Add regression test for "aligned" attribute

Expected results were obtained with GCC 5.4 and Clang 8.0

3 files changed, 120 insertions, 1 deletions

diff --git a/test/regression/Makefile b/test/regression/Makefile
index 5d40e2c9..760ee570 100644
--- a/test/regression/Makefile
+++ b/test/regression/Makefile
@@ -23,7 +23,7 @@ TESTS=int32 int64 floats floats-basics \
 TESTS_COMP=attribs1 bitfields1 bitfields2 bitfields3 bitfields4 \
   bitfields5 bitfields6 bitfields7 bitfields8 \
   builtins-$(ARCH) packedstruct1 packedstruct2 alignas \
-  varargs1 varargs2 varargs3 sections alias
+  varargs1 varargs2 varargs3 sections alias aligned
 
 # Can run, both in compiled mode and in interpreter mode,
 # but produce processor-dependent results, so no reference output in Results
diff --git a/test/regression/Results/aligned b/test/regression/Results/aligned
new file mode 100644
index 00000000..7a4f7c9f
--- /dev/null
+++ b/test/regression/Results/aligned
@@ -0,0 +1,11 @@
+a: size 1, offset mod 16 = 0
+b: size 3, offset mod 16 = 0
+c: size is that of a pointer, offset mod 16 is good
+d: size 1, offset mod 16 = 0
+f: size is that of a pointer, offset mod 16 is good
+g: size 32, offset mod 16 = 0
+h: size 16, offset mod 16 = 0
+i: size 16, offset mod 16 = 0
+j: size 16, offset mod 16 = 0
+T2: size 112, alignment 16
+T4: size is that of a pointer, alignment is that of a pointer
diff --git a/test/regression/aligned.c b/test/regression/aligned.c
new file mode 100644
index 00000000..3b5a9374
--- /dev/null
+++ b/test/regression/aligned.c
@@ -0,0 +1,108 @@
+/* The "aligned" attribute */
+
+#include <stdio.h>
+
+#define ALIGNED __attribute((aligned(16)))
+
+typedef ALIGNED char c16;
+
+struct s {
+  char y;
+  char ALIGNED x;
+};
+
+typedef struct { char y; } ALIGNED u;
+
+struct {
+  char filler1;
+
+  /* Base type */
+  char ALIGNED a;
+  /* Array */
+  /* Expected: array of 3 naturally-aligned chars -> size = 3 */
+  ALIGNED char b[3];
+  /* Pointer */
+  /* Expected: 16-aligned pointer to naturally-aligned char */
+  ALIGNED char * c;
+
+/* Typedef */
+
+  c16 d;
+  /* Expected: like char ALIGNED d */
+  // c16 e[3] = {2, 3, 4};
+  /* Expected: unclear.  This one is rejected by gcc.
+     clang says size = 16, alignment = 16, but initializes first 3 bytes only.
+     compcert says size = 3, alignment = 16. */
+  char filler2;
+  c16 * f;
+  /* Expected: naturally-aligned pointer to 16-aligned char */
+
+/* Struct */
+
+  struct s g;
+  /* Expected: alignment 16, size 17
+     (1 byte, padding to mod 16, 1 bytes) */
+
+  char filler3;
+
+  struct t {
+    char y;
+  } ALIGNED h;
+  /* Expected: type struct t and variable h have alignment 16 and size 1 */
+
+  char filler4;
+
+  struct t i;
+  /* Expected: alignment 16 and size 1.  This checks that the ALIGNED
+     attribute is attached to "struct t". */
+
+  char filler5;
+
+  u j;
+  /* Expected: type u and variable j have alignment 16 and size 1. */
+} x;
+
+typedef char T1[100];
+
+typedef struct { T1 mess[1]; } ALIGNED T2;
+/* Expected: alignment 16, size 112 = 100 aligned to 16 */
+
+typedef T2 T3[];
+
+typedef struct { T3 *area; } T4;
+/* Expected: size of a pointer, alignment of a pointer */
+
+void check(const char * msg, void * addr, size_t sz)
+{
+  printf("%s: size %zu, offset mod 16 = %lu\n",
+         msg, sz, (unsigned long) ((char *) addr - (char *) &x) % 16);
+}
+
+void checkptr(const char * msg, void * addr, size_t sz, size_t al)
+{
+  printf("%s: size %s that of a pointer, offset mod 16 %s\n",
+         msg,
+         sz == sizeof(void *) ? "is" : "IS NOT",
+         (((char *) addr - (char *) &x) % 16) == al ?
+            "is good" : "IS BAD");
+}
+
+int main()
+{
+  check("a", &(x.a), sizeof(x.a));
+  check("b", &(x.b), sizeof(x.b));
+  checkptr("c", &(x.c), sizeof(x.c), 0);
+  check("d", &(x.d), sizeof(x.d));
+  checkptr("f", &(x.f), sizeof(x.f), _Alignof(void *));
+  check("g", &(x.g), sizeof(x.g));
+  check("h", &(x.h), sizeof(x.h));
+  check("i", &(x.i), sizeof(x.i));
+  check("j", &(x.j), sizeof(x.j));
+
+  printf("T2: size %zu, alignment %zu\n", sizeof(T2), _Alignof(T2));
+  printf("T4: size %s that of a pointer, alignment %s that of a pointer\n",
+         sizeof(T4) == sizeof(void *) ? "is" : "IS NOT",
+         _Alignof(T4) == _Alignof(void *) ? "is" : "IS NOT");
+
+  return 0;
+}