Generic extern functions written in Rust have their names mangled, as well as their internal clownshoe __rust_abi functions. This allows e.g. specific monomorphizations of these functions to be used as callbacks.
Closes#12502.
As discovered in #15460, a particular #[link(kind = "static", ...)] line is not
actually guaranteed to link the library at all. The reason for this is that if
the external library doesn't have any referenced symbols in the object generated
by rustc, the entire library is dropped by the linker.
For dynamic native libraries, this is solved by passing -lfoo for all downstream
compilations unconditionally. For static libraries in rlibs this is solved
because the entire archive is bundled in the rlib. The only situation in which
this was a problem was when a static native library was linked to a rust dynamic
library.
This commit brings the behavior of dylibs in line with rlibs by passing the
--whole-archive flag to the linker when linking native libraries. On OSX, this
uses the -force_load flag. This flag ensures that the entire archive is
considered candidate for being linked into the final dynamic library.
This is a breaking change because if any static library is included twice in the
same compilation unit then the linker will start emitting errors about duplicate
definitions now. The fix for this would involve only statically linking to a
library once.
Closes#15460
[breaking-change]
Using the Show impl for Names created global symbols with names like
`"str\"str\"(1027)"`. This adjusts strings, binaries and vtables to
avoid using that impl.
Fixes#15799.
the CFG for match statements.
There were two bugs in issue #14684. One was simply that the borrow
check didn't know about the correct CFG for match statements: the
pattern must be a predecessor of the guard. This disallows the bad
behavior if there are bindings in the pattern. But it isn't enough to
prevent the memory safety problem, because of wildcards; thus, this
patch introduces a more restrictive rule, which disallows assignments
and mutable borrows inside guards outright.
I discussed this with Niko and we decided this was the best plan of
action.
This breaks code that performs mutable borrows in pattern guards. Most
commonly, the code looks like this:
impl Foo {
fn f(&mut self, ...) {}
fn g(&mut self, ...) {
match bar {
Baz if self.f(...) => { ... }
_ => { ... }
}
}
}
Change this code to not use a guard. For example:
impl Foo {
fn f(&mut self, ...) {}
fn g(&mut self, ...) {
match bar {
Baz => {
if self.f(...) {
...
} else {
...
}
}
_ => { ... }
}
}
}
Sometimes this can result in code duplication, but often it illustrates
a hidden memory safety problem.
Closes#14684.
[breaking-change]
When invoking the compiler in parallel, the intermediate output of the object
files and bytecode can stomp over one another if two crates with the same name
are being compiled.
The output file is already being disambiguated with `-C extra-filename`, so this
commit alters the naming of the temporary files to also mix in the extra
filename to ensure that file names don't clash.
In a cargo-driven world the primary location for the name of a crate will be in
its manifest, not in the source file itself. The purpose of this flag is to
reduce required duplication for new cargo projects.
This is a breaking change because the existing --crate-name flag actually
printed the crate name. This flag was renamed to --print-crate-name, and to
maintain consistence, the --crate-file-name flag was renamed to
--print-file-name.
To maintain backwards compatibility, the --crate-file-name flag is still
recognized, but it is deprecated.
[breaking-change]
This comit implements a new flag, --extern, which is used to specify where a
crate is located. The purpose of this flag is to bypass the normal crate
loading/matching of the compiler to point it directly at the right file.
This flag takes the form `--extern foo=bar` where `foo` is the name of a crate
and `bar` is the location at which to find the crate. Multiple `--extern`
directives are allowed with the same crate name to specify the rlib/dylib pair
for a crate. It is invalid to specify more than one rlib or more than one dylib,
and it's required that the crates are valid rust crates.
I have also added some extensive documentation to metadata::loader about how
crate loading should work.
RFC: 0035-remove-crate-id
floating point numbers for real.
This will break code that looks like:
let mut x = 0;
while ... {
x += 1;
}
println!("{}", x);
Change that code to:
let mut x = 0i;
while ... {
x += 1;
}
println!("{}", x);
Closes#15201.
[breaking-change]
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]
It was accidentally removed in #15006 and that somehow got past the
build bots, causing `src/test/run-make/c-dynamic-dylib` to fail on at
least my linux system.
This resolves#15103 (thanks to @alexcrichton!).
The nightly builds on linux have been failing over the past few days due to a
malformed LD_LIBRARY_PATH. It appears that the underlying cause is that one of
the tests, dep-info-custom, recursively invokes make but the RUSTC variable
passed down has the string "$LD_LIBRARY_PATH". This is intended to read the
host's original LD_LIBRARY_PATH, but it appears that the makefile is eagerly
expanding the "$L" to nothing, causing the original host's LD_LIBRARY_PATH to be
ignored.
This fix removes passing the string "$LD_LIBRARY_PATH" and rather expands it
eagerly to ensure that escaping doesn't happen at a later stage. I'm still not
entirely sure why the makefile is interpreting the dollar as a variable, but
this seems to fix the issue.
The nightly builds on linux have been failing over the past few days due to a
malformed LD_LIBRARY_PATH. It appears that the underlying cause is that one of
the tests, dep-info-custom, recursively invokes make but the RUSTC variable
passed down has the string "$LD_LIBRARY_PATH". This is intended to read the
host's original LD_LIBRARY_PATH, but it appears that the makefile is eagerly
expanding the "$L" to nothing, causing the original host's LD_LIBRARY_PATH to be
ignored.
This fix removes passing the string "$LD_LIBRARY_PATH" and rather expands it
eagerly to ensure that escaping doesn't happen at a later stage. I'm still not
entirely sure why the makefile is interpreting the dollar as a variable, but
this seems to fix the issue.
This involved a few changes to the local build system:
* Makefiles now prefer our own LD_LIBRARY_PATH over the user's LD_LIBRARY_PATH
in order to support building rust with rust already installed.
* The compiletest program was taught to correctly pass through the aux dir as a
component of LD_LIBRARY_PATH in more situations.
This change was spliced out of #14832 to consist of just the fixes to running
tests without an rpath setting embedded in executables.
* 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]
Adds the option -Zsave-analysis which will dump the results of syntax and type checking into CSV files. These can be interpreted by tools such as DXR to provide semantic information about Rust programs for code search, cross-reference, etc.
Authored by Nick Cameron and Peter Elmers (@pelmers; including enums, type parameters/generics).
* 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]
All rust functions are internal implementation details with respect to the ABI
exposed by crates, but extern fns are public components of the ABI and shouldn't
be stripped. This commit serializes reachable extern fns to metadata, so when
LTO is performed all of their symbols are not stripped.
Closes#14500
This is part of the ongoing renaming of the equality traits. See #12517 for more
details. All code using Eq/Ord will temporarily need to move to Partial{Eq,Ord}
or the Total{Eq,Ord} traits. The Total traits will soon be renamed to {Eq,Ord}.
cc #12517
[breaking-change]
This commit shuffles around some of the `rand` code, along with some
reorganization. The new state of the world is as follows:
* The librand crate now only depends on libcore. This interface is experimental.
* The standard library has a new module, `std::rand`. This interface will
eventually become stable.
Unfortunately, this entailed more of a breaking change than just shuffling some
names around. The following breaking changes were made to the rand library:
* Rng::gen_vec() was removed. This has been replaced with Rng::gen_iter() which
will return an infinite stream of random values. Previous behavior can be
regained with `rng.gen_iter().take(n).collect()`
* Rng::gen_ascii_str() was removed. This has been replaced with
Rng::gen_ascii_chars() which will return an infinite stream of random ascii
characters. Similarly to gen_iter(), previous behavior can be emulated with
`rng.gen_ascii_chars().take(n).collect()`
* {IsaacRng, Isaac64Rng, XorShiftRng}::new() have all been removed. These all
relied on being able to use an OSRng for seeding, but this is no longer
available in librand (where these types are defined). To retain the same
functionality, these types now implement the `Rand` trait so they can be
generated with a random seed from another random number generator. This allows
the stdlib to use an OSRng to create seeded instances of these RNGs.
* Rand implementations for `Box<T>` and `@T` were removed. These seemed to be
pretty rare in the codebase, and it allows for librand to not depend on
liballoc. Additionally, other pointer types like Rc<T> and Arc<T> were not
supported. If this is undesirable, librand can depend on liballoc and regain
these implementations.
* The WeightedChoice structure is no longer built with a `Vec<Weighted<T>>`,
but rather a `&mut [Weighted<T>]`. This means that the WeightedChoice
structure now has a lifetime associated with it.
* The `sample` method on `Rng` has been moved to a top-level function in the
`rand` module due to its dependence on `Vec`.
cc #13851
[breaking-change]
This has no tests because it's near impossible to test -- since TestFn uses
`proc`s, they can not be cloned or tested for equality. The only way to really
test this is making sure that for a given number of shards `a`, sharding from
1 to `a` yields the complete set of tests. But `filter_tests` takes its vector
by value and `proc`s cannot be compared.
[breaking-change]
Closes#10898
This has no tests because it's near impossible to test -- since TestFn uses
`proc`s, they can not be cloned or tested for equality. The only way to really
test this is making sure that for a given number of shards `a`, sharding from
1 to `a` yields the complete set of tests. But `filter_tests` takes its vector
by value and `proc`s cannot be compared.
[breaking-change]
Closes#10898
Two line summary: Distinguish HOST_RPATH and TARGET_RPATH; added
RPATH_LINK_SEARCH; skip tests broken in stage1; general cleanup.
`HOST_RPATH_VAR$(1)_T_$(2)_H_$(3)` and `TARGET_RPATH_VAR$(1)_T_$(2)_H_$(3)`
both match the format of the old `RPATH_VAR$(1)_T_$(2)_H_$(3)` (which
is still being set the same way that it was before, to one of either
HOST/TARGET depending on what stage we are building). Namely, the format
is <XXX>_RPATH_VAR = "<LD_LIB_PATH_ENVVAR>=<COLON_SEP_PATH_ENTRIES>"
What this commit does:
* Pass both of the (newly introduced) HOST and TARGET rpath setup vars
to `maketest.py`
* Update `maketest.py` to no longer update the LD_LIBRARY_PATH itself
Instead, it passes along the HOST and TARGET rpath setup vars in
environment variables `HOST_RPATH_ENV` and `TARGET_RPATH_ENV`
* Also, pass the current stage number to maketest.py; it in turn
passes it (via an env var) to run-make tests.
This allows the run-make tests to selectively change behavior
(e.g. turn themselves off) to deal with incompatibilities with
e.g. stage1.
* Cleanup: Distinguish in tools.mk between the command to run (`RUN`)
and the file to generate to drive that command (`RUN_BINFILE`). The
main thing this enables is that `RUN` can now setup the
`TARGET_RPATH_ENV` without having to dirty up the runner code in
each of the `run-make` Makefiles.
* Cleanup: Factored out commands to delete dylib/rlib into
REMOVE_DYLIBS/REMOVE_RLIBS.
There were places where we were only calling `rm $(call DYLIB,foo)`
even though we really needed to get rid of the whole glob (at least
based on alex's findings on #13753 that removing the symlink does not
suffice).
Therefore rather than peppering the code with the awkward
`rm $(TMPDIR)/$(call DYLIB_GLOB,foo)`, I instead introduced a common
`REMOVE_DYLIBS` user function that expands into that when called.
After I adding an analogous `REMOVE_RLIBS`, I changed all of the
existing calls that rm dylibs or rlibs to use these routines
instead.
Note that the latter is not a true refactoring since I may have
changed cases where it was our intent to only remove the sym-link.
(But if that is the case, then we need to more deeply investigate
alex's findings on #13753 where the system was still dynamically
loading up the non-symlinked libraries that it finds on the load
path.)
* Added RPATH_LINK_SEARCH command and use it on Linux.
On some platforms, namely Linux, when you have libboot.so that has
its internal rpath set (to e.g. $(ORIGIN)/path/to/HOSTDIR), the
linker still complains when you do the link step and it does not
know where to find libraries that libboot.so depends upon that live
in HOSTDIR (think e.g. librustuv.so).
As far as I can tell, the GNU linker will consult the
LD_LIBRARY_PATH as part of the linking process to find such
libraries. But if you want to be more careful and not override
LD_LIBRARY_PATH for the `gcc` invocation, then you need some other
way to tell the linker where it can find the libraries that
libboot.so needs. The solution to this on Linux is the
`-Wl,-rpath-link` command line option.
However, this command line option does not exist on Mac OS X, (which
appears to be figuring out how to resolve the libboot.dylib
dependency by some other means, perhaps by consulting the rpath
setting within libboot.dylib).
So, in order to abstract over this distinction, I added the
RPATH_LINK_SEARCH macro to the run-make infrastructure and added
calls to it where necessary to get Linux working. On architectures
other than Linux, the macro expands to nothing.
* Disable miscellaneous tests atop stage1.
* An especially interesting instance of the previous bullet point:
Excuse regex from doing rustdoc tests atop stage1.
This was a (nearly-) final step to get `make check-stage1` working
again.
The use of a special-case check for regex here is ugly but is
analogous other similar checks for regex such as the one that landed
in PR #13844.
The way this is written, the user will get a reminder that
doc-crate-regex is being skipped whenever their rules attempt to do
the crate documentation tests. This is deliberate: I want people
running `make check-stage1` to be reminded about which cases are
being skipped. (But if such echo noise is considered offensive, it
can obviously be removed.)
* Got windows working with the above changes.
This portion of the commit is a cleanup revision of the (previously
mentioned on try builds) re-architecting of how the LD_LIBRARY_PATH
setup and extension is handled in order to accommodate Windows' (1.)
use of `$PATH` for that purpose and (2.) use of spaces in `$PATH`
entries (problematic for make and for interoperation with tools at
the shell).
* In addition, since the code has been rearchitected to pass the
HOST_RPATH_DIR/TARGET_RPATH_DIR rather than a whole sh
environment-variable setting command, there is no need to for the
convert_path_spec calls in maketest.py, which in fact were put in
place to placate Windows but were now causing the Windows builds to
fail. Instead we just convert the paths to absolute paths just like
all of the other path arguments.
Also, note for makefile hackers: apparently you cannot quote operands
to `ifeq` in Makefile (or at least, you need to be careful about
adding them, e.g. to only one side).
Each test works by rendering the flowgraph for the last identified
block we see in expanded pretty-printed output, and comparing it (via
`diff`) against a checked in "foo.dot-expected.dot" file.
Each test post-processes the output to remove NodeIds ` (id=NUM)` so
that the expected output is somewhat stable (or at least independent
of how we assign NodeIds) and easier for a human to interpret when
looking at the expected output file itself.
----
Test writing style notes:
I usually tried to write the tests in a way that would avoid duplicate
labels in the output rendered flow graph, when possible.
The tests that have string literals "unreachable" in the program text
are deliberately written that way to remind the reader that the
unreachable nodes in the resulting graph are not an error in the
control flow computation, but rather a natural consequence of its
construction.
The existing APIs for spawning processes took strings for the command
and arguments, but the underlying system may not impose utf8 encoding,
so this is overly limiting.
The assumption we actually want to make is just that the command and
arguments are viewable as [u8] slices with no interior NULLs, i.e., as
CStrings. The ToCStr trait is a handy bound for types that meet this
requirement (such as &str and Path).
However, since the commands and arguments are often a mixture of
strings and paths, it would be inconvenient to take a slice with a
single T: ToCStr bound. So this patch revamps the process creation API
to instead use a builder-style interface, called `Command`, allowing
arguments to be added one at a time with differing ToCStr
implementations for each.
The initial cut of the builder API has some drawbacks that can be
addressed once issue #13851 (libstd as a facade) is closed. These are
detailed as FIXMEs.
Closes#11650.
[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]
Currently, rustc requires that a linkage be a product of 100% rlibs or 100%
dylibs. This is to satisfy the requirement that each object appear at most once
in the final output products. This is a bit limiting, and the upcoming libcore
library cannot exist as a dylib, so these rules must change.
The goal of this commit is to enable *some* use cases for mixing rlibs and
dylibs, primarily libcore's use case. It is not targeted at allowing an
exhaustive number of linkage flavors.
There is a new dependency_format module in rustc which calculates what format
each upstream library should be linked as in each output type of the current
unit of compilation. The module itself contains many gory details about what's
going on here.
cc #10729
This has long since not been too relevant since the introduction of many crate
type outputs. This commit removes the flag entirely, adjusting all logic to do
the most reasonable thing when building both a library and an executable.
Closes#13337
This has long since not been too relevant since the introduction of many crate
type outputs. This commit removes the flag entirely, adjusting all logic to do
the most reasonable thing when building both a library and an executable.
Closes#13337
Currently, rustc requires that a linkage be a product of 100% rlibs or 100%
dylibs. This is to satisfy the requirement that each object appear at most once
in the final output products. This is a bit limiting, and the upcoming libcore
library cannot exist as a dylib, so these rules must change.
The goal of this commit is to enable *some* use cases for mixing rlibs and
dylibs, primarily libcore's use case. It is not targeted at allowing an
exhaustive number of linkage flavors.
There is a new dependency_format module in rustc which calculates what format
each upstream library should be linked as in each output type of the current
unit of compilation. The module itself contains many gory details about what's
going on here.
cc #10729
It didn't work because it tried to call itself but symbols are not
exported as default in executables.
Note that `fun5` is not internal anymore since it is in library.
The filestem of the desired output isn't necessarily a valid crate id, and
calling unwrap() will trigger an ICE in rustc. This tries a little harder to
infer a "valid crate id" from a crate, with an eventual fallback to a generic
crate id if alll else fails.
Closes#11107
Before, the `--crate-file-name` flag only checked crate attributes for
possible crate types. Now, if any type is specified by one or more
`--crate-type` flags, only the filenames for those types will be
emitted, and any types specified by crate attributes will be ignored.
Before, normal compilation and the --crate-file-name flag would
generate output based on both #![crate_type] attributes and
--crate-type flags. Now, if one or more flag is specified by command
line, only those will be used.
Closes#11573.
This bug was introduced in #13384 by accident, and this commit continues the
work of #13384 by finishing support for loading a syntax extension crate without
registering it with the local cstore.
Closes#13495
This bug was introduced in #13384 by accident, and this commit continues the
work of #13384 by finishing support for loading a syntax extension crate without
registering it with the local cstore.
Closes#13495
Previously, upstream C libraries were linked in a nondeterministic fashion
because they were collected through iter_crate_data() which is a nodeterministic
traversal of a hash map. When upstream rlibs had interdependencies among their
native libraries (such as libfoo depending on libc), then the ordering would
occasionally be wrong, causing linkage to fail.
This uses the topologically sorted list of libraries to collect native
libraries, so if a native library depends on libc it just needs to make sure
that the rust crate depends on liblibc.
`Reader`, `Writer`, `MemReader`, `MemWriter`, and `MultiWriter` now work with `Vec<u8>` instead of `~[u8]`. This does introduce some extra copies since `from_utf8_owned` isn't usable anymore, but I think that can't be helped until `~str`'s representation changes.
Rust currently defaults to `RelocPIC` regardless. This patch adds a new
codegen option that allows choosing different relocation-model. The
available models are:
- default (Use the target-specific default model)
- static
- pic
- no-pic
For a more detailed information use `llc --help`
Rust currently defaults to `RelocPIC` regardless. This patch adds a new
codegen option that allows choosing different relocation-model. The
available models are:
- default (Use the target-specific default model)
- static
- pic
- no-pic
For a more detailed information use `llc --help`
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.
All it checks, unfortunately, is that you actually printed at least
two lines for crateA paths and at least one line for crateB paths.
But that's enough to capture the spirit of the bug, I think. I did
not bother trying to verify that the paths themselves reflected where
the crates end up.
This is the final nail in the coffin for the crate map. The `start` function for
libgreen now has a new added parameter which is the event loop factory instead
of inferring it from the crate map. The two current valid values for this
parameter are `green::basic::event_loop` and `rustuv::event_loop`.
Fixes#12992
Store compressed bitcode files in rlibs with a different extension. Compression doesn't interfere with --emit=bc.
Regression test compares outputs.
The compiler will no longer inject libgreen as the default runtime for rust
programs, this commit switches it over to libnative by default. Now that
libnative has baked for some time, it is ready enough to start getting more
serious usage as the default runtime for rustc generated binaries.
We've found that there isn't really a correct decision in choosing a 1:1 or M:N
runtime as a default for all applications, but it seems that a larger number of
programs today would work more reasonable with a native default rather than a
green default.
With this commit come a number of bugfixes:
* The main native task is now named "<main>"
* The main native task has the stack bounds set up properly
* #[no_uv] was renamed to #[no_start]
* The core-run-destroy test was rewritten for both libnative and libgreen and
one of the tests was modified to be more robust.
* The process-detach test was locked to libgreen because it uses signal handling
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
This commit moves all logging out of the standard library into an external
crate. This crate is the new crate which is responsible for all logging macros
and logging implementation. A few reasons for this change are:
* The crate map has always been a bit of a code smell among rust programs. It
has difficulty being loaded on almost all platforms, and it's used almost
exclusively for logging and only logging. Removing the crate map is one of the
end goals of this movement.
* The compiler has a fair bit of special support for logging. It has the
__log_level() expression as well as generating a global word per module
specifying the log level. This is unfairly favoring the built-in logging
system, and is much better done purely in libraries instead of the compiler
itself.
* Initialization of logging is much easier to do if there is no reliance on a
magical crate map being available to set module log levels.
* If the logging library can be written outside of the standard library, there's
no reason that it shouldn't be. It's likely that we're not going to build the
highest quality logging library of all time, so third-party libraries should
be able to provide just as high-quality logging systems as the default one
provided in the rust distribution.
With a migration such as this, the change does not come for free. There are some
subtle changes in the behavior of liblog vs the previous logging macros:
* The core change of this migration is that there is no longer a physical
log-level per module. This concept is still emulated (it is quite useful), but
there is now only a global log level, not a local one. This global log level
is a reflection of the maximum of all log levels specified. The previously
generated logging code looked like:
if specified_level <= __module_log_level() {
println!(...)
}
The newly generated code looks like:
if specified_level <= ::log::LOG_LEVEL {
if ::log::module_enabled(module_path!()) {
println!(...)
}
}
Notably, the first layer of checking is still intended to be "super fast" in
that it's just a load of a global word and a compare. The second layer of
checking is executed to determine if the current module does indeed have
logging turned on.
This means that if any module has a debug log level turned on, all modules
with debug log levels get a little bit slower (they all do more expensive
dynamic checks to determine if they're turned on or not).
Semantically, this migration brings no change in this respect, but
runtime-wise, this will have a perf impact on some code.
* A `RUST_LOG=::help` directive will no longer print out a list of all modules
that can be logged. This is because the crate map will no longer specify the
log levels of all modules, so the list of modules is not known. Additionally,
warnings can no longer be provided if a malformed logging directive was
supplied.
The new "hello world" for logging looks like:
#[phase(syntax, link)]
extern crate log;
fn main() {
debug!("Hello, world!");
}
Linker argument order with respect to libraries is important enough that we
shouldn't be attempting to filter out libraries getting passed through to the
linker. When linking with a native library that has multiple dependant native
libraries, it's useful to have control over the link argument order.
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.
With linkers on unix systems, libraries on the right of the command line are
used to resolve symbols in those on the left of the command line. This means
that arguments must have a right-to-left dependency chain (things on the left
depend on things on the right).
This is currently done by ordering the linker arguments as
1. Local object
2. Local native libraries
3. Upstream rust libraries
4. Upstream native libraries
This commit swaps the order of 2 and 3 so upstream rust libraries have access to
local native libraries. It has been seen that some upstream crates don't specify
the library that they link to because the name varies per platform (e.g.
lua/glfw/etc).
This commit enables building these libraries by allowing the upstream rust crate
to have access to local native libraries. I believe that the failure mode for
this scheme is when an upstream rust crate depends on a symbol in an upstream
library which is then redefined in a local library. This failure mode is
incredibly uncommon, and the failure mode also varies per platform (OSX behaves
differently), so I believe that a change like this is fine to make.
Closes#12446
Apparently weak linkage and dlopen aren't quite working out for applications
like servo on android. There appears to be a bug or two in how android loads
dynamic libraries and for some reason libservo.so isn't being found.
As a temporary solution, add an extern "C" function to libstd which can be
called if you have a handle to the crate map manually. When crawling the crate
map, we then check this manual symbol before falling back to the old solutions.
cc #11731
They are still are not completely correct, since it does not handle
graphemes at all, just codepoints, but at least it handles the common
case correctly.
The calculation was previously very wrong (rather than just a little bit
wrong): it wasn't accounting for the fact that every character is 1
byte, and so multibyte characters were pretending to be zero width.
cc #8706
file.
Previously multibyte UTF-8 chars were being recorded as byte offsets
from the start of the file, and then later compared against global byte
positions, resulting in the compiler possibly thinking it had a byte
position pointing inside a multibyte character, if there were multibyte
characters in any non-crate files. (Although, sometimes the byte offsets
line up just right to not ICE, but that was a coincidence.)
Fixes#11136.
Fixes#11178.
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
This adds simple syntax highlighting based off libsyntax's lexer to be sure to
stay up to date with rust's grammar. Some of the highlighting is a bit ad-hoc,
but it definitely seems to get the job done!
This currently doesn't highlight rustdoc-rendered function signatures and
structs that are emitted to each page because the colors already signify what's
clickable and I think we'd have to figure out a different scheme before
colorizing them. This does, however, colorize all code examples and source code.
Closes#11393
