diff options
Diffstat (limited to 'doc/gccgo_install.html')
| -rw-r--r-- | doc/gccgo_install.html | 42 |
1 files changed, 27 insertions, 15 deletions
diff --git a/doc/gccgo_install.html b/doc/gccgo_install.html index 3ffd6a645..393e57963 100644 --- a/doc/gccgo_install.html +++ b/doc/gccgo_install.html @@ -224,12 +224,9 @@ gccgo -o main main.o mypackage.o # Explicitly links with mypackage.o <p> Some Go features are not yet implemented in <code>gccgo</code>. As of -2009-11-06, the following are not implemented: +2010-08-23, the following are not implemented: <ul> -<li>Garbage collection is not implemented. There is no way to free memory. - Thus long running programs are not supported. - <li>goroutines are implemented as NPTL threads. If you can not use the gold linker as described above, they are created with a fixed stack size, and the number of goroutines that may be created at @@ -263,14 +260,13 @@ Pointers in Go are pointers in C. A Go <code>struct</code> is the same as C <code>struct</code> with the same fields and types. <p> -The Go <code>string</code> type is a pointer to a structure. -The current definition is -(this is <b style="color: red;">expected to change</b>): +The Go <code>string</code> type is currently defined as a two-element +structure (this is <b style="color: red;">subject to change</b>): <pre> struct __go_string { - size_t __length; - unsigned char __data[]; + const unsigned char *__data; + int __length; }; </pre> @@ -310,9 +306,10 @@ when the functions have equivalent types. <p> Go <code>interface</code>, <code>channel</code>, and <code>map</code> -types have no corresponding C type (they roughly correspond to pointers -to structs in C, but the structs are deliberately undocumented). C -<code>enum</code> types correspond to some Go type, but precisely +types have no corresponding C type (<code>interface</code> is a +two-element struct and <code>channel</code> and <code>map</code> are +pointers to structs in C, but the structs are deliberately undocumented). C +<code>enum</code> types correspond to some integer type, but precisely which one is difficult to predict in general; use a cast. C <code>union</code> types have no corresponding Go type. C <code>struct</code> types containing bitfields have no corresponding Go type. C++ <code>class</code> types have @@ -359,12 +356,15 @@ i := c_open(&name[0], os.O_RDONLY, 0); <p> 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 -<code>package.Functionname</code>. To call it from C you must set the -name using a <code>gcc</code> extension similar to the <code>gccgo</code> +<code>prefix.package.Functionname</code>. The prefix is set by +the <code>-fgo-prefix</code> option used when the package is compiled; +if the option is not used, the default is simply <code>go</code>. +To call the function from C you must set the name using +a <code>gcc</code> extension similar to the <code>gccgo</code> extension. <pre> -extern int go_function(int) __asm__ ("mypackage.Function"); +extern int go_function(int) __asm__ ("myprefix.mypackage.Function"); </pre> <h3 id="Automatic_generation_of_Go_declarations_from_C_source_code"> @@ -395,3 +395,15 @@ grep '#GO' foo.s | grep -v INVALID | grep -v unknowndefine | grep -v undef > foo This procedure is full of unstated caveats and restrictions and we make no guarantee that it will not change in the future. It is more useful as a starting point for real Go code than as a regular procedure. + +<h2 id="RTEMS_Port">RTEMS Port</h2> +<p> +The <code>gccgo</code> compiler has been ported to <a href="http://www.rtems.com/"> +<code>RTEMS</code></a>. <code>RTEMS</code> is a real-time executive +that provides a high performance environment for embedded applications +on a range of processors and embedded hardware. The current <code>gccgo</code> +port is for x86. The goal is to extend the port to most of the +<a href="http://www.rtems.org/wiki/index.php/SupportedCPUs"> +architectures supported by <code>RTEMS</code></a>. For more information on the port, +as well as instructions on how to install it, please see this +<a href="http://www.rtems.com/wiki/index.php/GCCGoRTEMS"><code>RTEMS</code> Wiki page</a>. |