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slicing sentinel-terminated slice without end 

now results in a sentinel-terminated slice.
master
Andrew Kelley 2020-03-19 10:54:20 -04:00
parent 61266d2621
commit f824658e13
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GPG Key ID: 7C5F548F728501A9
2 changed files with 83 additions and 0 deletions
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4
src/ir.cpp
View File

@ -26249,6 +26249,7 @@ static IrInstGen *ir_analyze_instruction_slice(IrAnalyze *ira, IrInstSrcSlice *i
end = nullptr;
}
ZigValue *slice_sentinel_val = nullptr;
ZigType *non_sentinel_slice_ptr_type;
ZigType *elem_type;
@ -26299,6 +26300,7 @@ static IrInstGen *ir_analyze_instruction_slice(IrAnalyze *ira, IrInstSrcSlice *i
}
} else if (is_slice(array_type)) {
ZigType *maybe_sentineled_slice_ptr_type = array_type->data.structure.fields[slice_ptr_index]->type_entry;
slice_sentinel_val = maybe_sentineled_slice_ptr_type->data.pointer.sentinel;
non_sentinel_slice_ptr_type = adjust_ptr_sentinel(ira->codegen, maybe_sentineled_slice_ptr_type, nullptr);
elem_type = non_sentinel_slice_ptr_type->data.pointer.child_type;
} else {
@ -26376,6 +26378,8 @@ static IrInstGen *ir_analyze_instruction_slice(IrAnalyze *ira, IrInstSrcSlice *i
PtrLenSingle, ptr_byte_alignment, 0, 0, false);
goto done_with_return_type;
}
} else if (array_sentinel == nullptr && end == nullptr) {
array_sentinel = slice_sentinel_val;
}
if (array_sentinel != nullptr) {
// TODO deal with non-abi-alignment here

79
test/stage1/behavior/slice.zig
View File

@ -130,3 +130,82 @@ test "empty array to slice" {
S.doTheTest();
comptime S.doTheTest();
}
test "@ptrCast slice to pointer" {
const S = struct {
fn doTheTest() void {
var array align(@alignOf(u16)) = [5]u8{ 0xff, 0xff, 0xff, 0xff, 0xff };
var slice: []u8 = &array;
var ptr = @ptrCast(*u16, slice);
expect(ptr.* == 65535);
}
};
S.doTheTest();
comptime S.doTheTest();
}
test "slicing producing an array" {
const S = struct {
fn doTheTest() void {
testArray();
testArrayZ();
testPointer();
testPointerZ();
testSlice();
testSliceZ();
}
fn testArray() void {
var array = [5]u8{ 1, 2, 3, 4, 5 };
var slice = array[1..3];
comptime expect(@TypeOf(slice) == *[2]u8);
expect(slice[0] == 2);
expect(slice[1] == 3);
}
fn testArrayZ() void {
var array = [5:0]u8{ 1, 2, 3, 4, 5 };
comptime expect(@TypeOf(array[1..3]) == *[2]u8);
comptime expect(@TypeOf(array[1..5]) == *[4:0]u8);
comptime expect(@TypeOf(array[1..]) == *[4:0]u8);
comptime expect(@TypeOf(array[1..3 :4]) == *[2:4]u8);
}
fn testPointer() void {
var array = [5]u8{ 1, 2, 3, 4, 5 };
var pointer: [*]u8 = &array;
var slice = pointer[1..3];
comptime expect(@TypeOf(slice) == *[2]u8);
expect(slice[0] == 2);
expect(slice[1] == 3);
}
fn testPointerZ() void {
var array = [5:0]u8{ 1, 2, 3, 4, 5 };
var pointer: [*:0]u8 = &array;
comptime expect(@TypeOf(pointer[1..3]) == *[2]u8);
comptime expect(@TypeOf(pointer[1..3 :4]) == *[2:4]u8);
}
fn testSlice() void {
var array = [5]u8{ 1, 2, 3, 4, 5 };
var src_slice: []u8 = &array;
var slice = src_slice[1..3];
comptime expect(@TypeOf(slice) == *[2]u8);
expect(slice[0] == 2);
expect(slice[1] == 3);
}
fn testSliceZ() void {
var array = [5:0]u8{ 1, 2, 3, 4, 5 };
var slice: [:0]u8 = &array;
comptime expect(@TypeOf(slice[1..3]) == *[2]u8);
comptime expect(@TypeOf(slice[1..]) == [:0]u8);
comptime expect(@TypeOf(slice[1..3 :4]) == *[2:4]u8);
}
};
S.doTheTest();
comptime S.doTheTest();
}