof(E.One) == @sizeOf(c_int));
-
- try testing.expect(sizeof(S) == 4);
-
- try testing.expect(sizeof([_]u32{ 4, 5, 6 }) == 12);
- try testing.expect(sizeof([3]u32) == 12);
- try testing.expect(sizeof([3:0]u32) == 16);
- try testing.expect(sizeof(&[_]u32{ 4, 5, 6 }) == ptr_size);
-
- try testing.expect(sizeof(*u32) == ptr_size);
- try testing.expect(sizeof([*]u32) == ptr_size);
- try testing.expect(sizeof([*c]u32) == ptr_size);
- try testing.expect(sizeof(?*u32) == ptr_size);
- try testing.expect(sizeof(?[*]u32) == ptr_size);
- try testing.expect(sizeof(*c_void) == ptr_size);
- try testing.expect(sizeof(*void) == ptr_size);
- try testing.expect(sizeof(null) == ptr_size);
-
- try testing.expect(sizeof("foobar") == 7);
- try testing.expect(sizeof(&[_:0]u16{ 'f', 'o', 'o', 'b', 'a', 'r' }) == 14);
- try testing.expect(sizeof(*const [4:0]u8) == 5);
- try testing.expect(sizeof(*[4:0]u8) == ptr_size);
- try testing.expect(sizeof([*]const [4:0]u8) == ptr_size);
- try testing.expect(sizeof(*const *const [4:0]u8) == ptr_size);
- try testing.expect(sizeof(*const [4]u8) == ptr_size);
-
- try testing.expect(sizeof(sizeof) == @sizeOf(@TypeOf(sizeof)));
-
- try testing.expect(sizeof(void) == 1);
- try testing.expect(sizeof(c_void) == 1);
-}
-
-pub const CIntLiteralRadix = enum { decimal, octal, hexadecimal };
-
-fn PromoteIntLiteralReturnType(comptime SuffixType: type, comptime number: comptime_int, comptime radix: CIntLiteralRadix) type {
- const signed_decimal = [_]type{ c_int, c_long, c_longlong };
- const signed_oct_hex = [_]type{ c_int, c_uint, c_long, c_ulong, c_longlong, c_ulonglong };
- const unsigned = [_]type{ c_uint, c_ulong, c_ulonglong };
-
- const list: []const type = if (@typeInfo(SuffixType).Int.signedness == .unsigned)
- &unsigned
- else if (radix == .decimal)
- &signed_decimal
- else
- &signed_oct_hex;
-
- var pos = mem.indexOfScalar(type, list, SuffixType).?;
-
- while (pos < list.len) : (pos += 1) {
- if (number >= math.minInt(list[pos]) and number <= math.maxInt(list[pos])) {
- return list[pos];
- }
- }
- @compileError("Integer literal is too large");
-}
-
-/// Promote the type of an integer literal until it fits as C would.
-/// This is for translate-c and is not intended for general use.
-pub fn promoteIntLiteral(
- comptime SuffixType: type,
- comptime number: comptime_int,
- comptime radix: CIntLiteralRadix,
-) PromoteIntLiteralReturnType(SuffixType, number, radix) {
- return number;
-}
-
-test "promoteIntLiteral" {
- const signed_hex = promoteIntLiteral(c_int, math.maxInt(c_int) + 1, .hexadecimal);
- try testing.expectEqual(c_uint, @TypeOf(signed_hex));
-
- if (math.maxInt(c_longlong) == math.maxInt(c_int)) return;
-
- const signed_decimal = promoteIntLiteral(c_int, math.maxInt(c_int) + 1, .decimal);
- const unsigned = promoteIntLiteral(c_uint, math.maxInt(c_uint) + 1, .hexadecimal);
-
- if (math.maxInt(c_long) > math.maxInt(c_int)) {
- try testing.expectEqual(c_long, @TypeOf(signed_decimal));
- try testing.expectEqual(c_ulong, @TypeOf(unsigned));
- } else {
- try testing.expectEqual(c_longlong, @TypeOf(signed_decimal));
- try testing.expectEqual(c_ulonglong, @TypeOf(unsigned));
- }
-}
-
/// For a given function type, returns a tuple type which fields will
/// correspond to the argument types.
///
@@ -1316,38 +1003,6 @@ pub fn globalOption(comptime name: []const u8, comptime T: type) ?T {
return @as(T, @field(root, name));
}
-/// This function is for translate-c and is not intended for general use.
-/// Convert from clang __builtin_shufflevector index to Zig @shuffle index
-/// clang requires __builtin_shufflevector index arguments to be integer constants.
-/// negative values for `this_index` indicate "don't care" so we arbitrarily choose 0
-/// clang enforces that `this_index` is less than the total number of vector elements
-/// See https://ziglang.org/documentation/master/#shuffle
-/// See https://clang.llvm.org/docs/LanguageExtensions.html#langext-builtin-shufflevector
-pub fn shuffleVectorIndex(comptime this_index: c_int, comptime source_vector_len: usize) i32 {
- if (this_index <= 0) return 0;
-
- const positive_index = @intCast(usize, this_index);
- if (positive_index < source_vector_len) return @intCast(i32, this_index);
- const b_index = positive_index - source_vector_len;
- return ~@intCast(i32, b_index);
-}
-
-test "shuffleVectorIndex" {
- const vector_len: usize = 4;
-
- try testing.expect(shuffleVectorIndex(-1, vector_len) == 0);
-
- try testing.expect(shuffleVectorIndex(0, vector_len) == 0);
- try testing.expect(shuffleVectorIndex(1, vector_len) == 1);
- try testing.expect(shuffleVectorIndex(2, vector_len) == 2);
- try testing.expect(shuffleVectorIndex(3, vector_len) == 3);
-
- try testing.expect(shuffleVectorIndex(4, vector_len) == -1);
- try testing.expect(shuffleVectorIndex(5, vector_len) == -2);
- try testing.expect(shuffleVectorIndex(6, vector_len) == -3);
- try testing.expect(shuffleVectorIndex(7, vector_len) == -4);
-}
-
/// Returns whether `error_union` contains an error.
pub fn isError(error_union: anytype) bool {
return if (error_union) |_| false else |_| true;
@@ -1357,34 +1012,3 @@ test "isError" {
try std.testing.expect(isError(math.absInt(@as(i8, -128))));
try std.testing.expect(!isError(math.absInt(@as(i8, -127))));
}
-
-/// This function is for translate-c and is not intended for general use.
-/// Constructs a [*c] pointer with the const and volatile annotations
-/// from SelfType for pointing to a C flexible array of ElementType.
-pub fn FlexibleArrayType(comptime SelfType: type, ElementType: type) type {
- switch (@typeInfo(SelfType)) {
- .Pointer => |ptr| {
- return @Type(TypeInfo{ .Pointer = .{
- .size = .C,
- .is_const = ptr.is_const,
- .is_volatile = ptr.is_volatile,
- .alignment = @alignOf(ElementType),
- .child = ElementType,
- .is_allowzero = true,
- .sentinel = null,
- } });
- },
- else => |info| @compileError("Invalid self type \"" ++ @tagName(info) ++ "\" for flexible array getter: " ++ @typeName(SelfType)),
- }
-}
-
-test "Flexible Array Type" {
- const Container = extern struct {
- size: usize,
- };
-
- try testing.expectEqual(FlexibleArrayType(*Container, c_int), [*c]c_int);
- try testing.expectEqual(FlexibleArrayType(*const Container, c_int), [*c]const c_int);
- try testing.expectEqual(FlexibleArrayType(*volatile Container, c_int), [*c]volatile c_int);
- try testing.expectEqual(FlexibleArrayType(*const volatile Container, c_int), [*c]const volatile c_int);
-}