This breaks a fair amount of code. The typical patterns are:
* `for _ in range(0, 10)`: change to `for _ in range(0u, 10)`;
* `println!("{}", 3)`: change to `println!("{}", 3i)`;
* `[1, 2, 3].len()`: change to `[1i, 2, 3].len()`.
RFC #30. Closes#6023.
[breaking-change]
* The select/plural methods from format strings are removed
* The # character no longer needs to be escaped
* The \-based escapes have been removed
* '{{' is now an escape for '{'
* '}}' is now an escape for '}'
Closes#14810
[breaking-change]
This commit revisits the `cast` module in libcore and libstd, and scrutinizes
all functions inside of it. The result was to remove the `cast` module entirely,
folding all functionality into the `mem` module. Specifically, this is the fate
of each function in the `cast` module.
* transmute - This function was moved to `mem`, but it is now marked as
#[unstable]. This is due to planned changes to the `transmute`
function and how it can be invoked (see the #[unstable] comment).
For more information, see RFC 5 and #12898
* transmute_copy - This function was moved to `mem`, with clarification that is
is not an error to invoke it with T/U that are different
sizes, but rather that it is strongly discouraged. This
function is now #[stable]
* forget - This function was moved to `mem` and marked #[stable]
* bump_box_refcount - This function was removed due to the deprecation of
managed boxes as well as its questionable utility.
* transmute_mut - This function was previously deprecated, and removed as part
of this commit.
* transmute_mut_unsafe - This function doesn't serve much of a purpose when it
can be achieved with an `as` in safe code, so it was
removed.
* transmute_lifetime - This function was removed because it is likely a strong
indication that code is incorrect in the first place.
* transmute_mut_lifetime - This function was removed for the same reasons as
`transmute_lifetime`
* copy_lifetime - This function was moved to `mem`, but it is marked
`#[unstable]` now due to the likelihood of being removed in
the future if it is found to not be very useful.
* copy_mut_lifetime - This function was also moved to `mem`, but had the same
treatment as `copy_lifetime`.
* copy_lifetime_vec - This function was removed because it is not used today,
and its existence is not necessary with DST
(copy_lifetime will suffice).
In summary, the cast module was stripped down to these functions, and then the
functions were moved to the `mem` module.
transmute - #[unstable]
transmute_copy - #[stable]
forget - #[stable]
copy_lifetime - #[unstable]
copy_mut_lifetime - #[unstable]
[breaking-change]
This adds the target triple to the crate metadata.
When searching for a crate the phase (link, syntax) is taken into account.
During link phase only crates matching the target triple are considered.
During syntax phase, either the target or host triple will be accepted, unless
the crate defines a macro_registrar, in which case only the host triple will
match.
This is an optimization which is quite impactful for compiling small crates.
Reading libstd's metadata takes about 50ms, and a hello world before this change
took about 100ms (this change halves that time).
Recent changes made it such that this optimization wasn't performed, but I think
it's a better idea do to this for now. See #10786 for tracking this issue.
Fix#13266.
There is a little bit of acrobatics in the definition of `crate_paths`
to avoid calling `clone()` on the dylib/rlib unless we actually are
going to need them.
The other oddity is that I have replaced the `root_ident: Option<&str>`
parameter with a `root: &Option<CratePaths>`, which may surprise one
who was expecting to see something like: `root: Option<&CratePaths>`.
I went with the approach here because I could not come up with code for
the alternative that was acceptable to the borrow checker.
(i.e. semi-generalized version of prior errorinfo gathering.)
Also revised presentation to put each path on its own line, prefixed
by file:linenum information.
The recent pull request to remove libc from libstd has hit a wall in compiling
on windows, and I've been trying to investigate on the try bots as to why (it
compiles locally just fine). To the best of my knowledge, the LLVM section
iterator is behaving badly when iterating over the sections of the libc DLL.
Upon investigating the LLVMGetSectionName function in LLVM, I discovered that
this function doesn't always return a null-terminated string. It returns the
data pointer of a StringRef instance (LLVM's equivalent of &str essentially),
but it has no method of returning the length of the name of the section.
This commit modifies the section iteration when loading libraries to invoke a
custom LLVMRustGetSectionName which will correctly return both the length and
the data pointer.
I have not yet verified that this will fix landing liblibc, as it will require a
snapshot before doing a full test. Regardless, this is a worrisome situation
regarding the LLVM API, and should likely be fixed anyway.
Fix#13266.
There is a little bit of acrobatics in the definition of `crate_paths`
to avoid calling `clone()` on the dylib/rlib unless we actually are
going to need them.
The other oddity is that I have replaced the `root_ident: Option<&str>`
parameter with a `root: &Option<CratePaths>`, which may surprise one
who was expecting to see something like: `root: Option<&CratePaths>`.
I went with the approach here because I could not come up with code for
the alternative that was acceptable to the borrow checker.
Previously, any library of the pattern `lib<name>-<hash>-<version>.so` was
>considered a candidate (rightly so) for loading a crate. Sets are generated for
each unique `<hash>`, and then from these sets a candidate is selected. If a set
contained more than one element, then it immediately generated an error saying
that multiple copies of the same dylib were found.
This is incorrect because each candidate needs to be validated to actually
contain a rust library (valid metadata). This commit alters the logic to filter
each set of candidates for a hash to only libraries which are actually rust
libraries. This means that if multiple false positives are found with the right
name pattern, they're all ignored.
Closes#13010
Previously, any library of the pattern `lib<name>-<hash>-<version>.so` was
>considered a candidate (rightly so) for loading a crate. Sets are generated for
each unique `<hash>`, and then from these sets a candidate is selected. If a set
contained more than one element, then it immediately generated an error saying
that multiple copies of the same dylib were found.
This is incorrect because each candidate needs to be validated to actually
contain a rust library (valid metadata). This commit alters the logic to filter
each set of candidates for a hash to only libraries which are actually rust
libraries. This means that if multiple false positives are found with the right
name pattern, they're all ignored.
Closes#13010
Refactored get_metadata_section to return a Result<MetadataBlob,~str> instead of a Option<MetadataBlob>. This provides more clarity to the user through the debug output when using --ls.
This is kind of a continuation of my original closed pull request 2 months ago (#11544), but I think the time-span constitutes a new pull request.
When the metadata format changes, old libraries often cause librustc to abort
when reading their metadata. This should all change with the introduction of SVH
markers, but the loader for crates should gracefully handle libraries without
SVH markers still.
This commit adds support for tripping fewer assertions when loading libraries by
using maybe_get_doc when initially parsing metadata. It's still possible for
some libraries to fall through the cracks, but this should deal with a fairly
large number of them up front.
This new SVH is used to uniquely identify all crates as a snapshot in time of
their ABI/API/publicly reachable state. This current calculation is just a hash
of the entire crate's AST. This is obviously incorrect, but it is currently the
reality for today.
This change threads through the new Svh structure which originates from crate
dependencies. The concept of crate id hash is preserved to provide efficient
matching on filenames for crate loading. The inspected hash once crate metadata
is opened has been changed to use the new Svh.
The goal of this hash is to identify when upstream crates have changed but
downstream crates have not been recompiled. This will prevent the def-id drift
problem where upstream crates were recompiled, thereby changing their metadata,
but downstream crates were not recompiled.
In the future this hash can be expanded to exclude contents of the AST like doc
comments, but limitations in the compiler prevent this change from being made at
this time.
Closes#10207
The previous code passed around a {name,version} pair everywhere, but this is
better expressed as a CrateId. This patch changes these paths to store and pass
around crate ids instead of these pairs of name/version. This also prepares the
code to change the type of hash that is stored in crates.
This commit implements a layman's version of realpath() for metadata::loader to
use in order to not error on symlinks pointing to the same file.
Closes#12459
These two containers are indeed collections, so their place is in
libcollections, not in libstd. There will always be a hash map as part of the
standard distribution of Rust, but by moving it out of the standard library it
makes libstd that much more portable to more platforms and environments.
This conveniently also removes the stuttering of 'std::hashmap::HashMap',
although 'collections::HashMap' is only one character shorter.
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.
This commit rewrites crate loading internally in attempt to look at less
metadata and provide nicer errors. The loading is now split up into a few
stages:
1. Collect a mapping of (hash => ~[Path]) for a set of candidate libraries for a
given search. The hash is the hash in the filename and the Path is the
location of the library in question. All candidates are filtered based on
their prefix/suffix (dylib/rlib appropriate) and then the hash/version are
split up and are compared (if necessary).
This means that if you're looking for an exact hash of library you don't have
to open up the metadata of all libraries named the same, but also in your
path.
2. Once this mapping is constructed, each (hash, ~[Path]) pair is filtered down
to just a Path. This is necessary because the same rlib could show up twice
in the path in multiple locations. Right now the filenames are based on just
the crate id, so this could be indicative of multiple version of a crate
during one crate_id lifetime in the path. If multiple duplicate crates are
found, an error is generated.
3. Now that we have a mapping of (hash => Path), we error on multiple versions
saying that multiple versions were found. Only if there's one (hash => Path)
pair do we actually return that Path and its metadata.
With this restructuring, it restructures code so errors which were assertions
previously are now first-class errors. Additionally, this should read much less
metadata with lots of crates of the same name or same version in a path.
Closes#11908
