From ffde4970d06fd0b03a3e06893ae916894f2cce8f Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Thu, 20 Jun 2013 14:49:15 -0700 Subject: [PATCH] doc: update gccgo docs R=golang-dev, r CC=golang-dev https://golang.org/cl/10401046 --- doc/gccgo_contribute.html | 4 +++ doc/gccgo_install.html | 54 ++++++++++++++++++++++++--------------- 2 files changed, 38 insertions(+), 20 deletions(-) diff --git a/doc/gccgo_contribute.html b/doc/gccgo_contribute.html index b2a0b651cc..ad2ce46ac9 100644 --- a/doc/gccgo_contribute.html +++ b/doc/gccgo_contribute.html @@ -10,6 +10,10 @@ For information on contributing to parts of Go other than gccgo, see Contributing to the Go project. For information on building gccgo for yourself, see Setting up and using gccgo. +For more of the gritty details on the process of doing development +with the gccgo frontend, +see the +file HACKING in the gofrontend repository.

Legal Prerequisites

diff --git a/doc/gccgo_install.html b/doc/gccgo_install.html index a8d7396e53..aee21d13cf 100644 --- a/doc/gccgo_install.html +++ b/doc/gccgo_install.html @@ -32,10 +32,14 @@ will include Go support.

-The GCC 4.7.0 release includes Go support that is very close to -Go 1. Due to release timing it will not -include the last few changes to the Go 1 libraries. The GCC 4.7.1 -release should include a complete Go 1 compiler and libraries. +The GCC 4.7.1 release and all later 4.7 releases include a complete +Go 1 compiler and libraries. +

+ +

+Due to timing, the GCC 4.8.0 and 4.8.1 releases are close to but not +identical to Go 1.1. The GCC 4.8.2 release is expected to include a +complete Go 1.1.1 implementation.

Source code

@@ -125,6 +129,8 @@ described on the gcc web site. It is important to install all the prerequisites before running the gcc configure script. +The prerequisite libraries can be conveniently downloaded using the +script contrib/download_prerequisites in the GCC sources.

Build commands

@@ -147,11 +153,11 @@ make install

A note on Ubuntu

-Current versions of Ubuntu and current versions of gcc disagree on +Current versions of Ubuntu and versions of GCC before 4.8 disagree on where system libraries and header files are found. This is not a -gccgo issue, and we hope this will be resolved soon. Until it is, -setting these environment variables while configuring and building -gccgo may fix the problem. +gccgo issue. When building older versions of GCC, setting these +environment variables while configuring and building gccgo may fix the +problem. 

@@ -309,7 +315,7 @@ gccgo.  Both options take directories to search. The
 

 
 

-The gccgo compiler does not currently (2012-03-20) record
+The gccgo compiler does not currently (2013-06-20) record
 the file name of imported packages in the object file. You must
 arrange for the imported data to be linked into the program.
 

@@ -385,23 +391,23 @@ struct __go_slice {

-The type of a Go function with no receiver is equivalent to a C function -whose parameter types are equivalent. When a Go function returns more -than one value, the C function returns a struct. For example, these -functions have equivalent types: +The type of a Go function is a pointer to a struct (this is +subject to change). The first field in the +struct points to the code of the function, which will be equivalent to +a pointer to a C function whose parameter types are equivalent, with +an additional trailing parameter. The trailing parameter is the +closure, and the argument to pass is a pointer to the Go function +struct. + +When a Go function returns more than one value, the C function returns +a struct. For example, these functions are roughly equivalent: 

 func GoFunction(int) (int, float64)
-struct { int i; float64 f; } CFunction(int)
+struct { int i; float64 f; } CFunction(int, void*)
-

-A pointer to a Go function is equivalent to a pointer to a C function -when the functions have equivalent types (this is -subject to change). -

-

Go interface, channel, and map types have no corresponding C type (interface is a @@ -457,6 +463,14 @@ i := c_open(&name[0], syscall.O_RDONLY, 0); os.Open function instead).

+

+Note that if the C function can block, such as in a call +to read, calling the C function may block the Go program. +Unless you have a clear understanding of what you are doing, all calls +between C and Go should be implemented through cgo or SWIG, as for +the gc compiler. +

+

The name of Go functions accessed from C is subject to change. At present the name of a Go function that does not have a receiver is