[PATCH] Don't ICE on invalid asm memory input (PR inline-asm/67448)

[Marek Polacek]

In this PR, we were crashing on an invalid asm.  I think let's just reject
MODIFY_EXPRs as memory inputs - I'll wager those aren't meant to be supported
anyway.

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2015-09-04  Marek Polacek  <pola...@redhat.com>

        PR inline-asm/67448
        * gimplify.c (gimplify_asm_expr): Don't allow MODIFY_EXPR as
        a memory input.

        * gcc.dg/asm-10.c: New test.

diff --git gcc/gimplify.c gcc/gimplify.c
index c8f2718..b7a918b 100644
--- gcc/gimplify.c
+++ gcc/gimplify.c
@@ -5210,7 +5210,8 @@ gimplify_asm_expr (tree *expr_p, gimple_seq *pre_p, 
gimple_seq *post_p)
          if (TREE_CODE (inputv) == PREDECREMENT_EXPR
              || TREE_CODE (inputv) == PREINCREMENT_EXPR
              || TREE_CODE (inputv) == POSTDECREMENT_EXPR
-             || TREE_CODE (inputv) == POSTINCREMENT_EXPR)
+             || TREE_CODE (inputv) == POSTINCREMENT_EXPR
+             || TREE_CODE (inputv) == MODIFY_EXPR)
            TREE_VALUE (link) = error_mark_node;
          tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
                                is_gimple_lvalue, fb_lvalue | fb_mayfail);
diff --git gcc/testsuite/gcc.dg/asm-10.c gcc/testsuite/gcc.dg/asm-10.c
index e69de29..e6c03c6 100644
--- gcc/testsuite/gcc.dg/asm-10.c
+++ gcc/testsuite/gcc.dg/asm-10.c
@@ -0,0 +1,12 @@
+/* PR inline-asm/67448 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+void
+f (int i)
+{
+  asm ("" : : "m"(i += 1)); /* { dg-error "not directly addressable" } */
+  asm ("" : : "m"(i++)); /* { dg-error "not directly addressable" } */
+  asm ("" : : "m"(++i)); /* { dg-error "not directly addressable" } */
+  asm ("" : : "m"(i = 0)); /* { dg-error "not directly addressable" } */
+}

        Marek