With these changes, exchange allocator headers are never initialized, read or written to. Removing the header will now just involve updating the code in trans using an offset to only do it if the type contained is managed.
The only thing blocking removing the initialization of the last field in the header was ~fn since it uses it to store the dynamic size/types due to captures. I temporarily switched it to a `closure_exchange_alloc` lang item (it uses the same `exchange_free`) and #7496 is filed about removing that.
Since the `exchange_free` call is now inlined all over the codebase, I don't think we should have an assert for null. It doesn't currently ever happen, but it would be fine if we started generating code that did do it. The `exchange_free` function also had a comment declaring that it must not fail, but a regular assert would cause a failure. I also removed the atomic counter because valgrind can already find these leaks, and we have valgrind bots now.
Note that exchange free does not currently print an error an out-of-memory when it aborts, because our `io` code may allocate. We could probably get away with a `#[rust_stack]` call to a `stdio` function but it would be better to make a write system call.
Currently we pass all "self" arguments by reference, for the pointer
variants this means that we end up with double indirection which causes
a unnecessary performance hit.
The fix itself is pretty straight-forward and just means that "self"
needs to be handled like any other argument, except for by-value "self"
which still needs to be passed by reference. This is because
non-pointer types can't just be stuffed into the environment slot which
is used to pass "self".
What made things tricky is that there was also a bug in the typechecker
where the method map entries are created. For type impls, that stored
the base type instead of the actual self-type in the method map, e.g.
Foo instead of &Foo for &self. That worked with pass-by-reference, but
fails with pass-by-value which needs the real type.
Code that makes use of methods seems to be about 10% faster with this
change. Also, build times are reduced by about 4%.
Fixes#4355, #4402, #5280, #4406 and #7285
Currently we pass all "self" arguments by reference, for the pointer
variants this means that we end up with double indirection which causes
a unnecessary performance hit.
The fix itself is pretty straight-forward and just means that "self"
needs to be handled like any other argument, except for by-value "self"
which still needs to be passed by reference. This is because
non-pointer types can't just be stuffed into the environment slot which
is used to pass "self".
What made things tricky is that there was also a bug in the typechecker
where the method map entries are created. For type impls, that stored
the base type instead of the actual self-type in the method map, e.g.
Foo instead of &Foo for &self. That worked with pass-by-reference, but
fails with pass-by-value which needs the real type.
Code that makes use of methods seems to be about 10% faster with this
change. Also, build times are reduced by about 4%.
Fixes#4355, #4402, #5280, #4406 and #7285
The code that tried to revoke the cleanup for the self argument tried
to use "llself" to do so, but the cleanup might actually be registered
with a different ValueRef due to e.g. casting. Currently, this is
worked around by early revocation of the cleanup for self in
trans_self_arg.
To handle this correctly, we have to put the ValueRef for the cleanup
into the MethodData, so trans_call_inner can use it to revoke the
cleanup when it's actually supposed to.
"self" is always passed as an opaque box, so there's no point in using
the concrete self type when translating the argument. All it does it
causing the value to be casted back to an opaque box right away.
Instead of determining paths from the path tag, we iterate through
modules' children recursively in the metadata. This will allow for
lazy external module resolution.
This removes the `namegen` thunk that was in `common.rs`. I also take the opportunity to refactor a few uses where we had a `str -> ident -> str` chain that seemed somewhat redundant to me.
Also cleans up some warnings that made their way in already.
Mostly just low-haning fruit, i.e. function arguments that were @ even
though & would work just as well.
Reduces librustc.so size by 200k when compiling without -O, by 100k when
compiling with -O.
This PR contains no real code changes. Just some documentation additions in the form of comments and some internal reordering of functions within debuginfo.rs.
This adds a `#[no_drop_flag]` attribute. This attribute tells the compiler to omit the drop flag from the struct, if it has a destructor. When the destructor is run, instead of setting the drop flag, it instead zeroes-out the struct. This means the destructor can run multiple times and therefore it is up to the developer to use it safely.
The primary usage case for this is smart-pointer types like `Rc<T>` as the extra flag caused the struct to be 1 word larger because of alignment.
This closes#7271 and #7138
This sets the `get_tydesc()` return type correctly and removes the intrinsic module. See #3730, #3475.
Update: this now also removes the unused shape fields in tydescs.
To achieve this, the following changes were made:
* Move TyDesc, TyVisitor and Opaque to std::unstable::intrinsics
* Convert TyDesc, TyVisitor and Opaque to lang items instead of specially
handling the intrinsics module
* Removed TypeDesc, FreeGlue and get_type_desc() from sys
Fixes#3475.
This fixes part of #3730, but not all.
Also changes the TyDesc struct to be equivalent with the generated
code, with the hope that the above issue may one day be closed for good,
i.e. that the TyDesc type can completely be specified in the Rust
sources and not be generated.
I removed the `static-method-test.rs` test because it was heavily based
on `BaseIter` and there are plenty of other more complex uses of static
methods anyway.
This makes the handling of atomic operations more generic, which
does impose a specific naming convention for the intrinsics, but
that seems ok with me, rather than having an individual case for
each name.
It also adds the intrinsics to the the intrinsics file.
The changes in these commits improve the IR codegen by removing unnecessary copies for certain function call arguments and stopping to allocate return values for functions returning nil. They reduce compile times by about 10% in total.
By using "void" instead of "{}" as the LLVM type for nil, we can avoid
the alloca/store/load sequence for the return value, resulting in less
and simpler IR code.
This reduces compile times by about 10%.
The removed test for issue #2611 is well covered by the `std::iterator`
module itself.
This adds the `count` method to `IteratorUtil` to replace `EqIter`.
This fixes the large number of problems that prevented cross crate
methods from ever working. It also fixes a couple lingering bugs with
polymorphic default methods and cleans up some of the code paths.
Closes#4102. Closes#4103.
r? nikomatsakis
This fixes the large number of problems that prevented cross crate
methods from ever working. It also fixes a couple lingering bugs with
polymorphic default methods and cleans up some of the code paths.
Closes#4102. Closes#4103.
Currently, by-copy function arguments are always stored into a scratch
datum, which serves two purposes. First, it is required to be able to
have a temporary cleanup, in case that the call fails before the callee
actually takes ownership of the value. Second, if the argument is to be
passed by reference, the copy is required, so that the function doesn't
get a reference to the original value.
But in case that the datum does not need a drop glue call and it is
passed by value, there's no need to perform the extra copy.
Currently, cleanup blocks are only reused when there are nested scopes, the
child scope's cleanup block will terminate with a jump to the parent
scope's cleanup block. But within a single scope, adding or revoking
any cleanup will force a fresh cleanup block. This means quadratic
growth with the number of allocations in a scope, because each
allocation needs a landing pad.
Instead of forcing a fresh cleanup block, we can keep a list chained
cleanup blocks that form a prefix of the currently required cleanups.
That way, the next cleanup block only has to handle newly added
cleanups. And by keeping the whole list instead of just the latest
block, we can also handle revocations more efficiently, by only
dropping those blocks that are no longer required, instead of all of
them.
Reduces the size of librustc by about 5% and the time required to build
it by about 10%.
Currently, cleanup blocks are only reused when there are nested scopes, the
child scope's cleanup block will terminate with a jump to the parent
scope's cleanup block. But within a single scope, adding or revoking
any cleanup will force a fresh cleanup block. This means quadratic
growth with the number of allocations in a scope, because each
allocation needs a landing pad.
Instead of forcing a fresh cleanup block, we can keep a list chained
cleanup blocks that form a prefix of the currently required cleanups.
That way, the next cleanup block only has to handle newly added
cleanups. And by keeping the whole list instead of just the latest
block, we can also handle revocations more efficiently, by only
dropping those blocks that are no longer required, instead of all of
them.
Reduces the size of librustc by about 5% and the time required to build
it by about 10%.
Moves all the remaining functions that could reasonably be methods to be methods, except for some FFI ones (which I believe @erickt is working on, possibly) and `each_split_within`, since I'm not really sure the details of it (I believe @kimundi wrote the current implementation, so maybe he could convert it to an external iterator method on `StrSlice`, e.g. `word_wrap_iter(&self) -> WordWrapIterator<'self>`, where `WordWrapIterator` impls `Iterator<&'self str>`. It probably won't be too hard, since it's already a state machine.)
This also cleans up the comparison impls for the string types, except I'm not sure how the lang items `eq_str` and `eq_str_uniq` need to be handled, so they (`eq_slice` and `eq`) remain stand-alone functions.
Remove all the explicit @mut-fields from CrateContext, though many
fields are still @-ptrs.
This required changing every single function call that explicitly
took a @CrateContext, so I took advantage and changed as many as I
could get away with to &-ptrs or &mut ptrs.
Currently, when calling glue functions, we cast the function to match
the argument type. This interacts very badly with LLVM and breaks
inlining of the glue code.
It's more efficient to use a unified function type for the glue
functions and always cast the function argument instead of the function.
The resulting code for rustc is about 13% faster (measured up to and
including the "trans" pass) and the resulting librustc is about 5%
smaller.
This un-reverts the reverts of the rusti commits made awhile back. These were reverted for an LLVM failure in rustpkg. I believe that this is not a problem with these commits, but rather that rustc is being used in parallel for rustpkg tests (in-process). This is not working yet (almost! see #7011), so I serialized all the tests to run one after another.
@brson, I'm mainly just guessing as to the cause of the LLVM failures in rustpkg tests. I'm confident that running tests in parallel is more likely to be the problem than those commits I made.
Additionally, this fixes two recently reported issues with rusti.
The lookups for these items in external crates currently cause repeated
decoding of the EBML metadata, which is pretty slow. Adding caches to
avoid the repeated decoding reduces the time required for the type
checking of librustc by about 25%.
This fixes the strange random crashes in compile-fail tests.
This reverts commit 96cd61ad03.
Conflicts:
src/librustc/driver/driver.rs
src/libstd/str.rs
src/libsyntax/ext/quote.rs
This almost removes the StringRef wrapper, since all strings are
Equiv-alent now. Removes a lot of `/* bad */ copy *`'s, and converts
several things to be &'static str (the lint table and the intrinsics
table).
There are many instances of .to_managed(), unfortunately.
There are now only half-a-dozen or so functions left `std::str` that should be methods.
Highlights:
- `.substr` was removed, since most of the uses of it in the code base were actually incorrect (it had a weird mixing of a byte index and a unicode character count), adding `.slice_chars` if one wants to handle characters, and the normal `.slice` method to handle bytes.
- Code duplication between the two impls for `connect` and `concat` was removed via a new `Str` trait, that is purely designed to allow an explicit -> `&str` conversion (`.as_slice()`)
- Deconfuse the 5 different functions for converting to `[u8]` (3 of which had actually incorrect documentation: implying that they didn't have the null terminator), into 3: `as_bytes` (all strings), `as_bytes_with_null` (`&'static str`, `@str` and `~str`) and `as_bytes_with_null_consume` (`~str`). None of these allocate, unlike the old versions.
(cc @thestinger)
The confusing mixture of byte index and character count meant that every
use of .substr was incorrect; replaced by slice_chars which only uses
character indices. The old behaviour of `.substr(start, n)` can be emulated
via `.slice_from(start).slice_chars(0, n)`.
This was a lot more painful than just changing `x.each` to `x.iter().advance` . I ran into my old friend #5898 and had to add underscores to some method names as a temporary workaround.
The borrow checker also had other ideas because rvalues aren't handled very well yet so temporary variables had to be added. However, storing the temporary in a variable led to dynamic `@mut` failures, so those had to be wrapped in blocks except where the scope ends immediately.
Anyway, the ugliness will be fixed as the compiler issues are fixed and this change will amount to `for x.each |x|` becoming `for x.iter |x|` and making all the iterator adaptors available.
I dropped the run-pass tests for `old_iter` because there's not much point in fixing a module that's on the way out in the next week or so.
For types that are passed by value, we can't just cast the value to a
pointer, but have to use an alloca and copy the value there. This
handling is already present for all other arguments, but was missing
for "self".
Fixes#6682, #4850 and #4878
The `callee_id` in `ast::expr` in only used in a couple expression variants. This moves the `callee_id` into those branches to make it more clear when its should be used.
Also, it fixes a bug in a std::run test when there is a symlink in the path rust where was checked out.
Fix a laundry list of warnings involving unused imports that glutted
up compilation output. There are more, but there seems to be some
false positives (where 'remedy' appears to break the build), but this
particular set of fixes seems safe.
Fix a laundry list of warnings involving unused imports that glutted
up compilation output. There are more, but there seems to be some
false positives (where 'remedy' appears to break the build), but this
particular set of fixes seems safe.
Fix for #6575. In the trans phase, rustc emits code for a function parameter that goes completely unused in the event the return type of the function in question happens to be an immediate.
This patch modifies rustc & parts of rustrt to ensure that the vestigial parameter is no longer present in compiled code.
The compiler guarantees that there are no other references to a unique pointer when it's passed by-value to a function.
The existence of the header and annihilator don't matter since it's not relevant to the call:
> For a call to the parent function, dependencies between memory references from before or after the call and from those during the call are “irrelevant” to the noalias keyword for the arguments and return value used in that call.
@graydon's tracing garbage collector stores the metadata outside of the boxes, so that won't be a problem. I'm unsure if updating the header while inside a function where it's marked as `noalias` would be a problem anyway since you never actually read or write to the header.
@nikomatsakis: r?
Simple patch series to fix up all the warnings a rustc compile is giving at the moment. It also fixes a NOTE in `to_bytes.rs` to remove the `to_bytes::iter_bytes_<N>` functions.
The way we deal with unreachable expressions in trans is pretty ad hoc,
but this at least doesn't make it worse, and eliminates the LLVM
assertion failure reported in #5741.
This adds a lint mode for detecting unnecessary allocations on the heap. This isn't super fancy, currently it only has two rules
1. For a function's arguments, if you allocate a `[~|@]str` literal, when the type of the argument is a `&str`, emit a warning.
2. For the same case, emit warnings for boxed vectors when slices are required.
After adding the lint, I rampaged through the libraries and removed all the unnecessary allocations I could find.
With this, the build is almost 100% warning free.
One more can be fixed after the next snapshot, and there's one other that I filed an issue about already.
