compiler() string
	linker() string
}

type noToolchain struct{}

func noCompiler() error {
	log.Fatalf("unknown compiler %q", cfg.BuildContext.Compiler)
	return nil
}

func (noToolchain) compiler() string {
	noCompiler()
	return ""
}

func (noToolchain) linker() string {

//		If the package uses cgo or SWIG, these will be compiled with the
//		OS-native compiler (typically gcc); otherwise they will
//		trigger an error.
//	.cc, .cpp, .cxx, .hh, .hpp, .hxx
//		C++ source files. Only useful with cgo or SWIG, and always
//		compiled with the OS-native compiler.
//	.m
//		Objective-C source files. Only useful with cgo, and always
//		compiled with the OS-native compiler.
//	.s, .S, .sx

#include "tensorflow/compiler/mlir/lite/utils/stateful_ops_utils.h"
#include "tensorflow/compiler/mlir/lite/utils/string_utils.h"
#include "tensorflow/compiler/mlir/op_or_arg_name_mapper.h"
#include "tensorflow/compiler/mlir/tensorflow/ir/tf_dialect.h"
#include "tensorflow/compiler/mlir/tensorflow/ir/tf_executor.h"
#include "tensorflow/compiler/mlir/tensorflow/ir/tf_ops.h"
#include "tensorflow/compiler/mlir/tensorflow/ir/tf_saved_model.h"

      %compile:2 = "tf._TPUCompileMlir"(...)
      %get_layout = "tf.TPUGetLayoutOp"(%compile#1) {...}
      %copy_to_device = "tf.TPUCopyWithLayout"(%input, %get_layout)
          {device = "/TPU:0"}
      %execute = "tf.TPUExecute"(%copy_to_device, ..., %compile#1)
          {device = "/TPU:0"}
    ```

    This way, %compile will determine the layout, which will be respected by

#include "tensorflow/compiler/mlir/tensorflow/ir/tf_device.h"
#include "tensorflow/compiler/mlir/tensorflow/ir/tf_executor.h"
#include "tensorflow/compiler/mlir/tensorflow/ir/tf_ops.h"
#include "tensorflow/compiler/mlir/tensorflow/transforms/passes.h"
#include "tensorflow/compiler/mlir/tensorflow/translate/mlir_roundtrip_flags.h"
#include "tensorflow/compiler/mlir/tensorflow/utils/dynamic_shape_utils.h"

					sb.SetType(sym.SDYNIMPORT)
				} else if strings.HasPrefix(ldr.SymName(rs), "go:info.") {
					// Skip go.info symbols. They are only needed to communicate
					// DWARF info between the compiler and linker.
					continue
				}
			} else if target.IsPPC64() && ldr.SymName(rs) == ".TOC." {
				// TOC symbol doesn't have a type but we do assign a value
				// (see the address pass) and we can resolve it.

	// evaluate program size.
	if len(re) > 1024 {
		return fmt.Errorf("%q: regex is too large, max length allowed is 1024", where)
	}

	_, err := regexp.Compile(re)
	if err == nil {
		return nil
	}

	return fmt.Errorf("%q: %w; Istio uses RE2 style regex-based match (https://github.com/google/re2/wiki/Syntax)", where, err)
}