gorootBin = pathf("%s/bin", goroot)

	// Don't run just 'go' because the build infrastructure
	// runs cmd/dist inside go/bin often, and on Windows
	// it will be found in the current directory and refuse to exec.
	// All exec calls rewrite "go" into gorootBinGo.
	gorootBinGo = pathf("%s/bin/go", goroot)

	b = os.Getenv("GOOS")
	if b == "" {
		b = gohostos
	}
	goos = b
	if find(goos, okgoos) < 0 {

== Precompiled Headers

Precompiled headers are a performance optimization that reduces the cost of compiling widely used headers multiple times. This feature _precompiles_ a header such that the compiled object file can be reused when compiling each source file rather than recompiling the header each time. This support is available for C, C+\+, Objective-C, and Objective-C++ builds.

In addition, Kotlin delegated properties can easily be renamed via IDE refactoring.

The following sample does the exact same things as the one in the previous section, but it uses delegated properties and reuses those references in place of string-literal task paths:

.Using Kotlin delegated properties
====

#define Y0    V2 // Not modified
#define Y1    V3 // Not modified
#define T0    V4 // Result
#define T1    V5 // Result
#define P0    V30 // Not modified
#define P1    V31 // Not modified

// Temporaries: lots of reused vector regs
#define YDIG  V6 // Overloaded with CAR2
#define ADD1H V7 // Overloaded with ADD3H
#define ADD2H V8 // Overloaded with ADD4H
#define ADD3  V9 // Overloaded with SEL2,SEL5

				t = ldr.SymValue(tramp) - (ldr.SymValue(s) + int64(r.Off()))

				// With internal linking, the trampoline can be used if it is not too far.
				// With external linking, the trampoline must be in this section for it to be reused.
				if (ctxt.IsInternal() && int64(int32(t<<6)>>6) == t) || (ctxt.IsExternal() && ldr.SymSect(s) == ldr.SymSect(tramp)) {
					break
				}
			}
			if ldr.SymType(tramp) == 0 {

	flags unwindFlags
}

// init initializes u to start unwinding gp's stack and positions the
// iterator on gp's innermost frame. gp must not be the current G.
//
// A single unwinder can be reused for multiple unwinds.
func (u *unwinder) init(gp *g, flags unwindFlags) {
	// Implementation note: This starts the iterator on the first frame and we
	// provide a "valid" method. Alternatively, this could start in a "before

//
// - The outer parentheses in CompileAssert<(bool(expr))> are necessary
//   to work around a bug in gcc 3.4.4 and 4.0.1.  If we had written
//
//     CompileAssert<bool(expr)>
//
//   instead, these compilers will refuse to compile
//
//     GTEST_COMPILE_ASSERT_(5 > 0, some_message);
//
//   (They seem to think the ">" in "5 > 0" marks the end of the
//   template argument list.)
//

//
// - The outer parentheses in CompileAssert<(bool(expr))> are necessary
//   to work around a bug in gcc 3.4.4 and 4.0.1.  If we had written
//
//     CompileAssert<bool(expr)>
//
//   instead, these compilers will refuse to compile
//
//     GTEST_COMPILE_ASSERT_(5 > 0, some_message);
//
//   (They seem to think the ">" in "5 > 0" marks the end of the
//   template argument list.)
//

// must be JSONMap. A patch can be created from an original and modified document by
// calling CreateTwoWayMergeMapPatch.
// Warning: the original and patch JSONMap objects are mutated by this function and should not be reused.
func StrategicMergeMapPatch(original, patch JSONMap, dataStruct interface{}) (JSONMap, error) {
	schema, err := NewPatchMetaFromStruct(dataStruct)
	if err != nil {
		return nil, err
	}

		return fn(path)
	}

	f, err := os.Open(path)
	if err != nil {
		return nil, err // nil interface
	}
	return f, nil
}

// isFile determines whether path is a file by trying to open it.
// It reuses openFile instead of adding another function to the
// list in Context.
func (ctxt *Context) isFile(path string) bool {
	f, err := ctxt.openFile(path)
	if err != nil {
		return false
	}
	f.Close()