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Diffstat (limited to 'gcc/testsuite/gcc.dg/gnu99-const-expr-3.c')
| -rw-r--r-- | gcc/testsuite/gcc.dg/gnu99-const-expr-3.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/gnu99-const-expr-3.c b/gcc/testsuite/gcc.dg/gnu99-const-expr-3.c new file mode 100644 index 000000000..aba7da542 --- /dev/null +++ b/gcc/testsuite/gcc.dg/gnu99-const-expr-3.c @@ -0,0 +1,32 @@ +/* Test for constant expressions: cases involving VLAs and typeof. */ +/* Origin: Joseph Myers <joseph@codesourcery.com> */ +/* { dg-do compile } */ +/* { dg-options "-std=gnu99 -pedantic-errors" } */ + +/* It appears address constants may contain casts to variably modified + types. Whether they should be permitted was discussed in + <http://groups.google.com/group/comp.std.c/msg/923eee5ab690fd98> + <LV7g2Vy3ARF$Ew9Q@romana.davros.org>; since static pointers to VLAs + are definitely permitted within functions and may be initialized + and such initialization involves implicit conversion to a variably + modified type, allowing explicit casts seems appropriate. Thus, + GCC allows them as long as the "evaluated" size expressions do not + contain the various operators not permitted to be evaluated in a + constant expression, and as long as the result is genuinely + constant (meaning that pointer arithmetic using the size of the VLA + is generally not permitted). */ + +static int sa[100]; + +int +f (int m, int n) +{ + static int (*a1)[n] = &sa; + static int (*a2)[n] = (__typeof__(int (*)[n]))sa; + static int (*a3)[n] = (__typeof__(int (*)[(int){m++}]))sa; /* { dg-error "constant" } */ + static int (*a4)[n] = (__typeof__((int (*)[n])sa))sa; + static int (*a5)[n] = (__typeof__((int (*)[m++])sa))sa; /* { dg-error "constant" } */ + static int (*a6)[n] = (__typeof__((int (*)[100])(int (*)[m++])sa))sa; + static int (*a7)[n] = (__typeof__((int (*)[n])sa + m++))sa; /* { dg-error "constant" } */ + return n; +} |