build system: immediately report what users are supposed to look into

Instead of just logging "Check out that file over there for this type
of values", why not emit them directly?

Change-Id: I54630afce4011ab9ee3eda415e95d5b7d5812e6b
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57508
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/toolchain.inc b/toolchain.inc
index 80dab78..893f7d1 100644
--- a/toolchain.inc
+++ b/toolchain.inc
@@ -108,7 +108,8 @@
 # e.g.: smm special class uses i386 as compiler set
 define create_class_compiler
 $(if $(2),,$(warning *** The toolchain architecture for $(1) is unknown.) \
-	$(error Check your .config file for CONFIG_ARCH_$(1)_* settings))
+	$(warning CONFIG_ARCH_$(1)_* settings in $(DOTCONFIG):) \
+	$(error $(shell grep CONFIG_ARCH_$(1)_ $(DOTCONFIG))))
 CC_$(1) := $(CC_$(2))
 GCC_$(1) := $(GCC_CC_$(2))
 LD_$(1) := $(LD_$(2))