1122 lines
46 KiB
Rust
1122 lines
46 KiB
Rust
//! 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 type-check/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. If the crate
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//! we're looking for was originally compiled with -C extra-filename, the
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//! extra filename will be included in this prefix to reduce reading
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//! metadata from crates that would otherwise share our prefix.
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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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//! ```compile_fail,E0463
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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 crate::creader::Library;
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use crate::rmeta::{rustc_version, MetadataBlob, METADATA_HEADER};
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use rustc_data_structures::fx::{FxHashMap, FxHashSet};
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use rustc_data_structures::owning_ref::OwningRef;
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use rustc_data_structures::svh::Svh;
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use rustc_data_structures::sync::MetadataRef;
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use rustc_errors::struct_span_err;
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use rustc_middle::middle::cstore::{CrateSource, MetadataLoader};
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use rustc_session::config::{self, CrateType};
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use rustc_session::filesearch::{FileDoesntMatch, FileMatches, FileSearch};
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use rustc_session::search_paths::PathKind;
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use rustc_session::utils::CanonicalizedPath;
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use rustc_session::{CrateDisambiguator, Session};
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use rustc_span::symbol::{sym, Symbol};
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use rustc_span::Span;
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use rustc_target::spec::{Target, TargetTriple};
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use snap::read::FrameDecoder;
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use std::io::{Read, Result as IoResult, Write};
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use std::ops::Deref;
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use std::path::{Path, PathBuf};
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use std::{cmp, fmt, fs};
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use tracing::{debug, info, warn};
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#[derive(Clone)]
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crate struct CrateLocator<'a> {
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// Immutable per-session configuration.
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sess: &'a Session,
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metadata_loader: &'a dyn MetadataLoader,
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// Immutable per-search configuration.
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crate_name: Symbol,
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exact_paths: Vec<CanonicalizedPath>,
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pub hash: Option<Svh>,
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pub host_hash: Option<Svh>,
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extra_filename: Option<&'a str>,
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pub target: &'a Target,
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pub triple: TargetTriple,
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pub filesearch: FileSearch<'a>,
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root: Option<&'a CratePaths>,
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pub is_proc_macro: Option<bool>,
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// Mutable in-progress state or output.
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rejected_via_hash: Vec<CrateMismatch>,
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rejected_via_triple: Vec<CrateMismatch>,
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rejected_via_kind: Vec<CrateMismatch>,
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rejected_via_version: Vec<CrateMismatch>,
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rejected_via_filename: Vec<CrateMismatch>,
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}
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#[derive(Clone)]
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crate struct CratePaths {
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name: Symbol,
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source: CrateSource,
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}
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impl CratePaths {
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crate fn new(name: Symbol, source: CrateSource) -> CratePaths {
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CratePaths { name, source }
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}
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}
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#[derive(Copy, Clone, PartialEq)]
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crate 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<'a> CrateLocator<'a> {
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crate fn new(
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sess: &'a Session,
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metadata_loader: &'a dyn MetadataLoader,
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crate_name: Symbol,
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hash: Option<Svh>,
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host_hash: Option<Svh>,
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extra_filename: Option<&'a str>,
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is_host: bool,
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path_kind: PathKind,
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root: Option<&'a CratePaths>,
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is_proc_macro: Option<bool>,
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) -> CrateLocator<'a> {
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CrateLocator {
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sess,
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metadata_loader,
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crate_name,
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exact_paths: if hash.is_none() {
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sess.opts
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.externs
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.get(&crate_name.as_str())
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.into_iter()
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.filter_map(|entry| entry.files())
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.flatten()
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.cloned()
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.collect()
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} else {
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// SVH being specified means this is a transitive dependency,
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// so `--extern` options do not apply.
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Vec::new()
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},
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hash,
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host_hash,
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extra_filename,
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target: if is_host { &sess.host } else { &sess.target },
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triple: if is_host {
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TargetTriple::from_triple(config::host_triple())
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} else {
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sess.opts.target_triple.clone()
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},
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filesearch: if is_host {
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sess.host_filesearch(path_kind)
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} else {
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sess.target_filesearch(path_kind)
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},
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root,
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is_proc_macro,
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rejected_via_hash: Vec::new(),
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rejected_via_triple: Vec::new(),
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rejected_via_kind: Vec::new(),
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rejected_via_version: Vec::new(),
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rejected_via_filename: Vec::new(),
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}
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}
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crate fn reset(&mut self) {
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self.rejected_via_hash.clear();
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self.rejected_via_triple.clear();
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self.rejected_via_kind.clear();
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self.rejected_via_version.clear();
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self.rejected_via_filename.clear();
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}
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crate fn maybe_load_library_crate(&mut self) -> Result<Option<Library>, CrateError> {
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if !self.exact_paths.is_empty() {
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return self.find_commandline_library();
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}
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let mut seen_paths = FxHashSet::default();
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if let Some(extra_filename) = self.extra_filename {
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if let library @ Some(_) = self.find_library_crate(extra_filename, &mut seen_paths)? {
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return Ok(library);
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}
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}
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self.find_library_crate("", &mut seen_paths)
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}
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fn find_library_crate(
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&mut self,
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extra_prefix: &str,
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seen_paths: &mut FxHashSet<PathBuf>,
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) -> Result<Option<Library>, CrateError> {
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// want: crate_name.dir_part() + prefix + crate_name.file_part + "-"
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let dylib_prefix = format!("{}{}{}", self.target.dll_prefix, self.crate_name, extra_prefix);
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let rlib_prefix = format!("lib{}{}", self.crate_name, extra_prefix);
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let staticlib_prefix =
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format!("{}{}{}", self.target.staticlib_prefix, self.crate_name, extra_prefix);
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let mut candidates: FxHashMap<_, (FxHashMap<_, _>, FxHashMap<_, _>, FxHashMap<_, _>)> =
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Default::default();
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let mut staticlibs = vec![];
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// First, find all possible candidate rlibs and dylibs purely based on
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// the name of the files themselves. We're trying to match against an
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// exact crate name and a possibly an exact hash.
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//
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// During this step, we can filter all found libraries based on the
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// name and id found in the crate id (we ignore the path portion for
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// filename matching), as well as the exact hash (if specified). If we
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// end up having many candidates, we must look at the metadata to
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// perform exact matches against hashes/crate ids. Note that opening up
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// the metadata is where we do an exact match against the full contents
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// of the crate id (path/name/id).
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//
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// The goal of this step is to look at as little metadata as possible.
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self.filesearch.search(|spf, kind| {
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let file = match &spf.file_name_str {
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None => return FileDoesntMatch,
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Some(file) => file,
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};
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let (hash, found_kind) = if file.starts_with(&rlib_prefix) && file.ends_with(".rlib") {
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(&file[(rlib_prefix.len())..(file.len() - ".rlib".len())], CrateFlavor::Rlib)
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} else if file.starts_with(&rlib_prefix) && file.ends_with(".rmeta") {
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(&file[(rlib_prefix.len())..(file.len() - ".rmeta".len())], CrateFlavor::Rmeta)
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} else if file.starts_with(&dylib_prefix) && file.ends_with(&self.target.dll_suffix) {
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(
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&file[(dylib_prefix.len())..(file.len() - self.target.dll_suffix.len())],
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CrateFlavor::Dylib,
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)
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} else {
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if file.starts_with(&staticlib_prefix)
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&& file.ends_with(&self.target.staticlib_suffix)
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{
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staticlibs
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.push(CrateMismatch { path: spf.path.clone(), got: "static".to_string() });
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}
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return FileDoesntMatch;
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};
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info!("lib candidate: {}", spf.path.display());
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let (rlibs, rmetas, dylibs) = candidates.entry(hash.to_string()).or_default();
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let path = fs::canonicalize(&spf.path).unwrap_or_else(|_| spf.path.clone());
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if seen_paths.contains(&path) {
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return FileDoesntMatch;
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};
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seen_paths.insert(path.clone());
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match found_kind {
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CrateFlavor::Rlib => rlibs.insert(path, kind),
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CrateFlavor::Rmeta => rmetas.insert(path, kind),
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CrateFlavor::Dylib => dylibs.insert(path, kind),
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};
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FileMatches
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});
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self.rejected_via_kind.extend(staticlibs);
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// We have now collected all known libraries into a set of candidates
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// keyed of the filename hash listed. For each filename, we also have a
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// list of rlibs/dylibs that apply. Here, we map each of these lists
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// (per hash), to a Library candidate for returning.
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//
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// A Library candidate is created if the metadata for the set of
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// libraries corresponds to the crate id and hash criteria that this
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// search is being performed for.
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let mut libraries = FxHashMap::default();
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for (_hash, (rlibs, rmetas, dylibs)) in candidates {
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if let Some((svh, lib)) = self.extract_lib(rlibs, rmetas, dylibs)? {
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libraries.insert(svh, lib);
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}
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}
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// Having now translated all relevant found hashes into libraries, see
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// what we've got and figure out if we found multiple candidates for
|
|
// libraries or not.
|
|
match libraries.len() {
|
|
0 => Ok(None),
|
|
1 => Ok(Some(libraries.into_iter().next().unwrap().1)),
|
|
_ => Err(CrateError::MultipleMatchingCrates(self.crate_name, libraries)),
|
|
}
|
|
}
|
|
|
|
fn extract_lib(
|
|
&mut self,
|
|
rlibs: FxHashMap<PathBuf, PathKind>,
|
|
rmetas: FxHashMap<PathBuf, PathKind>,
|
|
dylibs: FxHashMap<PathBuf, PathKind>,
|
|
) -> Result<Option<(Svh, Library)>, CrateError> {
|
|
let mut slot = None;
|
|
// Order here matters, rmeta should come first. See comment in
|
|
// `extract_one` below.
|
|
let source = CrateSource {
|
|
rmeta: self.extract_one(rmetas, CrateFlavor::Rmeta, &mut slot)?,
|
|
rlib: self.extract_one(rlibs, CrateFlavor::Rlib, &mut slot)?,
|
|
dylib: self.extract_one(dylibs, CrateFlavor::Dylib, &mut slot)?,
|
|
};
|
|
Ok(slot.map(|(svh, metadata)| (svh, Library { source, metadata })))
|
|
}
|
|
|
|
fn needs_crate_flavor(&self, flavor: CrateFlavor) -> bool {
|
|
if flavor == CrateFlavor::Dylib && self.is_proc_macro == Some(true) {
|
|
return true;
|
|
}
|
|
|
|
// The all loop is because `--crate-type=rlib --crate-type=rlib` is
|
|
// legal and produces both inside this type.
|
|
let is_rlib = self.sess.crate_types().iter().all(|c| *c == CrateType::Rlib);
|
|
let needs_object_code = self.sess.opts.output_types.should_codegen();
|
|
// If we're producing an rlib, then we don't need object code.
|
|
// Or, if we're not producing object code, then we don't need it either
|
|
// (e.g., if we're a cdylib but emitting just metadata).
|
|
if is_rlib || !needs_object_code {
|
|
flavor == CrateFlavor::Rmeta
|
|
} else {
|
|
// we need all flavors (perhaps not true, but what we do for now)
|
|
true
|
|
}
|
|
}
|
|
|
|
// 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)>,
|
|
) -> Result<Option<(PathBuf, PathKind)>, CrateError> {
|
|
// If we are producing an rlib, and we've already loaded metadata, then
|
|
// we should not attempt to discover further crate sources (unless we're
|
|
// locating a proc macro; exact logic is in needs_crate_flavor). This means
|
|
// that under -Zbinary-dep-depinfo we will not emit a dependency edge on
|
|
// the *unused* rlib, and by returning `None` here immediately we
|
|
// guarantee that we do indeed not use it.
|
|
//
|
|
// See also #68149 which provides more detail on why emitting the
|
|
// dependency on the rlib is a bad thing.
|
|
//
|
|
// We currently do not verify that these other sources are even in sync,
|
|
// and this is arguably a bug (see #10786), but because reading metadata
|
|
// is quite slow (especially from dylibs) we currently do not read it
|
|
// from the other crate sources.
|
|
if slot.is_some() {
|
|
if m.is_empty() || !self.needs_crate_flavor(flavor) {
|
|
return Ok(None);
|
|
} else if m.len() == 1 {
|
|
return Ok(Some(m.into_iter().next().unwrap()));
|
|
}
|
|
}
|
|
|
|
let mut ret: Option<(PathBuf, PathKind)> = None;
|
|
let mut err_data: Option<Vec<PathBuf>> = None;
|
|
for (lib, kind) in m {
|
|
info!("{} reading metadata from: {}", flavor, lib.display());
|
|
let (hash, metadata) =
|
|
match get_metadata_section(self.target, flavor, &lib, self.metadata_loader) {
|
|
Ok(blob) => {
|
|
if let Some(h) = self.crate_matches(&blob, &lib) {
|
|
(h, blob)
|
|
} else {
|
|
info!("metadata mismatch");
|
|
continue;
|
|
}
|
|
}
|
|
Err(err) => {
|
|
warn!("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) {
|
|
if let Some(candidates) = err_data {
|
|
return Err(CrateError::MultipleCandidates(
|
|
self.crate_name,
|
|
flavor,
|
|
candidates,
|
|
));
|
|
}
|
|
err_data = Some(vec![ret.as_ref().unwrap().0.clone()]);
|
|
*slot = None;
|
|
}
|
|
if let Some(candidates) = &mut err_data {
|
|
candidates.push(lib);
|
|
continue;
|
|
}
|
|
|
|
// Ok so at this point we've determined that `(lib, kind)` above is
|
|
// a candidate crate to load, and that `slot` is either none (this
|
|
// is the first crate of its kind) or if some the previous path has
|
|
// the exact same hash (e.g., it's the exact same crate).
|
|
//
|
|
// In principle these two candidate crates are exactly the same so
|
|
// we can choose either of them to link. As a stupidly gross hack,
|
|
// however, we favor crate in the sysroot.
|
|
//
|
|
// You can find more info in rust-lang/rust#39518 and various linked
|
|
// issues, but the general gist is that during testing libstd the
|
|
// compilers has two candidates to choose from: one in the sysroot
|
|
// and one in the deps folder. These two crates are the exact same
|
|
// crate but if the compiler chooses the one in the deps folder
|
|
// it'll cause spurious errors on Windows.
|
|
//
|
|
// As a result, we favor the sysroot crate here. Note that the
|
|
// candidates are all canonicalized, so we canonicalize the sysroot
|
|
// as well.
|
|
if let Some((prev, _)) = &ret {
|
|
let sysroot = &self.sess.sysroot;
|
|
let sysroot = sysroot.canonicalize().unwrap_or_else(|_| sysroot.to_path_buf());
|
|
if prev.starts_with(&sysroot) {
|
|
continue;
|
|
}
|
|
}
|
|
*slot = Some((hash, metadata));
|
|
ret = Some((lib, kind));
|
|
}
|
|
|
|
if let Some(candidates) = err_data {
|
|
Err(CrateError::MultipleCandidates(self.crate_name, flavor, candidates))
|
|
} else {
|
|
Ok(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(expected_is_proc_macro) = self.is_proc_macro {
|
|
let is_proc_macro = root.is_proc_macro_crate();
|
|
if is_proc_macro != expected_is_proc_macro {
|
|
info!(
|
|
"Rejecting via proc macro: expected {} got {}",
|
|
expected_is_proc_macro, is_proc_macro
|
|
);
|
|
return None;
|
|
}
|
|
}
|
|
|
|
if self.exact_paths.is_empty() && 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().to_string(),
|
|
});
|
|
return None;
|
|
}
|
|
|
|
let hash = root.hash();
|
|
if let Some(expected_hash) = self.hash {
|
|
if hash != expected_hash {
|
|
info!("Rejecting via hash: expected {} got {}", expected_hash, hash);
|
|
self.rejected_via_hash
|
|
.push(CrateMismatch { path: libpath.to_path_buf(), got: hash.to_string() });
|
|
return None;
|
|
}
|
|
}
|
|
|
|
Some(hash)
|
|
}
|
|
|
|
fn find_commandline_library(&mut self) -> Result<Option<Library>, CrateError> {
|
|
// 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 mut rlibs = FxHashMap::default();
|
|
let mut rmetas = FxHashMap::default();
|
|
let mut dylibs = FxHashMap::default();
|
|
for loc in &self.exact_paths {
|
|
if !loc.canonicalized().exists() {
|
|
return Err(CrateError::ExternLocationNotExist(
|
|
self.crate_name,
|
|
loc.original().clone(),
|
|
));
|
|
}
|
|
let file = match loc.original().file_name().and_then(|s| s.to_str()) {
|
|
Some(file) => file,
|
|
None => {
|
|
return Err(CrateError::ExternLocationNotFile(
|
|
self.crate_name,
|
|
loc.original().clone(),
|
|
));
|
|
}
|
|
};
|
|
|
|
if file.starts_with("lib") && (file.ends_with(".rlib") || file.ends_with(".rmeta"))
|
|
|| file.starts_with(&self.target.dll_prefix)
|
|
&& file.ends_with(&self.target.dll_suffix)
|
|
{
|
|
// Make sure there's at most one rlib and at most one dylib.
|
|
// Note to take care and match against the non-canonicalized name:
|
|
// some systems save build artifacts into content-addressed stores
|
|
// that do not preserve extensions, and then link to them using
|
|
// e.g. symbolic links. If we canonicalize too early, we resolve
|
|
// the symlink, the file type is lost and we might treat rlibs and
|
|
// rmetas as dylibs.
|
|
let loc_canon = loc.canonicalized().clone();
|
|
let loc = loc.original();
|
|
if loc.file_name().unwrap().to_str().unwrap().ends_with(".rlib") {
|
|
rlibs.insert(loc_canon, PathKind::ExternFlag);
|
|
} else if loc.file_name().unwrap().to_str().unwrap().ends_with(".rmeta") {
|
|
rmetas.insert(loc_canon, PathKind::ExternFlag);
|
|
} else {
|
|
dylibs.insert(loc_canon, PathKind::ExternFlag);
|
|
}
|
|
} else {
|
|
self.rejected_via_filename
|
|
.push(CrateMismatch { path: loc.original().clone(), got: String::new() });
|
|
}
|
|
}
|
|
|
|
// Extract the dylib/rlib/rmeta triple.
|
|
Ok(self.extract_lib(rlibs, rmetas, dylibs)?.map(|(_, lib)| lib))
|
|
}
|
|
|
|
crate fn into_error(self) -> CrateError {
|
|
CrateError::LocatorCombined(CombinedLocatorError {
|
|
crate_name: self.crate_name,
|
|
root: self.root.cloned(),
|
|
triple: self.triple,
|
|
dll_prefix: self.target.dll_prefix.clone(),
|
|
dll_suffix: self.target.dll_suffix.clone(),
|
|
rejected_via_hash: self.rejected_via_hash,
|
|
rejected_via_triple: self.rejected_via_triple,
|
|
rejected_via_kind: self.rejected_via_kind,
|
|
rejected_via_version: self.rejected_via_version,
|
|
rejected_via_filename: self.rejected_via_filename,
|
|
})
|
|
}
|
|
}
|
|
|
|
/// A trivial wrapper for `Mmap` that implements `StableDeref`.
|
|
struct StableDerefMmap(memmap2::Mmap);
|
|
|
|
impl Deref for StableDerefMmap {
|
|
type Target = [u8];
|
|
|
|
fn deref(&self) -> &[u8] {
|
|
self.0.deref()
|
|
}
|
|
}
|
|
|
|
unsafe impl stable_deref_trait::StableDeref for StableDerefMmap {}
|
|
|
|
fn get_metadata_section(
|
|
target: &Target,
|
|
flavor: CrateFlavor,
|
|
filename: &Path,
|
|
loader: &dyn MetadataLoader,
|
|
) -> Result<MetadataBlob, String> {
|
|
if !filename.exists() {
|
|
return Err(format!("no such file: '{}'", filename.display()));
|
|
}
|
|
let raw_bytes: MetadataRef = match flavor {
|
|
CrateFlavor::Rlib => loader.get_rlib_metadata(target, filename)?,
|
|
CrateFlavor::Dylib => {
|
|
let buf = loader.get_dylib_metadata(target, filename)?;
|
|
// The header is uncompressed
|
|
let header_len = METADATA_HEADER.len();
|
|
debug!("checking {} bytes of metadata-version stamp", header_len);
|
|
let header = &buf[..cmp::min(header_len, buf.len())];
|
|
if header != METADATA_HEADER {
|
|
return Err(format!(
|
|
"incompatible metadata version found: '{}'",
|
|
filename.display()
|
|
));
|
|
}
|
|
|
|
// Header is okay -> inflate the actual metadata
|
|
let compressed_bytes = &buf[header_len..];
|
|
debug!("inflating {} bytes of compressed metadata", compressed_bytes.len());
|
|
let mut inflated = Vec::new();
|
|
match FrameDecoder::new(compressed_bytes).read_to_end(&mut inflated) {
|
|
Ok(_) => rustc_erase_owner!(OwningRef::new(inflated).map_owner_box()),
|
|
Err(_) => {
|
|
return Err(format!("failed to decompress metadata: {}", filename.display()));
|
|
}
|
|
}
|
|
}
|
|
CrateFlavor::Rmeta => {
|
|
// mmap the file, because only a small fraction of it is read.
|
|
let file = std::fs::File::open(filename)
|
|
.map_err(|_| format!("failed to open rmeta metadata: '{}'", filename.display()))?;
|
|
let mmap = unsafe { memmap2::Mmap::map(&file) };
|
|
let mmap = mmap
|
|
.map_err(|_| format!("failed to mmap rmeta metadata: '{}'", filename.display()))?;
|
|
|
|
rustc_erase_owner!(OwningRef::new(StableDerefMmap(mmap)).map_owner_box())
|
|
}
|
|
};
|
|
let blob = MetadataBlob::new(raw_bytes);
|
|
if blob.is_compatible() {
|
|
Ok(blob)
|
|
} else {
|
|
Err(format!("incompatible metadata version found: '{}'", filename.display()))
|
|
}
|
|
}
|
|
|
|
/// Look for a plugin registrar. Returns its library path and crate disambiguator.
|
|
pub fn find_plugin_registrar(
|
|
sess: &Session,
|
|
metadata_loader: &dyn MetadataLoader,
|
|
span: Span,
|
|
name: Symbol,
|
|
) -> (PathBuf, CrateDisambiguator) {
|
|
match find_plugin_registrar_impl(sess, metadata_loader, name) {
|
|
Ok(res) => res,
|
|
Err(err) => err.report(sess, span),
|
|
}
|
|
}
|
|
|
|
fn find_plugin_registrar_impl<'a>(
|
|
sess: &'a Session,
|
|
metadata_loader: &dyn MetadataLoader,
|
|
name: Symbol,
|
|
) -> Result<(PathBuf, CrateDisambiguator), CrateError> {
|
|
info!("find plugin registrar `{}`", name);
|
|
let mut locator = CrateLocator::new(
|
|
sess,
|
|
metadata_loader,
|
|
name,
|
|
None, // hash
|
|
None, // host_hash
|
|
None, // extra_filename
|
|
true, // is_host
|
|
PathKind::Crate,
|
|
None, // root
|
|
None, // is_proc_macro
|
|
);
|
|
|
|
match locator.maybe_load_library_crate()? {
|
|
Some(library) => match library.source.dylib {
|
|
Some(dylib) => Ok((dylib.0, library.metadata.get_root().disambiguator())),
|
|
None => Err(CrateError::NonDylibPlugin(name)),
|
|
},
|
|
None => Err(locator.into_error()),
|
|
}
|
|
}
|
|
|
|
/// A diagnostic function for dumping crate metadata to an output stream.
|
|
pub fn list_file_metadata(
|
|
target: &Target,
|
|
path: &Path,
|
|
metadata_loader: &dyn MetadataLoader,
|
|
out: &mut dyn Write,
|
|
) -> IoResult<()> {
|
|
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, metadata_loader) {
|
|
Ok(metadata) => metadata.list_crate_metadata(out),
|
|
Err(msg) => write!(out, "{}\n", msg),
|
|
}
|
|
}
|
|
|
|
// ------------------------------------------ Error reporting -------------------------------------
|
|
|
|
#[derive(Clone)]
|
|
struct CrateMismatch {
|
|
path: PathBuf,
|
|
got: String,
|
|
}
|
|
|
|
/// Candidate rejection reasons collected during crate search.
|
|
/// If no candidate is accepted, then these reasons are presented to the user,
|
|
/// otherwise they are ignored.
|
|
crate struct CombinedLocatorError {
|
|
crate_name: Symbol,
|
|
root: Option<CratePaths>,
|
|
triple: TargetTriple,
|
|
dll_prefix: String,
|
|
dll_suffix: String,
|
|
rejected_via_hash: Vec<CrateMismatch>,
|
|
rejected_via_triple: Vec<CrateMismatch>,
|
|
rejected_via_kind: Vec<CrateMismatch>,
|
|
rejected_via_version: Vec<CrateMismatch>,
|
|
rejected_via_filename: Vec<CrateMismatch>,
|
|
}
|
|
|
|
crate enum CrateError {
|
|
NonAsciiName(Symbol),
|
|
ExternLocationNotExist(Symbol, PathBuf),
|
|
ExternLocationNotFile(Symbol, PathBuf),
|
|
MultipleCandidates(Symbol, CrateFlavor, Vec<PathBuf>),
|
|
MultipleMatchingCrates(Symbol, FxHashMap<Svh, Library>),
|
|
SymbolConflictsCurrent(Symbol),
|
|
SymbolConflictsOthers(Symbol),
|
|
StableCrateIdCollision(Symbol, Symbol),
|
|
DlOpen(String),
|
|
DlSym(String),
|
|
LocatorCombined(CombinedLocatorError),
|
|
NonDylibPlugin(Symbol),
|
|
}
|
|
|
|
impl CrateError {
|
|
crate fn report(self, sess: &Session, span: Span) -> ! {
|
|
let mut err = match self {
|
|
CrateError::NonAsciiName(crate_name) => sess.struct_span_err(
|
|
span,
|
|
&format!("cannot load a crate with a non-ascii name `{}`", crate_name),
|
|
),
|
|
CrateError::ExternLocationNotExist(crate_name, loc) => sess.struct_span_err(
|
|
span,
|
|
&format!("extern location for {} does not exist: {}", crate_name, loc.display()),
|
|
),
|
|
CrateError::ExternLocationNotFile(crate_name, loc) => sess.struct_span_err(
|
|
span,
|
|
&format!("extern location for {} is not a file: {}", crate_name, loc.display()),
|
|
),
|
|
CrateError::MultipleCandidates(crate_name, flavor, candidates) => {
|
|
let mut err = struct_span_err!(
|
|
sess,
|
|
span,
|
|
E0465,
|
|
"multiple {} candidates for `{}` found",
|
|
flavor,
|
|
crate_name,
|
|
);
|
|
for (i, candidate) in candidates.iter().enumerate() {
|
|
err.span_note(span, &format!("candidate #{}: {}", i + 1, candidate.display()));
|
|
}
|
|
err
|
|
}
|
|
CrateError::MultipleMatchingCrates(crate_name, libraries) => {
|
|
let mut err = struct_span_err!(
|
|
sess,
|
|
span,
|
|
E0464,
|
|
"multiple matching crates for `{}`",
|
|
crate_name
|
|
);
|
|
let candidates = libraries
|
|
.iter()
|
|
.filter_map(|(_, lib)| {
|
|
let crate_name = &lib.metadata.get_root().name().as_str();
|
|
match (&lib.source.dylib, &lib.source.rlib) {
|
|
(Some((pd, _)), Some((pr, _))) => Some(format!(
|
|
"\ncrate `{}`: {}\n{:>padding$}",
|
|
crate_name,
|
|
pd.display(),
|
|
pr.display(),
|
|
padding = 8 + crate_name.len()
|
|
)),
|
|
(Some((p, _)), None) | (None, Some((p, _))) => {
|
|
Some(format!("\ncrate `{}`: {}", crate_name, p.display()))
|
|
}
|
|
(None, None) => None,
|
|
}
|
|
})
|
|
.collect::<String>();
|
|
err.note(&format!("candidates:{}", candidates));
|
|
err
|
|
}
|
|
CrateError::SymbolConflictsCurrent(root_name) => struct_span_err!(
|
|
sess,
|
|
span,
|
|
E0519,
|
|
"the current crate is indistinguishable from one of its dependencies: it has the \
|
|
same crate-name `{}` and was compiled with the same `-C metadata` arguments. \
|
|
This will result in symbol conflicts between the two.",
|
|
root_name,
|
|
),
|
|
CrateError::SymbolConflictsOthers(root_name) => struct_span_err!(
|
|
sess,
|
|
span,
|
|
E0523,
|
|
"found two different crates with name `{}` that are not distinguished by differing \
|
|
`-C metadata`. This will result in symbol conflicts between the two.",
|
|
root_name,
|
|
),
|
|
CrateError::StableCrateIdCollision(crate_name0, crate_name1) => {
|
|
let msg = format!(
|
|
"found crates (`{}` and `{}`) with colliding StableCrateId values.",
|
|
crate_name0, crate_name1
|
|
);
|
|
sess.struct_span_err(span, &msg)
|
|
}
|
|
CrateError::DlOpen(s) | CrateError::DlSym(s) => sess.struct_span_err(span, &s),
|
|
CrateError::LocatorCombined(locator) => {
|
|
let crate_name = locator.crate_name;
|
|
let add = match &locator.root {
|
|
None => String::new(),
|
|
Some(r) => format!(" which `{}` depends on", r.name),
|
|
};
|
|
let mut msg = "the following crate versions were found:".to_string();
|
|
let mut err = if !locator.rejected_via_hash.is_empty() {
|
|
let mut err = struct_span_err!(
|
|
sess,
|
|
span,
|
|
E0460,
|
|
"found possibly newer version of crate `{}`{}",
|
|
crate_name,
|
|
add,
|
|
);
|
|
err.note("perhaps that crate needs to be recompiled?");
|
|
let mismatches = locator.rejected_via_hash.iter();
|
|
for CrateMismatch { path, .. } in mismatches {
|
|
msg.push_str(&format!("\ncrate `{}`: {}", crate_name, path.display()));
|
|
}
|
|
if let Some(r) = locator.root {
|
|
for path in r.source.paths() {
|
|
msg.push_str(&format!("\ncrate `{}`: {}", r.name, path.display()));
|
|
}
|
|
}
|
|
err.note(&msg);
|
|
err
|
|
} else if !locator.rejected_via_triple.is_empty() {
|
|
let mut err = struct_span_err!(
|
|
sess,
|
|
span,
|
|
E0461,
|
|
"couldn't find crate `{}` with expected target triple {}{}",
|
|
crate_name,
|
|
locator.triple,
|
|
add,
|
|
);
|
|
let mismatches = locator.rejected_via_triple.iter();
|
|
for CrateMismatch { path, got } in mismatches {
|
|
msg.push_str(&format!(
|
|
"\ncrate `{}`, target triple {}: {}",
|
|
crate_name,
|
|
got,
|
|
path.display(),
|
|
));
|
|
}
|
|
err.note(&msg);
|
|
err
|
|
} else if !locator.rejected_via_kind.is_empty() {
|
|
let mut err = struct_span_err!(
|
|
sess,
|
|
span,
|
|
E0462,
|
|
"found staticlib `{}` instead of rlib or dylib{}",
|
|
crate_name,
|
|
add,
|
|
);
|
|
err.help("please recompile that crate using --crate-type lib");
|
|
let mismatches = locator.rejected_via_kind.iter();
|
|
for CrateMismatch { path, .. } in mismatches {
|
|
msg.push_str(&format!("\ncrate `{}`: {}", crate_name, path.display()));
|
|
}
|
|
err.note(&msg);
|
|
err
|
|
} else if !locator.rejected_via_version.is_empty() {
|
|
let mut err = struct_span_err!(
|
|
sess,
|
|
span,
|
|
E0514,
|
|
"found crate `{}` compiled by an incompatible version of rustc{}",
|
|
crate_name,
|
|
add,
|
|
);
|
|
err.help(&format!(
|
|
"please recompile that crate using this compiler ({})",
|
|
rustc_version(),
|
|
));
|
|
let mismatches = locator.rejected_via_version.iter();
|
|
for CrateMismatch { path, got } in mismatches {
|
|
msg.push_str(&format!(
|
|
"\ncrate `{}` compiled by {}: {}",
|
|
crate_name,
|
|
got,
|
|
path.display(),
|
|
));
|
|
}
|
|
err.note(&msg);
|
|
err
|
|
} else {
|
|
let mut err = struct_span_err!(
|
|
sess,
|
|
span,
|
|
E0463,
|
|
"can't find crate for `{}`{}",
|
|
crate_name,
|
|
add,
|
|
);
|
|
|
|
if (crate_name == sym::std || crate_name == sym::core)
|
|
&& locator.triple != TargetTriple::from_triple(config::host_triple())
|
|
{
|
|
err.note(&format!("the `{}` target may not be installed", locator.triple));
|
|
} else if crate_name == sym::profiler_builtins {
|
|
err.note(&"the compiler may have been built without the profiler runtime");
|
|
}
|
|
err.span_label(span, "can't find crate");
|
|
err
|
|
};
|
|
|
|
if !locator.rejected_via_filename.is_empty() {
|
|
let mismatches = locator.rejected_via_filename.iter();
|
|
for CrateMismatch { path, .. } in mismatches {
|
|
err.note(&format!(
|
|
"extern location for {} is of an unknown type: {}",
|
|
crate_name,
|
|
path.display(),
|
|
))
|
|
.help(&format!(
|
|
"file name should be lib*.rlib or {}*.{}",
|
|
locator.dll_prefix, locator.dll_suffix
|
|
));
|
|
}
|
|
}
|
|
err
|
|
}
|
|
CrateError::NonDylibPlugin(crate_name) => struct_span_err!(
|
|
sess,
|
|
span,
|
|
E0457,
|
|
"plugin `{}` only found in rlib format, but must be available in dylib format",
|
|
crate_name,
|
|
),
|
|
};
|
|
|
|
err.emit();
|
|
sess.abort_if_errors();
|
|
unreachable!();
|
|
}
|
|
}
|