tests: Split Makefile to allow for making host-side test tools

This patch is based on similar changes [1] done in Depthcharge projects,
which aimed to provide unified way to build host-side programs for
testing internal code. New test tools might benefit from it by having
same base code as unit-tests.

[1] https://crrev.com/c/3412108

TEST=make unit-tests
TEST=COV=1 make unit-tests coverage-report

Signed-off-by: Jakub Czapiga <jacz@semihalf.com>
Change-Id: Iac4517ab6146fa3f2d2b7a20df54601ab2d04c3d
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63637
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/tests/Makefile.common b/tests/Makefile.common
new file mode 100644
index 0000000..03ae7c4
--- /dev/null
+++ b/tests/Makefile.common
@@ -0,0 +1,169 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+# This file contains common definitions, macros and targets for depthcharge
+# unit-tests and screenshot utility. It requires list of defined variables:
+# - src - source directory
+# - testobj - build directory of tests
+# - objutil - utility programs/libraries output directory
+
+testsrc := $(top)/tests
+
+cmockasrc := 3rdparty/cmocka
+cmockaobj := $(objutil)/cmocka
+coverage_dir := coverage_reports
+
+CMOCKA_LIB := $(cmockaobj)/src/libcmocka.so
+
+CMAKE := cmake
+OBJCOPY ?= objcopy
+OBJDUMP ?= objdump
+
+TEST_DEFAULT_CONFIG := $(top)/configs/config.emulation_qemu_x86_i440fx
+TEST_DOTCONFIG := $(testobj)/.config
+TEST_KCONFIG_AUTOHEADER := $(testobj)/config.src.h
+TEST_KCONFIG_AUTOCONFIG := $(testobj)/auto.conf
+TEST_KCONFIG_DEPENDENCIES := $(testobj)/auto.conf.cmd
+TEST_KCONFIG_SPLITCONFIG := $(testobj)/config/
+TEST_KCONFIG_TRISTATE := $(testobj)/tristate.conf
+
+TEST_CFLAGS := -include $(src)/include/kconfig.h \
+	-include $(src)/commonlib/bsd/include/commonlib/bsd/compiler.h \
+	-include $(src)/include/rules.h
+
+# Include generic test mock headers, before original ones
+TEST_CFLAGS += -I$(testsrc)/include/mocks -I$(testsrc)/include
+
+TEST_CFLAGS += -I$(src) -I$(src)/include -I$(src)/commonlib/include \
+	-I$(src)/commonlib/bsd/include -I$(src)/arch/x86/include \
+	-I$(top)/3rdparty/vboot/firmware/include
+
+# Note: This is intentionally just a subset of the warnings in the toplevel
+# Makefile.inc. We don't need to be as strict with test code, and things like
+# -Wmissing-prototypes just make working with the test framework cumbersome.
+# Only put conservative warnings here that really detect code that's obviously
+# unintentional.
+TEST_CFLAGS += -Wall -Werror -Wundef -Wstrict-prototypes -Wno-inline-asm
+TEST_CFLAGS += -Wno-unknown-warning-option -Wno-source-mgr -Wno-main-return-type
+
+# Path for Kconfig autoheader
+TEST_CFLAGS += -I$(dir $(TEST_KCONFIG_AUTOHEADER))
+
+TEST_CFLAGS += -std=gnu11 -Os -ffunction-sections -fdata-sections -fno-builtin
+
+TEST_CFLAGS += -D__TEST__
+
+TEST_CFLAGS += -I$(cmockasrc)/include
+
+ifneq ($(filter-out 0,$(TEST_PRINT)),)
+TEST_CFLAGS += -DTEST_PRINT=1
+endif
+
+# Link against Cmocka
+TEST_LDFLAGS := -L$(cmockaobj)/src -lcmocka -Wl,-rpath=$(cmockaobj)/src
+TEST_LDFLAGS += -Wl,--gc-sections
+
+# Some memlayout symbols don't work with userspace relocation -- disable it.
+TEST_CFLAGS += -fno-pie -fno-pic
+TEST_LDFLAGS += -no-pie
+
+# Extra attributes for unit tests, declared per test
+attributes := srcs cflags config mocks stage
+
+# Copy attributes of one test to another.
+# $1 - input test name
+# $2 - output test name
+copy-test = $(foreach attr,$(attributes), \
+		$(eval $(strip $(2))-$(attr) := $($(strip $(1))-$(attr))))
+
+# Create actual targets for unit test binaries
+# $1 - test name
+define TEST_CC_template
+
+# Generate custom config.h redefining given config symbols, and declaring mocked
+# functions weak. It is important that the compiler already sees that they are
+# weak (and they aren't just turned weak at a later stage) to prevent certain
+# optimizations that would break if the function gets replaced. (For clang this
+# file needs to be marked `system_header` to prevent it from warning about
+# #pragma weak entries without a matching function declaration, since there's no
+# -Wno-xxx command line option for that.)
+$(1)-config-file := $(testobj)/$(1)/config.h
+$$($(1)-config-file): $(TEST_KCONFIG_AUTOHEADER)
+	mkdir -p $$(dir $$@)
+	printf '// File generated by tests/Makefile.inc\n// Do not change\n' > $$@
+	printf '#include <%s>\n\n' "$(notdir $(TEST_KCONFIG_AUTOHEADER))" >> $$@
+	for kv in $$($(1)-config); do \
+		key="`echo $$$$kv | cut -d '=' -f -1`"; \
+		value="`echo $$$$kv | cut -d '=' -f 2-`"; \
+		printf '#undef %s\n' "$$$$key" >> $$@; \
+		printf '#define %s %s\n\n' "$$$$key" "$$$$value" >> $$@; \
+	done
+	printf '#ifdef __clang__\n' >> $$@;
+	printf '#pragma clang system_header\n' >> $$@;
+	printf '#endif\n' >> $$@;
+	printf '#ifdef __TEST_SRCOBJ__\n' >> $$@;
+	for m in $$($(1)-mocks); do \
+		printf '#pragma weak %s\n' "$$$$m" >> $$@; \
+	done
+	printf '#endif\n' >> $$@;
+
+$($(1)-objs): TEST_CFLAGS += -I$$(dir $$($(1)-config-file)) \
+	-D__$$(shell echo $$($(1)-stage) | tr '[:lower:]' '[:upper:]')__ \
+	-D__TEST_NAME__=\"$(subst /,_,$(1))\" \
+	-D__TEST_DATA_DIR__=\"$(testsrc)/data\"
+
+# Give us a way to distinguish between coreboot source files and test files in code.
+$($(1)-srcobjs): TEST_CFLAGS += -D__TEST_SRCOBJ__
+
+# Compile sources and apply mocking/wrapping of selected symbols.
+# For each listed mock add new symbol with prefix `__real_`,
+# and pointing to the same section:address.
+$($(1)-objs): $(testobj)/$(1)/%.o: $$$$*.c $$($(1)-config-file)
+	mkdir -p $$(dir $$@)
+	$(HOSTCC) $(HOSTCFLAGS) $$(TEST_CFLAGS) $($(1)-cflags) -MMD \
+		-MF $$(basename $$@).d -MT $$@ -c $$< -o $$@.orig
+	objcopy_wrap_flags=''; \
+	for sym in $$($(1)-mocks); do \
+		sym_line="$$$$($(OBJDUMP) -t $$@.orig \
+			| grep -E "[0-9a-fA-F]+\\s+w\\s+F\\s+.*\\s$$$$sym$$$$")"; \
+		if [ ! -z "$$$$sym_line" ] ; then \
+			addr="$$$$(echo "$$$$sym_line" | awk '{ print $$$$1 }')"; \
+			section="$$$$(echo "$$$$sym_line" | awk '{ print $$$$(NF - 2) }')"; \
+			objcopy_wrap_flags="$$$$objcopy_wrap_flags --add-symbol __real_$$$${sym}=$$$${section}:0x$$$${addr},function,global"; \
+		fi \
+	done ; \
+	$(OBJCOPY) $$@.orig $$$$objcopy_wrap_flags $$@
+
+$($(1)-bin): $($(1)-objs) $(CMOCKA_LIB)
+	$(HOSTCC) $$^ $($(1)-cflags) $$(TEST_LDFLAGS) -o $$@
+
+endef
+
+# Build cmocka
+$(CMOCKA_LIB):
+	echo "*** Building CMOCKA ***"
+	mkdir -p $(cmockaobj)
+	cd $(cmockaobj) && $(CMAKE) $(abspath $(cmockasrc))
+	$(MAKE) -C $(cmockaobj)
+
+# Kconfig targets
+$(TEST_DOTCONFIG):
+	mkdir -p $(dir $@)
+	cp $(TEST_DEFAULT_CONFIG) $(TEST_DOTCONFIG)
+
+# Don't override default Kconfig variables, since this will affect all
+# Kconfig targets. Change them only when calling sub-make instead.
+$(TEST_KCONFIG_AUTOHEADER): TEST_KCONFIG_FLAGS := DOTCONFIG=$(TEST_DOTCONFIG) \
+        KCONFIG_AUTOHEADER=$(TEST_KCONFIG_AUTOHEADER) \
+        KCONFIG_AUTOCONFIG=$(TEST_KCONFIG_AUTOCONFIG) \
+        KCONFIG_DEPENDENCIES=$(TEST_KCONFIG_DEPENDENCIES) \
+        KCONFIG_SPLITCONFIG=$(TEST_KCONFIG_SPLITCONFIG) \
+        KCONFIG_TRISTATE=$(TEST_KCONFIG_TRISTATE) \
+        KBUILD_DEFCONFIG=$(TEST_DEFAULT_CONFIG)
+
+$(TEST_KCONFIG_AUTOHEADER): $(TEST_DOTCONFIG) $(objutil)/kconfig/conf
+	mkdir -p $(dir $@)
+	$(MAKE) $(TEST_KCONFIG_FLAGS) olddefconfig
+	$(MAKE) $(TEST_KCONFIG_FLAGS) syncconfig
+
+$(TEST_KCONFIG_AUTOCONFIG): $(TEST_KCONFIG_AUTOHEADER)
+	true
diff --git a/tests/Makefile.inc b/tests/Makefile.inc
index 847beaf..10caf0a 100644
--- a/tests/Makefile.inc
+++ b/tests/Makefile.inc
@@ -1,7 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
-testsrc := $(top)/tests
-
 # Place the build output in one of two places depending on COV, so that code
 # built with code coverage never mixes with code built without code coverage.
 ifeq ($(COV),1)
@@ -10,63 +8,7 @@
 testobj := $(obj)/tests
 endif
 
-cmockasrc := 3rdparty/cmocka
-cmockaobj := $(objutil)/cmocka
-coverage_dir := coverage_reports
-
-CMOCKA_LIB := $(cmockaobj)/src/libcmocka.so
-
-CMAKE := cmake
-OBJCOPY ?= objcopy
-OBJDUMP ?= objdump
-
-TEST_DEFAULT_CONFIG := $(top)/configs/config.emulation_qemu_x86_i440fx
-TEST_DOTCONFIG := $(testobj)/.config
-TEST_KCONFIG_AUTOHEADER := $(testobj)/config.src.h
-TEST_KCONFIG_AUTOCONFIG := $(testobj)/auto.conf
-TEST_KCONFIG_DEPENDENCIES := $(testobj)/auto.conf.cmd
-TEST_KCONFIG_SPLITCONFIG := $(testobj)/config/
-TEST_KCONFIG_TRISTATE := $(testobj)/tristate.conf
-
-TEST_CFLAGS := -include $(src)/include/kconfig.h \
-	-include $(src)/commonlib/bsd/include/commonlib/bsd/compiler.h \
-	-include $(src)/include/rules.h
-
-# Include generic test mock headers, before original ones
-TEST_CFLAGS += -I$(testsrc)/include/mocks -I$(testsrc)/include
-
-TEST_CFLAGS += -I$(src) -I$(src)/include -I$(src)/commonlib/include \
-	-I$(src)/commonlib/bsd/include -I$(src)/arch/x86/include \
-	-I$(top)/3rdparty/vboot/firmware/include
-
-# Note: This is intentionally just a subset of the warnings in the toplevel
-# Makefile.inc. We don't need to be as strict with test code, and things like
-# -Wmissing-prototypes just make working with the test framework cumbersome.
-# Only put conservative warnings here that really detect code that's obviously
-# unintentional.
-TEST_CFLAGS += -Wall -Werror -Wundef -Wstrict-prototypes -Wno-inline-asm
-TEST_CFLAGS += -Wno-unknown-warning-option -Wno-source-mgr -Wno-main-return-type
-
-# Path for Kconfig autoheader
-TEST_CFLAGS += -I$(dir $(TEST_KCONFIG_AUTOHEADER))
-
-TEST_CFLAGS += -std=gnu11 -Os -ffunction-sections -fdata-sections -fno-builtin
-
-TEST_CFLAGS += -D__TEST__
-
-TEST_CFLAGS += -I$(cmockasrc)/include
-
-ifneq ($(filter-out 0,$(TEST_PRINT)),)
-TEST_CFLAGS += -DTEST_PRINT=1
-endif
-
-# Link against Cmocka
-TEST_LDFLAGS := -L$(cmockaobj)/src -lcmocka -Wl,-rpath=$(cmockaobj)/src
-TEST_LDFLAGS += -Wl,--gc-sections
-
-# Some memlayout symbols don't work with userspace relocation -- disable it.
-TEST_CFLAGS += -fno-pie -fno-pic
-TEST_LDFLAGS += -no-pie
+include $(top)/tests/Makefile.common
 
 # Enable code coverage if COV=1
 ifeq ($(COV),1)
@@ -74,9 +16,6 @@
 TEST_LDFLAGS += --coverage
 endif
 
-# Extra attributes for unit tests, declared per test
-attributes := srcs cflags config mocks stage
-
 stages := decompressor bootblock romstage smm verstage
 stages += ramstage rmodule postcar libagesa
 
@@ -100,78 +39,9 @@
 		Check your $(dir $(1)$(2))Makefile.inc))
 endef
 
-# Copy attributes of one test to another.
-# $1 - input test name
-# $2 - output test name
-copy-test = $(foreach attr,$(attributes), \
-		$(eval $(strip $(2))-$(attr) := $($(strip $(1))-$(attr))))
-
 $(call add-special-class, tests)
 $(call evaluate_subdirs)
 
-# Create actual targets for unit test binaries
-# $1 - test name
-define TEST_CC_template
-
-# Generate custom config.h redefining given config symbols, and declaring mocked
-# functions weak. It is important that the compiler already sees that they are
-# weak (and they aren't just turned weak at a later stage) to prevent certain
-# optimizations that would break if the function gets replaced. (For clang this
-# file needs to be marked `system_header` to prevent it from warning about
-# #pragma weak entries without a matching function declaration, since there's no
-# -Wno-xxx command line option for that.)
-$(1)-config-file := $(testobj)/$(1)/config.h
-$$($(1)-config-file): $(TEST_KCONFIG_AUTOHEADER)
-	mkdir -p $$(dir $$@)
-	printf '// File generated by tests/Makefile.inc\n// Do not change\n' > $$@
-	printf '#include <%s>\n\n' "$(notdir $(TEST_KCONFIG_AUTOHEADER))" >> $$@
-	for kv in $$($(1)-config); do \
-		key="`echo $$$$kv | cut -d '=' -f -1`"; \
-		value="`echo $$$$kv | cut -d '=' -f 2-`"; \
-		printf '#undef %s\n' "$$$$key" >> $$@; \
-		printf '#define %s %s\n\n' "$$$$key" "$$$$value" >> $$@; \
-	done
-	printf '#ifdef __clang__\n' >> $$@;
-	printf '#pragma clang system_header\n' >> $$@;
-	printf '#endif\n' >> $$@;
-	printf '#ifdef __TEST_SRCOBJ__\n' >> $$@;
-	for m in $$($(1)-mocks); do \
-		printf '#pragma weak %s\n' "$$$$m" >> $$@; \
-	done
-	printf '#endif\n' >> $$@;
-
-$($(1)-objs): TEST_CFLAGS += -I$$(dir $$($(1)-config-file)) \
-	-D__$$(shell echo $$($(1)-stage) | tr '[:lower:]' '[:upper:]')__ \
-	-D__TEST_NAME__=\"$(subst /,_,$(1))\" \
-	-D__TEST_DATA_DIR__=\"$(testsrc)/data\"
-
-# Give us a way to distinguish between coreboot source files and test files in code.
-$($(1)-srcobjs): TEST_CFLAGS += -D__TEST_SRCOBJ__
-
-# Compile sources and apply mocking/wrapping of selected symbols.
-# For each listed mock add new symbol with prefix `__real_`,
-# and pointing to the same section:address.
-$($(1)-objs): $(testobj)/$(1)/%.o: $$$$*.c $$($(1)-config-file)
-	mkdir -p $$(dir $$@)
-	$(HOSTCC) $(HOSTCFLAGS) $$(TEST_CFLAGS) $($(1)-cflags) -MMD \
-		-MF $$(basename $$@).d -MT $$@ -c $$< -o $$@.orig
-	objcopy_wrap_flags=''; \
-	for sym in $$($(1)-mocks); do \
-		sym_line="$$$$($(OBJDUMP) -t $$@.orig \
-			| grep -E "[0-9a-fA-F]+\\s+w\\s+F\\s+.*\\s$$$$sym$$$$")"; \
-		if [ ! -z "$$$$sym_line" ] ; then \
-			addr="$$$$(echo "$$$$sym_line" | awk '{ print $$$$1 }')"; \
-			section="$$$$(echo "$$$$sym_line" | awk '{ print $$$$(NF - 2) }')"; \
-			objcopy_wrap_flags="$$$$objcopy_wrap_flags --add-symbol __real_$$$${sym}=$$$${section}:0x$$$${addr},function,global"; \
-		fi \
-	done ; \
-	$(OBJCOPY) $$@.orig $$$$objcopy_wrap_flags $$@
-
-$($(1)-bin): $($(1)-objs) $(CMOCKA_LIB)
-	$(HOSTCC) $$^ $($(1)-cflags) $$(TEST_LDFLAGS) -o $$@
-
-endef
-
 $(foreach test, $(alltests), \
 	$(eval $(test)-srcobjs := $(addprefix $(testobj)/$(test)/, \
 		$(patsubst %.c,%.o,$(filter src/%,$($(test)-srcs))))) \
@@ -190,36 +60,6 @@
 DEPENDENCIES += $(addsuffix .d,$(basename $(all-test-objs)))
 -include $(DEPENDENCIES)
 
-# Build cmocka
-$(CMOCKA_LIB):
-	echo "*** Building CMOCKA ***"
-	mkdir -p $(cmockaobj)
-	cd $(cmockaobj) && $(CMAKE) $(abspath $(cmockasrc))
-	$(MAKE) -C $(cmockaobj)
-
-# Kconfig targets
-$(TEST_DOTCONFIG):
-	mkdir -p $(dir $@)
-	cp $(TEST_DEFAULT_CONFIG) $(TEST_DOTCONFIG)
-
-# Don't override default Kconfig variables, since this will affect all
-# Kconfig targets. Change them only when calling sub-make instead.
-$(TEST_KCONFIG_AUTOHEADER): TEST_KCONFIG_FLAGS := DOTCONFIG=$(TEST_DOTCONFIG) \
-        KCONFIG_AUTOHEADER=$(TEST_KCONFIG_AUTOHEADER) \
-        KCONFIG_AUTOCONFIG=$(TEST_KCONFIG_AUTOCONFIG) \
-        KCONFIG_DEPENDENCIES=$(TEST_KCONFIG_DEPENDENCIES) \
-        KCONFIG_SPLITCONFIG=$(TEST_KCONFIG_SPLITCONFIG) \
-        KCONFIG_TRISTATE=$(TEST_KCONFIG_TRISTATE) \
-        KBUILD_DEFCONFIG=$(TEST_DEFAULT_CONFIG)
-
-$(TEST_KCONFIG_AUTOHEADER): $(TEST_DOTCONFIG) $(objutil)/kconfig/conf
-	mkdir -p $(dir $@)
-	$(MAKE) $(TEST_KCONFIG_FLAGS) olddefconfig
-	$(MAKE) $(TEST_KCONFIG_FLAGS) syncconfig
-
-$(TEST_KCONFIG_AUTOCONFIG): $(TEST_KCONFIG_AUTOHEADER)
-	true
-
 .PHONY: $(alltests) $(addprefix clean-,$(alltests))
 .PHONY: unit-tests build-unit-tests run-unit-tests clean-unit-tests