Reversal on the decision: the Allocator interface is the correct place
for the memset to undefined because it allows Allocator implementations
to bypass the interface and use a backing allocator directly, skipping
the performance penalty of memsetting the entire allocation, which may
be very large, as well as having valuable zeroes on them.
closes#4298
This one changes the size of an allocation, allowing it to be relocated.
However, the implementation will still return `null` if it would be
equivalent to
new = alloc
memcpy(new, old)
free(old)
Mainly this prepares for taking advantage of `mremap` which I thought
would be a bigger deal but apparently is only available on Linux. Still,
we should use it on Linux.
This keeps the implementation matching master branch, however,
introduces a compile error that applications can work around by
explicitly setting page_size_max and page_size_min to match their
computer's settings, in the case that those values are not already
equal.
I plan to rework this allocator in a follow-up enhancement with the goal
of reducing total active memory mappings.
* fix merge conflicts
* rename the declarations
* reword documentation
* extract FixedBufferAllocator to separate file
* take advantage of locals
* remove the assertion about max alignment in Allocator API, leaving it
Allocator implementation defined
* fix non-inline function call in start logic
The GeneralPurposeAllocator implementation is totally broken because it
uses global state but I didn't address that in this commit.
heap.zig: define new default page sizes
heap.zig: add min/max_page_size and their options
lib/std/c: add miscellaneous declarations
heap.zig: add pageSize() and its options
switch to new page sizes, especially in GPA/stdlib
mem.zig: remove page_size
This check doesn't make sense with the modern Allocator API; it's left over
from when realloc could change alignment. It's statically known (but not
comptime-known) to be true always. This check was one of the things
blocking Allocator from being used at comptime (related: #1291).
This was done by regex substitution with `sed`. I then manually went
over the entire diff and fixed any incorrect changes.
This diff also changes a lot of `callconv(.C)` to `callconv(.c)`, since
my regex happened to also trigger here. I opted to leave these changes
in, since they *are* a correct migration, even if they're not the one I
was trying to do!
It wasn't immediately clear from the implementation whether passing
zero-length memory to free() was undefined behavior or intentionally
supported. Since ArrayList and other core data structures rely on
this behavior working correctly, this should be explicitly documented
as part of the public API contract.
The compiler actually doesn't need any functional changes for this: Sema
does reification based on the tag indices of `std.builtin.Type` already!
So, no zig1.wasm update is necessary.
This change is necessary to disallow name clashes between fields and
decls on a type, which is a prerequisite of #9938.
* Move functionality from generic functions that doesn't depend on the type into a function that only depends on comptime alignment.
This reduces comptime code duplication because e.g. `alloc(u32, )` and `alloc(i32, )` now use the same function `allocWithFoo(4, 4, )` under the hood.
Most of this migration was performed automatically with `zig fmt`. There
were a few exceptions which I had to manually fix:
* `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten
* `@truncate`'s fixup is incorrect for vectors
* Test cases are not formatted, and their error locations change
Anecdote 1: The generic version is way more popular than the non-generic
one in Zig codebase:
git grep -w alignForward | wc -l
56
git grep -w alignForwardGeneric | wc -l
149
git grep -w alignBackward | wc -l
6
git grep -w alignBackwardGeneric | wc -l
15
Anecdote 2: In my project (turbonss) that does much arithmetic and
alignment I exclusively use the Generic functions.
Anecdote 3: we used only the Generic versions in the Macho Man's linker
workshop.
* Sema: upgrade operands to array pointers if possible when emitting
AIR.
* Implement safety checks for length mismatch and aliasing.
* AIR: make ptrtoint support slice operands. Implement in LLVM backend.
* C backend: implement new `@memset` semantics. `@memcpy` is not done
yet.
Now they use slices or array pointers with any element type instead of
requiring byte pointers.
This is a breaking enhancement to the language.
The safety check for overlapping pointers will be implemented in a
future commit.
closes#14040
This reverts commit abc9530a88d24350481d9264edcde300f293929a.
This patch implies that the idiomatic Zig way of handling anytype
parameter is to write a bunch of boilerplate instead of directly
accessing type information and relying on the compiler to be useful.
I don't want it to be this way.
It is the compiler's job to make useful error messages when the wrong
field of a type info result is accessed, and it is the zig programmer's
job to understand what it means when a compile error points at the field
access of `@typeInfo` (along with the relevant callsites).
One thing that might be useful would be having the compiler be aware of
module boundaries and highlighting the boundaries of them. The first
reference note after crossing a module boundary is likely the most
interesting one.
There are still a few occurrences of "stage1" in the standard library
and self-hosted compiler source, however, these instances need a bit
more careful inspection to ensure no breakage.
Fixes#11353
The renderer treats comments and doc comments differently since doc
comments are parsed into the Ast. This commit adds a check after getting
the text for the doc comment and trims whitespace at the end before
rendering.
The `a = 0,` in the test is here to avoid a ParseError while parsing the
test.
