2cdde5aef4
When cross compiling with procedural macros, the crate loader starts by looking for a target crate, before trying with a host crate. Rather than emitting an error immediately if the host and target extension differ, the compiler should delay it until both attempts have failed. Fixes #37899 r? @jseyfried
985 lines
39 KiB
Rust
985 lines
39 KiB
Rust
// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! Finds crate binaries and loads their metadata
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//!
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//! Might I be the first to welcome you to a world of platform differences,
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//! version requirements, dependency graphs, conflicting desires, and fun! This
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//! is the major guts (along with metadata::creader) of the compiler for loading
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//! crates and resolving dependencies. Let's take a tour!
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//!
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//! # The problem
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//!
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//! Each invocation of the compiler is immediately concerned with one primary
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//! problem, to connect a set of crates to resolved crates on the filesystem.
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//! Concretely speaking, the compiler follows roughly these steps to get here:
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//!
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//! 1. Discover a set of `extern crate` statements.
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//! 2. Transform these directives into crate names. If the directive does not
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//! have an explicit name, then the identifier is the name.
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//! 3. For each of these crate names, find a corresponding crate on the
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//! filesystem.
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//!
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//! Sounds easy, right? Let's walk into some of the nuances.
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//!
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//! ## Transitive Dependencies
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//!
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//! Let's say we've got three crates: A, B, and C. A depends on B, and B depends
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//! on C. When we're compiling A, we primarily need to find and locate B, but we
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//! also end up needing to find and locate C as well.
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//!
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//! The reason for this is that any of B's types could be composed of C's types,
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//! any function in B could return a type from C, etc. To be able to guarantee
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//! that we can always typecheck/translate any function, we have to have
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//! complete knowledge of the whole ecosystem, not just our immediate
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//! dependencies.
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//!
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//! So now as part of the "find a corresponding crate on the filesystem" step
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//! above, this involves also finding all crates for *all upstream
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//! dependencies*. This includes all dependencies transitively.
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//!
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//! ## Rlibs and Dylibs
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//!
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//! The compiler has two forms of intermediate dependencies. These are dubbed
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//! rlibs and dylibs for the static and dynamic variants, respectively. An rlib
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//! is a rustc-defined file format (currently just an ar archive) while a dylib
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//! is a platform-defined dynamic library. Each library has a metadata somewhere
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//! inside of it.
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//!
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//! A third kind of dependency is an rmeta file. These are metadata files and do
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//! not contain any code, etc. To a first approximation, these are treated in the
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//! same way as rlibs. Where there is both an rlib and an rmeta file, the rlib
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//! gets priority (even if the rmeta file is newer). An rmeta file is only
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//! useful for checking a downstream crate, attempting to link one will cause an
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//! error.
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//!
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//! When translating a crate name to a crate on the filesystem, we all of a
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//! sudden need to take into account both rlibs and dylibs! Linkage later on may
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//! use either one of these files, as each has their pros/cons. The job of crate
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//! loading is to discover what's possible by finding all candidates.
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//!
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//! Most parts of this loading systems keep the dylib/rlib as just separate
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//! variables.
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//!
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//! ## Where to look?
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//!
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//! We can't exactly scan your whole hard drive when looking for dependencies,
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//! so we need to places to look. Currently the compiler will implicitly add the
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//! target lib search path ($prefix/lib/rustlib/$target/lib) to any compilation,
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//! and otherwise all -L flags are added to the search paths.
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//!
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//! ## What criterion to select on?
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//!
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//! This a pretty tricky area of loading crates. Given a file, how do we know
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//! whether it's the right crate? Currently, the rules look along these lines:
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//!
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//! 1. Does the filename match an rlib/dylib pattern? That is to say, does the
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//! filename have the right prefix/suffix?
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//! 2. Does the filename have the right prefix for the crate name being queried?
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//! This is filtering for files like `libfoo*.rlib` and such.
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//! 3. Is the file an actual rust library? This is done by loading the metadata
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//! from the library and making sure it's actually there.
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//! 4. Does the name in the metadata agree with the name of the library?
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//! 5. Does the target in the metadata agree with the current target?
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//! 6. Does the SVH match? (more on this later)
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//!
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//! If the file answers `yes` to all these questions, then the file is
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//! considered as being *candidate* for being accepted. It is illegal to have
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//! more than two candidates as the compiler has no method by which to resolve
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//! this conflict. Additionally, rlib/dylib candidates are considered
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//! separately.
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//!
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//! After all this has happened, we have 1 or two files as candidates. These
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//! represent the rlib/dylib file found for a library, and they're returned as
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//! being found.
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//!
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//! ### What about versions?
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//!
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//! A lot of effort has been put forth to remove versioning from the compiler.
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//! There have been forays in the past to have versioning baked in, but it was
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//! largely always deemed insufficient to the point that it was recognized that
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//! it's probably something the compiler shouldn't do anyway due to its
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//! complicated nature and the state of the half-baked solutions.
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//!
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//! With a departure from versioning, the primary criterion for loading crates
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//! is just the name of a crate. If we stopped here, it would imply that you
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//! could never link two crates of the same name from different sources
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//! together, which is clearly a bad state to be in.
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//!
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//! To resolve this problem, we come to the next section!
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//!
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//! # Expert Mode
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//!
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//! A number of flags have been added to the compiler to solve the "version
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//! problem" in the previous section, as well as generally enabling more
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//! powerful usage of the crate loading system of the compiler. The goal of
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//! these flags and options are to enable third-party tools to drive the
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//! compiler with prior knowledge about how the world should look.
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//!
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//! ## The `--extern` flag
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//!
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//! The compiler accepts a flag of this form a number of times:
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//!
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//! ```text
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//! --extern crate-name=path/to/the/crate.rlib
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//! ```
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//!
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//! This flag is basically the following letter to the compiler:
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//!
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//! > Dear rustc,
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//! >
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//! > When you are attempting to load the immediate dependency `crate-name`, I
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//! > would like you to assume that the library is located at
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//! > `path/to/the/crate.rlib`, and look nowhere else. Also, please do not
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//! > assume that the path I specified has the name `crate-name`.
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//!
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//! This flag basically overrides most matching logic except for validating that
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//! the file is indeed a rust library. The same `crate-name` can be specified
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//! twice to specify the rlib/dylib pair.
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//!
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//! ## Enabling "multiple versions"
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//!
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//! This basically boils down to the ability to specify arbitrary packages to
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//! the compiler. For example, if crate A wanted to use Bv1 and Bv2, then it
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//! would look something like:
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//!
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//! ```ignore
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//! extern crate b1;
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//! extern crate b2;
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//!
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//! fn main() {}
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//! ```
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//!
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//! and the compiler would be invoked as:
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//!
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//! ```text
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//! rustc a.rs --extern b1=path/to/libb1.rlib --extern b2=path/to/libb2.rlib
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//! ```
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//!
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//! In this scenario there are two crates named `b` and the compiler must be
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//! manually driven to be informed where each crate is.
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//!
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//! ## Frobbing symbols
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//!
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//! One of the immediate problems with linking the same library together twice
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//! in the same problem is dealing with duplicate symbols. The primary way to
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//! deal with this in rustc is to add hashes to the end of each symbol.
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//!
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//! In order to force hashes to change between versions of a library, if
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//! desired, the compiler exposes an option `-C metadata=foo`, which is used to
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//! initially seed each symbol hash. The string `foo` is prepended to each
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//! string-to-hash to ensure that symbols change over time.
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//!
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//! ## Loading transitive dependencies
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//!
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//! Dealing with same-named-but-distinct crates is not just a local problem, but
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//! one that also needs to be dealt with for transitive dependencies. Note that
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//! in the letter above `--extern` flags only apply to the *local* set of
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//! dependencies, not the upstream transitive dependencies. Consider this
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//! dependency graph:
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//!
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//! ```text
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//! A.1 A.2
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//! | |
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//! | |
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//! B C
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//! \ /
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//! \ /
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//! D
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//! ```
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//!
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//! In this scenario, when we compile `D`, we need to be able to distinctly
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//! resolve `A.1` and `A.2`, but an `--extern` flag cannot apply to these
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//! transitive dependencies.
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//!
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//! Note that the key idea here is that `B` and `C` are both *already compiled*.
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//! That is, they have already resolved their dependencies. Due to unrelated
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//! technical reasons, when a library is compiled, it is only compatible with
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//! the *exact same* version of the upstream libraries it was compiled against.
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//! We use the "Strict Version Hash" to identify the exact copy of an upstream
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//! library.
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//!
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//! With this knowledge, we know that `B` and `C` will depend on `A` with
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//! different SVH values, so we crawl the normal `-L` paths looking for
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//! `liba*.rlib` and filter based on the contained SVH.
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//!
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//! In the end, this ends up not needing `--extern` to specify upstream
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//! transitive dependencies.
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//!
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//! # Wrapping up
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//!
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//! That's the general overview of loading crates in the compiler, but it's by
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//! no means all of the necessary details. Take a look at the rest of
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//! metadata::locator or metadata::creader for all the juicy details!
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use cstore::MetadataBlob;
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use creader::Library;
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use schema::{METADATA_HEADER, rustc_version};
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use rustc::hir::svh::Svh;
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use rustc::session::{config, Session};
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use rustc::session::filesearch::{FileSearch, FileMatches, FileDoesntMatch};
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use rustc::session::search_paths::PathKind;
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use rustc::util::common;
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use rustc::util::nodemap::FxHashMap;
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use rustc_llvm as llvm;
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use rustc_llvm::{False, ObjectFile, mk_section_iter};
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use rustc_llvm::archive_ro::ArchiveRO;
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use errors::DiagnosticBuilder;
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use syntax::symbol::Symbol;
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use syntax_pos::Span;
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use rustc_back::target::Target;
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use std::cmp;
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use std::fmt;
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use std::fs::{self, File};
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use std::io::{self, Read};
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use std::path::{Path, PathBuf};
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use std::ptr;
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use std::slice;
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use std::time::Instant;
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use flate;
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pub struct CrateMismatch {
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path: PathBuf,
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got: String,
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}
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pub struct Context<'a> {
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pub sess: &'a Session,
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pub span: Span,
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pub ident: Symbol,
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pub crate_name: Symbol,
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pub hash: Option<&'a Svh>,
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// points to either self.sess.target.target or self.sess.host, must match triple
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pub target: &'a Target,
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pub triple: &'a str,
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pub filesearch: FileSearch<'a>,
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pub root: &'a Option<CratePaths>,
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pub rejected_via_hash: Vec<CrateMismatch>,
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pub rejected_via_triple: Vec<CrateMismatch>,
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pub rejected_via_kind: Vec<CrateMismatch>,
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pub rejected_via_version: Vec<CrateMismatch>,
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pub rejected_via_filename: Vec<CrateMismatch>,
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pub should_match_name: bool,
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pub is_proc_macro: Option<bool>,
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}
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pub struct ArchiveMetadata {
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_archive: ArchiveRO,
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// points into self._archive
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data: *const [u8],
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}
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pub struct CratePaths {
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pub ident: String,
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pub dylib: Option<PathBuf>,
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pub rlib: Option<PathBuf>,
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pub rmeta: Option<PathBuf>,
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}
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pub const METADATA_FILENAME: &'static str = "rust.metadata.bin";
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#[derive(Copy, Clone, PartialEq)]
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enum CrateFlavor {
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Rlib,
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Rmeta,
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Dylib,
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}
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impl fmt::Display for CrateFlavor {
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fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
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f.write_str(match *self {
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CrateFlavor::Rlib => "rlib",
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CrateFlavor::Rmeta => "rmeta",
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CrateFlavor::Dylib => "dylib",
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})
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}
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}
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impl CratePaths {
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fn paths(&self) -> Vec<PathBuf> {
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self.dylib.iter().chain(self.rlib.iter()).chain(self.rmeta.iter()).cloned().collect()
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}
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}
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impl<'a> Context<'a> {
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pub fn maybe_load_library_crate(&mut self) -> Option<Library> {
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self.find_library_crate()
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}
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pub fn load_library_crate(&mut self) -> Library {
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self.find_library_crate().unwrap_or_else(|| self.report_errs())
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}
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pub fn report_errs(&mut self) -> ! {
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let add = match self.root {
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&None => String::new(),
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&Some(ref r) => format!(" which `{}` depends on", r.ident),
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};
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let mut err = if !self.rejected_via_hash.is_empty() {
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struct_span_err!(self.sess,
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self.span,
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E0460,
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"found possibly newer version of crate `{}`{}",
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self.ident,
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add)
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} else if !self.rejected_via_triple.is_empty() {
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struct_span_err!(self.sess,
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self.span,
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E0461,
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||
"couldn't find crate `{}` with expected target triple {}{}",
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self.ident,
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self.triple,
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add)
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} else if !self.rejected_via_kind.is_empty() {
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struct_span_err!(self.sess,
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self.span,
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E0462,
|
||
"found staticlib `{}` instead of rlib or dylib{}",
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self.ident,
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add)
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} else if !self.rejected_via_version.is_empty() {
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struct_span_err!(self.sess,
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self.span,
|
||
E0514,
|
||
"found crate `{}` compiled by an incompatible version of rustc{}",
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self.ident,
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add)
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} else {
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let mut err = struct_span_err!(self.sess,
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self.span,
|
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E0463,
|
||
"can't find crate for `{}`{}",
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self.ident,
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add);
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|
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if (self.ident == "std" || self.ident == "core")
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&& self.triple != config::host_triple() {
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err.note(&format!("the `{}` target may not be installed", self.triple));
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}
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err.span_label(self.span, &format!("can't find crate"));
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err
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};
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if !self.rejected_via_triple.is_empty() {
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let mismatches = self.rejected_via_triple.iter();
|
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for (i, &CrateMismatch { ref path, ref got }) in mismatches.enumerate() {
|
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err.note(&format!("crate `{}`, path #{}, triple {}: {}",
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self.ident,
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i + 1,
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got,
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path.display()));
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}
|
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}
|
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if !self.rejected_via_hash.is_empty() {
|
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err.note("perhaps that crate needs to be recompiled?");
|
||
let mismatches = self.rejected_via_hash.iter();
|
||
for (i, &CrateMismatch { ref path, .. }) in mismatches.enumerate() {
|
||
err.note(&format!("crate `{}` path #{}: {}", self.ident, i + 1, path.display()));
|
||
}
|
||
match self.root {
|
||
&None => {}
|
||
&Some(ref r) => {
|
||
for (i, path) in r.paths().iter().enumerate() {
|
||
err.note(&format!("crate `{}` path #{}: {}",
|
||
r.ident,
|
||
i + 1,
|
||
path.display()));
|
||
}
|
||
}
|
||
}
|
||
}
|
||
if !self.rejected_via_kind.is_empty() {
|
||
err.help("please recompile that crate using --crate-type lib");
|
||
let mismatches = self.rejected_via_kind.iter();
|
||
for (i, &CrateMismatch { ref path, .. }) in mismatches.enumerate() {
|
||
err.note(&format!("crate `{}` path #{}: {}", self.ident, i + 1, path.display()));
|
||
}
|
||
}
|
||
if !self.rejected_via_version.is_empty() {
|
||
err.help(&format!("please recompile that crate using this compiler ({})",
|
||
rustc_version()));
|
||
let mismatches = self.rejected_via_version.iter();
|
||
for (i, &CrateMismatch { ref path, ref got }) in mismatches.enumerate() {
|
||
err.note(&format!("crate `{}` path #{}: {} compiled by {:?}",
|
||
self.ident,
|
||
i + 1,
|
||
path.display(),
|
||
got));
|
||
}
|
||
}
|
||
if !self.rejected_via_filename.is_empty() {
|
||
let dylibname = self.dylibname();
|
||
let mismatches = self.rejected_via_filename.iter();
|
||
for &CrateMismatch { ref path, .. } in mismatches {
|
||
err.note(&format!("extern location for {} is of an unknown type: {}",
|
||
self.crate_name,
|
||
path.display()))
|
||
.help(&format!("file name should be lib*.rlib or {}*.{}",
|
||
dylibname.0,
|
||
dylibname.1));
|
||
}
|
||
}
|
||
|
||
err.emit();
|
||
self.sess.abort_if_errors();
|
||
unreachable!();
|
||
}
|
||
|
||
fn find_library_crate(&mut self) -> Option<Library> {
|
||
// If an SVH is specified, then this is a transitive dependency that
|
||
// must be loaded via -L plus some filtering.
|
||
if self.hash.is_none() {
|
||
self.should_match_name = false;
|
||
if let Some(s) = self.sess.opts.externs.get(&self.crate_name.as_str()) {
|
||
return self.find_commandline_library(s.iter());
|
||
}
|
||
self.should_match_name = true;
|
||
}
|
||
|
||
let dypair = self.dylibname();
|
||
let staticpair = self.staticlibname();
|
||
|
||
// want: crate_name.dir_part() + prefix + crate_name.file_part + "-"
|
||
let dylib_prefix = format!("{}{}", dypair.0, self.crate_name);
|
||
let rlib_prefix = format!("lib{}", self.crate_name);
|
||
let staticlib_prefix = format!("{}{}", staticpair.0, self.crate_name);
|
||
|
||
let mut candidates = FxHashMap();
|
||
let mut staticlibs = vec![];
|
||
|
||
// First, find all possible candidate rlibs and dylibs purely based on
|
||
// the name of the files themselves. We're trying to match against an
|
||
// exact crate name and a possibly an exact hash.
|
||
//
|
||
// During this step, we can filter all found libraries based on the
|
||
// name and id found in the crate id (we ignore the path portion for
|
||
// filename matching), as well as the exact hash (if specified). If we
|
||
// end up having many candidates, we must look at the metadata to
|
||
// perform exact matches against hashes/crate ids. Note that opening up
|
||
// the metadata is where we do an exact match against the full contents
|
||
// of the crate id (path/name/id).
|
||
//
|
||
// The goal of this step is to look at as little metadata as possible.
|
||
self.filesearch.search(|path, kind| {
|
||
let file = match path.file_name().and_then(|s| s.to_str()) {
|
||
None => return FileDoesntMatch,
|
||
Some(file) => file,
|
||
};
|
||
let (hash, found_kind) =
|
||
if file.starts_with(&rlib_prefix[..]) && file.ends_with(".rlib") {
|
||
(&file[(rlib_prefix.len())..(file.len() - ".rlib".len())], CrateFlavor::Rlib)
|
||
} else if file.starts_with(&rlib_prefix[..]) && file.ends_with(".rmeta") {
|
||
(&file[(rlib_prefix.len())..(file.len() - ".rmeta".len())], CrateFlavor::Rmeta)
|
||
} else if file.starts_with(&dylib_prefix) &&
|
||
file.ends_with(&dypair.1) {
|
||
(&file[(dylib_prefix.len())..(file.len() - dypair.1.len())], CrateFlavor::Dylib)
|
||
} else {
|
||
if file.starts_with(&staticlib_prefix[..]) && file.ends_with(&staticpair.1) {
|
||
staticlibs.push(CrateMismatch {
|
||
path: path.to_path_buf(),
|
||
got: "static".to_string(),
|
||
});
|
||
}
|
||
return FileDoesntMatch;
|
||
};
|
||
info!("lib candidate: {}", path.display());
|
||
|
||
let hash_str = hash.to_string();
|
||
let slot = candidates.entry(hash_str)
|
||
.or_insert_with(|| (FxHashMap(), FxHashMap(), FxHashMap()));
|
||
let (ref mut rlibs, ref mut rmetas, ref mut dylibs) = *slot;
|
||
fs::canonicalize(path)
|
||
.map(|p| {
|
||
match found_kind {
|
||
CrateFlavor::Rlib => { rlibs.insert(p, kind); }
|
||
CrateFlavor::Rmeta => { rmetas.insert(p, kind); }
|
||
CrateFlavor::Dylib => { dylibs.insert(p, kind); }
|
||
}
|
||
FileMatches
|
||
})
|
||
.unwrap_or(FileDoesntMatch)
|
||
});
|
||
self.rejected_via_kind.extend(staticlibs);
|
||
|
||
// We have now collected all known libraries into a set of candidates
|
||
// keyed of the filename hash listed. For each filename, we also have a
|
||
// list of rlibs/dylibs that apply. Here, we map each of these lists
|
||
// (per hash), to a Library candidate for returning.
|
||
//
|
||
// A Library candidate is created if the metadata for the set of
|
||
// libraries corresponds to the crate id and hash criteria that this
|
||
// search is being performed for.
|
||
let mut libraries = FxHashMap();
|
||
for (_hash, (rlibs, rmetas, dylibs)) in candidates {
|
||
let mut slot = None;
|
||
let rlib = self.extract_one(rlibs, CrateFlavor::Rlib, &mut slot);
|
||
let rmeta = self.extract_one(rmetas, CrateFlavor::Rmeta, &mut slot);
|
||
let dylib = self.extract_one(dylibs, CrateFlavor::Dylib, &mut slot);
|
||
if let Some((h, m)) = slot {
|
||
libraries.insert(h,
|
||
Library {
|
||
dylib: dylib,
|
||
rlib: rlib,
|
||
rmeta: rmeta,
|
||
metadata: m,
|
||
});
|
||
}
|
||
}
|
||
|
||
// Having now translated all relevant found hashes into libraries, see
|
||
// what we've got and figure out if we found multiple candidates for
|
||
// libraries or not.
|
||
match libraries.len() {
|
||
0 => None,
|
||
1 => Some(libraries.into_iter().next().unwrap().1),
|
||
_ => {
|
||
let mut err = struct_span_err!(self.sess,
|
||
self.span,
|
||
E0464,
|
||
"multiple matching crates for `{}`",
|
||
self.crate_name);
|
||
err.note("candidates:");
|
||
for (_, lib) in libraries {
|
||
if let Some((ref p, _)) = lib.dylib {
|
||
err.note(&format!("path: {}", p.display()));
|
||
}
|
||
if let Some((ref p, _)) = lib.rlib {
|
||
err.note(&format!("path: {}", p.display()));
|
||
}
|
||
note_crate_name(&mut err, &lib.metadata.get_root().name.as_str());
|
||
}
|
||
err.emit();
|
||
None
|
||
}
|
||
}
|
||
}
|
||
|
||
// Attempts to extract *one* library from the set `m`. If the set has no
|
||
// elements, `None` is returned. If the set has more than one element, then
|
||
// the errors and notes are emitted about the set of libraries.
|
||
//
|
||
// With only one library in the set, this function will extract it, and then
|
||
// read the metadata from it if `*slot` is `None`. If the metadata couldn't
|
||
// be read, it is assumed that the file isn't a valid rust library (no
|
||
// errors are emitted).
|
||
fn extract_one(&mut self,
|
||
m: FxHashMap<PathBuf, PathKind>,
|
||
flavor: CrateFlavor,
|
||
slot: &mut Option<(Svh, MetadataBlob)>)
|
||
-> Option<(PathBuf, PathKind)> {
|
||
let mut ret: Option<(PathBuf, PathKind)> = None;
|
||
let mut error = 0;
|
||
|
||
if slot.is_some() {
|
||
// FIXME(#10786): for an optimization, we only read one of the
|
||
// libraries' metadata sections. In theory we should
|
||
// read both, but reading dylib metadata is quite
|
||
// slow.
|
||
if m.is_empty() {
|
||
return None;
|
||
} else if m.len() == 1 {
|
||
return Some(m.into_iter().next().unwrap());
|
||
}
|
||
}
|
||
|
||
let mut err: Option<DiagnosticBuilder> = None;
|
||
for (lib, kind) in m {
|
||
info!("{} reading metadata from: {}", flavor, lib.display());
|
||
let (hash, metadata) = match get_metadata_section(self.target, flavor, &lib) {
|
||
Ok(blob) => {
|
||
if let Some(h) = self.crate_matches(&blob, &lib) {
|
||
(h, blob)
|
||
} else {
|
||
info!("metadata mismatch");
|
||
continue;
|
||
}
|
||
}
|
||
Err(err) => {
|
||
info!("no metadata found: {}", err);
|
||
continue;
|
||
}
|
||
};
|
||
// If we see multiple hashes, emit an error about duplicate candidates.
|
||
if slot.as_ref().map_or(false, |s| s.0 != hash) {
|
||
let mut e = struct_span_err!(self.sess,
|
||
self.span,
|
||
E0465,
|
||
"multiple {} candidates for `{}` found",
|
||
flavor,
|
||
self.crate_name);
|
||
e.span_note(self.span,
|
||
&format!(r"candidate #1: {}",
|
||
ret.as_ref()
|
||
.unwrap()
|
||
.0
|
||
.display()));
|
||
if let Some(ref mut e) = err {
|
||
e.emit();
|
||
}
|
||
err = Some(e);
|
||
error = 1;
|
||
*slot = None;
|
||
}
|
||
if error > 0 {
|
||
error += 1;
|
||
err.as_mut().unwrap().span_note(self.span,
|
||
&format!(r"candidate #{}: {}",
|
||
error,
|
||
lib.display()));
|
||
continue;
|
||
}
|
||
*slot = Some((hash, metadata));
|
||
ret = Some((lib, kind));
|
||
}
|
||
|
||
if error > 0 {
|
||
err.unwrap().emit();
|
||
None
|
||
} else {
|
||
ret
|
||
}
|
||
}
|
||
|
||
fn crate_matches(&mut self, metadata: &MetadataBlob, libpath: &Path) -> Option<Svh> {
|
||
let rustc_version = rustc_version();
|
||
let found_version = metadata.get_rustc_version();
|
||
if found_version != rustc_version {
|
||
info!("Rejecting via version: expected {} got {}",
|
||
rustc_version,
|
||
found_version);
|
||
self.rejected_via_version.push(CrateMismatch {
|
||
path: libpath.to_path_buf(),
|
||
got: found_version,
|
||
});
|
||
return None;
|
||
}
|
||
|
||
let root = metadata.get_root();
|
||
if let Some(is_proc_macro) = self.is_proc_macro {
|
||
if root.macro_derive_registrar.is_some() != is_proc_macro {
|
||
return None;
|
||
}
|
||
}
|
||
|
||
if self.should_match_name {
|
||
if self.crate_name != root.name {
|
||
info!("Rejecting via crate name");
|
||
return None;
|
||
}
|
||
}
|
||
|
||
if root.triple != self.triple {
|
||
info!("Rejecting via crate triple: expected {} got {}",
|
||
self.triple,
|
||
root.triple);
|
||
self.rejected_via_triple.push(CrateMismatch {
|
||
path: libpath.to_path_buf(),
|
||
got: root.triple,
|
||
});
|
||
return None;
|
||
}
|
||
|
||
if let Some(myhash) = self.hash {
|
||
if *myhash != root.hash {
|
||
info!("Rejecting via hash: expected {} got {}", *myhash, root.hash);
|
||
self.rejected_via_hash.push(CrateMismatch {
|
||
path: libpath.to_path_buf(),
|
||
got: myhash.to_string(),
|
||
});
|
||
return None;
|
||
}
|
||
}
|
||
|
||
Some(root.hash)
|
||
}
|
||
|
||
|
||
// Returns the corresponding (prefix, suffix) that files need to have for
|
||
// dynamic libraries
|
||
fn dylibname(&self) -> (String, String) {
|
||
let t = &self.target;
|
||
(t.options.dll_prefix.clone(), t.options.dll_suffix.clone())
|
||
}
|
||
|
||
// Returns the corresponding (prefix, suffix) that files need to have for
|
||
// static libraries
|
||
fn staticlibname(&self) -> (String, String) {
|
||
let t = &self.target;
|
||
(t.options.staticlib_prefix.clone(), t.options.staticlib_suffix.clone())
|
||
}
|
||
|
||
fn find_commandline_library<'b, LOCS>(&mut self, locs: LOCS) -> Option<Library>
|
||
where LOCS: Iterator<Item = &'b String>
|
||
{
|
||
// First, filter out all libraries that look suspicious. We only accept
|
||
// files which actually exist that have the correct naming scheme for
|
||
// rlibs/dylibs.
|
||
let sess = self.sess;
|
||
let dylibname = self.dylibname();
|
||
let mut rlibs = FxHashMap();
|
||
let mut rmetas = FxHashMap();
|
||
let mut dylibs = FxHashMap();
|
||
{
|
||
let locs = locs.map(|l| PathBuf::from(l)).filter(|loc| {
|
||
if !loc.exists() {
|
||
sess.err(&format!("extern location for {} does not exist: {}",
|
||
self.crate_name,
|
||
loc.display()));
|
||
return false;
|
||
}
|
||
let file = match loc.file_name().and_then(|s| s.to_str()) {
|
||
Some(file) => file,
|
||
None => {
|
||
sess.err(&format!("extern location for {} is not a file: {}",
|
||
self.crate_name,
|
||
loc.display()));
|
||
return false;
|
||
}
|
||
};
|
||
if file.starts_with("lib") &&
|
||
(file.ends_with(".rlib") || file.ends_with(".rmeta")) {
|
||
return true;
|
||
} else {
|
||
let (ref prefix, ref suffix) = dylibname;
|
||
if file.starts_with(&prefix[..]) && file.ends_with(&suffix[..]) {
|
||
return true;
|
||
}
|
||
}
|
||
|
||
self.rejected_via_filename.push(CrateMismatch {
|
||
path: loc.clone(),
|
||
got: String::new(),
|
||
});
|
||
|
||
false
|
||
});
|
||
|
||
// Now that we have an iterator of good candidates, make sure
|
||
// there's at most one rlib and at most one dylib.
|
||
for loc in locs {
|
||
if loc.file_name().unwrap().to_str().unwrap().ends_with(".rlib") {
|
||
rlibs.insert(fs::canonicalize(&loc).unwrap(), PathKind::ExternFlag);
|
||
} else if loc.file_name().unwrap().to_str().unwrap().ends_with(".rmeta") {
|
||
rmetas.insert(fs::canonicalize(&loc).unwrap(), PathKind::ExternFlag);
|
||
} else {
|
||
dylibs.insert(fs::canonicalize(&loc).unwrap(), PathKind::ExternFlag);
|
||
}
|
||
}
|
||
};
|
||
|
||
// Extract the rlib/dylib pair.
|
||
let mut slot = None;
|
||
let rlib = self.extract_one(rlibs, CrateFlavor::Rlib, &mut slot);
|
||
let rmeta = self.extract_one(rmetas, CrateFlavor::Rmeta, &mut slot);
|
||
let dylib = self.extract_one(dylibs, CrateFlavor::Dylib, &mut slot);
|
||
|
||
if rlib.is_none() && rmeta.is_none() && dylib.is_none() {
|
||
return None;
|
||
}
|
||
match slot {
|
||
Some((_, metadata)) => {
|
||
Some(Library {
|
||
dylib: dylib,
|
||
rlib: rlib,
|
||
rmeta: rmeta,
|
||
metadata: metadata,
|
||
})
|
||
}
|
||
None => None,
|
||
}
|
||
}
|
||
}
|
||
|
||
pub fn note_crate_name(err: &mut DiagnosticBuilder, name: &str) {
|
||
err.note(&format!("crate name: {}", name));
|
||
}
|
||
|
||
impl ArchiveMetadata {
|
||
fn new(ar: ArchiveRO) -> Option<ArchiveMetadata> {
|
||
let data = {
|
||
let section = ar.iter()
|
||
.filter_map(|s| s.ok())
|
||
.find(|sect| sect.name() == Some(METADATA_FILENAME));
|
||
match section {
|
||
Some(s) => s.data() as *const [u8],
|
||
None => {
|
||
debug!("didn't find '{}' in the archive", METADATA_FILENAME);
|
||
return None;
|
||
}
|
||
}
|
||
};
|
||
|
||
Some(ArchiveMetadata {
|
||
_archive: ar,
|
||
data: data,
|
||
})
|
||
}
|
||
|
||
pub fn as_slice<'a>(&'a self) -> &'a [u8] {
|
||
unsafe { &*self.data }
|
||
}
|
||
}
|
||
|
||
fn verify_decompressed_encoding_version(blob: &MetadataBlob,
|
||
filename: &Path)
|
||
-> Result<(), String> {
|
||
if !blob.is_compatible() {
|
||
Err((format!("incompatible metadata version found: '{}'",
|
||
filename.display())))
|
||
} else {
|
||
Ok(())
|
||
}
|
||
}
|
||
|
||
// Just a small wrapper to time how long reading metadata takes.
|
||
fn get_metadata_section(target: &Target,
|
||
flavor: CrateFlavor,
|
||
filename: &Path)
|
||
-> Result<MetadataBlob, String> {
|
||
let start = Instant::now();
|
||
let ret = get_metadata_section_imp(target, flavor, filename);
|
||
info!("reading {:?} => {:?}",
|
||
filename.file_name().unwrap(),
|
||
start.elapsed());
|
||
return ret;
|
||
}
|
||
|
||
fn get_metadata_section_imp(target: &Target,
|
||
flavor: CrateFlavor,
|
||
filename: &Path)
|
||
-> Result<MetadataBlob, String> {
|
||
if !filename.exists() {
|
||
return Err(format!("no such file: '{}'", filename.display()));
|
||
}
|
||
if flavor == CrateFlavor::Rlib {
|
||
// Use ArchiveRO for speed here, it's backed by LLVM and uses mmap
|
||
// internally to read the file. We also avoid even using a memcpy by
|
||
// just keeping the archive along while the metadata is in use.
|
||
let archive = match ArchiveRO::open(filename) {
|
||
Some(ar) => ar,
|
||
None => {
|
||
debug!("llvm didn't like `{}`", filename.display());
|
||
return Err(format!("failed to read rlib metadata: '{}'", filename.display()));
|
||
}
|
||
};
|
||
return match ArchiveMetadata::new(archive).map(|ar| MetadataBlob::Archive(ar)) {
|
||
None => Err(format!("failed to read rlib metadata: '{}'", filename.display())),
|
||
Some(blob) => {
|
||
verify_decompressed_encoding_version(&blob, filename)?;
|
||
Ok(blob)
|
||
}
|
||
};
|
||
} else if flavor == CrateFlavor::Rmeta {
|
||
let mut file = File::open(filename).map_err(|_|
|
||
format!("could not open file: '{}'", filename.display()))?;
|
||
let mut buf = vec![];
|
||
file.read_to_end(&mut buf).map_err(|_|
|
||
format!("failed to read rlib metadata: '{}'", filename.display()))?;
|
||
let blob = MetadataBlob::Raw(buf);
|
||
verify_decompressed_encoding_version(&blob, filename)?;
|
||
return Ok(blob);
|
||
}
|
||
unsafe {
|
||
let buf = common::path2cstr(filename);
|
||
let mb = llvm::LLVMRustCreateMemoryBufferWithContentsOfFile(buf.as_ptr());
|
||
if mb as isize == 0 {
|
||
return Err(format!("error reading library: '{}'", filename.display()));
|
||
}
|
||
let of = match ObjectFile::new(mb) {
|
||
Some(of) => of,
|
||
_ => {
|
||
return Err((format!("provided path not an object file: '{}'", filename.display())))
|
||
}
|
||
};
|
||
let si = mk_section_iter(of.llof);
|
||
while llvm::LLVMIsSectionIteratorAtEnd(of.llof, si.llsi) == False {
|
||
let mut name_buf = ptr::null();
|
||
let name_len = llvm::LLVMRustGetSectionName(si.llsi, &mut name_buf);
|
||
let name = slice::from_raw_parts(name_buf as *const u8, name_len as usize).to_vec();
|
||
let name = String::from_utf8(name).unwrap();
|
||
debug!("get_metadata_section: name {}", name);
|
||
if read_meta_section_name(target) == name {
|
||
let cbuf = llvm::LLVMGetSectionContents(si.llsi);
|
||
let csz = llvm::LLVMGetSectionSize(si.llsi) as usize;
|
||
let cvbuf: *const u8 = cbuf as *const u8;
|
||
let vlen = METADATA_HEADER.len();
|
||
debug!("checking {} bytes of metadata-version stamp", vlen);
|
||
let minsz = cmp::min(vlen, csz);
|
||
let buf0 = slice::from_raw_parts(cvbuf, minsz);
|
||
let version_ok = buf0 == METADATA_HEADER;
|
||
if !version_ok {
|
||
return Err((format!("incompatible metadata version found: '{}'",
|
||
filename.display())));
|
||
}
|
||
|
||
let cvbuf1 = cvbuf.offset(vlen as isize);
|
||
debug!("inflating {} bytes of compressed metadata", csz - vlen);
|
||
let bytes = slice::from_raw_parts(cvbuf1, csz - vlen);
|
||
match flate::inflate_bytes(bytes) {
|
||
Ok(inflated) => {
|
||
let blob = MetadataBlob::Inflated(inflated);
|
||
verify_decompressed_encoding_version(&blob, filename)?;
|
||
return Ok(blob);
|
||
}
|
||
Err(_) => {}
|
||
}
|
||
}
|
||
llvm::LLVMMoveToNextSection(si.llsi);
|
||
}
|
||
Err(format!("metadata not found: '{}'", filename.display()))
|
||
}
|
||
}
|
||
|
||
pub fn meta_section_name(target: &Target) -> &'static str {
|
||
// Historical note:
|
||
//
|
||
// When using link.exe it was seen that the section name `.note.rustc`
|
||
// was getting shortened to `.note.ru`, and according to the PE and COFF
|
||
// specification:
|
||
//
|
||
// > Executable images do not use a string table and do not support
|
||
// > section names longer than 8 characters
|
||
//
|
||
// https://msdn.microsoft.com/en-us/library/windows/hardware/gg463119.aspx
|
||
//
|
||
// As a result, we choose a slightly shorter name! As to why
|
||
// `.note.rustc` works on MinGW, that's another good question...
|
||
|
||
if target.options.is_like_osx {
|
||
"__DATA,.rustc"
|
||
} else {
|
||
".rustc"
|
||
}
|
||
}
|
||
|
||
pub fn read_meta_section_name(_target: &Target) -> &'static str {
|
||
".rustc"
|
||
}
|
||
|
||
// A diagnostic function for dumping crate metadata to an output stream
|
||
pub fn list_file_metadata(target: &Target, path: &Path, out: &mut io::Write) -> io::Result<()> {
|
||
let filename = path.file_name().unwrap().to_str().unwrap();
|
||
let flavor = if filename.ends_with(".rlib") {
|
||
CrateFlavor::Rlib
|
||
} else if filename.ends_with(".rmeta") {
|
||
CrateFlavor::Rmeta
|
||
} else {
|
||
CrateFlavor::Dylib
|
||
};
|
||
match get_metadata_section(target, flavor, path) {
|
||
Ok(metadata) => metadata.list_crate_metadata(out),
|
||
Err(msg) => write!(out, "{}\n", msg),
|
||
}
|
||
}
|