This is a bit of an interesting upgrade to LLVM. Upstream LLVM has started using C++11 features, so they require a C++11 compiler to build. I've updated all the bots to have a C++11 compiler, and they appear to be building LLVM successfully:
* Linux bots - I added gcc/g++ 4.7 (good enough)
* Android bots - same as the linux ones
* Mac bots - I installed the most recent command line tools for Lion which gives us clang 3.2, but LLVM wouldn't build unless it was explicitly asked to link to `libc++` instead of `libstdc++`. This involved tweaking `mklldeps.py` and the `configure` script to get things to work out
* Windows bots - mingw-w64 has gcc 4.8.1 which is sufficient for building LLVM (hurray!)
* BSD bots - I updated FreeBSD to 10.0 which brought with it a relevant version of clang.
The largest fallout I've seen so far is that the test suite doesn't work at all on FreeBSD 10. We've already stopped gating on FreeBSD due to #13427 (we used to be on freebsd 9), so I don't think this puts us in too bad of a situation. I will continue to attempt to fix FreeBSD and the breakage on there.
The LLVM update brings with it all of the recently upstreamed LLVM patches. We only have one local patch now which is just an optimization, and isn't required to use upstream LLVM. I want to maintain compatibility with LLVM 3.3 and 3.4 while we can, and this upgrade is keeping us up to date with the 3.5 release. Once 3.5 is release we will in theory no longer require a bundled LLVM.
This comes with a number of fixes to be compatible with upstream LLVM:
* Previously all monomorphizations of "mem::size_of()" would receive the same
symbol. In the past LLVM would silently rename duplicated symbols, but it
appears to now be dropping the duplicate symbols and functions now. The symbol
names of monomorphized functions are now no longer solely based on the type of
the function, but rather the type and the unique hash for the
monomorphization.
* Split stacks are no longer a global feature controlled by a flag in LLVM.
Instead, they are opt-in on a per-function basis through a function attribute.
The rust #[no_split_stack] attribute will disable this, otherwise all
functions have #[split_stack] attached to them.
* The compare and swap instruction now takes two atomic orderings, one for the
successful case and one for the failure case. LLVM internally has an
implementation of calculating the appropriate failure ordering given a
particular success ordering (previously only a success ordering was
specified), and I copied that into the intrinsic translation so the failure
ordering isn't supplied on a source level for now.
* Minor tweaks to LLVM's API in terms of debuginfo, naming, c++11 conventions,
etc.
Part of this required added an override of `fold_type_method` in the
Folder for Ctx impl; it follows the same pattern as `fold_method`.
Also, as a drive-by fix, I moved all of the calls to `folder.new_id`
in syntax::fold's no-op default traversal to really be the first
statement in each function.
* This is to uphold the invariant that `folder.new_id` is always
called first (an unfortunate requirement of the current `ast_map`
code), an invariant that we seemingly were breaking in e.g. the
previous `noop_fold_block`.
* Now it should be easier to see when adding new code that this
invariant must be upheld.
* (note that the breakage in `noop_fold_block` may not have mattered
so much previously, since the only thing that blocks can bind are
lifetimes, which I am only adding support for now.)
This change removes the AbiSet from the AST, converting all usage to have just
one Abi value. The current scheme selects a relevant ABI given a list of ABIs
based on the target architecture and how relevant each ABI is to that
architecture.
Instead of this mildly complicated scheme, only one ABI will be allowed in abi
strings, and pseudo-abis will be created for special cases as necessary. For
example the "system" abi exists for stdcall on win32 and C on win64.
Closes#10049
Closes#12366.
Parentheses around assignment statements such as
let mut a = (0);
a = (1);
a += (2);
are not necessary and therefore an unnecessary_parens warning is raised when
statements like this occur.
The warning mechanism was refactored along the way to allow for code reuse
between the routines for checking expressions and statements.
Code had to be adopted throughout the compiler and standard libraries to comply
with this modification of the lint.
Error messages cleaned in librustc/middle
Error messages cleaned in libsyntax
Error messages cleaned in libsyntax more agressively
Error messages cleaned in librustc more aggressively
Fixed affected tests
Fixed other failing tests
Last failing tests fixed
NodeIds are sequential integers starting at zero, so we can achieve some
memory savings by just storing the items all in a line in a vector.
The occupancy for typical crates seems to be 75-80%, so we're already
more efficient than a HashMap (maximum occupancy 75%), not even counting
the extra book-keeping that HashMap does.
Major changes:
- Define temporary scopes in a syntax-based way that basically defaults
to the innermost statement or conditional block, except for in
a `let` initializer, where we default to the innermost block. Rules
are documented in the code, but not in the manual (yet).
See new test run-pass/cleanup-value-scopes.rs for examples.
- Refactors Datum to better define cleanup roles.
- Refactor cleanup scopes to not be tied to basic blocks, permitting
us to have a very large number of scopes (one per AST node).
- Introduce nascent documentation in trans/doc.rs covering datums and
cleanup in a more comprehensive way.
This is broken, and results in poor performance due to the undefined
behaviour in the LLVM IR. LLVM's `mergefunc` is a *much* better way of
doing this since it merges based on the equality of the bytecode.
For example, consider `std::repr`. It generates different code per
type, but is not included in the type bounds of generics.
The `mergefunc` pass works for most of our code but currently hits an
assert on libstd. It is receiving attention upstream so it will be
ready soon, but I don't think removing this broken code should wait any
longer. I've opened #9536 about enabling it by default.
Closes#8651Closes#3547Closes#2537Closes#6971Closes#9222
The `noalias` attributes were being set only on function definitions,
not on all declarations. This is harmless for `noalias`, but prevented
some optimization opportunities and is *not* harmless for other
attributes like `sret` with ABI implications.
Closes#9104
This removes another large chunk of this odd 'clownshoes' identifier showing up
in symbol names. These all originated from external crates because the encoded
items were encoded independently of the paths calculated in ast_map. The
encoding of these paths now uses the helper function in ast_map to calculate the
"pretty name" for an impl block.
Unfortunately there is still no information about generics in the symbol name,
but it's certainly vastly better than before
hash::__extensions__::write::_version::v0.8
becomes
hash::Writer$SipState::write::hversion::v0.8
This also fixes bugs in which lots of methods would show up as `meth_XXX`, they
now only show up as `meth` and throw some extra characters onto the version
string.
Monomorphize's normalization results in a 2% decrease in non-optimized
code size for libstd, so there's a negligible cost to removing it. This
also fixes several visit glue bugs because normalize wasn't considering
the differences in visit glue between types.
Closes#8720
The first commit message is pretty good, but whomever reviews this should probably also at least glance at the changes I made in LLVM. I basically reorganized our pending patch queue to be a bit more organized and clearer in what needs to go where. After this, our queue would be:
* Add the `no-split-stack` attribute
* Add the `fixedstacksegment` attribute
* Add split-stacks for arm android
* Add split-stacks for arm linux
* Add split stacks for mips
Then there's a patch which I added to get rust to build at all on LLVM-head, and I'm not quite sure why it's there, but nothing seems to be crashing for now! (famous last words).
Otherwise, I just updated code to reflect the changes I made in LLVM with the only major change being the advent of the new `no_split_stack` attribute. This is work towards #1226, but someone more familiar with the code should probably actually assign the attribute to the appropriate functions.
Also as a bonus, I've verified that this closes#5774
