added a test related to pr#1102 - we can now return structs by value when they are max. 4 bytes

test/val/pr1102.c

@@ -0,0 +1,77 @@
+
+/* pr#1102 - Passing structs/unions <= 4 bytes to/from functions */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+typedef struct test1_s {
+    char a;
+    int b;
+    char c;
+} test1_t;
+
+test1_t test1(int a, int b, int c)
+{
+    test1_t res;
+    res.a = a;
+    res.b = b;
+    res.c = c;
+    return res;
+}
+
+int test2(test1_t s)
+{
+    printf("a: %d b: %d c: %d\n", s.a, s.b, s.c);
+    if ((s.a != 13) || (s.b != 4711) || (s.c != 99)) {
+        return 0;
+    }
+    return 1;
+}
+
+typedef struct test2_s {
+    char a;
+    char b;
+    char c;
+    char d;
+} test2_t;
+
+test2_t test3(test1_t s)
+{
+    test2_t ret;
+    printf("a: %d b: %d c: %d\n", s.a, s.b, s.c);
+    ret.a = s.c;
+    ret.b = s.b & 0xff;
+    ret.c = s.b >> 8;
+    ret.d = s.a;
+    return ret;
+}
+
+int main(void) {
+    test1_t t1;
+    test2_t t2;
+
+    t1 = test1(12, 1842, 23);
+    printf("a: %d b: %d c: %d\n", t1.a, t1.b, t1.c);
+    if ((t1.a != 12) || (t1.b != 1842) || (t1.c != 23)) {
+        return EXIT_FAILURE;
+    }
+
+    t1.a = 13;
+    t1.b = 4711;
+    t1.c = 99;
+    if (test2(t1) != 1) {
+        return EXIT_FAILURE;
+    }
+
+    t1.a = 66;
+    t1.b = 0x7788;
+    t1.c = 22;
+    t2 = test3(t1);
+    printf("a: %d b: %d c: %d d: %d\n", t2.a, t2.b, t2.c, t2.d);
+    if ((t2.a != 22) || (t2.b != 0x88) || (t2.c != 0x77) || (t2.d != 66)) {
+        return EXIT_FAILURE;
+    }
+
+    printf("all fine\n");
+    return EXIT_SUCCESS;
+}