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_util.mk b/make/lib_util.mk
new file mode 100644
index 0000000..768558b
--- /dev/null
+++ b/make/lib_util.mk
@@ -0,0 +1,56 @@
+# Library Utility Functions
+#
+# This should be included following 'lib_info.mk'.
+
+# Function: SelectFunctionDir config arch function-name optimized
+#
+# Choose the appropriate implementation directory to use for 'function-name' in
+# the configuration 'config' and on given arch.
+SelectFunctionDir = $(strip \
+ $(call Set,Tmp.SelectFunctionDir,$(call SelectFunctionDirs,$(1),$(2),$(3),$(4)))\
+ $(if $(call streq,1,$(words $(Tmp.SelectFunctionDir))),\
+ $(Tmp.SelectFunctionDir),\
+ $(error SelectFunctionDir: invalid function name "$(3)" ($(strip\
+ $(if $(call streq,0,$(words $(Tmp.SelectFunctionDir))),\
+ no such function,\
+ function implemented in multiple directories!!!))))))
+
+# Helper functions that select the entire list of subdirs where a function is
+# defined with a certain specificity.
+SelectFunctionDirs_Opt_ConfigAndArch = $(strip \
+ $(foreach key,$(AvailableIn.$(3)),\
+ $(if $(and $(call streq,Optimized,$($(key).Target)),\
+ $(call contains,$($(key).OnlyConfigs),$(1)),\
+ $(call contains,$($(key).OnlyArchs),$(2))),$(key),)))
+SelectFunctionDirs_Opt_Config = $(strip \
+ $(foreach key,$(AvailableIn.$(3)),\
+ $(if $(and $(call streq,Optimized,$($(key).Target)),\
+ $(call contains,$($(key).OnlyConfigs),$(1))),$(key),)))
+SelectFunctionDirs_Opt_Arch = $(strip \
+ $(foreach key,$(AvailableIn.$(3)),\
+ $(if $(and $(call streq,Optimized,$($(key).Target)),\
+ $(call contains,$($(key).OnlyArchs),$(2))),$(key),)))
+SelectFunctionDirs_Gen = $(strip \
+ $(foreach key,$(AvailableIn.$(3)),\
+ $(if $(call streq,Generic,$($(key).Target)),$(key))))
+
+# Helper function to select the right set of dirs in generic priority order.
+SelectFunctions_Gen = \
+ $(or $(call SelectFunctionDirs_Gen,$(1),$(2),$(3)),\
+ $(call SelectFunctionDirs_Opt_ConfigAndArch,$(1),$(2),$(3)), \
+ $(call SelectFunctionDirs_Opt_Config,$(1),$(2),$(3)), \
+ $(call SelectFunctionDirs_Opt_Arch,$(1),$(2),$(3)))
+
+# Helper function to select the right set of dirs in optimized priority order.
+SelectFunctions_Opt = \
+ $(or $(call SelectFunctionDirs_Opt_ConfigAndArch,$(1),$(2),$(3)), \
+ $(call SelectFunctionDirs_Opt_Config,$(1),$(2),$(3)), \
+ $(call SelectFunctionDirs_Opt_Arch,$(1),$(2),$(3)), \
+ $(call SelectFunctionDirs_Gen,$(1),$(2),$(3)))
+
+# Helper function to select the right set of dirs (which should be exactly one)
+# for a function.
+SelectFunctionDirs = \
+ $(if $(call streq,1,$(4)),\
+ $(call SelectFunctions_Opt,$(1),$(2),$(3)),\
+ $(call SelectFunctions_Gen,$(1),$(2),$(3)))