From 4a53e1ef9d137af590425f77f02a4e974f370656 Mon Sep 17 00:00:00 2001
From: Stuart Hastings <stuart@apple.com>
Date: Thu, 22 Oct 2009 17:22:37 +0000
Subject: [PATCH] Trying again to tweak the top-level Makefile to facilitate an
 Apple-style build. Now with Clang-compatibility.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84872 91177308-0d34-0410-b5e6-96231b3b80d8
---
 Makefile                  | 12 ++++++++++++
 utils/buildit/GNUmakefile |  2 +-
 utils/buildit/build_llvm  |  4 ++++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index f3bf3f2345e..d2000b48387 100644
--- a/Makefile
+++ b/Makefile
@@ -19,6 +19,12 @@ LEVEL := .
 #
 # When cross-compiling, there are some things (tablegen) that need to
 # be build for the build system first.
+
+# If "RC_ProjectName" exists in the environment, and its value is
+# "llvmCore", then this is an "Apple-style" build; search for
+# "Apple-style" in the comments for more info.  Anything else is a
+# normal build.
+ifneq ($(RC_ProjectName),llvmCore)  # Normal build (not "Apple-style").
 ifeq ($(BUILD_DIRS_ONLY),1)
   DIRS := lib/System lib/Support utils
   OPTIONAL_DIRS :=
@@ -211,3 +217,9 @@ happiness: update all check unittests
 
 .NOTPARALLEL:
 
+else # Building "Apple-style."
+# In an Apple-style build, once configuration is done, lines marked
+# "Apple-style" are removed with sed!  Please don't remove these!
+# Look for the string "Apple-style" in utils/buildit/build_llvm.
+include $(shell find . -name GNUmakefile) # Building "Apple-style."
+endif # Building "Apple-style."
diff --git a/utils/buildit/GNUmakefile b/utils/buildit/GNUmakefile
index e3b334a045d..997188333c1 100644
--- a/utils/buildit/GNUmakefile
+++ b/utils/buildit/GNUmakefile
@@ -59,7 +59,7 @@ endif
 # NOTE : Always put version numbers at the end because they are optional.
 install: $(OBJROOT) $(SYMROOT) $(DSTROOT)
 	cd $(OBJROOT) && \
-	  $(SRC)/build_llvm "$(RC_ARCHS)" "$(TARGETS)" \
+	  $(SRC)/utils/buildit/build_llvm "$(RC_ARCHS)" "$(TARGETS)" \
 	    $(SRC) $(PREFIX) $(DSTROOT) $(SYMROOT) \
 	    $(LLVM_ASSERTIONS) $(LLVM_OPTIMIZED) \
 	    $(RC_ProjectSourceVersion) $(RC_ProjectSourceSubversion) 
diff --git a/utils/buildit/build_llvm b/utils/buildit/build_llvm
index 91fbe15be47..2bdb208237d 100755
--- a/utils/buildit/build_llvm
+++ b/utils/buildit/build_llvm
@@ -82,6 +82,10 @@ SRC_DIR=$DIR/src
 rm -rf $SRC_DIR || exit 1
 mkdir $SRC_DIR || exit 1
 ln -s $ORIG_SRC_DIR/* $SRC_DIR/ || exit 1
+# We can't use the top-level Makefile as-is.  Remove the soft link:
+rm $SRC_DIR/Makefile || exit 1
+# Now create our own by editing the top-level Makefile, deleting every line marked "Apple-style":
+sed -e '/[Aa]pple-style/d' -e '/include.*GNUmakefile/d' $ORIG_SRC_DIR/Makefile > $SRC_DIR/Makefile || exit 1
 
 # Build the LLVM tree universal.
 mkdir -p $DIR/obj-llvm || exit 1