* Reuse bytes of async function frames when non-async functions
make `noasync` calls. This prevents explosive stack growth.
* Zig now passes a stack size argument to the linker when linking ELF
binaries. Linux ignores this value, but it is available as a program
header called GNU_STACK. I prototyped some code that memory maps
extra space to the stack using this program header, but there was
still a problem when accessing stack memory very far down. Stack
probing is needed or not working or something. I also prototyped
using `@newStackCall` to call main and that does work around the
issue but it also brings its own issues. That code is commented out
for now in std/special/start.zig. I'm on a plane with no Internet,
but I plan to consult with the musl community for advice when I get a
chance.
* Added `noasync` to a bunch of function calls in std.debug. It's very
messy but it's a workaround that makes stack traces functional with
evented I/O enabled. Eventually these will be cleaned up as the root
bugs are found and fixed. Programs built in blocking mode are
unaffected.
* Lowered the default stack size of std.io.InStream (for the async
version) to 1 MiB instead of 4. Until we figure out how to get
choosing a stack size working (see 2nd bullet point above), 4 MiB
tends to cause segfaults due to stack size running out, or usage of
stack memory too far apart, or something like that.
* Default thread stack size is bumped from 8 MiB to 16 to match the
size we give for the main thread. It's planned to eventually remove
this hard coded value and have Zig able to determine this value
during semantic analysis, with call graph analysis and function
pointer annotations and extern function annotations.
- Replace @intCast with a checked version (std/debug.zig)
- Replace @intCast with i64() when casting from a smaller type (std/fs/file.zig)
- Replace `nakedcc` with appropriate calling convention for linking with c (std/os/linux/arm-eabi.zig)
- Only check if hwcap contains TLS when the hwcap field actually exists (std/os/linux/tls.zig)
- Use sys_*stat*64 instead of sys_*stat* where appropriate
- Fix overflow when calculating atime, ctime and mtime on File.stat()
- Fix compilation error casting getEndPos to usize.
Previously, the stack trace iteration code was using the number of
frames collected as the number of frames to print, not recognizing the
fixed size of the buffer. So it would redundantly print items, matching
the total number of frames ever collected.
Now the iteration code is limited to the actual stack trace frame count,
and will not print duplicate frames.
Closes#2447Closes#2151
The return address may not point to an area covered by the debug infos
so we hope for the best and decrement the address so that it points to
the caller instruction.
* Correct parsing of DWARF line_info section
* Fix reading of udata/sdata encoded attributes
* Add definition for DW_AT_alignment
Even though it's been standardized in DWARF5 some compilers produce it
anyway for DWARF4 infos too.
* Fix reading of reference attributes
* Distinguish between absolute/relative addresses
Before, allocator implementations had to provide `allocFn`,
`reallocFn`, and `freeFn`.
Now, they must provide only `reallocFn` and `shrinkFn`.
Reallocating from a zero length slice is allocation, and
shrinking to a zero length slice is freeing.
When the new memory size is less than or equal to the
previous allocation size, `reallocFn` now has the option
to return `error.OutOfMemory` to indicate that the allocator
would not be able to take advantage of the new size.
For more details see #1306. This commit closes#1306.
This commit paves the way to solving #2009.
This commit also introduces a memory leak to all coroutines.
There is an issue where a coroutine calls the function and it
frees its own stack frame, but then the return value of `shrinkFn`
is a slice, which is implemented as an sret struct. Writing to
the return pointer causes invalid memory write. We could work
around it by having a global helper function which has a void
return type and calling that instead. But instead this hack will
suffice until I rework coroutines to be non-allocating. Basically
coroutines are not supported right now until they are reworked as
in #1194.
