Fixes#9882
Note that the actual checking code is inside a if false in order to compile libstd properly.
libstd uses asm! in rt. If we put ```#[feature(asm)]``` in libstd, it fails to build at stage0 beacause the
asm feature is not known yet by the snapshot compiler.
We must wait that this PR arrives into the snapshot in order to actually activate the checking code.
This commit re-introduces the functionality of __morestack in a way that it was
not originally anticipated. Rust does not currently have segmented stacks,
rather just large stack segments. We do not detect when these stack segments are
overrun currently, but this commit leverages __morestack in order to check this.
This commit purges a lot of the old __morestack and stack limit C++
functionality, migrating the necessary chunks to rust. The stack limit is now
entirely maintained in rust, and the "main logic bits" of __morestack are now
also implemented in rust as well.
I put my best effort into validating that this currently builds and runs successfully on osx and linux 32/64 bit, but I was unable to get this working on windows. We never did have unwinding through __morestack frames, and although I tried poking at it for a bit, I was unable to understand why we don't get unwinding right now.
A focus of this commit is to implement as much of the logic in rust as possible. This involved some liberal usage of `no_split_stack` in various locations, along with some use of the `asm!` macro (scary). I modified a bit of C++ to stop calling `record_sp_limit` because this is no longer defined in C++, rather in rust.
Another consequence of this commit is that `thread_local_storage::{get, set}` must both be flagged with `#[rust_stack]`. I've briefly looked at the implementations on osx/linux/windows to ensure that they're pretty small stacks, and I'm pretty sure that they're definitely less than 20K stacks, so we probably don't have a lot to worry about.
Other things worthy of note:
* The default stack size is now 4MB instead of 2MB. This is so that when we request 2MB to call a C function you don't immediately overflow because you have consumed any stack at all.
* `asm!` is actually pretty cool, maybe we could actually define context switching with it?
* I wanted to add links to the internet about all this jazz of storing information in TLS, but I was only able to find a link for the windows implementation. Otherwise my suggestion is just "disassemble on that arch and see what happens"
* I put my best effort forward on arm/mips to tweak __morestack correctly, we have no ability to test this so an extra set of eyes would be useful on these spots.
* This is all really tricky stuff, so I tried to put as many comments as I thought were necessary, but if anything is still unclear (or I completely forgot to take something into account), I'm willing to write more!
This commit resumes management of the stack boundaries and limits when switching
between tasks. This additionally leverages the __morestack function to run code
on "stack overflow". The current behavior is to abort the process, but this is
probably not the best behavior in the long term (for deails, see the comment I
wrote up in the stack exhaustion routine).
r? @alexcrichton On most platforms, the time granularity is 1 sec or more, so comparing
dates in tests that check whether rebuilding did or didn't happen leads
to spurious failures. Instead, test the same thing by making an output
file read-only and trapping attempts to write to it.
This stops labeling everything as "is private" when in fact the destination may
be public. Instead, the clause "is inaccessible" is used and the private part of
the flag is called out with a "is private" message.
Closes#9793
Previously an ExprLit was created *per byte* causing a huge increase in memory
bloat. This adds a new `lit_binary` to contain a literal of binary data, which
is currently only used by the include_bin! syntax extension. This massively
speeds up compilation times of the shootout-k-nucleotide-pipes test
before:
time: 469s
memory: 6GB
assertion failure in LLVM (section too large)
after:
time: 2.50s
memory: 124MB
Closes#2598
Previously an ExprLit was created *per byte* causing a huge increase in memory
bloat. This adds a new `lit_binary` to contain a literal of binary data, which
is currently only used by the include_bin! syntax extension. This massively
speeds up compilation times of the shootout-k-nucleotide-pipes test
before:
time: 469s
memory: 6GB
assertion failure in LLVM (section too large)
after:
time: 2.50s
memory: 124MB
Closes#2598
The code generation previously assumed a reference could not alter the
value in a way the destructor would notice. This is an incorrect
assumption for `&mut`, and is also incorrect for an `&` pointer to a
non-`Freeze` type.
Closes#7972
The code generation previously assumed a reference could not alter the
value in a way the destructor would notice. This is an incorrect
assumption for `&mut`, and is also incorrect for an `&` pointer to a
non-`Freeze` type.
Closes#7972
The goal here is to avoid requiring a division or multiplication to compare against the length. The bounds check previously used an incorrect micro-optimization to replace the division by a multiplication, but now neither is necessary *for slices*. Unique/managed vectors will have to do a division to get the length until they are reworked/replaced.
Delete the following API functions:
- set_dirname()
- with_dirname()
- set_filestem()
- with_filestem()
- add_extension()
- file_path()
Also change pop() to return a boolean instead of an owned copy of the
old filename.
Standardize the is_sep() functions to be the same in both posix and
windows, and re-export from path. Update extra::glob to use this.
Remove the usage of either, as it's going away.
Move the WindowsPath-specific methods out of WindowsPath and make them
top-level functions of path::windows instead. This way you cannot
accidentally write code that will fail to compile on non-windows
architectures without typing ::windows anywhere.
Remove GenericPath::from_c_str() and just impl BytesContainer for
CString instead.
Remove .join_path() and .push_path() and just implement BytesContainer
for Path instead.
Remove FilenameDisplay and add a boolean flag to Display instead.
Remove .each_parent(). It only had one caller, so just inline its
definition there.
Add a new trait BytesContainer that is implemented for both byte vectors
and strings.
Convert Path::from_vec and ::from_str to one function, Path::new().
Remove all the _str-suffixed mutation methods (push, join, with_*,
set_*) and modify the non-suffixed versions to use BytesContainer.
Remove the old path.
Rename path2 to path.
Update all clients for the new path.
Also make some miscellaneous changes to the Path APIs to help the
adoption process.
This stops labeling everything as "is private" when in fact the destination may
be public. Instead, the clause "is inaccessible" is used and the private part of
the flag is called out with a "is private" message.
Closes#9793
Example:
void ({ i64, %tydesc*, i8*, i8*, i8 }*, i64*, %"struct.std::fmt::Formatter[#1]"*)*
Before, we would print 20 levels deep due to recursion in the type
definition.
There's currently a fair amount of code which is being ignored on unnamed blocks
(which are the default now), and I opted to leave it commented out for now. I
intend on very soon revisiting on how we perform linking with extern crates in
an effort to support static linking.
There's currently a fair amount of code which is being ignored on unnamed blocks
(which are the default now), and I opted to leave it commented out for now. I
intend on very soon revisiting on how we perform linking with extern crates in
an effort to support static linking.
I borrow some ideas from clang's ABIInfo.h and TargetInfo.cpp.
LLVMType is replaced with ArgType, which is similar to clang's ABIArgInfo,
and I also merge attrs of FnType into it.
Now ABI implementation doesn't need to insert hidden return pointer
to arg_tys of FnType. Instead it is handled in foreign.rs.
This change also fixes LLVM assertion failure when compiling MIPS target.
This fixes a bug in which the visibility rules were approximated by
reachability, but forgot to cover the case where a 'pub use' reexports a private
item. This fixes the commit by instead using the results of the privacy pass of
the compiler to create the initial working set of the reachability pass.
This may have the side effect of increasing the size of metadata, but it's
difficult to avoid for correctness purposes sadly.
Closes#9790
This fixes a bug in which the visibility rules were approximated by
reachability, but forgot to cover the case where a 'pub use' reexports a private
item. This fixes the commit by instead using the results of the privacy pass of
the compiler to create the initial working set of the reachability pass.
This may have the side effect of increasing the size of metadata, but it's
difficult to avoid for correctness purposes sadly.
Closes#9790
Bare functions are another example of a scalar but non-numeric
type (like char) that should be handled separately in casts.
This disallows expressions like `0 as extern "Rust" fn() -> int;`.
It might be advantageous to allow casts between bare functions
and raw pointers in unsafe code in the future, to pass function
pointers between Rust and C.
Closes#8728
This disallows `str[0] = foo` along with `foo = &mut str[i]` to prevent strings
from being modified at runtime (except possibly through the `str` module)
Closes#8891
Since lint check attributes are the preferred way of selectively
enabling/disabling lint checks, the output format of a failed
default check has been changed to reflect that.
When lint checks are being explicitly set by a command-line flag
or an attribute, the behavior is unchanged, so that the user can
quickly pinpoint the source.
Closes#6580
