1 files changed, 166 insertions, 0 deletions
diff --git a/cgen.c b/cgen.c
new file mode 100644
index 0000000..46ea085
--- /dev/null
+++ b/cgen.c
@@ -0,0 +1,166 @@
+#include "cgen.h"
+#include "fn.h"
+#include "lex.h"
+#include "lit.h"
+#include "parse.h"
+#include "storage.h"
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+void cgen_free(struct cgen *c)
+{
+}
+
+const char *cgen_sz(const size_t sz)
+{
+    switch (sz)
+    {
+        case 1:
+            return "b";
+        case 2:
+            return "h";
+        case 4:
+            return "w";
+        case 8:
+            return "l";
+        default:
+            break;
+    }
+
+    return NULL;
+}
+
+const char *cgen_type(const struct type *t)
+{
+    switch (t->sz)
+    {
+    case 1:
+        return t->sign ? "b" : "ub";
+    case 2:
+        return t->sign ? "h" : "uh";
+    case 4:
+        return t->sign ? "w" : "uw";
+    case 8:
+        return t->sign ? "l" : "ul";
+
+    default:
+        break;
+    }
+
+    return NULL;
+}
+
+const char *cgen_abity(const struct type *t)
+{
+    switch (t->sz)
+    {
+    case 1:
+        return t->sign ? "b" : "ub";
+    case 2:
+        return t->sign ? "h" : "uh";
+    case 4:
+        return "w";
+    case 8:
+        return "l";
+
+    default:
+        break;
+    }
+
+    return NULL;
+}
+
+const char *cgen_load(const struct type *t)
+{
+    switch (t->sz)
+    {
+    case 1:
+        return t->sign ? "sb" : "ub";
+    case 2:
+        return t->sign ? "sh" : "uh";
+    case 4:
+        return t->sign ? "sw" : "uw";
+    case 8:
+        return "l";
+
+    default:
+        break;
+    }
+
+    return NULL;
+}
+
+int cgen_param(const struct fn *fn, const struct stentry *e)
+{
+    const struct pr *pr = fn->pr;
+    const char *name = e->tk->s;
+
+    for (size_t i = 0; i < pr->nparams; i++)
+        if (!strcmp(pr->params[i].tk->s, name))
+            return 1;
+
+    return 0;
+}
+
+int cgen_global(const struct fn *fn, const struct stentry *e)
+{
+    const struct storage *ws = fn->ws, *gl = fn->gl;
+    const struct pr *pr = fn->pr;
+    const struct param *ret = pr->ret;
+    const char *name = e->tk->s;
+
+    /* A variable is only global if it is defined inside the global
+     * variables section ("gl"), or if it is not listed on the working
+     * storage section ("ws"), as a function parameter or a return value. */
+
+    if (gl)
+        for (size_t i = 0; i < gl->nentries; i++)
+            if (!strcmp(gl->entries[i].tk->s, name))
+                return 1;
+
+    if (cgen_param(fn, e))
+        return 0;
+
+    if (ret && !strcmp(ret->tk->s, name))
+        return 0;
+
+    if (ws)
+        for (size_t i = 0; i < ws->nentries; i++)
+            if (!strcmp(ws->entries[i].tk->s, name))
+                return 0;
+
+    return 1;
+}
+
+static void pushfmt(const char *type, const char *fmt)
+{
+    printf("data $____fmt%s = { b \"%s\" , b 0 }\n", type, fmt);
+}
+
+int cgen(const struct ast *ast, struct cgen *c)
+{
+    /* generate literals to use with printf(3) */
+    pushfmt("b", "%hhd");
+    pushfmt("h", "%hd");
+    pushfmt("w", "%d");
+    pushfmt("l", "%ld");
+    pushfmt("ub", "%hhu");
+    pushfmt("uh", "%hu");
+    pushfmt("uw", "%u");
+    pushfmt("ul", "%lu");
+    pushfmt("bx", "%#hhx");
+    pushfmt("hx", "%#hx");
+    pushfmt("wx", "%#x");
+    pushfmt("lx", "%#lx");
+
+    for (const struct lit *l = ast->lits; l; l = l->next)
+        if (lit_cgen(l))
+            return-1;
+
+    for (size_t i = 0; i < ast->nfns; i++)
+        if (fn_cgen((c->fn = &ast->fns[i]), c))
+            return -1;
+
+    return 0;
+}