# HG changeset patch
# User William Astle <lost@l-w.ca>
# Date 1378680959 21600
# Node ID c648fc4bd006f87089e6261a08461c38afaf87e9
# Parent  b67a118dbdb702c841f8f464e50f062637d2dbf4
Updated lwcc README with info on the runtime support files

Added description of -B and the runtime support files required for the lwcc
program.

diff -r b67a118dbdb7 -r c648fc4bd006 lwcc/README.txt
--- a/lwcc/README.txt	Sun Sep 08 16:55:21 2013 -0600
+++ b/lwcc/README.txt	Sun Sep 08 16:55:59 2013 -0600
@@ -23,3 +23,57 @@
 output. This is usually assembly routines to support complex operations not
 directly supported by the CPU instruction set.
 
+
+RUNTIME INFORMATION
+===================
+
+The compiler driver has a built in base directory where it searches for its
+various components as needed. In the discussion below, BASEDIR stands for
+that directory.
+
+BASEDIR may be specified by the -B option to the driver. Care must be taken
+when doing so, however, because specifying an invalid -B will cause the
+compiler to fail completely. It will completely override the built in search
+paths for the compiler provided files and programs.
+
+Because BASEDIR is part of the actual compiler, it is not affected by
+--sysroot or -isysroot options.
+
+If BASEDIR does not exist, compiler component programs will be searched for
+in the standard execution paths. This may lead to incorrect results so it is
+important to make certain that the specified BASEDIR exists.
+
+If -B is not specified, the default BASEDIR is
+$(PREFIX)/lib/lwcc/$(VERSION)/ where PREFIX is the build prefix from the
+Makefile and VERSION is the lwtools version.
+
+The contents of BASEDIR are as follows:
+
+BASEDIR/bin
+
+Various binaries for the parts of the compiler system. Notably, this
+includes the preprocessor and compiler proper. The specific names and
+contents of this directory cannot be relied upon and these programs should
+not be called directly. Ever. Don't do it.
+
+
+BASEDIR/lib
+
+This directory contains various libraries that provide support for any
+portion of the compiler's output. The driver will arrange to pass the
+appropriate arguments to the linker to include these as required.
+
+The most notable file in this directory is liblwcc.a wich contains the
+support routines for the compiler's code generation. Depending on ABI and
+code generation options supported, there may be multiple versions of
+liblwcc.a. The driver will arrange for the correct one to be referenced.
+
+
+BASEDIR/include
+
+This directory contains any C header files that the compiler provides.
+Notably, this includes stdint.h, stdarg.h, and setjmp.h as these are
+specific to the compiler. The driver will arrange for this directory to be
+searched prior to the standard system directories so that these files will
+override any present in those directories.
+