Makefile: compile objects individually, then link

This commit updates the Makefile to complile each .c source file into
an object before linking. The benefit of this is that only the necessary
files will be recompiled when modifying the code.

We also move the Makefile and build.bat up to the root directory of the
repo. This is so that calling make directly builds the binaries.
Both files are updated to adapt to the new directory structure.

With this change, initial build times are increased from ~3s to ~10s on
my machine. However, subsequent build times are improved.

As a result of this change, SConstruct is somewhat deprecated. We can
update this as well if necessary in a future change.

I verified that the build completes successfully and tests pass for
both ubuntu and windows 10.

A future change could compile src/ files into a static library to be
linked with cli/, if necessary.

Issue: #64

.github/workflows/build.yml

@@ -19,8 +19,7 @@ jobs:
       - uses: actions/checkout@v2
       - name: Run the Makefile.
         run: |
-          cd build
+          make all
-          make
       - name: Run tests.
         run: |
           python3 tests/tests.py
@@ -32,7 +31,6 @@ jobs:
       - uses: actions/checkout@v2      
       - name: Run build batch script.
         run: |
-          cd build
           cmd /c build.bat
       - name: Run tests.
         run: |
@@ -45,8 +43,7 @@ jobs:
       - uses: actions/checkout@v2
       - name: Run the Makefile.
         run: |
-          cd build
+          make all
-          make
       - name: Run tests.
         run: |
           python3 tests/tests.py

.gitignore

@@ -2,8 +2,9 @@
 # PocketLang ignore list
 .vs/
 .vscode/
+build/
 
-# It's a convinent batch scrpit to run pyton script
+# It's a convinent batch script to run pyton script
 # changing directory and run another script.
 # Which are compile wasm and generate pages.
 docs/build.bat

Makefile

@@ -0,0 +1,59 @@
+
+# ##  Copyright (c) 2020-2021 Thakee Nathees
+# ##  Distributed Under The MIT License
+
+CC             = gcc
+CFLAGS         = -fPIC -Wno-int-to-pointer-cast
+DEBUG_CFLAGS   = -D DEBUG -g3 -Og
+RELEASE_CFLAGS = -g -O3
+LDFLAGS        = -lm
+
+TARGET_EXEC = pocket
+BUILD_DIR   = ./build
+
+SRC_DIRS = ./src ./cli
+INC_DIRS = ./src/include
+
+SRCS := $(shell find $(SRC_DIRS) -maxdepth 1 -name *.c)
+OBJS := $(SRCS:.c=.o)
+DEPS := $(OBJS:.o=.d)
+
+INC_FLAGS := $(addprefix -I,$(INC_DIRS))
+DEP_FLAGS  = -MMD -MP
+CC_FLAGS   = $(INC_FLAGS) $(DEP_FLAGS) $(CFLAGS)
+
+DEBUG_DIR     = $(BUILD_DIR)/debug
+DEBUG_TARGET  = $(DEBUG_DIR)/$(TARGET_EXEC)
+DEBUG_OBJS   := $(addprefix $(DEBUG_DIR)/, $(OBJS))
+
+RELEASE_DIR     = $(BUILD_DIR)/release
+RELEASE_TARGET  = $(RELEASE_DIR)/$(TARGET_EXEC)
+RELEASE_OBJS   := $(addprefix $(RELEASE_DIR)/, $(OBJS))
+
+.PHONY: debug release all clean
+
+# default; target if run as `make`
+debug: $(DEBUG_TARGET)
+
+$(DEBUG_TARGET): $(DEBUG_OBJS)
+	$(CC) $^ -o $@ $(LDFLAGS)
+
+$(DEBUG_DIR)/%.o: %.c
+	@mkdir -p $(dir $@)
+	$(CC) $(CC_FLAGS) $(DEBUG_CFLAGS) -c $< -o $@
+
+release: $(RELEASE_TARGET)
+
+$(RELEASE_TARGET): $(RELEASE_OBJS)
+	$(CC) $^ -o $@ $(LDFLAGS)
+
+$(RELEASE_DIR)/%.o: %.c
+	@mkdir -p $(dir $@)
+	$(CC) $(CC_FLAGS) $(RELEASE_CFLAGS) -c $< -o $@
+
+all: debug release
+
+clean:
+	rm -rf $(BUILD_DIR)
+
+-include $(DEPS)

build.bat

@@ -95,11 +95,11 @@ set root_dir=..\..\..\
 
 if "%debug_build%"=="false" (
 	set cflags=%cflags% -O2 -MD
-	set target_dir=release\
+	set target_dir=build\release\
 ) else (
 	set cflags=%cflags% -MDd -ZI
 	set addnl_cdefines=%addnl_cdefines% /DDEBUG
-	set target_dir=debug\
+	set target_dir=build\debug\
 )
 
 if "%shared_lib%"=="true" (

build/.gitignore

@@ -1,5 +0,0 @@
-*
-!.gitignore
-!SConstruct
-!build.bat
-!Makefile

build/Makefile

@@ -1,22 +0,0 @@
-
-##  Copyright (c) 2020-2021 Thakee Nathees
-##  Distributed Under The MIT License
-
-CC          = gcc
-CFLAGS      = -lm -fPIC -Wno-int-to-pointer-cast
-INCLUDE_DIR = -I../src/include
-SOURCES     = ../cli/*.c ../src/*.c
-
-all: debug
-
-debug:
-	@mkdir -p debug/
-	$(CC) -o debug/pocket $(SOURCES) $(INCLUDE_DIR) $(CFLAGS) -D DEBUG -g3 -Og
-
-release:
-	@mkdir -p release/
-	$(CC) -o release/pocket $(SOURCES) $(INCLUDE_DIR) $(CFLAGS) -g -O3
-
-clean:
-	rm -rf debug/
-	rm -rf release/