add a small Go script to generate the Makefile

1 files changed, 115 insertions, 0 deletions

diff --git a/tools/makefile.go b/tools/makefile.go
new file mode 100644
index 0000000..968b6d1
--- /dev/null
+++ b/tools/makefile.go
@@ -0,0 +1,115 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io/fs"
+	"os"
+	"path"
+	"strings"
+)
+
+var (
+	outputExe       = "game"
+	compilerExe     = "g++"
+	compilerOptions = []string{
+		"-m64",
+		"-fno-strict-aliasing",
+		"-pedantic",
+		"-Wall",
+		"-Wextra",
+		"-Wno-unused-parameter",
+		"-Wno-format-truncation",
+		"-std=c++11",
+		"-DOS_LINUX=1",
+		"-DARCH_X64=1",
+	}
+	linkerOptions = []string{
+		"-Wl,-t",
+	}
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Println("USAGE: makefile.exe SRCDIR")
+		os.Exit(1)
+	}
+
+	sourceDir := os.Args[1]
+	buildDir := path.Join(path.Dir(sourceDir), "build")
+
+	type Object struct{ obj, src string }
+	objectFiles := []Object{}
+	headerFiles := []string{}
+
+	fs.WalkDir(os.DirFS(sourceDir), ".",
+		func(rel string, d fs.DirEntry, err error) error {
+			if err == nil && !d.IsDir() {
+				ext := path.Ext(rel)
+				switch ext {
+				case ".cpp", ".cxx", ".cc", ".c":
+					src := rel
+					obj := rel[:len(src)-len(ext)] + ".obj"
+					objectFiles = append(objectFiles, Object{obj, src})
+				case ".hpp", ".hxx", ".hh", ".h":
+					hdr := rel
+					headerFiles = append(headerFiles, hdr)
+				}
+			}
+			return nil
+		})
+
+	output := bytes.Buffer{}
+
+	// VARIABLES
+	fmt.Fprintf(&output, "SRCDIR = %v\n", sourceDir)
+	fmt.Fprintf(&output, "BUILDDIR = %v\n", buildDir)
+	fmt.Fprintf(&output, "OUTPUTEXE = %v\n", outputExe)
+	fmt.Fprint(&output, "\n")
+
+	fmt.Fprintf(&output, "CC = %v\n", compilerExe)
+	fmt.Fprintf(&output, "CFLAGS = %v\n", strings.Join(compilerOptions, " "))
+	fmt.Fprintf(&output, "LFLAGS = %v\n", strings.Join(linkerOptions, " "))
+	fmt.Fprint(&output, "\n")
+
+	// DEBUG SWITCH
+	fmt.Fprint(&output, "DEBUG ?= 0\n")
+	fmt.Fprint(&output, "ifneq ($(DEBUG), 0)\n")
+	fmt.Fprint(&output, "\tCFLAGS += -g -O0\n")
+	fmt.Fprint(&output, "else\n")
+	fmt.Fprint(&output, "\tCFLAGS += -O2\n")
+	fmt.Fprint(&output, "endif\n")
+
+	// HEADERS
+	fmt.Fprint(&output, "HEADERS =")
+	for _, header := range headerFiles {
+		fmt.Fprintf(&output, " $(SRCDIR)/%v", header)
+	}
+	fmt.Fprint(&output, "\n\n")
+
+	// EXECUTABLE
+	fmt.Fprint(&output, "$(BUILDDIR)/$(OUTPUTEXE):")
+	for _, object := range objectFiles {
+		fmt.Fprintf(&output, " $(BUILDDIR)/%v", object.obj)
+	}
+	fmt.Fprint(&output, "\n")
+	fmt.Fprint(&output, "\t$(CC) $(CFLAGS) $(LFLAGS) -o $@ $^\n\n")
+
+	// OBJECTS
+	for _, object := range objectFiles {
+		fmt.Fprintf(&output, "$(BUILDDIR)/%v: $(SRCDIR)/%v $(HEADERS)\n", object.obj, object.src)
+		fmt.Fprint(&output, "\t@mkdir -p $(@D)\n")
+		fmt.Fprint(&output, "\t$(CC) -c $(CFLAGS) -o $@ $<\n\n")
+	}
+
+	// PHONY
+	fmt.Fprint(&output, ".PHONY: clean\n\n")
+	fmt.Fprint(&output, "clean:\n\t@rm -r $(BUILDDIR)\n\n")
+
+	if err := os.WriteFile("Makefile", output.Bytes(), 0644); err != nil {
+		fmt.Printf("failed to write Makefile: %v\n", err)
+		os.Exit(1)
+	}
+
+	return
+}