toolchain.inc: Update comments

This fixes some nits that were pointed out in a previous review, and
adds a couple additional comments to explain what is happening.

Change-Id: I1ca4bf59ba79744f79fbe73f4e226feeea1cc2ab
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/13019
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 13 insertions, 7 deletions

diff --git a/toolchain.inc b/toolchain.inc
index eb1f0876bd..640c793901 100644
--- a/toolchain.inc
+++ b/toolchain.inc
@@ -152,13 +152,14 @@ $(call init_stages)
 
 # Test for coreboot toolchain (except when explicitly not requested)
 ifneq ($(NOCOMPILE),1)
-# only run if we're doing a build (not for tests, kconfig, ...)
+# Only run if we're doing a build (not for tests, kconfig, ...)
 # rationale: gcc versions by Linux distributions tend to be quite messed up
 # llvm/clang also needs patches supplied by the coreboot build
 COMPILERFAIL:=0
 IASLFAIL:=0
 
 ifneq ($(CONFIG_ANY_TOOLCHAIN),y)
+# Verify that the coreboot toolchain is being used.
 $(foreach arch,$(sort $(foreach stage,\
 	$(COREBOOT_STANDARD_STAGES),$(ARCH-$(stage)-y))), \
 	$(if $(shell if [ -n "$(CC_$(arch))" ]; then \
@@ -167,8 +168,8 @@ $(foreach arch,$(sort $(foreach stage,\
 		$(eval COMPILERFAIL:=1)\
 		$(warning The coreboot toolchain for '$(arch)'\
 			architecture was not found.)))
-#if iasl doesn't match the current coreboot version, fail the test
-#TODO: Figure out if iasl is even needed for the build.
+# If iasl doesn't match the current coreboot version, fail the test
+# TODO: Figure out if iasl is even needed for the build.
 $(if $(shell if [ -n "$(IASL)" ]; then \
 	$(IASL) -v 2>&1 | grep -q "$(shell util/crossgcc/buildgcc -s iasl)" || \
 	echo not-coreboot; else echo not-coreboot; fi), \
@@ -176,17 +177,20 @@ $(if $(shell if [ -n "$(IASL)" ]; then \
 	$(warning The coreboot toolchain version of iasl \
 		'$(shell util/crossgcc/buildgcc -s iasl)' was not found))
 else #$(CONFIG_ANY_TOOLCHAIN)
+# If the coreboot toolchain isn't being used, verify that there is A toolchain
 $(foreach arch,$(sort \
 	$(foreach stage,$(COREBOOT_STANDARD_STAGES),$(ARCH-$(stage)-y))), \
 	$(if $(CC_$(arch)),, $(eval COMPILERFAIL:=1) \
 	$(warning No compiler found for '$(arch)' architecture. \
 		Install one or use the coreboot toolchain?)) )
-#if iasl isn't present, fail
-#TODO: Figure out if iasl is even needed for the build.
+# If iasl isn't present, fail
+# TODO: Figure out if iasl is even needed for the build.
 $(if $(IASL),, $(eval COMPILERFAIL:=1)$(eval IASLFAIL:=1) \
 	$(warning iasl not found. \
 		Please install it or use the coreboot toolchain.))
 endif
+
+# If the compiler check failed, print out warnings
 ifeq ($(COMPILERFAIL),1)
 ifneq ($(XGCCPATH),)
 $(warning )
@@ -213,6 +217,8 @@ endif #($(COMPILERFAIL),1)
 
 endif #($(NOCOMPILE),1)
 
+# Run the toolchain version checks if the requested target is 'test-toolchain'
+# Checks the versions of GCC, binutils, clang, and IASL
 ifneq ($(MAKECMDGOALS),)
 ifneq ($(filter test-toolchain,$(MAKECMDGOALS)),)
 $(foreach arch, $(ARCH_SUPPORTED), \
@@ -244,5 +250,5 @@ $(if $(shell if [ -n "$(IASL)" ]; then $(IASL) -v 2>&1 | \
 	$(eval COMPILER_OUT_OF_DATE:=1)\
 	$(warning The coreboot toolchain version of iasl \
 		is not the current version))
-endif # ifneq ($(filter crossgcc_check%,$(MAKECMDGOALS)),)
-endif # ifneq ($(MAKECMDGOALS),)
+endif #($(filter crossgcc_check%,$(MAKECMDGOALS)),)
+endif #($(MAKECMDGOALS),)