Add 'SelectFunctionDir' function, to select appropriate function implementation based on a configuration and architecture.
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@93717 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/make/lib_info.mk b/make/lib_info.mk
new file mode 100644
index 0000000..d7fc607
--- /dev/null
+++ b/make/lib_info.mk
@@ -0,0 +1,45 @@
+# compiler-rt Library Info
+#
+# This should be included once the subdirectory information has been loaded, and
+# uses the utilities in 'util.mk'.
+#
+# This defines the following variables describing compiler-rt:
+# AvailableFunctions - The entire list of function names (unmangled) the
+# library can provide.
+# CommonFunctions - The list of generic functions available.
+# ArchFunctions.<arch> - The list of functions commonly available for
+# 'arch'. This does not include any config specific
+# functions.
+#
+# AvailableIn.<function> - The list of subdir keys where 'function' is
+# defined.
+
+AvailableArchs := $(sort $(foreach key,$(SubDirKeys),\
+ $($(key).OnlyArchs)))
+
+AvailableFunctions := $(sort $(foreach key,$(SubDirKeys),\
+ $(basename $($(key).ObjNames))))
+
+CommonFunctions := $(sort\
+ $(foreach key,$(SubDirKeys),\
+ $(if $(call strneq,,$(strip $($(key).OnlyArchs) $($(key).OnlyConfigs))),,\
+ $(basename $($(key).ObjNames)))))
+
+# Compute common arch functions.
+$(foreach key,$(SubDirKeys),\
+ $(if $(call strneq,,$($(key).OnlyConfigs)),,\
+ $(foreach arch,$($(key).OnlyArchs),\
+ $(call Append,ArchFunctions.$(arch),$(sort \
+ $(basename $($(key).ObjNames)))))))
+
+# Compute arch only functions.
+$(foreach arch,$(AvailableArchs),\
+ $(call Set,ArchFunctions.$(arch),$(sort $(ArchFunctions.$(arch))))\
+ $(call Set,ArchOnlyFunctions.$(arch),\
+ $(call set_difference,$(ArchFunctions.$(arch)),$(CommonFunctions))))
+
+# Compute lists of where each function is available.
+$(foreach key,$(SubDirKeys),\
+ $(foreach fn,$(basename $($(key).ObjNames)),\
+ $(call Append,AvailableIn.$(fn),$(key))))
+