This change allows the interpreter to execute tests and benchmarks
functions provided by packages.
The test subcommand is similar to the "go test" command and
all the relevant flags have been kept.
The ability to evaluate a directory or a package has also been added.
A new method Symbol to access exported symbol values of an interpreted
package has been added. This method is used by the test subcommand.
An EvalTest method has been added to evaluate all Go files, including "*_test.go".
The testing packages from the standard library have been added to stdlib used
symbols.
This change fixes two distinct data races:
1) some global vars of type *itype of the interp package are actually
mutated during the lifecycle of an Interpreter. Even worse: if more than
one Interpreter instance are created and used at a given time, they are
actually racing each other for these global vars.
Therefore, this change replaces these global vars with generator
functions that create the needed type on the fly.
2) the symbols given as argument of Interpreter.Use were directly copied
as reference (since they're maps) when mapped inside an Interpreter
instance. Since the usual case is to give the symbols from the stdlib
package, it means when the interpreter mutates its own symbols in
fixStdio, it would actually mutate the corresponding global vars of the
stdlib package. Again, this is at least racy as soon as several
instances of an Intepreter are concurrently running.
This change fixes the race by making sure Interpreter.Use actually
copies the symbol values instead of copying the references.
The goal is to provide greater control of input, output and error
streams of the interpreter. It is now possible to specify those
as options when creating a new interpreter. The provided values
are propagated to relevant stdlib symbols (i.e fmt.Print, etc).
Care is taken to not update the global variables os.Stdout, os.Stdin
and os.Stderr, as to not interfere with the host process.
The REPL function is now simplified. The deprecated version is removed.
The tests are updated to take advantage of the simplified access
to the interpreter output and errors.
Fixes#752.
In interactive mode, a line starting with the "func" keyword is usually
"wrapped", by prepending to it a "package main" statement, to make it
a valid piece of Go source code.
However, when the line is actually an anonymous function call, such as:
func() { println(3) }()
then this wrapping is not enough, as this is not valid Go in the global
context. Therefore, this kind of of expression must also be wrapped
inside a main func (as is the default case for most REPL inputs).
Since the detection and handling of such a case turned out to be quite
unelegant, this PR instead introduces a retrying phase when a parsing
error occurs for a particular class of cases. That is to say, when a
"func expression" wrapped in a main package fails to be parsed, it is
then wrapped in a main func before parsing is retried.
N.B. TestEvalScanner has been disabled for this change, because the additional test cases revealed a (most-likely already existing) data race.
Fixes#721
The input scanning is now performed in a sub goroutine and
the interrupt is listened in another goroutine, either to cancel Eval
or to cancel the current line scan.
Entering a '\n' after a 'Ctrl-C` to get the prompt is
not necessary anymore.
The recent changes that added some redeclaration checks implicitly added more
strictness related to namespaces and scopes which, among other things, broke
some uses that "accidentally" used to work.
For example, given
const script1 = `
import "fmt"
// more code
`
const script2 = `
import "fmt"
// some other code
`
If one Evals script1, then script2, with the same interpreter, without
specifying any scope, as the two fragments would be considered part of the same
(.go file) scope by default, a redeclaration error would be triggered because
import "fmt" is seen twice.
A work-around would have been to specify (a different) i.Name before each Eval
call, so that each script is considered as coming from a different .go file, and
hence are respectively in different scopes with respect to imports.
That lead us to realize we had to make specifying things such as file-scope, and
"incremental mode" (aka REPL), more obvious in the context of an Eval call.
In addition, we want to lay down the foundations for Yaegi being able to behave
more like the go tool wrt to various inputs, i.e. it should be able to take a
package directory, or an import path, as input, instead of just a .go file.
Hence the introduction of a new kind of Eval method (whose signature is not fixed yet):
func (interp *Interpreter) EvalPath(path string) (res reflect.Value, err error)
It partially solves the problem described above because:
1. the path given to EvalPath can be used as the file-scope hint mentioned
above, for now (even though the related implementation details might change).
2. Eval always runs in incremental mode, whereas EvalPath always runs in
non-incremental mode, hence clarifying the situation in that respect.
And to avoid confusion, the Name field of Interpreter is now non-exported,
since it is somewhat redundant with the path argument of EvalPath.
Note that #731 is not fully fixed (and might never be), as a requirement of the
proposed solution is to move the input bits of code into respective files
(instead of leaving them as strings).
Finally, some related bugfixes, documention changes, and some refactoring have
been included. Notably, there is no "empty scope" anymore, i.e. name defaults
to "_.go" when it is not specified.
Updates #731Fixes#778Fixes#798Fixes#789
Co-authored-by: Marc Vertes <mvertes@free.fr>
Avoid goroutines leak, accumulation of defered functions and
spurious resets of signal handlers. Effectively catch interrupt
signal (Ctrl-C) to cancel current eval.
Fixes#713.
So far the REPL loop was treating any parsing error coming from
go/parser to generate the AST, as having occurred because the source
code was not yet complete (unfinished block). And it was therefore
ignoring all of them.
However, some of these errors are legitimate, and must be caught as soon
as they occur, otherwise the REPL cycle would stay in an errored state
forever (even when the block terminates), without the user getting any
feedback about it.
Therefore, this change adds an extra check when a parsing error occurs,
i.e. it verifies that it looks like an "EOF" error (unfinished block)
before it ignores it (as the user is supposed to terminate the block
eventually). Otherwise the error is treated just like a "non-parsing"
(cfg, gta, ...) error and printed out.
Fixes#637
* fix: constant definition loop on out of order vars
* fix: do not wire global varDecl
* fix: wire and execute global vars
* chore: add tests
* fix: refactor and lint
* feature: restrict symbols which can exit the interpreter process
Some symbols such as os.Exit or log.Fatal, which make the current process
to exit, are now restricted. They are replaced by a version which panics
instead of exiting, as panics are recovered by Eval.
The restricted os.FindProcess version is identical to the original
except it errors when trying to return the self process, in order to
forbid killing or signaling the interpreter process from script.
The os/exec symbols are available only through unrestricted package.
The original symbols are stored in an unrestricted package, which
requires an explicit Use, as for unsafe and syscall packages.
The Use() interpreter method has been slightly modified to allow inplace
updating of package symbols, allowing to replace some symbols but not
the entire imported package.
A command line option -unrestricted has been added to yaegi CLI to use
the unrestricted symbols.
Fixes#486.
* fix: lint
* fix: make interpreter methods discoverable by runtime
When generating an interface wrapper, lookup existing wrappers by method
to get the one with the biggest set of methods implemented by interpreter.
A string method is also added to wrappers, in order to provide a string
representation of the interpreter value rather than the wrapper itself
(at least for %s and %v verbs).
This allows the runtime to pickup an interpreter method automatically
even if the conversion to the interface is not specified in the script. As
in Go spec, it is enough for the type to implement the required methods.
A current limitation is that only single wrappers can be instantiated,
not allowing to compose interfaces.
This limitation can be removed when the Go reflect issue
https://github.com/golang/go/issues/15924 is fixed.
Fixes#435.
* test: add a simpler test
