## Assembler {#assembler}

## Linker {#linker}

<!-- go.dev/issue/67401, CL 585556, CL 587220, and many more -->
The linker now disallows using a `//go:linkname` directive to refer to
internal symbols in the standard library (including the runtime) that
are not marked with `//go:linkname` on their definitions.
Similarly, the linker disallows references to such symbols from assembly
code.

        "//tensorflow/compiler/mlir:tf_mlir_opt_main",
    ],
    alwayslink = 1,
)

# Binary with no hardwares linked.
tf_cc_binary(
    name = "tac-opt",
    testonly = True,
    deps = [
        ":tac-opt_lib",
    ],
)

# Binary with all backends linked.
tf_cc_binary(
    name = "tac-opt-all-backends",
    testonly = True,
    deps = [
        ":tac-opt_lib",

// But -no-pie is not supported by all compilers, and clang spells it -nopie.
func (b *Builder) gccNoPie(linker []string) string {
	if b.gccSupportsFlag(linker, "-no-pie") {
		return "-no-pie"
	}
	if b.gccSupportsFlag(linker, "-nopie") {
		return "-nopie"
	}
	return ""
}

// gccSupportsFlag checks to see if the compiler supports a flag.

        given:
        def configurationCache = newConfigurationCacheFixture()

        and: "a project that has a provider having undeclared configuration inputs, which is linked to a task"
        buildFile("""
            abstract class MyTask extends DefaultTask {
                @Input
                abstract Property<String> getMyProperty();

                @OutputFile

// the groundwork for turning a given relocation into an external reloc
// (to be applied by the external linker). For more on how relocations
// work in general, see
//
//	"Linkers and Loaders", by John R. Levine (Morgan Kaufmann, 1999), ch. 7
//
// This is a performance-critical function for the linker; be careful
// to avoid introducing unnecessary allocations in the main loop.

build:release_linux_base --copt=-Wno-error=array-parameter
build:release_linux_base --copt=-Wno-error=unused-command-line-argument
# Set lld as the linker.
build:release_linux_base --linkopt="-fuse-ld=lld"
build:release_linux_base --linkopt="-lm"

# We have some invalid linker scripts in the build,
# so we need to disable this check
build:release_linux_base --linkopt=-Wl,--undefined-version

	}

	return schema, schema.err
}

// This unrolling is needed to show to the compiler the exact set of methods
// that can be used on the modelType.
// Prior to go1.22 any use of MethodByName would cause the linker to
// abandon dead code elimination for the entire binary.
// As of go1.22 the compiler supports one special case of a string constant
// being passed to MethodByName. For enterprise customers or those building

  if is_ppc64le():
    # Enable MMA Dynamic Dispatch support if 'gcc' and if linker >= 2.35
    gcc_env = get_gcc_compiler(environ_cp)
    if gcc_env is not None:

      # Use gold linker if 'gcc' and if 'ppc64le'
      write_to_bazelrc('build --linkopt="-fuse-ld=gold"')

      # Get the linker version
      ld_version = run_shell([gcc_env, '-Wl,-version']).split()

	// CloSlot holds the compiler-synthesized name (".closureptr")
	// where we spill the closure pointer for range func bodies.
	CloSlot *ir.Name

	freeValues *Value // free Values linked by argstorage[0].  All other fields except ID are 0/nil.
	freeBlocks *Block // free Blocks linked by succstorage[0].b.  All other fields except ID are 0/nil.

	cachedPostorder  []*Block   // cached postorder traversal
	cachedIdom       []*Block   // cached immediate dominators

		Like CGO_CFLAGS, CGO_CFLAGS_ALLOW, and CGO_CFLAGS_DISALLOW,
		but for the Fortran compiler.
	CGO_LDFLAGS, CGO_LDFLAGS_ALLOW, CGO_LDFLAGS_DISALLOW
		Like CGO_CFLAGS, CGO_CFLAGS_ALLOW, and CGO_CFLAGS_DISALLOW,
		but for the linker.
	CXX
		The command to use to compile C++ code.
	FC
		The command to use to compile Fortran code.
	PKG_CONFIG
		Path to pkg-config tool.

Architecture-specific environment variables:

	GOARM