This patch is a combination of two related changes:
1. The compiler now allows other types than `int` when specifying the
size of a channel in a make(chan ..., size) call.
2. The compiler now checks for maximum allowed channel sizes. Such
checks are trivially optimized out in the vast majority of cases as
channel sizes are usually constant.
I discovered this issue when trying out channels on AVR.
Previously using defer with an exported function generated an invalid function call due to differences between TinyGo's calling convention and the C calling convention.
This might sound crazy, but I think it's better to enable the GC by
default to avoid surprises. It costs 1130 bytes of flash and 16 bytes of
RAM (plus heap overhead) so it's not exactly free, but if needed it can
easily be disabled with `-gc=leaking`. On the Uno (32kB flash, 2kB RAM)
that's not massive, on the DigiSpark (8kB flash, 0.5kB RAM) that may be
too much depending on the application.
This implementation simply casts types without special support to an
interface, to make the implementation simpler and possibly reducing the
code size too. It will likely be slower than the canonical Go
implementation though (which builds special compare and hash functions
at compile time).
Instead of putting the magic in the AST, generate regular accessor
methods. This avoids a number of special cases in the compiler, and
avoids missing any of them.
The resulting union accesses are somewhat clunkier to use, but the
compiler implementation has far less coupling between the CGo
implementation and the IR generator.
When using reflect, arbitrary types can be synthesized. This invalidates
a few assumptions in the interface-lowering pass, that think they can
see all types that are in use in a program and optimize accordingly.
The file size impact depends on the specific program. Sometimes it's
nonexistent, sometimes it's rather hefty (up to 30% bigger). Especially
the samd21 targets seem to be affected, with a 2000-6000 bytes increase
in code size. A moderately large case (the stdlib test) increases by
4%/6%/15% depending on the target.
I hope that this increase could be mitigated, but I don't see an obvious
way to do that.
Previously, the cycle was broken by inserting an unsafe.Pointer type in
some places. This is of course incorrect, and makes debugging harder.
However, LLVM provides a way to make temporary nodes that are later
replaced, exactly for this purpose.
This commit uses those temporary metadata nodes to allow such recursive
types.
This implements the copy() built-in function. It may not work in all
cases, but should work in most cases.
This commit gets the following 3 packages to compile, according to
tinygo-site/imports/main.go:
* encoding/base32
* encoding/base64
* encoding/pem (was blocked by encoding/base64)
This commit allows starting a new goroutine directly from a func value,
not just when the static callee is known.
This is necessary to support the whole time package, not just the
commonly used subset that was compiled with the SimpleDCE pass enabled.
This scheduler is intended to live along the (stackless) coroutine based
scheduler which is needed for WebAssembly and unsupported platforms. The
stack based scheduler is somewhat simpler in implementation as it does
not require full program transform passes and supports things like
function pointers and interface methods out of the box with no changes.
Code size is reduced in most cases, even in the case where no scheduler
scheduler is used at all. I'm not exactly sure why but these changes
likely allowed some further optimizations somewhere. Even RAM is
slightly reduced, perhaps some global was elminated in the process as
well.
Linked lists are usually implemented as follows:
type linkedList struct {
next *linkedList
data int // whatever
}
This caused a stack overflow while writing out the reflect run-time type
information. This has now been fixed by splitting the allocation of a
named type number from setting the underlying type in the sidetable.
There are a lot more fields that are important when comparing structs
with each other. Take them into account when building the unique ID per
struct type.
Example code that differs between the compilers:
https://play.golang.org/p/nDX4tSHOf_T
With this change, it becomes possible to get the element type of named
slices, pointers, and channels.
This is a prerequisite to enable the common named struct types. There's
more to come.
This commit fixes the following issue:
https://github.com/tinygo-org/tinygo/issues/309
Also, it prepares for some other reflect-related changes that should
make it easier to add support for named types (etc.) in the future.
strings.IndexByte was implemented in the runtime up to Go 1.11. It is
implemented using a direct call to internal/bytealg.IndexByte since Go
1.12.
Make sure we remain compatible with both.
Enum types are implemented as named types (with possible accompanying
typedefs as type aliases). The constants inside the enums are treated as
Go constants like in the Go toolchain.
This is a big commit that does a few things:
* It moves CGo processing into a separate package. It never really
belonged in the loader package, and certainly not now that the
loader package may be refactored into a driver package.
* It adds support for multiple CGo files (files that import package
"C") in a single package. Previously, this led to multiple
definition errors in the Go typecheck phase because certain C
symbols were defined multiple times in all the files. Now it
generates a new fake AST that defines these, to avoid multiple
definition errors.
* It improves debug info in a few edge cases that are probably not
relevant outside of bugs in cgo itself.
