doc doc doc

R=r
http://go/go-review/1016039

src/cmd/cgo/doc.go

+// 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.
+
+/*
+
+Cgo enables the creation of Go packages that call C code.
+
+Usage: cgo [compiler options] file.go
+
+The compiler options are passed through uninterpreted when
+invoking gcc to compile the C parts of the package.
+
+The input file.go is a syntactically valid Go source file that imports
+the pseudo-package "C" and then refers to types such as C.size_t,
+variables such as C.stdout, or functions such as C.putchar.
+
+If the import of "C" is immediately preceded by a comment, that
+comment is used as a header when compiling the C parts of
+the package.  For example:
+
+	// #include <stdio.h>
+	// #include <errno.h>
+	import "C"
+
+Cgo transforms the input file into four output files: two Go source
+files, a C file for 6c (or 8c or 5c), and a C file for gcc.
+
+The standard package makefile rules in Make.pkg automate the
+process of using cgo.  See $GOROOT/misc/cgo/stdio and
+$GOROOT/misc/cgo/gmp for examples.
+
+Cgo does not yet work with gccgo.
+*/
+package documentation

src/cmd/cov/doc.go

+// 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.
+
+/*
+
+Cov is a rudimentary code coverage tool.
+
+Given a command to run, it runs the command while tracking which
+sections of code have been executed.  When the command finishes,
+cov prints the line numbers of sections of code in the binary that
+were not executed.   With no arguments it assumes the command "6.out".
+
+Usage: cov [-lsv] [-g substring] [-m minlines] [6.out args]
+
+The options are:
+
+	-l
+		print full path names instead of paths relative to the current directory
+	-s
+		show the source code that didn't execute, in addition to the line numbers.
+	-v
+		print debugging information during the run.
+	-g substring
+		restrict the coverage analysis to functions or files whose names contain substring
+	-m minlines
+		only report uncovered sections of code larger than minlines lines
+
+For reasons of disambiguation it is installed as 6cov although it also serves
+as an 8cov and a 5cov.
+
+*/
+package documentation

src/cmd/godefs/doc.go

+// 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.
+
+/*
+
+Godefs is a bootstrapping tool for porting the Go runtime to new systems.
+It translates C type declarations into C or Go type declarations
+with the same memory layout. 
+
+Usage: godefs [-g package] [-c cc] [-f cc-arg]... [defs.c ...]
+
+Godefs takes as input a host-compilable C file that includes
+standard system headers.  From that input file, it generates
+a standalone (no #includes) C or Go file containing equivalent
+definitions.
+
+The input to godefs is a C input file that can be compiled by
+the host system's standard C compiler (typically gcc).
+This file is expected to define new types and enumerated constants
+whose names begin with $ (a legal identifier character in gcc). 
+Godefs compile the given input file with the host compiler and
+then parses the debug info embedded in the assembly output.
+This is far easier than reading system headers on most machines.
+
+The output from godefs is either C output intended for the
+Plan 9 C compiler tool chain (6c, 8c, or 5c) or Go output.	
+
+The options are:
+
+	-g package
+		generate Go output using the given package name.
+		In the Go output, struct fields have leading xx_ prefixes
+		removed and the first character capitalized (exported).
+
+	-c cc
+		set the name of the host system's C compiler (default "gcc")
+	
+	-f cc-arg
+		add cc-arg to the command line when invoking the system C compiler
+		(for example, -f -m64 to invoke gcc -m64).
+		Repeating this option adds multiple flags to the command line.
+
+For example, if this is x.c:
+
+	#include <sys/stat.h>
+
+	typedef struct timespec $Timespec;
+	enum {
+		$S_IFMT = S_IFMT,
+		$S_IFIFO = S_IFIFO,
+		$S_IFCHR = S_IFCHR,
+	};
+
+then "godefs x.c" generates:
+
+	// godefs x.c
+	// MACHINE GENERATED - DO NOT EDIT.
+	
+	// Constants
+	enum {
+		S_IFMT = 0xf000,
+		S_IFIFO = 0x1000,
+		S_IFCHR = 0x2000,
+	};
+	
+	// Types
+	#pragma pack on
+	
+	typedef struct Timespec Timespec;
+	struct Timespec {
+		int64 tv_sec;
+		int64 tv_nsec;
+	};
+	#pragma pack off
+
+and "godefs -g MyPackage x.c" generates:
+
+	// godefs -g MyPackage x.c
+	// MACHINE GENERATED - DO NOT EDIT.
+	
+	package MyPackage
+	
+	// Constants
+	const (
+		S_IFMT = 0xf000;
+		S_IFIFO = 0x1000;
+		S_IFCHR = 0x2000;
+	)
+	
+	// Types
+	
+	type Timespec struct {
+		Sec int64;
+		Nsec int64;
+	}
+
+*/
+package documentation

src/cmd/godefs/main.c

@@ -85,7 +85,7 @@
 void
 usage(void)
 {
-	fprint(2, "usage: godefs [-g package] [-c cc] [-f cc-flag] [defs.c ...]\n");
+	fprint(2, "usage: godefs [-g package] [-c cc] [-f cc-arg] [defs.c ...]\n");
 	exit(1);
 }