[experiment] add alternative wasm sqlite3 implementation available via build-tag (#2863)

This allows for building GoToSocial with [SQLite transpiled to WASM](https://github.com/ncruces/go-sqlite3) and accessed through [Wazero](https://wazero.io/).

1 files changed, 100 insertions, 0 deletions

diff --git a/vendor/github.com/tetratelabs/wazero/internal/engine/wazevo/backend/machine.go b/vendor/github.com/tetratelabs/wazero/internal/engine/wazevo/backend/machine.go
new file mode 100644
index 000000000..54ce89e46
--- /dev/null
+++ b/vendor/github.com/tetratelabs/wazero/internal/engine/wazevo/backend/machine.go
@@ -0,0 +1,100 @@
+package backend
+
+import (
+	"context"
+
+	"github.com/tetratelabs/wazero/internal/engine/wazevo/backend/regalloc"
+	"github.com/tetratelabs/wazero/internal/engine/wazevo/ssa"
+	"github.com/tetratelabs/wazero/internal/engine/wazevo/wazevoapi"
+)
+
+type (
+	// Machine is a backend for a specific ISA machine.
+	Machine interface {
+		ExecutableContext() ExecutableContext
+
+		// DisableStackCheck disables the stack check for the current compilation for debugging/testing.
+		DisableStackCheck()
+
+		// SetCurrentABI initializes the FunctionABI for the given signature.
+		SetCurrentABI(abi *FunctionABI)
+
+		// SetCompiler sets the compilation context used for the lifetime of Machine.
+		// This is only called once per Machine, i.e. before the first compilation.
+		SetCompiler(Compiler)
+
+		// LowerSingleBranch is called when the compilation of the given single branch is started.
+		LowerSingleBranch(b *ssa.Instruction)
+
+		// LowerConditionalBranch is called when the compilation of the given conditional branch is started.
+		LowerConditionalBranch(b *ssa.Instruction)
+
+		// LowerInstr is called for each instruction in the given block except for the ones marked as already lowered
+		// via Compiler.MarkLowered. The order is reverse, i.e. from the last instruction to the first one.
+		//
+		// Note: this can lower multiple instructions (which produce the inputs) at once whenever it's possible
+		// for optimization.
+		LowerInstr(*ssa.Instruction)
+
+		// Reset resets the machine state for the next compilation.
+		Reset()
+
+		// InsertMove inserts a move instruction from src to dst whose type is typ.
+		InsertMove(dst, src regalloc.VReg, typ ssa.Type)
+
+		// InsertReturn inserts the return instruction to return from the current function.
+		InsertReturn()
+
+		// InsertLoadConstantBlockArg inserts the instruction(s) to load the constant value into the given regalloc.VReg.
+		InsertLoadConstantBlockArg(instr *ssa.Instruction, vr regalloc.VReg)
+
+		// Format returns the string representation of the currently compiled machine code.
+		// This is only for testing purpose.
+		Format() string
+
+		// RegAlloc does the register allocation after lowering.
+		RegAlloc()
+
+		// PostRegAlloc does the post register allocation, e.g. setting up prologue/epilogue, redundant move elimination, etc.
+		PostRegAlloc()
+
+		// ResolveRelocations resolves the relocations after emitting machine code.
+		//  * refToBinaryOffset: the map from the function reference (ssa.FuncRef) to the executable offset.
+		//  * executable: the binary to resolve the relocations.
+		//  * relocations: the relocations to resolve.
+		//  * callTrampolineIslandOffsets: the offsets of the trampoline islands in the executable.
+		ResolveRelocations(
+			refToBinaryOffset []int,
+			executable []byte,
+			relocations []RelocationInfo,
+			callTrampolineIslandOffsets []int,
+		)
+
+		// Encode encodes the machine instructions to the Compiler.
+		Encode(ctx context.Context) error
+
+		// CompileGoFunctionTrampoline compiles the trampoline function  to call a Go function of the given exit code and signature.
+		CompileGoFunctionTrampoline(exitCode wazevoapi.ExitCode, sig *ssa.Signature, needModuleContextPtr bool) []byte
+
+		// CompileStackGrowCallSequence returns the sequence of instructions shared by all functions to
+		// call the stack grow builtin function.
+		CompileStackGrowCallSequence() []byte
+
+		// CompileEntryPreamble returns the sequence of instructions shared by multiple functions to
+		// enter the function from Go.
+		CompileEntryPreamble(signature *ssa.Signature) []byte
+
+		// LowerParams lowers the given parameters.
+		LowerParams(params []ssa.Value)
+
+		// LowerReturns lowers the given returns.
+		LowerReturns(returns []ssa.Value)
+
+		// ArgsResultsRegs returns the registers used for arguments and return values.
+		ArgsResultsRegs() (argResultInts, argResultFloats []regalloc.RealReg)
+
+		// CallTrampolineIslandInfo returns the interval of the offset where the trampoline island is placed, and
+		// the size of the trampoline island. If islandSize is zero, the trampoline island is not used on this machine.
+		CallTrampolineIslandInfo(numFunctions int) (interval, islandSize int, err error)
+	}
+)