disable configure caching in gdb, courtesy of Fathi Boudra

toolchain/gdb/gdb.mk

@@ -84,13 +84,14 @@ GDB_TARGET_CONFIGURE_VARS:= \
 
 $(GDB_TARGET_DIR)/.configured: $(GDB_DIR)/.unpacked
 	mkdir -p $(GDB_TARGET_DIR)
-	(cd $(GDB_TARGET_DIR); rm -rf config.cache; \
+	(cd $(GDB_TARGET_DIR); \
 		gdb_cv_func_sigsetjmp=yes \
 		$(TARGET_CONFIGURE_OPTS) \
 		CFLAGS_FOR_TARGET="$(TARGET_CFLAGS) $(TARGET_LDFLAGS) -Wno-error" \
 		CFLAGS="$(TARGET_CFLAGS) $(TARGET_LDFLAGS) -Wno-error" \
 		$(GDB_TARGET_CONFIGURE_VARS) \
 		$(GDB_DIR)/configure \
+		--cache-file=/dev/null \
 		--build=$(GNU_HOST_NAME) \
 		--host=$(REAL_GNU_TARGET_NAME) \
 		--target=$(REAL_GNU_TARGET_NAME) \
@@ -135,11 +136,12 @@ GDB_SERVER_DIR:=$(BUILD_DIR)/gdbserver-$(GDB_VERSION)
 
 $(GDB_SERVER_DIR)/.configured: $(GDB_DIR)/.unpacked
 	mkdir -p $(GDB_SERVER_DIR)
-	(cd $(GDB_SERVER_DIR); rm -rf config.cache; \
+	(cd $(GDB_SERVER_DIR); \
 		$(TARGET_CONFIGURE_OPTS) \
 		gdb_cv_func_sigsetjmp=yes \
 		bash_cv_have_mbstate_t=yes \
 		$(GDB_DIR)/gdb/gdbserver/configure \
+		--cache-file=/dev/null \
 		--build=$(GNU_HOST_NAME) \
 		--host=$(REAL_GNU_TARGET_NAME) \
 		--target=$(REAL_GNU_TARGET_NAME) \
@@ -165,6 +167,7 @@ $(GDB_SERVER_DIR)/gdbserver: $(GDB_SERVER_DIR)/.configured
 	$(MAKE) CC=$(TARGET_CC) MT_CFLAGS="$(TARGET_CFLAGS)" \
 		-C $(GDB_SERVER_DIR)
 	$(STRIPCMD) $(GDB_SERVER_DIR)/gdbserver
+
 $(TARGET_DIR)/usr/bin/gdbserver: $(GDB_SERVER_DIR)/gdbserver
 ifeq ($(strip $(BR2_CROSS_TOOLCHAIN_TARGET_UTILS)),y)
 	mkdir -p $(STAGING_DIR)/$(REAL_GNU_TARGET_NAME)/target_utils
@@ -191,10 +194,11 @@ GDB_HOST_DIR:=$(TOOL_BUILD_DIR)/gdbhost-$(GDB_VERSION)
 
 $(GDB_HOST_DIR)/.configured: $(GDB_DIR)/.unpacked
 	mkdir -p $(GDB_HOST_DIR)
-	(cd $(GDB_HOST_DIR); rm -rf config.cache; \
+	(cd $(GDB_HOST_DIR); \
 		gdb_cv_func_sigsetjmp=yes \
 		bash_cv_have_mbstate_t=yes \
 		$(GDB_DIR)/configure \
+		--cache-file=/dev/null \
 		--prefix=$(STAGING_DIR) \
 		--build=$(GNU_HOST_NAME) \
 		--host=$(GNU_HOST_NAME) \
@@ -226,8 +230,6 @@ gdbhost-clean:
 gdbhost-dirclean:
 	rm -rf $(GDB_HOST_DIR)
 
-
-
 #############################################################
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