Use := instead of = for list of files

This will make sure we don't look twice.

Also make a single call to find the common file formats
rather than many calls.

core/erlc.mk

@@ -91,8 +91,10 @@ app-build: ebin/$(PROJECT).app
 
 # Source files.
 
-ERL_FILES = $(sort $(call core_find,src/,*.erl))
-CORE_FILES = $(sort $(call core_find,src/,*.core))
+ALL_SRC_FILES := $(sort $(call core_find,src/,*))
+
+ERL_FILES := $(filter %.erl,$(ALL_SRC_FILES))
+CORE_FILES := $(filter %.core,$(ALL_SRC_FILES))
 
 # ASN.1 files.
 
@@ -125,11 +127,11 @@ endif
 
 # Leex and Yecc files.
 
-XRL_FILES = $(sort $(call core_find,src/,*.xrl))
+XRL_FILES := $(filter %.xrl,$(ALL_SRC_FILES))
 XRL_ERL_FILES = $(addprefix src/,$(patsubst %.xrl,%.erl,$(notdir $(XRL_FILES))))
 ERL_FILES += $(XRL_ERL_FILES)
 
-YRL_FILES = $(sort $(call core_find,src/,*.yrl))
+YRL_FILES := $(filter %.yrl,$(ALL_SRC_FILES))
 YRL_ERL_FILES = $(addprefix src/,$(patsubst %.yrl,%.erl,$(notdir $(YRL_FILES))))
 ERL_FILES += $(YRL_ERL_FILES)
 

plugins/ct.mk

@@ -6,11 +6,13 @@
 # Configuration.
 
 CT_OPTS ?=
+
 ifneq ($(wildcard $(TEST_DIR)),)
-	CT_SUITES ?= $(sort $(subst _SUITE.erl,,$(notdir $(call core_find,$(TEST_DIR)/,*_SUITE.erl))))
-else
-	CT_SUITES ?=
+ifndef CT_SUITES
+CT_SUITES := $(sort $(subst _SUITE.erl,,$(notdir $(call core_find,$(TEST_DIR)/,*_SUITE.erl))))
+endif
 endif
+CT_SUITES ?=
 
 # Core targets.
 

plugins/erlydtl.mk

@@ -16,7 +16,7 @@ dtl_verbose = $(dtl_verbose_$(V))
 # Core targets.
 
 DTL_PATH := $(abspath $(DTL_PATH))
-DTL_FILES = $(call core_find,$(DTL_PATH),*.dtl)
+DTL_FILES := $(sort $(call core_find,$(DTL_PATH),*.dtl))
 
 ifneq ($(DTL_FILES),)