Added a build rule to generate compile_commands.json

Makefile

@@ -2,49 +2,81 @@ KERNEL_EXEC := socks_kernel
 
 ARCH := x86_64
 
+MAKEFILE_PATH := $(abspath $(lastword $(MAKEFILE_LIST)))
+ROOT_DIR := $(patsubst %/,%,$(dir $(MAKEFILE_PATH)))
+
 include tools/make/gcc-cross-compile.mk
 include arch/$(ARCH)/config.mk
 
-BUILDDIR := build
+BUILD_DIR := build
+
+####################################
+# Architecture-specific source files
+####################################
 
 ARCH_C_FILES := $(wildcard arch/$(ARCH)/*.c)
 ARCH_ASM_FILES := $(wildcard arch/$(ARCH)/*.S)
-ARCH_OBJ := $(addprefix $(BUILDDIR)/,$(ARCH_C_FILES:.c=.o) $(ARCH_ASM_FILES:.S=.o))
+ARCH_OBJ := $(addprefix $(BUILD_DIR)/,$(ARCH_C_FILES:.c=.o) $(ARCH_ASM_FILES:.S=.o))
 
-SRC_DIRS := core
-KERNEL_C_FILES := $(foreach dir,$(SRC_DIRS),$(wildcard $(dir)/*.c))
-KERNEL_OBJ := $(addprefix $(BUILDDIR)/,$(KERNEL_C_FILES:.c=.o))
+####################################
+# Platform-independent kernel source files
+####################################
+
+KERNEL_SRC_DIRS := init kernel
+KERNEL_C_FILES := $(foreach dir,$(KERNEL_SRC_DIRS),$(wildcard $(dir)/*.c))
+KERNEL_OBJ := $(addprefix $(BUILD_DIR)/,$(KERNEL_C_FILES:.c=.o))
+
+####################################
+# Kernel libc source files
+####################################
+
+LIBC_SRC_DIRS := stdio string ctype
+LIBC_C_FILES := $(foreach dir,$(LIBC_SRC_DIRS),$(wildcard libc/$(dir)/*.c))
+LIBC_OBJ := $(addprefix $(BUILD_DIR)/,$(LIBC_C_FILES:.c=.o))
 
 BUILD_ID := $(shell tools/generate_build_id.py --arch $(ARCH))
 
-CFLAGS := $(CFLAGS) -DBUILD_ID=\"$(BUILD_ID)\" -g
+CFLAGS := $(CFLAGS) -DBUILD_ID=\"$(BUILD_ID)\" -g \
+	"-I$(ROOT_DIR)/include" "-I$(ROOT_DIR)/arch/$(ARCH)/include" "-I$(ROOT_DIR)/libc/include"
+
 ASMFLAGS := $(ASMFLAGS) -DBUILD_ID=\"$(BUILD_ID)\"
 LDFLAGS := $(LDFLAGS) -g
 
-$(BUILDDIR)/$(KERNEL_EXEC): $(KERNEL_OBJ) $(ARCH_OBJ)
+ALL_KERNEL_OBJECT_FILES := $(KERNEL_OBJ) $(ARCH_OBJ) $(LIBC_OBJ)
+
+$(BUILD_DIR)/$(KERNEL_EXEC): $(ALL_KERNEL_OBJECT_FILES)
 	@echo "    \033[1;36mLINK\033[0m   \033[1m$@\033[0m"
 	@mkdir -p $(@D)
 	@$(LD) $^ -o $@ $(LDFLAGS) $(ARCH_LDFLAGS)
 
-$(BUILDDIR)/%.o: %.S
+$(BUILD_DIR)/%.o: %.S
 	@echo "    \033[1;32mASM\033[0m    $<"
 	@mkdir -p $(@D)
 	@$(ASM) $< -o $@ -c $(ASMFLAGS) $(ARCH_ASMFLAGS)
 
-$(BUILDDIR)/%.o: %.c
+$(BUILD_DIR)/%.o: %.c
 	@echo "    \033[1;32mCC\033[0m     $<"
 	@mkdir -p $(@D)
 	@$(CC) $< -o $@ -c $(CFLAGS) $(ARCH_CFLAGS)
 
 clean:
 	@echo "    \033[1;93mCLEAN\033[0m  Deleting build artefacts."
-	@rm -rf $(BUILDDIR)
+	@rm -rf $(BUILD_DIR)
 
 
-all: $(BUILDDIR)/$(KERNEL_EXEC)
+all: $(BUILD_DIR)/$(KERNEL_EXEC)
+
+$(BUILD_DIR)/compile_commands.json:
+	@$(MAKE) clean
+
+	@echo "    \033[1;93mGEN\033[0m    Generating compiler database."
+
+	@./tools/make/generate_compile_commands.py
+
+compile-db: $(BUILD_DIR)/compile_commands.json
 
 include arch/$(ARCH)/extra.mk
 
-.PHONY: all
+.PHONY: all compile-db
 
 .INTERMEDIATE: $(ARCH_TEMP_FILES)

tools/make/generate_compile_commands.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+import json
+import subprocess
+import os
+
+
+def is_source_file(filepath):
+    return filepath.endswith('.c') or filepath.endswith('.h') or filepath.endswith('.S')
+
+rootdir = os.getcwd()
+
+compile_db = []
+
+make_output = subprocess.check_output(['make', '-n']).decode('utf-8')
+
+make_output_lines = make_output.split('\n')
+
+for line in make_output_lines:
+    line_parts = line.split(' ')
+    new_line_parts = []
+
+    if 'gcc' not in line_parts[0]:
+        continue
+
+    src_file = ''
+    for part in line_parts:
+        part = part.strip()
+        if is_source_file(part):
+            src_file = part
+            part = '../{}'.format(part)
+
+        new_line_parts.append(part)
+
+    if len(src_file) == 0:
+        continue
+
+    db_entry = {
+            'directory': '{}/build'.format(rootdir),
+            'command': ' '.join(new_line_parts).strip(),
+            'file': '{}/{}'.format(rootdir, src_file)
+    }
+
+    compile_db.append(db_entry)
+
+os.system('make')
+
+out_file = open('build/compile_commands.json', 'w')
+json.dump(compile_db, out_file, indent=4)
+