since it is copied into two different C output files, it must not
contain any definitions, only declarations. If a file contains both
definitions and declarations, then the two output files will produce
duplicate symbols and the linker will fail. To avoid this, definitions
must be placed in preambles in other files, or in C source files.

# Passing pointers

Go is a garbage collected language, and the garbage collector needs to

case x == 4: f3()
}
</pre>

<p>
Implementation restriction: A compiler may disallow multiple case
expressions evaluating to the same constant.
For instance, the current compilers disallow duplicate integer,
floating point, or string constants in case expressions.
</p>

<h4 id="Type_switches">Type switches</h4>

<p>
A type switch compares types rather than values. It is otherwise similar

	isDup bool
}

type fileInfoDirEntry interface {
	fs.FileInfo
	fs.DirEntry
}

func (f *fileListEntry) stat() (fileInfoDirEntry, error) {
	if f.isDup {
		return nil, errors.New(f.name + ": duplicate entries in zip file")
	}
	if !f.isDir {
		return headerFileInfo{&f.file.FileHeader}, nil
	}
	return f, nil
}

// Only used for directories.

// converts names to upper case, and rewrites _ into Pad_godefs_n,
// so that all fields are exported.
func godefsFields(fld []*ast.Field) {
	prefix := fieldPrefix(fld)

	// Issue 48396: check for duplicate field names.
	if prefix != "" {
		names := make(map[string]bool)
	fldLoop:
		for _, f := range fld {
			for _, n := range f.Names {
				name := n.Name
				if name == "_" {
					continue

pkg syscall (windows-386), const DNS_TYPE_WKS ideal-int
pkg syscall (windows-386), const DNS_TYPE_X25 ideal-int
pkg syscall (windows-386), const DUPLICATE_CLOSE_SOURCE ideal-int
pkg syscall (windows-386), const DUPLICATE_SAME_ACCESS ideal-int
pkg syscall (windows-386), const EADV Errno
pkg syscall (windows-386), const EBADE Errno
pkg syscall (windows-386), const EBADFD Errno

Don't profile the marked function.  This flag is deprecated.
</li>
<li>
<code>DUPOK</code> = 2
<br>
It is legal to have multiple instances of this symbol in a single binary.
The linker will choose one of the duplicates to use.
</li>
<li>
<code>NOSPLIT</code> = 4
<br>
(For <code>TEXT</code> items.)
Don't insert the preamble to check if the stack must be split.

		{"VADDPD.A.A X0, X1, X2", `unknown suffix "A"; duplicate suffix "A"`},
		{"VADDPD.A.A.A X0, X1, X2", `unknown suffix "A"; duplicate suffix "A"`},
		{"VADDPD.A.B X0, X1, X2", `unknown suffix "A"; unknown suffix "B"`},
		{"VADDPD.Z.A X0, X1, X2", `Z suffix should be the last; unknown suffix "A"`},
		{"VADDPD.Z.Z X0, X1, X2", `Z suffix should be the last; duplicate suffix "Z"`},

// Copyright 2019 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.

//go:build cgo && !windows

// Issue 29563: internal linker fails on duplicate weak symbols.
// No runtime test; just make sure it compiles.

package cgotest

			case scanner.Ident:
				if !acceptArg {
					in.Error("bad syntax in definition for macro:", name)
				}
				arg := in.Stack.Text()
				if i := lookup(args, arg); i >= 0 {
					in.Error("duplicate argument", arg, "in definition for macro:", name)
				}
				args = append(args, arg)
				acceptArg = false
			default:
				in.Error("bad definition for macro:", name)
			}
		}
	}
	var tokens []Token

			hi := lo
			if p.peek() == '-' {
				p.next()
				hi = p.registerNumber(p.next().String())
			}
			if hi < lo {
				lo, hi = hi, lo
			}
			// Check there are no duplicates in the register list.
			for i := 0; lo <= hi && i < maxReg; i++ {
				if bits&(1<<lo) != 0 {
					p.errorf("register R%d already in list", lo)
				}
				bits |= 1 << lo
				lo++
			}
		default: