Add readme and spiff up makefile header

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10254 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/runtime/GCCLibraries/crtend/Makefile b/runtime/GCCLibraries/crtend/Makefile
index 666a88b28a1fc198b0e4a9c273fb17ed2c8a7292..361bad002b03bebba8233d4bc128c758eb3370f5 100644 (file)
--- a/runtime/GCCLibraries/crtend/Makefile
+++ b/runtime/GCCLibraries/crtend/Makefile
@@ -1,4 +1,4 @@
-##===- runtime/GCCLibraries/crtend/Makefile ------------------------------*- Makefile -*-===##
+##===- runtime/GCCLibraries/crtend/Makefile ----------------*- Makefile -*-===##
 # 
 #                     The LLVM Compiler Infrastructure
 #
@@ -6,6 +6,12 @@
 # the University of Illinois Open Source License. See LICENSE.TXT for details.
 # 
 ##===----------------------------------------------------------------------===##
+#
+# This directory contains the C and C++ runtime libraries for the LLVM GCC
+# front-ends.
+#
+##===----------------------------------------------------------------------===##
+
 LEVEL = ../../..
 BYTECODE_LIBRARY=1
 DONT_BUILD_RELINKED=1

diff --git a/runtime/GCCLibraries/crtend/README.txt b/runtime/GCCLibraries/crtend/README.txt
new file mode 100644 (file)
index 0000000..ff070c4
--- /dev/null
+++ b/runtime/GCCLibraries/crtend/README.txt
@@ -0,0 +1,15 @@
+This directory contains the C and C++ runtime libraries for the LLVM GCC
+front-ends.  It is composed of four distinct pieces:
+
+1. __main and static ctor/dtor support.  This is used by both C and C++ codes.
+
+2. Generic EH support routines.  This is used by C/C++ programs that use
+   setjmp/longjmp, and by C++ programs that make use of exceptions.
+
+3. setjmp/longjmp EH support.  This is used by C/C++ programs that call SJLJ.
+
+4. C++ exception handling runtime support.
+
+These four components are compiled together into an archive file, so that
+applications using a subset of the four do not pull in unnecessary code and
+dependencies.