[hackers] [scc] [cc2-qbe] Add allocation of parameters || Roberto E. Vargas Caballero

[git]

commit a914d8f2874b128360789b7c2e2511b0aa078978
Author:     Roberto E. Vargas Caballero <k...@shike2.com>
AuthorDate: Fri Apr 22 13:32:34 2016 +0200
Commit:     Roberto E. Vargas Caballero <k...@shike2.com>
CommitDate: Fri Apr 22 13:32:34 2016 +0200

    [cc2-qbe] Add allocation of parameters
    
    Qbe needs explicitely allocate the stack space for the parameters,
    which are considered only the values passed as parameters, not
    the local variables that parameter are to.

diff --git a/cc2/arch/qbe/code.c b/cc2/arch/qbe/code.c
index b956dfb..0900add 100644
--- a/cc2/arch/qbe/code.c
+++ b/cc2/arch/qbe/code.c
@@ -246,31 +246,53 @@ data(Node *np)
        putchar('\n');
 }
 
+static void
+alloc(Symbol *sym)
+{
+       Type *tp = &sym->type;
+
+       printf("\t%s %s=\talloc%lld\t%lld\n",
+              symname(sym), size2asm(tp),
+              (long long) tp->size, (long long) tp->align);
+}
+
 void
 writeout(void)
 {
        Symbol *p;
        Type *tp;
-       char *sep;
+       char *sep, *name;
 
        if (curfun->kind == SGLOB)
                fputs("export ", stdout);
        printf("function %s %s(", size2asm(&curfun->rtype), symname(curfun));
 
+       /* declare formal parameters */
        for (sep = "", p = locals; p; p = p->next, sep = ",") {
                if ((p->type.flags & PARF) == 0)
                        break;
-               printf("%s%s %s", sep, size2asm(&p->type), symname(p));
+               printf("%s%s %s.val", sep, size2asm(&p->type), symname(p));
        }
-       puts(")");
+       puts(")\n{");
+
+       /* allocate stack space for parameters */
+       for (p = locals; p && (p->type.flags & PARF) == 0; p = p->next)
+               alloc(p);
 
-       for ( ; p && p->id != TMPSYM; p = p->next) {
+       /* allocate stack space for local variables) */
+       for ( ; p && p->id != TMPSYM; p = p->next)
+               alloc(p);
+
+       /* store formal parameters in parameters */
+       for (p = locals; p; p = p->next) {
                tp = &p->type;
-               printf("\t%s %s=\talloc%lld\t%lld\n",
-                      symname(p), size2asm(tp),
-                      (long long) tp->size, (long long) tp->align);
+               if ((tp->flags & PARF) == 0)
+                       break;
+               name = symname(p);
+               printf("\t\tstore%s\t%s.val,%s\n", size2asm(tp), name, name);
        }
 
+       /* emit assembler instructions */
        for (pc = prog; pc; pc = pc->next) {
                if (pc->label)
                        printf("%s:\n", symname(pc->label));