error messages, debug information, and object files. In practice,
parsing these is significantly less work and more robust than parsing
C source.

Cgo first invokes gcc -E -dM on the preamble, in order to find out
about simple #defines for constants and the like. These are recorded
for later use.

Next, cgo needs to identify the kinds for each identifier. For the
identifiers C.foo, cgo generates this C program:

	<preamble>

// license that can be found in the LICENSE file.

package asm

import (
	"internal/buildcfg"
	"strings"
	"testing"

	"cmd/asm/internal/arch"
	"cmd/asm/internal/lex"
	"cmd/internal/obj"
)

// A simple in-out test: Do we print what we parse?

func setArch(goarch string) (*arch.Arch, *obj.Link) {
	buildcfg.GOOS = "linux" // obj can handle this OS for all architectures.
	buildcfg.GOARCH = goarch

<p>
Slice expressions construct a substring or slice from a string, array, pointer
to array, or slice. There are two variants: a simple form that specifies a low
and high bound, and a full form that also specifies a bound on the capacity.
</p>

<h4>Simple slice expressions</h4>

<p>
For a string, array, pointer to array, or slice <code>a</code>, the primary expression
</p>

<pre>

		}
	}
	return string(b[0:nb])
}

func TestReaderSimple(t *testing.T) {
	data := "hello world"
	b := NewReader(strings.NewReader(data))
	if s := readBytes(b); s != "hello world" {
		t.Errorf("simple hello world test failed: got %q", s)
	}

	b = NewReader(newRot13Reader(strings.NewReader(data)))
	if s := readBytes(b); s != "uryyb jbeyq" {
		t.Errorf("rot13 hello world test failed: got %q", s)
	}
}

package lex

import (
	"go/build/constraint"
	"io"
	"os"
	"strings"
	"text/scanner"
	"unicode"

	"cmd/asm/internal/flags"
	"cmd/internal/objabi"
	"cmd/internal/src"
)

// A Tokenizer is a simple wrapping of text/scanner.Scanner, configured
// for our purposes and made a TokenReader. It forms the lowest level,
// turning text from readers into tokens.
type Tokenizer struct {
	tok  ScanToken
	s    *scanner.Scanner

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package bytes

// Simple byte buffer for marshaling data.

import (
	"errors"
	"io"
	"unicode/utf8"
)

// smallBufferSize is an initial allocation minimal capacity.
const smallBufferSize = 64

//
//	_cgoIndexNN := a
//	_cgoNN := &cgoIndexNN[i] // with type conversions, if any
//
// to sb, and writes
//
//	_cgoCheckPointer(_cgoNN, _cgoIndexNN)
//
// to sbCheck, and returns true. If a is a simple variable or field reference,
// it writes
//
//	_cgoIndexNN := &a
//
// and dereferences the uses of _cgoIndexNN. Taking the address avoids
// making a copy of an array.
//

pkg runtime/metrics, type Float64Histogram struct, Buckets []float64
pkg runtime/metrics, type Float64Histogram struct, Counts []uint64
pkg runtime/metrics, type Sample struct
pkg runtime/metrics, type Sample struct, Name string
pkg runtime/metrics, type Sample struct, Value Value
pkg runtime/metrics, type Value struct
pkg runtime/metrics, type ValueKind int

pkg regexp/syntax, const OpStar Op
pkg regexp/syntax, const OpWordBoundary Op
pkg regexp/syntax, const POSIX Flags
pkg regexp/syntax, const Perl Flags
pkg regexp/syntax, const PerlX Flags
pkg regexp/syntax, const Simple Flags
pkg regexp/syntax, const UnicodeGroups Flags
pkg regexp/syntax, const WasDollar Flags
pkg regexp/syntax, func Compile(*Regexp) (*Prog, error)
pkg regexp/syntax, func EmptyOpContext(int32, int32) EmptyOp

	switch *flags.Spectre {
	default:
		log.Printf("unknown setting -spectre=%s", *flags.Spectre)
		os.Exit(2)
	case "":
		// nothing
	case "index":
		// known to compiler; ignore here so people can use
		// the same list with -gcflags=-spectre=LIST and -asmflags=-spectrre=LIST
	case "all", "ret":
		ctxt.Retpoline = true
	}

	ctxt.Bso = bufio.NewWriter(os.Stdout)
	defer ctxt.Bso.Flush()