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std: check types of pointers passed to allocator functions

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This commit is contained in:
Leo Constantinides
2023-02-12 00:04:27 +00:00
committed by GitHub
parent e10c0eefde
commit abc9530a88
2 changed files with 35 additions and 8 deletions
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8
lib/std/heap/general_purpose_allocator.zig
View File

@@ -397,7 +397,9 @@ pub fn GeneralPurposeAllocator(comptime config: Config) type {
const prev = bucket.prev;
if (config.never_unmap) {
// free page that was intentionally leaked by never_unmap
self.backing_allocator.free(bucket.page[0..page_size]);
const array_ptr = bucket.page[0..page_size];
comptime assert(@TypeOf(array_ptr) == *align(page_size) [page_size]u8);
self.backing_allocator.free(@as([]align(page_size) u8, array_ptr));
}
// alloc_cursor was set to slot count when bucket added to empty_buckets
self.freeBucket(bucket, @divExact(page_size, bucket.alloc_cursor));
@@ -814,7 +816,9 @@ pub fn GeneralPurposeAllocator(comptime config: Config) type {
self.buckets[bucket_index] = bucket.prev;
}
if (!config.never_unmap) {
self.backing_allocator.free(bucket.page[0..page_size]);
const array_ptr = bucket.page[0..page_size];
comptime assert(@TypeOf(array_ptr) == *align(page_size) [page_size]u8);
self.backing_allocator.free(@as([]align(page_size) u8, array_ptr));
}
if (!config.retain_metadata) {
self.freeBucket(bucket, size_class);

35
lib/std/mem/Allocator.zig
View File

@@ -109,7 +109,7 @@ pub fn create(self: Allocator, comptime T: type) Error!*T {
/// `ptr` should be the return value of `create`, or otherwise
/// have the same address and alignment property.
pub fn destroy(self: Allocator, ptr: anytype) void {
const info = @typeInfo(@TypeOf(ptr)).Pointer;
const info = ensureSlice(@TypeOf(ptr), "destroy", .One);
const T = info.child;
if (@sizeOf(T) == 0) return;
const non_const_ptr = @intToPtr([*]u8, @ptrToInt(ptr));
@@ -224,7 +224,7 @@ pub fn allocAdvancedWithRetAddr(
/// the pointer, however the allocator implementation may refuse the resize
/// request by returning `false`.
pub fn resize(self: Allocator, old_mem: anytype, new_n: usize) bool {
const Slice = @typeInfo(@TypeOf(old_mem)).Pointer;
const Slice = ensureSlice(@TypeOf(old_mem), "resize", .Slice);
const T = Slice.child;
if (new_n == 0) {
self.free(old_mem);
@@ -245,7 +245,7 @@ pub fn resize(self: Allocator, old_mem: anytype, new_n: usize) bool {
/// can be larger, smaller, or the same size as the old memory allocation.
/// If `new_n` is 0, this is the same as `free` and it always succeeds.
pub fn realloc(self: Allocator, old_mem: anytype, new_n: usize) t: {
const Slice = @typeInfo(@TypeOf(old_mem)).Pointer;
const Slice = ensureSlice(@TypeOf(old_mem), "realloc", .Slice);
break :t Error![]align(Slice.alignment) Slice.child;
} {
return self.reallocAdvanced(old_mem, new_n, @returnAddress());
@@ -257,10 +257,10 @@ pub fn reallocAdvanced(
new_n: usize,
return_address: usize,
) t: {
const Slice = @typeInfo(@TypeOf(old_mem)).Pointer;
const Slice = ensureSlice(@TypeOf(old_mem), "reallocAdvanced", .Slice);
break :t Error![]align(Slice.alignment) Slice.child;
} {
const Slice = @typeInfo(@TypeOf(old_mem)).Pointer;
const Slice = ensureSlice(@TypeOf(old_mem), "reallocAdvanced", .Slice);
const T = Slice.child;
if (old_mem.len == 0) {
return self.allocAdvancedWithRetAddr(T, Slice.alignment, new_n, return_address);
@@ -293,7 +293,7 @@ pub fn reallocAdvanced(
/// Free an array allocated with `alloc`. To free a single item,
/// see `destroy`.
pub fn free(self: Allocator, memory: anytype) void {
const Slice = @typeInfo(@TypeOf(memory)).Pointer;
const Slice = ensureSlice(@TypeOf(memory), "free", .Slice);
const bytes = mem.sliceAsBytes(memory);
const bytes_len = bytes.len + if (Slice.sentinel != null) @sizeOf(Slice.child) else 0;
if (bytes_len == 0) return;
@@ -318,6 +318,29 @@ pub fn dupeZ(allocator: Allocator, comptime T: type, m: []const T) ![:0]T {
return new_buf[0..m.len :0];
}
inline fn ensureSlice(
comptime Type: type,
comptime function_name: []const u8,
comptime expected_size: std.builtin.Type.Pointer.Size,
) std.builtin.Type.Pointer {
const expectation = switch (expected_size) {
.One => "a single item pointer",
.Slice => "a slice",
else => unreachable,
};
const type_info = @typeInfo(Type);
if (type_info == .Pointer) {
const pointer = type_info.Pointer;
if (pointer.size == expected_size) {
return pointer;
}
}
@compileError(std.fmt.comptimePrint("{s} expects {s} but received a value of type `{s}`", .{ function_name, expectation, @typeName(Type) }));
}
/// TODO replace callsites with `@log2` after this proposal is implemented:
/// https://github.com/ziglang/zig/issues/13642
inline fn log2a(x: anytype) switch (@typeInfo(@TypeOf(x))) {