Improve Makefile bootstrap verification

Author: steven-studio

Makefile

@@ -1,6 +1,8 @@
-CFLAGS := -O -g \
-	-std=c99 -pedantic
+# Compiler and flags
+CC ?= gcc
+CFLAGS := -O -g -std=c99 -pedantic
 
+# Flags to check for compiler support
 CFLAGS_TO_CHECK := \
 	-fwrapv \
 	-Wall -Wextra \
@@ -16,122 +18,119 @@ CFLAGS_TO_CHECK := \
 	-Wno-format-pedantic \
 	-Wno-overflow
 
-SUPPORTED_CFLAGS :=
-# Check if a specific compiler flag is supported, attempting a dummy compilation
-# with flags. If successful, it returns the flag string; otherwise, it returns
-# an empty string.
-# Usage: $(call check_flag, -some-flag)
-check_flag = $(shell $(CC) $(1) -S -o /dev/null -xc /dev/null 2>/dev/null; \
-              if test $$? -eq 0; then echo "$(1)"; fi)
+# Check if a specific compiler flag is supported
+check_flag = $(shell $(CC) $(1) -S -o /dev/null -xc /dev/null 2>/dev/null && echo "$(1)")
 
-# Iterate through the list of all potential flags, effectively filtering out all
-# unsupported flags.
-$(foreach flag, $(CFLAGS_TO_CHECK), $(eval CFLAGS += $(call check_flag, $(flag))))
+# Add supported flags
+$(foreach flag,$(CFLAGS_TO_CHECK),$(eval CFLAGS += $(call check_flag,$(flag))))
 
+# Build configuration
 BUILD_SESSION := .session.mk
-
 -include $(BUILD_SESSION)
 
+# Stage definitions
 STAGE0 := shecc
 STAGE1 := shecc-stage1.elf
 STAGE2 := shecc-stage2.elf
 
+# Directory structure
 OUT ?= out
-ARCHS = arm riscv
-ARCH ?= $(firstword $(ARCHS))
-HOST_ARCH = $(shell arch 2>/dev/null)
 SRCDIR := $(shell find src -type d)
 LIBDIR := $(shell find lib -type d)
 
-SRCS := $(wildcard $(patsubst %,%/main.c, $(SRCDIR)))
+# Architecture configuration
+ARCHS := arm riscv
+ARCH ?= $(firstword $(ARCHS))
+HOST_ARCH := $(shell arch 2>/dev/null)
+
+# Source files
+SRCS := $(wildcard $(patsubst %,%/main.c,$(SRCDIR)))
 OBJS := $(SRCS:%.c=$(OUT)/%.o)
-deps := $(OBJS:%.o=%.o.d)
+DEPS := $(OBJS:%.o=%.o.d)
+
+# Test files
 TESTS := $(wildcard tests/*.c)
 TESTBINS := $(TESTS:%.c=$(OUT)/%.elf)
-SNAPSHOTS := $(foreach SNAPSHOT_ARCH,$(ARCHS), $(patsubst tests/%.c, tests/snapshots/%-$(SNAPSHOT_ARCH).json, $(TESTS)))
+SNAPSHOTS := $(foreach SNAPSHOT_ARCH,$(ARCHS),$(patsubst tests/%.c,tests/snapshots/%-$(SNAPSHOT_ARCH).json,$(TESTS)))
 
-all: config bootstrap
+# Build targets
+.PHONY: all config bootstrap clean distclean
+.PHONY: check check-stage0 check-stage2 check-sanitizer check-snapshots check-snapshot
+.PHONY: update-snapshots update-snapshot sanitizer help
 
-sanitizer: CFLAGS += -fsanitize=address -fsanitize=undefined -fno-omit-frame-pointer -O0
-sanitizer: LDFLAGS += -fsanitize=address -fsanitize=undefined
-sanitizer: config $(OUT)/$(STAGE0)-sanitizer
-	$(VECHO) "  Built stage 0 compiler with sanitizers\n"
+.DEFAULT_GOAL := all
+
+all: config bootstrap
 
+help:
+	@echo "Available targets:"
+	@echo "  all              - Build with bootstrap (default)"
+	@echo "  bootstrap        - Build and verify self-hosting compiler"
+	@echo "  config           - Configure target architecture"
+	@echo "  sanitizer        - Build with address/undefined sanitizers"
+	@echo "  check            - Run all tests"
+	@echo "  check-stage0     - Test stage 0 compiler"
+	@echo "  check-stage2     - Test stage 2 compiler"
+	@echo "  check-sanitizer  - Test with sanitizers"
+	@echo "  check-snapshots  - Verify IR snapshots"
+	@echo "  update-snapshots - Update IR snapshots"
+	@echo "  clean            - Remove build artifacts"
+	@echo "  distclean        - Remove all generated files"
+	@echo ""
+	@echo "Variables:"
+	@echo "  ARCH={arm,riscv} - Target architecture (default: $(ARCH))"
+	@echo "  OUT=<dir>        - Output directory (default: $(OUT))"
+	@echo "  CC=<compiler>    - C compiler (default: $(CC))"
+
+# Validate architecture selection
 ifeq (,$(filter $(ARCH),$(ARCHS)))
-$(error Support ARM and RISC-V only. Select the target with "ARCH=arm" or "ARCH=riscv")
+$(error Unsupported architecture '$(ARCH)'. Use ARCH=arm or ARCH=riscv)
 endif
+
 include mk/$(ARCH).mk
 include mk/common.mk
 
+# Configuration target
 config:
-	$(Q)ln -s $(PWD)/$(SRCDIR)/$(ARCH)-codegen.c $(SRCDIR)/codegen.c
+	$(Q)mkdir -p $(OUT) $(OUT)/$(SRCDIR) $(OUT)/tests
+	$(Q)ln -sf $(PWD)/$(SRCDIR)/$(ARCH)-codegen.c $(SRCDIR)/codegen.c
 	$(Q)$(PRINTF) $(ARCH_DEFS) > $@
-	$(VECHO) "Target machine code switch to %s\n" $(ARCH)
-	$(Q)$(MAKE) $(BUILD_SESSION) --silent
+	$(VECHO) "Target architecture: %s\n" $(ARCH)
+	$(Q)$(MAKE) $(BUILD_SESSION) --no-print-directory
 	$(Q)$(CONFIG_CHECK_CMD)
 
-$(OUT)/tests/%.elf: tests/%.c $(OUT)/$(STAGE0)
-	$(VECHO) "  SHECC\t$@\n"
-	$(Q)$(OUT)/$(STAGE0) --dump-ir -o $@ $< > $(basename $@).log ; \
-	chmod +x $@ ; $(PRINTF) "Running $@ ...\n"
-	$(Q)$(TARGET_EXEC) $@ && $(call pass)
-
-check: check-stage0 check-stage2
-
-check-stage0: $(OUT)/$(STAGE0) $(TESTBINS) tests/driver.sh
-	$(VECHO) "  TEST STAGE 0\n"
-	tests/driver.sh 0
-
-check-stage2: $(OUT)/$(STAGE2) $(TESTBINS) tests/driver.sh
-	$(VECHO) "  TEST STAGE 2\n"
-	tests/driver.sh 2
-
-check-sanitizer: $(OUT)/$(STAGE0)-sanitizer tests/driver.sh
-	$(VECHO) "  TEST STAGE 0 (with sanitizers)\n"
-	$(Q)cp $(OUT)/$(STAGE0)-sanitizer $(OUT)/shecc
-	tests/driver.sh 0
-	$(Q)rm $(OUT)/shecc
-
-check-snapshots: $(OUT)/$(STAGE0) $(SNAPSHOTS) tests/check-snapshots.sh
-	$(Q)$(foreach SNAPSHOT_ARCH, $(ARCHS), $(MAKE) distclean config check-snapshot ARCH=$(SNAPSHOT_ARCH) --silent;)
-	$(VECHO) "Switching backend back to %s\n" $(ARCH)
-	$(Q)$(MAKE) distclean config ARCH=$(ARCH) --silent
-
-check-snapshot: $(OUT)/$(STAGE0) tests/check-snapshots.sh
-	$(VECHO) "Checking snapshot for %s\n" $(ARCH)
-	tests/check-snapshots.sh $(ARCH)
-	$(VECHO) "  OK\n"
-
-update-snapshots: tests/update-snapshots.sh
-	$(Q)$(foreach SNAPSHOT_ARCH, $(ARCHS), $(MAKE) distclean config update-snapshot ARCH=$(SNAPSHOT_ARCH) --silent;)
-	$(VECHO) "Switching backend back to %s\n" $(ARCH)
-	$(Q)$(MAKE) distclean config ARCH=$(ARCH) --silent
+$(BUILD_SESSION):
+	@$(PRINTF) "ARCH=$(ARCH)\n" > $@
 
-update-snapshot: $(OUT)/$(STAGE0) tests/update-snapshots.sh
-	$(VECHO) "Updating snapshot for %s\n" $(ARCH)
-	tests/update-snapshots.sh $(ARCH)
-	$(VECHO) "  OK\n"
+# Sanitizer build
+sanitizer: CFLAGS += -fsanitize=address -fsanitize=undefined -fno-omit-frame-pointer -O0
+sanitizer: LDFLAGS += -fsanitize=address -fsanitize=undefined
+sanitizer: config $(OUT)/$(STAGE0)-sanitizer
+	$(VECHO) "Built stage 0 compiler with sanitizers\n"
 
-$(OUT)/%.o: %.c
+# Object file compilation
+$(OUT)/%.o: %.c | $(OUT)
 	$(VECHO) "  CC\t$@\n"
+	$(Q)mkdir -p $(dir $@)
 	$(Q)$(CC) -o $@ $(CFLAGS) -c -MMD -MF $@.d $<
 
-SHELL_HACK := $(shell mkdir -p $(OUT) $(OUT)/$(SRCDIR) $(OUT)/tests)
+# Tool binaries
+$(OUT)/norm-lf: tools/norm-lf.c | $(OUT)
+	$(VECHO) "  CC+LD\t$@\n"
+	$(Q)$(CC) $(CFLAGS) -o $@ $^
 
-$(OUT)/norm-lf: tools/norm-lf.c
+$(OUT)/inliner: tools/inliner.c | $(OUT)
 	$(VECHO) "  CC+LD\t$@\n"
 	$(Q)$(CC) $(CFLAGS) -o $@ $^
 
-$(OUT)/libc.inc: $(OUT)/inliner $(OUT)/norm-lf $(LIBDIR)/c.c
+# Generate libc include
+$(OUT)/libc.inc: $(OUT)/inliner $(OUT)/norm-lf $(LIBDIR)/c.c | $(OUT)
 	$(VECHO) "  GEN\t$@\n"
 	$(Q)$(OUT)/norm-lf $(LIBDIR)/c.c $(OUT)/c.normalized.c
 	$(Q)$(OUT)/inliner $(OUT)/c.normalized.c $@
 	$(Q)$(RM) $(OUT)/c.normalized.c
 
-$(OUT)/inliner: tools/inliner.c
-	$(VECHO) "  CC+LD\t$@\n"
-	$(Q)$(CC) $(CFLAGS) -o $@ $^
-
+# Stage 0: Host compiler build
 $(OUT)/$(STAGE0): $(OUT)/libc.inc $(OBJS)
 	$(VECHO) "  LD\t$@\n"
 	$(Q)$(CC) $(OBJS) $(LDFLAGS) -o $@
@@ -140,35 +139,94 @@ $(OUT)/$(STAGE0)-sanitizer: $(OUT)/libc.inc $(OBJS)
 	$(VECHO) "  LD\t$@ (with sanitizers)\n"
 	$(Q)$(CC) $(OBJS) $(LDFLAGS) -o $@
 
+# Stage 1: Self-compiled compiler
 $(OUT)/$(STAGE1): $(OUT)/$(STAGE0)
 	$(Q)$(STAGE1_CHECK_CMD)
 	$(VECHO) "  SHECC\t$@\n"
 	$(Q)$(OUT)/$(STAGE0) --dump-ir -o $@ $(SRCDIR)/main.c > $(OUT)/shecc-stage1.log
 	$(Q)chmod a+x $@
 
+# Stage 2: Verify bootstrap
 $(OUT)/$(STAGE2): $(OUT)/$(STAGE1)
 	$(VECHO) "  SHECC\t$@\n"
 	$(Q)$(TARGET_EXEC) $(OUT)/$(STAGE1) -o $@ $(SRCDIR)/main.c
+	$(Q)chmod a+x $@
 
+# Bootstrap verification
 bootstrap: $(OUT)/$(STAGE2)
-	$(Q)chmod 775 $(OUT)/$(STAGE2)
-	$(Q)if ! diff -q $(OUT)/$(STAGE1) $(OUT)/$(STAGE2); then \
-	echo "Unable to bootstrap. Aborting"; false; \
+	$(Q)if cmp -s $(OUT)/$(STAGE1) $(OUT)/$(STAGE2); then \
+		echo "Bootstrap successful: Stage 1 and Stage 2 are identical"; \
+	else \
+		echo "ERROR: Bootstrap failed - Stage 1 and Stage 2 differ"; \
+		exit 1; \
 	fi
 
-$(BUILD_SESSION):
-	$(PRINTF) "ARCH=$(ARCH)" > $@
+# Test compilation
+$(OUT)/tests/%.elf: tests/%.c $(OUT)/$(STAGE0)
+	$(VECHO) "  SHECC\t$@\n"
+	$(Q)$(OUT)/$(STAGE0) --dump-ir -o $@ $< > $(basename $@).log
+	$(Q)chmod +x $@
+	$(Q)$(PRINTF) "Running $@ ...\n"
+	$(Q)$(TARGET_EXEC) $@ && $(call pass)
+
+# Test targets
+check: check-stage0 check-stage2
 
-.PHONY: clean
+check-stage0: $(OUT)/$(STAGE0) $(TESTBINS) tests/driver.sh
+	$(VECHO) "Testing Stage 0 compiler\n"
+	@tests/driver.sh 0
+
+check-stage2: $(OUT)/$(STAGE2) $(TESTBINS) tests/driver.sh
+	$(VECHO) "Testing Stage 2 compiler\n"
+	@tests/driver.sh 2
+
+check-sanitizer: $(OUT)/$(STAGE0)-sanitizer tests/driver.sh
+	$(VECHO) "Testing Stage 0 with sanitizers\n"
+	$(Q)cp $(OUT)/$(STAGE0)-sanitizer $(OUT)/shecc
+	@tests/driver.sh 0
+	$(Q)rm $(OUT)/shecc
+
+# Snapshot testing
+check-snapshots: $(OUT)/$(STAGE0) $(SNAPSHOTS) tests/check-snapshots.sh
+	$(Q)$(foreach SNAPSHOT_ARCH,$(ARCHS),$(MAKE) distclean config check-snapshot ARCH=$(SNAPSHOT_ARCH) --no-print-directory;)
+	$(VECHO) "Switching backend back to %s\n" $(ARCH)
+	$(Q)$(MAKE) distclean config ARCH=$(ARCH) --no-print-directory
+
+check-snapshot: $(OUT)/$(STAGE0) tests/check-snapshots.sh
+	$(VECHO) "Checking snapshot for %s\n" $(ARCH)
+	@tests/check-snapshots.sh $(ARCH)
+	$(VECHO) "  OK\n"
+
+update-snapshots: tests/update-snapshots.sh
+	$(Q)$(foreach SNAPSHOT_ARCH,$(ARCHS),$(MAKE) distclean config update-snapshot ARCH=$(SNAPSHOT_ARCH) --no-print-directory;)
+	$(VECHO) "Switching backend back to %s\n" $(ARCH)
+	$(Q)$(MAKE) distclean config ARCH=$(ARCH) --no-print-directory
+
+update-snapshot: $(OUT)/$(STAGE0) tests/update-snapshots.sh
+	$(VECHO) "Updating snapshot for %s\n" $(ARCH)
+	@tests/update-snapshots.sh $(ARCH)
+	$(VECHO) "  OK\n"
+
+# Directory creation
+$(OUT):
+	@mkdir -p $(OUT) $(OUT)/$(SRCDIR) $(OUT)/tests
+
+# Clean targets
 clean:
-	-$(RM) $(OUT)/$(STAGE0) $(OUT)/$(STAGE1) $(OUT)/$(STAGE2)
-	-$(RM) $(OBJS) $(deps)
-	-$(RM) $(TESTBINS) $(OUT)/tests/*.log $(OUT)/tests/*.lst
-	-$(RM) $(OUT)/shecc*.log
-	-$(RM) $(OUT)/libc.inc
+	$(VECHO) "Cleaning build artifacts\n"
+	-$(Q)$(RM) -f $(OUT)/$(STAGE0) $(OUT)/$(STAGE1) $(OUT)/$(STAGE2)
+	-$(Q)$(RM) -f $(OUT)/$(STAGE0)-sanitizer
+	-$(Q)$(RM) -f $(OBJS) $(DEPS)
+	-$(Q)$(RM) -f $(TESTBINS) $(OUT)/tests/*.log $(OUT)/tests/*.lst
+	-$(Q)$(RM) -f $(OUT)/shecc*.log
+	-$(Q)$(RM) -f $(OUT)/libc.inc $(OUT)/c.normalized.c
 
 distclean: clean
-	-$(RM) $(OUT)/inliner $(OUT)/norm-lf $(OUT)/target $(SRCDIR)/codegen.c config $(BUILD_SESSION)
-	-$(RM) DOM.dot CFG.dot
-
--include $(deps)
+	$(VECHO) "Removing all generated files\n"
+	-$(Q)$(RM) -f $(OUT)/inliner $(OUT)/norm-lf $(OUT)/target
+	-$(Q)$(RM) -f $(SRCDIR)/codegen.c config $(BUILD_SESSION)
+	-$(Q)$(RM) -f DOM.dot CFG.dot
+	-$(Q)$(RM) -rf $(OUT)
+
+# Include dependencies
+-include $(DEPS)