This commit removes all internal support for the previously used __log_level()
expression. The logging subsystem was previously modified to not rely on this
magical expression. This also removes the only other function to use the
module_data map in trans, decl_gc_metadata. It appears that this is an ancient
function from a GC only used long ago.
This does not remove the crate map entirely, as libgreen still uses it to hook
in to the event loop provided by libgreen.
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!");
}
It is often convenient to have forms of weak linkage or other various types of
linkage. Sadly, just using these flavors of linkage are not compatible with
Rust's typesystem and how it considers some pointers to be non-null.
As a compromise, this commit adds support for weak linkage to external symbols,
but it requires that this is only placed on extern statics of type `*T`.
Codegen-wise, we get translations like:
// rust code
extern {
#[linkage = "extern_weak"]
static foo: *i32;
}
// generated IR
@foo = extern_weak global i32
@_some_internal_symbol = internal global *i32 @foo
All references to the rust value of `foo` then reference `_some_internal_symbol`
instead of the symbol `_foo` itself. This allows us to guarantee that the
address of `foo` will never be null while the value may sometimes be null.
An example was implemented in `std::rt::thread` to determine if
`__pthread_get_minstack()` is available at runtime, and a test is checked in to
use it for a static value as well. Function pointers a little odd because you
still need to transmute the pointer value to a function pointer, but it's
thankfully better than not having this capability at all.
This leverages the new hashing framework and hashmap implementation to provide a
much speedier hashing algorithm for node ids and def ids. The hash algorithm
used is currentl FNV hashing, but it's quite easy to swap out.
I originally implemented hashing as the identity function, but this actually
ended up in slowing down rustc compiling libstd from 8s to 13s. I would suspect
that this is a result of a large number of collisions.
With FNV hashing, we get these timings (compiling with --no-trans, in seconds):
| | before | after |
|-----------|---------:|--------:|
| libstd | 8.324 | 6.703 |
| stdtest | 47.674 | 46.857 |
| libsyntax | 9.918 | 8.400 |
The llvm.copysign and llvm.round intrinsics weren't added until LLVM 3.4, so if
we're on LLVM 3.3 we lower these to calls in libm instead of LLVM intrinsics.
This should fix our travis failures.
The llvm.copysign and llvm.round intrinsics weren't added until LLVM 3.4, so if
we're on LLVM 3.3 we lower these to calls in libm instead of LLVM intrinsics.
This should fix our travis failures.
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.
The by-value argument is a copy that is only valid for the duration of
the function call, therefore keeping any pointer to it that outlives the
call is illegal.
This trades an O(n) allocation + memcpy for a O(1) proc allocation (for
the destructor). Most users only need &[u8] anyway (all of the users in
the main repo), and so this offers large gains.
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.
Previously an `unsafe` block created by the compiler (like those in the
formatting macros) would be "ignored" if surrounded by `unsafe`, that
is, the internal unsafety would be being legitimised by the external
block:
unsafe { println!("...") } =(expansion)=> unsafe { ... unsafe { ... } }
And the code in the inner block would be using the outer block, making
it considered used (and the inner one considered unused).
This patch forces the compiler to create a new unsafe context for
compiler generated blocks, so that their internal unsafety doesn't
escape to external blocks.
Fixes#12418.
Added allow(non_camel_case_types) to librustc where necesary
Tried to fix problems with non_camel_case_types outside rustc
fixed failing tests
Docs updated
Moved #[allow(non_camel_case_types)] a level higher.
markdown.rs reverted
Fixed timer that was failing tests
Fixed another timer
Previously an `unsafe` block created by the compiler (like those in the
formatting macros) would be "ignored" if surrounded by `unsafe`, that
is, the internal unsafety would be being legitimised by the external
block:
unsafe { println!("...") } =(expansion)=> unsafe { ... unsafe { ... } }
And the code in the inner block would be using the outer block, making
it considered used (and the inner one considered unused).
This patch forces the compiler to create a new unsafe context for
compiler generated blocks, so that their internal unsafety doesn't
escape to external blocks.
Fixes#12418.
Function parameters that are to be passed by value but don't fit into a
single register are currently passed by creating a copy on the stack and
passing a pointer to that copy to the callee. Since the copy is made
just for the function call, there are no aliases.
For example, this sometimes allows LLVM to eliminate unnecessary calls
to drop glue. Given
````rust
struct Foo {
a: int,
b: Option<~str>,
}
extern {
fn eat(eat: Option<~str>);
}
pub fn foo(v: Foo) {
match v {
Foo { a: _, b } => unsafe { eat(b) }
}
}
````
LLVM currently can't eliminate the drop call for the string, because it
only sees a _pointer_ to Foo, for which it has to expect an alias. So we
get:
````llvm
; Function Attrs: uwtable
define void @_ZN3foo20h9f32c90ae7201edbxaa4v0.0E(%struct.Foo* nocapture) unnamed_addr #0 {
"_ZN34std..option..Option$LT$$UP$str$GT$9glue_drop17hc39b3015f3b9c69dE.exit":
%1 = getelementptr inbounds %struct.Foo* %0, i64 0, i32 1, i32 0
%2 = load { i64, i64, [0 x i8] }** %1, align 8
store { i64, i64, [0 x i8] }* null, { i64, i64, [0 x i8] }** %1, align 8
%3 = ptrtoint { i64, i64, [0 x i8] }* %2 to i64
%.fca.0.insert = insertvalue { i64 } undef, i64 %3, 0
tail call void @eat({ i64 } %.fca.0.insert)
%4 = load { i64, i64, [0 x i8] }** %1, align 8
%5 = icmp eq { i64, i64, [0 x i8] }* %4, null
br i1 %5, label %_ZN3Foo9glue_drop17hf611996539d3036fE.exit, label %"_ZN8_$UP$str9glue_drop17h15dbdbe2b8897a98E.exit.i.i"
"_ZN8_$UP$str9glue_drop17h15dbdbe2b8897a98E.exit.i.i": ; preds = %"_ZN34std..option..Option$LT$$UP$str$GT$9glue_drop17hc39b3015f3b9c69dE.exit"
%6 = bitcast { i64, i64, [0 x i8] }* %4 to i8*
tail call void @free(i8* %6) #1
br label %_ZN3Foo9glue_drop17hf611996539d3036fE.exit
_ZN3Foo9glue_drop17hf611996539d3036fE.exit: ; preds = %"_ZN34std..option..Option$LT$$UP$str$GT$9glue_drop17hc39b3015f3b9c69dE.exit", %"_ZN8_$UP$str9glue_drop17h15dbdbe2b8897a98E.exit.i.i"
ret void
}
````
But with the `noalias` attribute, it can safely optimize that to:
````llvm
define void @_ZN3foo20hd28431f929f0d6c4xaa4v0.0E(%struct.Foo* noalias nocapture) unnamed_addr #0 {
_ZN3Foo9glue_drop17he9afbc09d4e9c851E.exit:
%1 = getelementptr inbounds %struct.Foo* %0, i64 0, i32 1, i32 0
%2 = load { i64, i64, [0 x i8] }** %1, align 8
store { i64, i64, [0 x i8] }* null, { i64, i64, [0 x i8] }** %1, align 8
%3 = ptrtoint { i64, i64, [0 x i8] }* %2 to i64
%.fca.0.insert = insertvalue { i64 } undef, i64 %3, 0
tail call void @eat({ i64 } %.fca.0.insert)
ret void
}
````
This patch replaces all `crate` usage with `krate` before introducing the
new keyword. This ensures that after introducing the keyword, there
won't be any compilation errors.
krate might not be the most expressive substitution for crate but it's a
very close abbreviation for it. `module` was already used in several
places already.
This also drops support for the managed pointer POISON_ON_FREE feature
as it's not worth adding back the support for it. After a snapshot, the
leftovers can be removed.
This commit removes the -c, --emit-llvm, -s, --rlib, --dylib, --staticlib,
--lib, and --bin flags from rustc, adding the following flags:
* --emit=[asm,ir,bc,obj,link]
* --crate-type=[dylib,rlib,staticlib,bin,lib]
The -o option has also been redefined to be used for *all* flavors of outputs.
This means that we no longer ignore it for libraries. The --out-dir remains the
same as before.
The new logic for files that rustc emits is as follows:
1. Output types are dictated by the --emit flag. The default value is
--emit=link, and this option can be passed multiple times and have all
options stacked on one another.
2. Crate types are dictated by the --crate-type flag and the #[crate_type]
attribute. The flags can be passed many times and stack with the crate
attribute.
3. If the -o flag is specified, and only one output type is specified, the
output will be emitted at this location. If more than one output type is
specified, then the filename of -o is ignored, and all output goes in the
directory that -o specifies. The -o option always ignores the --out-dir
option.
4. If the --out-dir flag is specified, all output goes in this directory.
5. If -o and --out-dir are both not present, all output goes in the current
directory of the process.
6. When multiple output types are specified, the filestem of all output is the
same as the name of the CrateId (derived from a crate attribute or from the
filestem of the crate file).
Closes#7791Closes#11056Closes#11667
For the purpose of deciding whether to truncate or extend the right hand side of bit shifts, use the size of the element type for SIMD vector types.
Fix#11900.
