Allow additional CFLAGS for extra sources

Since the addition of -Wconversion and -Wsign-conversion to the default
CFLAGS, compilation of the CMSIS files for AN547 fails.

This commit allows custom Makefiles to not only provide EXTRA_SOURCES
to specify additional sources, but also EXTRA_SOURCES_CFLAGS for additional
CFLAGS, which in particular may overwrite default CFLAGS (they apply later).

This is leveraged in the case of m55-an547/platform.mk to disable
conversion and sign-conversion warnings for all CMSIS files.

Port of
pq-code-package/mlkem-native@15fa58e

Signed-off-by: Matthias J. Kannwischer <[email protected]>

Author: mkannwischer

test/baremetal/platform/m55-an547/platform.mk

@@ -58,4 +58,7 @@ LDFLAGS += \
 
 # Extra sources to be included in test binaries
 EXTRA_SOURCES = $(wildcard $(M55_AN547_PATH)/*.c)
+# The CMSIS files fail compilation if conversion warnings are enabled
+EXTRA_SOURCES_CFLAGS = -Wno-conversion -Wno-sign-conversion
+
 EXEC_WRAPPER := $(realpath $(PLATFORM_PATH)/exec_wrapper.py)

test/mk/components.mk

@@ -70,3 +70,11 @@ $(foreach scheme,mldsa44 mldsa65 mldsa87, \
 $(ALL_TESTS:%=$(MLDSA44_DIR)/bin/%44): $(call MAKE_OBJS, $(MLDSA44_DIR), $(wildcard test/notrandombytes/*.c) $(EXTRA_SOURCES))
 $(ALL_TESTS:%=$(MLDSA65_DIR)/bin/%65): $(call MAKE_OBJS, $(MLDSA65_DIR), $(wildcard test/notrandombytes/*.c) $(EXTRA_SOURCES))
 $(ALL_TESTS:%=$(MLDSA87_DIR)/bin/%87): $(call MAKE_OBJS, $(MLDSA87_DIR), $(wildcard test/notrandombytes/*.c) $(EXTRA_SOURCES))
+
+# Apply EXTRA_CFLAGS to EXTRA_SOURCES object files
+ifneq ($(EXTRA_SOURCES),)
+$(call MAKE_OBJS, $(MLDSA44_DIR), $(EXTRA_SOURCES)): CFLAGS += $(EXTRA_SOURCES_CFLAGS)
+$(call MAKE_OBJS, $(MLDSA65_DIR), $(EXTRA_SOURCES)): CFLAGS += $(EXTRA_SOURCES_CFLAGS)
+$(call MAKE_OBJS, $(MLDSA87_DIR), $(EXTRA_SOURCES)): CFLAGS += $(EXTRA_SOURCES_CFLAGS)
+endif
+