Tree Exercise

gentree.c

#include <stdio.h>
#include <stdlib.h>

#define BEGIN \
	"#include <stdio.h>\n" \
	"#include <stdlib.h>\n" \
	"\n" \
	"static struct tree {\n" \
	"\tstruct tree *left, *right;\n" \
	"} *buf[BUFSIZ];\n" \
	"\n" \
	"static void output(tree)\n" \
	"\tstruct tree *tree;\n" \
	"{\n" \
	"\tif (!tree) {\n" \
	"\t\tputchar('0');\n" \
	"\t\treturn;\n" \
	"\t}\n" \
	"\n" \
	"\tputchar('1');\n" \
	"\toutput(tree->left);\n" \
	"\toutput(tree->right);\n" \
	"}\n" \
	"\n" \
	"int main()\n" \
	"{"

#define END \
	"\toutput(buf[0]);\n" \
	"\tputchar('\\n');\n" \
	"\treturn 0;\n" \
	"}"

/* Grammar: <tree> ::= '0' | '1' <tree> <tree>. */
static char *input;

static struct tree {
	struct tree *left, *right;
} *mktree()
{
	struct tree *tree = NULL;

	if ('1' == *input) {
		tree = malloc(sizeof *tree);
		++input;
		tree->left = mktree();
		++input;
		tree->right = mktree();
	}

	return tree;
}

static void gen(tree)
	struct tree *tree;
{
	/* TODO: print some code in stdout. */
}

int main(argc, argv)
	char *argv[];
{
	input = argv[argc - 1];

	puts(BEGIN);
	gen(mktree());
	puts(END);

	return 0;
}

Makefile

TEST = 0

all: gentree
	./gentree $(TEST) >output.c
	$(MAKE) output
	[ $(TEST) = $$(./output) ]

clean:
	-rm -f gentree output output.c