Add struct assignment

codegen.c

@@ -68,7 +68,7 @@ static void gen_addr(Node *node) {
 
 // Load a value from where %rax is pointing to.
 static void load(Type *ty) {
-  if (ty->kind == TY_ARRAY) {
+  if (ty->kind == TY_ARRAY || ty->kind == TY_STRUCT || ty->kind == TY_UNION) {
     // If it is an array, do not attempt to load a value to the
     // register because in general we can't load an entire array to a
     // register. As a result, the result of an evaluation of an array
@@ -88,6 +88,14 @@ static void load(Type *ty) {
 static void store(Type *ty) {
   pop("%rdi");
 
+  if (ty->kind == TY_STRUCT || ty->kind == TY_UNION) {
+    for (int i = 0; i < ty->size; i++) {
+      println("  mov %d(%%rax), %%r8b", i);
+      println("  mov %%r8b, %d(%%rdi)", i);
+    }
+    return;
+  }
+
   if (ty->size == 1)
     println("  mov %%al, (%%rdi)");
   else

test/struct.c

@@ -36,6 +36,16 @@ int main() {
   ASSERT(3, ({ struct t {char a;} x; struct t *y = &x; x.a=3; y->a; }));
   ASSERT(3, ({ struct t {char a;} x; struct t *y = &x; y->a=3; x.a; }));
 
+  ASSERT(3, ({ struct {int a,b;} x,y; x.a=3; y=x; y.a; }));
+  ASSERT(7, ({ struct t {int a,b;}; struct t x; x.a=7; struct t y; struct t *z=&y; *z=x; y.a; }));
+  ASSERT(7, ({ struct t {int a,b;}; struct t x; x.a=7; struct t y, *p=&x, *q=&y; *q=*p; y.a; }));
+  ASSERT(5, ({ struct t {char a, b;} x, y; x.a=5; y=x; y.a; }));
+
+  ASSERT(3, ({ struct {int a,b;} x,y; x.a=3; y=x; y.a; }));
+  ASSERT(7, ({ struct t {int a,b;}; struct t x; x.a=7; struct t y; struct t *z=&y; *z=x; y.a; }));
+  ASSERT(7, ({ struct t {int a,b;}; struct t x; x.a=7; struct t y, *p=&x, *q=&y; *q=*p; y.a; }));
+  ASSERT(5, ({ struct t {char a, b;} x, y; x.a=5; y=x; y.a; }));
+
   printf("OK\n");
   return 0;
 }

test/union.c

@@ -7,6 +7,9 @@ int main() {
   ASSERT(0, ({ union { int a; char b[4]; } x; x.a = 515; x.b[2]; }));
   ASSERT(0, ({ union { int a; char b[4]; } x; x.a = 515; x.b[3]; }));
 
+  ASSERT(3, ({ union {int a,b;} x,y; x.a=3; y.a=5; y=x; y.a; }));
+  ASSERT(3, ({ union {struct {int a,b;} c;} x,y; x.c.b=3; y.c.b=5; y=x; y.c.b; }));
+
   printf("OK\n");
   return 0;
 }