PR: #162 : Adding changes for creating weak stubs and linking the same in Makefile

Makefile

@@ -75,6 +75,18 @@ else # GTEST case
   SRCS := $(shell find $(SRC_DIRS) -type f \( -name '*.cpp' -o -name '*.c' \) | grep -v "$(EXCLUDE_DIRS)")
 endif
 
+# Check if BUILD_WEAK_STUBS_SRC is defined
+ifdef BUILD_WEAK_STUBS_SRC
+
+# Define variables for the static library and its source files
+WEAK_STUBS_LIB := $(LIB_DIR)/libweak_stubs_libs.so
+WEAK_STUBS_OUTPUT_DIR ?= $(BUILD_DIR)/weak_stubs/src
+WEAK_STUBS_SRC := $(shell find $(BUILD_WEAK_STUBS_SRC) -name *.c)
+WEAK_STUBS_OBJ := $(patsubst $(BUILD_WEAK_STUBS_SRC)/%, $(WEAK_STUBS_OUTPUT_DIR)/%, $(WEAK_STUBS_SRC:.c=.o)) # Apply the pattern substitution to create object file paths
+
+XLDFLAGS := $(XLDFLAGS) -L$(LIB_DIR) -lweak_stubs_libs
+endif
+
 VARIANT_FILE := .variant
 
 ifeq ($(TARGET),arm)
@@ -112,7 +124,7 @@ VPATH += $(UT_CORE_DIR) $(TOP_DIR)
 # Default target
 .PHONY: clean list arm linux framework test createdirs all printenv
 
-all: framework $(OBJS)
+all: framework $(OBJS) $(if $(BUILD_WEAK_STUBS_SRC),$(WEAK_STUBS_LIB))
 
 # Build framework
 # Recursive make is needed as src files are not available during the first iteration
@@ -133,7 +145,7 @@ download_and_build:
 	@${MAKE} -C $(UT_CONTROL) TARGET=${TARGET}
 
 # Build the test binary
-test: $(OBJS) createdirs
+test: $(OBJS) createdirs $(if $(BUILD_WEAK_STUBS_SRC),$(WEAK_STUBS_LIB))
 	@${ECHOE} ${GREEN}Linking $@ $(BUILD_DIR)/$(TARGET_EXEC)${NC}
 	@$(COMPILER) $(OBJS) -o $(BUILD_DIR)/$(TARGET_EXEC) $(XCFLAGS) $(XLDFLAGS)
 	@cp $(BUILD_DIR)/$(TARGET_EXEC) $(BIN_DIR)/
@@ -144,7 +156,7 @@ endif
 # Create necessary directories
 createdirs:
 	@echo "$(VARIANT)" > $(VARIANT_FILE)
-	@$(MKDIR_P) ${BIN_DIR} ${LIB_DIR}
+	@$(MKDIR_P) ${BIN_DIR} ${LIB_DIR} $(if $(BUILD_WEAK_STUBS_SRC),${WEAK_STUBS_OUTPUT_DIR})
 
 # Compilation rules
 $(BUILD_DIR)/%.o: %.c
@@ -171,6 +183,18 @@ checkvariantchange:
 		fi \
 	fi
 
+# Create the library weak_stubs_libs
+$(WEAK_STUBS_LIB): $(WEAK_STUBS_OBJ)
+	@${ECHOE} ${GREEN}Building shared library weak_stubs_libs...${NC}
+	@$(COMPILER) -shared -o $@ $^
+	@${ECHOE} ${GREEN}Copy shared library weak_stubs_libs to [${BIN_DIR}]${NC}
+	cp $(WEAK_STUBS_LIB) $(BIN_DIR)
+
+# Rule to compile .c files into .o files in the correct directory
+$(WEAK_STUBS_OUTPUT_DIR)/%.o: $(BUILD_WEAK_STUBS_SRC)/%.c
+	@$(MKDIR_P) $(dir $@)
+	@$(COMPILER) $(XCFLAGS) -fPIC -c $< -o $@
+
 arm:
 	make TARGET=arm
 
@@ -240,6 +264,8 @@ list:
 	@${ECHOE}
 	@${ECHOE} ${YELLOW}INC_FLAGS:${NC} $(INC_FLAGS)
 	@${ECHOE}
+	@${ECHOE} ${YELLOW}BUILD_WEAK_STUBS_SRC:${NC} $(BUILD_WEAK_STUBS_SRC)
+	@${ECHOE}
 	@${ECHOE} ${YELLOW}DEPS:${NC} $(DEPS)
 	@${ECHOE}
 	@${ECHOE} --------- ut_control ----------------

README.md

@@ -2,6 +2,7 @@
 
 | Date (DD/MM/YY)  | Comment | Document Version |
 |--------|---------|---------|
+| 24/12/24 | Updated usage of Weak Library | 2.0.3
 | 07/11/24 | Updated How to use Autogenerate script url | 2.0.2|
 | 19/06/24 | Extended LD_LIBRARY_PATH | 2.0.1|
 | 02/01/24 | Added Release Notes | 2.0.0|
@@ -216,6 +217,37 @@ This will build the following directories `src/*.c`, in addition to core functio
 
 The final output binary is build as `hal_test` and resides in the `bin` directory, the framework .so files will be copied to the same directory.
 
+### Feature: `BUILD_WEAK_STUBS_SRC` for Weak Library Compilation
+
+The `BUILD_WEAK_STUBS_SRC` variable enables clients to define and export a list of source files that will be compiled into a weak library. This allows testing suites to use stubbed implementations of functions during development, with the strong implementation provided by vendors or third parties at a later stage.
+
+#### Benefits:
+1. **Supports Testing Development**: Enables testing suites to run without waiting for strong implementations.
+2. **Decouples Development**: Testing can proceed independently of vendor timelines.
+3. **Seamless Replacement**: Strong implementations can replace weak stubs without changes to the testing suites.
+
+#### Key Makefile Logic:
+```make
+WEAK_STUBS_LIB := $(LIB_DIR)/libweak_stubs_libs.so
+WEAK_STUBS_OUTPUT_DIR ?= $(BUILD_DIR)/weak_stubs/src
+WEAK_STUBS_SRC := $(shell find $(BUILD_WEAK_STUBS_SRC) -name *.c)
+WEAK_STUBS_OBJ := $(patsubst $(BUILD_WEAK_STUBS_SRC)/%, $(WEAK_STUBS_OUTPUT_DIR)/%, $(WEAK_STUBS_SRC:.c=.o))
+```
+- `BUILD_WEAK_STUBS_SRC`: Path to source files for weak stubs.
+- `WEAK_STUBS_LIB`: Compiled weak library (`libweak_stubs_libs.so`).
+- `WEAK_STUBS_SRC` and `WEAK_STUBS_OBJ`: Dynamically map source to object files.
+
+#### Workflow:
+1. **Define Stubs**: Clients export `BUILD_WEAK_STUBS_SRC` with the path to stub source files.
+   ```bash
+   export BUILD_WEAK_STUBS_SRC=/path/to/stubs
+   ```
+2. **Build Library**: The Makefile compiles the stubs into a weak library.
+3. **Develop and Test**: Testing suites use the weak library.
+4. **Integrate Strong Implementation**: Vendors replace the weak stubs when ready.
+
+This approach ensures smooth testing suite development while awaiting third-party components.
+
 ## Running on the target
 
 Copy files from `bin/*` to the target.

tests/Makefile

@@ -24,6 +24,7 @@ TARGET_EXEC = ut-test
 
 # Switch on Linux & disable asserts for the testing suites
 CFLAGS += -DNDEBUG
+BUILD_WEAK_STUBS_SRC = $(ROOT_DIR)/src_weak
 ifneq ($(VARIANT),CPP)
 VARIANT = C
 XCFLAGS += -DUT_CUNIT
@@ -55,6 +56,7 @@ export TARGET
 export TARGET_EXEC
 export CFLAGS
 export LDFLAGS
+export BUILD_WEAK_STUBS_SRC
 
 GREEN='\033[0;32m'
 NC='\033[0m'