cui fliter <******@****.***> 1709194171 +0800

	Note that the arguments are for "gcc", not "ld".

	Example:
	//go:cgo_ldflag "-lpthread"
	//go:cgo_ldflag "-L/usr/local/sqlite3/lib"

A package compiled with cgo will include directives for both
internal and external linking; the linker will select the appropriate
subset for the chosen linking mode.

Example

As a simple example, consider a package that uses cgo to call C.sin.

A GODEBUG setting is a `key=value` pair
that controls the execution of certain parts of a Go program.
The environment variable `GODEBUG`
can hold a comma-separated list of these settings.
For example, if a Go program is running in an environment that contains

	GODEBUG=http2client=0,http2server=0

then that Go program will disable the use of HTTP/2 by default in both
the HTTP client and the HTTP server.

<p>
Constants are of the form <code>const_<i>name</i></code>.
For example, given the Go declaration <code>const bufSize =
1024</code>, assembly code can refer to the value of this constant
as <code>const_bufSize</code>.
</p>

<p>
Field offsets are of the form <code><i>type</i>_<i>field</i></code>.
Struct sizes are of the form <code><i>type</i>__size</code>.
For example, consider the following Go definition:
</p>

<pre>

	//
	// Some newer formats add their own extensions to PAX by defining their
	// own keys and assigning certain semantic meaning to the associated values.
	// For example, sparse file support in PAX is implemented using keys
	// defined by the GNU manual (e.g., "GNU.sparse.map").
	//
	// Reference:
	//	http://pubs.opengroup.org/onlinepubs/009695399/utilities/pax.html
	FormatPAX

				}
			}
		})
	}
}

type operandTest struct {
	input, output string
}

type badOperandTest struct {
	input, error string
}

// Examples collected by scanning all the assembly in the standard repo.

var amd64OperandTests = []operandTest{
	{"$(-1.0)", "$(-1.0)"},
	{"$(0.0)", "$(0.0)"},
	{"$(0x2000000+116)", "$33554548"},
	{"$(0x3F<<7)", "$8064"},

// deliver a final empty token (which is different from a nil token).
// One could achieve the same behavior with a custom error value but
// providing one here is tidier.
// See the emptyFinalToken example for a use of this value.
var ErrFinalToken = errors.New("final token")

// Scan advances the [Scanner] to the next token, which will then be

	defer func() {
		if recover() != nil {
			panic(ErrTooLarge)
		}
	}()
	// TODO(http://golang.org/issue/51462): We should rely on the append-make
	// pattern so that the compiler can call runtime.growslice. For example:
	//	return append(b, make([]byte, n)...)
	// This avoids unnecessary zero-ing of the first len(b) bytes of the
	// allocated slice, but this pattern causes b to escape onto the heap.
	//

and it must not allow a single write to write multiple values.
</p>

<p>
All the following examples assume that `*p` and `*q` refer to
memory locations accessible to multiple goroutines.
</p>

<p>
Not introducing data races into race-free programs means not moving
writes out of conditional statements in which they appear.
For example, a compiler must not invert the conditional in this program:
</p>

<pre>
*p = 1

// zero value of sparseHoles logically represents a normal file (i.e., there are
// no holes in it). On the other hand, the zero value of sparseDatas implies
// that the file has no data in it, which is rather odd.
//
// As an example, if the underlying raw file contains the 10-byte data:
//
//	var compactFile = "abcdefgh"
//
// And the sparse map has the following entries:
//
//	var spd sparseDatas = []sparseEntry{