1 files changed, 387 insertions, 0 deletions
diff --git a/fptr_ast/fptr.c b/fptr_ast/fptr.c
new file mode 100644
index 0000000..7959735
--- /dev/null
+++ b/fptr_ast/fptr.c
@@ -0,0 +1,387 @@
+#include <stdarg.h>
+#include <stdint.h>
+
+#include "common.h"
+
+typedef struct var {
+	char *name;
+	intptr_t v;
+} var;
+
+#define VEC_NAME vars
+#define VEC_TYPE var
+#include <conts/vec.h>
+typedef struct vars vars;
+
+typedef struct proc {
+	vars vars;
+} proc;
+
+static proc *gen_proc(int header, ...)
+{
+	(void)header;
+
+	proc *proc = calloc(1, sizeof(struct proc));
+	if (!proc)
+		return NULL;
+
+	proc->vars = vars_create(0);
+
+	va_list args;
+	va_start(args, header);
+	while (1) {
+		char *name = va_arg(args, char *);
+
+		/* NULL sentinel */
+		if (!name)
+			break;
+
+		var var = {
+			.name = name,
+			.v = 0
+		};
+		vars_append(&proc->vars, var);
+	}
+	va_end(args);
+
+	return proc;
+}
+
+#define gen_proc(...) gen_proc(0, __VA_ARGS__, NULL)
+
+static void proc_set(proc *proc, char *name, intptr_t v)
+{
+	foreach(vars, var, &proc->vars) {
+		if (strcmp(var->name, name) != 0)
+			continue;
+
+		var->v = v;
+		return;
+	}
+
+	/* abort? */
+}
+
+typedef struct node node;
+
+typedef intptr_t (*node_run_t)(struct node *);
+
+typedef struct node {
+	node_run_t run;
+} node;
+
+static intptr_t run(node *n)
+{
+	assert(n);
+	return n->run(n);
+}
+
+typedef struct load {
+	node node;
+	node *addr;
+} load;
+
+static intptr_t run_load(load *l)
+{
+	return *(intptr_t *)run(l->addr);
+}
+
+static node *gen_load(node *addr)
+{
+	load *l = calloc(1, sizeof(load));
+	if (!l)
+		return NULL;
+
+	l->node.run = (node_run_t)run_load;
+	l->addr = addr;
+	return &l->node;
+}
+
+typedef struct store {
+	node node;
+	node *addr;
+	node *val;
+} store;
+
+static intptr_t run_store(store *s)
+{
+	intptr_t *dst = (intptr_t *)run(s->addr);
+	intptr_t val = run(s->val);
+	*dst = val;
+	return 0;
+}
+
+static node *gen_store(node *addr, node *val)
+{
+	store *s = calloc(1, sizeof(store));
+	if (!s)
+		return NULL;
+
+	s->node.run = (node_run_t)run_store;
+	s->addr = addr;
+	s->val = val;
+	return &s->node;
+}
+
+typedef struct add {
+	node node;
+	node *l;
+	node *r;
+} add;
+
+static intptr_t run_add(add *a)
+{
+	intptr_t l = run(a->l);
+	intptr_t r = run(a->r);
+	return l + r;
+}
+
+static node *gen_add(node *l, node *r)
+{
+	add *a = calloc(1, sizeof(add));
+	if (!a)
+		return NULL;
+
+	a->node.run = (node_run_t)run_add;
+	a->l = l;
+	a->r = r;
+	return &a->node;
+}
+
+typedef struct mul {
+	node node;
+	node *l;
+	node *r;
+} mul;
+
+static intptr_t run_mul(mul *m)
+{
+	intptr_t l = run(m->l);
+	intptr_t r = run(m->r);
+	return l * r;
+}
+
+static node *gen_mul(node *l, node *r)
+{
+	mul *m = calloc(1, sizeof(mul));
+	if (!m)
+		return NULL;
+
+	m->node.run = (node_run_t)run_mul;
+	m->l = l;
+	m->r = r;
+	return &m->node;
+}
+
+typedef struct var_n {
+	node node;
+	intptr_t *varref;
+} var_n;
+
+static intptr_t run_var(var_n *v)
+{
+	return *v->varref;
+}
+
+static node *gen_var(proc *proc, char *name)
+{
+	assert(proc && name);
+
+	var_n *v = calloc(1, sizeof(var_n));
+	if (!v)
+		return NULL;
+
+	v->node.run = (node_run_t)run_var;
+	foreach(vars, var, &proc->vars) {
+		if (strcmp(var->name, name) != 0)
+			continue;
+
+		v->varref = &var->v;
+		return &v->node;
+	}
+
+	free(v);
+	return NULL;
+}
+
+typedef struct varref {
+	node node;
+	intptr_t *varref;
+} varref;
+
+static intptr_t run_varref(varref *v)
+{
+	return (intptr_t)v->varref;
+}
+
+static node *gen_varref(proc *proc, char *name)
+{
+	assert(proc && name);
+
+	/* technically speaking we could use the same trick here as in struct.c
+	 * since var and varref are the same shape, but feels a bit dirty. */
+
+	varref *v = calloc(1, sizeof(varref));
+	if (!v)
+		return NULL;
+
+	v->node.run = (node_run_t)run_varref;
+	foreach(vars, var, &proc->vars) {
+		if (strcmp(var->name, name) != 0)
+			continue;
+
+		v->varref = &var->v;
+		return &v->node;
+	}
+
+	free(v);
+	return NULL;
+}
+
+typedef struct const_n {
+	node node;
+	intptr_t v;
+} const_n;
+
+static intptr_t run_const_n(const_n *c)
+{
+	return c->v;
+}
+
+static node *gen_const(intptr_t v)
+{
+	const_n *c = calloc(1, sizeof(const_n));
+	if (!c)
+		return NULL;
+
+	c->node.run = (node_run_t)run_const_n;
+	c->v = v;
+	return &c->node;
+}
+
+typedef struct assign {
+	node node;
+	node *dst;
+	node *src;
+} assign;
+
+static intptr_t run_assign(assign *a)
+{
+	intptr_t *dst = (intptr_t *)run(a->dst);
+	intptr_t src = run(a->src);
+	*dst = src;
+	return 0;
+}
+
+static node *gen_assign(node *dst, node *src)
+{
+	assign *a = calloc(1, sizeof(assign));
+	if (!a)
+		return NULL;
+
+	a->node.run = (node_run_t)run_assign;
+	a->dst = dst;
+	a->src = src;
+	return &a->node;
+}
+
+typedef struct for_n {
+	node node;
+	node *init;
+	node *cond;
+	node *post;
+	node *body;
+} for_n;
+
+static intptr_t run_for(for_n *f)
+{
+	for (run(f->init); run(f->cond); run(f->post))
+		run(f->body);
+
+	return 0;
+}
+
+static node *gen_for(node *init, node *cond, node *post, node *body)
+{
+	for_n *f = calloc(1, sizeof(for_n));
+	if (!f)
+		return NULL;
+
+	f->node.run = (node_run_t)run_for;
+	f->init = init;
+	f->cond = cond;
+	f->post = post;
+	f->body = body;
+	return &f->node;
+}
+
+typedef struct lt {
+	node node;
+	node *l;
+	node *r;
+} lt;
+
+static intptr_t run_lt(lt *c)
+{
+	intptr_t l = run(c->l);
+	intptr_t r = run(c->r);
+	return l < r;
+}
+
+static node *gen_lt(node *l, node *r)
+{
+	lt *c = calloc(1, sizeof(lt));
+	if (!c)
+		return NULL;
+
+	c->node.run = (node_run_t)run_lt;
+	c->l = l;
+	c->r = r;
+	return &c->node;
+}
+
+#define VEC_NAME nodes
+#define VEC_TYPE node *
+#include <conts/vec.h>
+typedef struct nodes nodes;
+
+typedef struct body {
+	node node;
+	nodes list;
+} body;
+
+static intptr_t run_body(body *b)
+{
+	foreach(nodes, node, &b->list) {
+		run(*node);
+	}
+
+	return 0;
+}
+
+static node *gen_body(int header, ...)
+{
+	(void)header;
+	body *b = calloc(1, sizeof(body));
+	if (!b)
+		return NULL;
+
+	b->node.run = (node_run_t)run_body;
+	b->list = nodes_create(0);
+
+	va_list args;
+	va_start(args, header);
+	while (1) {
+		node *n = va_arg(args, node *);
+		if (!n)
+			break;
+
+		nodes_append(&b->list, n);
+	}
+
+	va_end(args);
+
+	return &b->node;
+}
+
+#define gen_body(...) gen_body(0, __VA_ARGS__, NULL)