This implements the block-based GC as a partially precise GC. This means
that for most heap allocations it is known which words contain a pointer
and which don't. This should in theory make the GC faster (because it
can skip non-pointer object) and have fewer false positives in a GC
cycle. It does however use a bit more RAM to store the layout of each
object.
Right now this GC seems to be slower than the conservative GC, but
should be less likely to run out of memory as a result of false
positives.
This makes it much easier to read the value at runtime, as pointer
indices are naturally little endian. It should not affect anything else
in the program.
These instructions sometimes pop up in LLVM 15, but they never occured
in LLVM 14. Implementing them is relatively straightforward: simply
generalize the code that already exists for llvm.ICmp interpreting.
A number of llvm.Const* functions (in particular extractvalue and
insertvalue) were removed in LLVM 15, so we have to use a builder
instead. This builder will create the same constant values, it simply
uses a different API.
This change triggers a revert whenever a basic block runs instructions at runtime twice.
As a result, a loop body with runtime-only instructions will no longer be unrolled.
This should help some extreme cases where loops can be expanded into hundreds or thousands of instructions.
This is necessary for the next commit. The next commit would otherwise
cause an issue with the following constant operation:
i64 add (i64 ptrtoint (%runtime.machHeader* @_mh_execute_header to i64), i64 32)
Bug:
1. fn.locals[v.value] returns 0 (the default value) if v.value is not
part of the fn.locals map.
2. locals[fn.locals[v.value]] then returns the first local value, which
is usually non-nil
3. This incorrect value is then used as the operand value.
The manifestation of this convoluted bug was
https://github.com/tinygo-org/tinygo/issues/2842. It didn't occur more
often probably because it only seems to happen in practice with inline
assembly.
Fixes https://github.com/tinygo-org/tinygo/issues/2842
Switch over to LLVM 14 for static builds. Keep using LLVM 13 for regular
builds for now.
This uses a branch of the upstream Espressif branch to fix an issue,
see: https://github.com/espressif/llvm-project/pull/59
Previously, a type assertion on a nil interface would result in an out-of-bounds operand access, as we assumed it was a ptrtoint.
This would usually result in an undefined value which happens not to have the same name as the asserted type (and therefore the assertion fails as expected).
However, with an LLVM build with asserts, LLVM throws an assertion error:
```
interp.test: /home/niaow/go/src/github.com/tinygo-org/tinygo/llvm-project/llvm/include/llvm/IR/User.h:170: llvm::Value* llvm::User::getOperand(unsigned int) const: Assertion `i < NumUserOperands && "getOperand() out of range!"' failed.
```
This change handles a type code of 0 specially.
This removes the parentHandle argument from the internal calling convention.
It was formerly used to implment coroutines.
Now that coroutines have been removed, it is no longer necessary.
Instead of storing an increasing version number in relevant packages
(compiler.Version, interp.Version, cgo.Version, ...), read the build ID
from the currently running executable. This has several benefits:
* All changes relevant to the compiled packages are caught.
* No need to bump the version for each change to these packages.
This avoids merge conflicts.
* During development, `go install` is enough. No need to run
`tinygo clean` all the time.
Of course, the drawback is that it might be updated a bit more often
than necessary but I think the overall benefit is big.
Regular release users shouldn't see any difference. Because the tinygo
binary stays the same, the cache works well.
This change prevents interp from trying to execute goroutine starts or checks.
This fixes a bug where a goroutine started by an init function would run before the init function.
Constant globals can't have been modified, even if a pointer is passed
externally. Therefore, don't treat it as such in hasExternalStore.
In addition, it doesn't make sense to update values of constant globals
after the interp pass is finished. So don't do this.
TODO: track whether objects are actually modified and only update the
globals if this is the case.
This commit will use the memory layout information for heap allocations
added in the previous commit to determine LLVM types, instead of
guessing their types based on the content. This fixes a bug in which
recursive data structures (such as doubly linked lists) would result in
a compiler stack overflow due to infinite recursion.
Not all heap allocations have a memory layout yet, but this can be
incrementally fixed in the future. So far, this commit should fix
(almost?) all cases of this stack overflow issue.
Instead of doing lots of complicated calculations to get the shortest
GEP, I'll just cast it to i8*, do the GEP, and optionally cast to the
requested type.
This currently produces ugly constant expressions, but once LLVM
switches to opaque pointer types all of this shouldn't matter anymore.
This is uncommon, but it does happen if the source pointer is a bitcast
of a global. For example, if a struct is cast to an i8*, it's possible
to index beyond what would appear to be the size of the pointer (i8*).
This layout parameter is currently always nil and ignored, but will
eventually contain a pointer to a memory layout.
This commit also adds module verification to the transform tests, as I
found out that it didn't (and therefore didn't initially catch all
bugs).
This commit simplifies the IR a little bit: instead of calling
pseudo-functions runtime.interfaceImplements and
runtime.interfaceMethod, real declared functions are being called that
are then defined in the interface lowering pass. This should simplify
the interaction between various transformation passes. It also reduces
the number of lines of code, which is generally a good thing.
Make sure that if a package initializer cannot be run, later package
initializers won't try to access any global variables touched by the
uninterpretable package initializer.
Previously, a package initializer that could not be reverted correctly
would be called at runtime. But the initializer would be called in the
wrong order: after later packages are initialized.
This commit fixes this oversight and adds a test to verify the new
behavior.
This fixes https://github.com/tinygo-org/tinygo/issues/1884.
My original plan to fix this was much more complicated, but then I
realized that the output type doesn't matter anyway and I can simply
cast the type to an *i8 and perform a GEP on that pointer.
This was triggered by the following code:
var smallPrimesProduct = new(big.Int).SetUint64(16294579238595022365)
It is part of the new TinyGo version of the crypto/rand package.
The markExternal function is used when a global (function or global
variable) is somehow run at runtime. All the other globals it refers to
are from then on no longer known at compile time, so can't be used by
the interp package anymore.
This can also include inline assembly. While it is possible to modify
globals that way, it is only possible to modify exported globals:
similar to calling an undefined function (in C for example).
The interp package is in many cases able to execute map functions in the
runtime directly. This is probably slower than adding special support
for them in the interp package and also doesn't cover all cases (most
importantly, map keys that contain pointers) but removing this code also
removes a large amount of code that needs to be maintained and is
susceptible to hard-to-find bugs.
As a side effect, this resulted in different output of the
testdata/map.go test because the test relied on the existing iteration
order of TinyGo maps. I've updated the test to not rely on this test,
making the output compatible with what the Go toolchain would output.
