[PATCH, CHKP, PR middle-end/70877] Support instrumentation of direct calls with a type cast

[Ilya Enkovich]

Hi,

Currently instrumentation ignores call type for direct calls.  This patch
fixes it to enable direct calls where function is casted to another function
type.

Bootstrapped and regtested on x86_64-unknown-linux-gnu on MPX enabled
hardware.  I'm going to port this patch to gcc-6-branch.

Thanks,
Ilya
--
gcc/

2016-05-10  Ilya Enkovich  <ilya.enkov...@intel.com>

        * tree-chkp.c (chkp_add_bounds_to_call_stmt): Handle
        calls with type casted fndecl.

gcc/testsuite/

2016-05-10  Ilya Enkovich  <ilya.enkov...@intel.com>

        * gcc.target/i386/pr70877.c: New test.


diff --git a/gcc/testsuite/gcc.target/i386/pr70877.c 
b/gcc/testsuite/gcc.target/i386/pr70877.c
new file mode 100644
index 0000000..4269e84
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr70877.c
@@ -0,0 +1,14 @@
+/* { dg-do compile { target { ! x32 } } } */
+/* { dg-options "-fcheck-pointer-bounds -mmpx" } */
+
+int foo(int);
+
+typedef struct {
+  double d;
+  int a;
+} str_t;
+
+void bar(double d, int i, str_t s)
+{
+  d = ((double (*) (int)) foo) (i); /* { dg-warning "function called through a 
non-compatible type" } */
+}
diff --git a/gcc/tree-chkp.c b/gcc/tree-chkp.c
index 3fba12c..960391f 100644
--- a/gcc/tree-chkp.c
+++ b/gcc/tree-chkp.c
@@ -1853,7 +1853,9 @@ chkp_add_bounds_to_call_stmt (gimple_stmt_iterator *gsi)
 
   /* If function decl is available then use it for
      formal arguments list.  Otherwise use function type.  */
-  if (fndecl && DECL_ARGUMENTS (fndecl))
+  if (fndecl
+      && DECL_ARGUMENTS (fndecl)
+      && gimple_call_fntype (call) == TREE_TYPE (fndecl))
     first_formal_arg = DECL_ARGUMENTS (fndecl);
   else
     {
@@ -1929,7 +1931,16 @@ chkp_add_bounds_to_call_stmt (gimple_stmt_iterator *gsi)
     {
       tree new_decl = chkp_maybe_create_clone (fndecl)->decl;
       gimple_call_set_fndecl (new_call, new_decl);
-      gimple_call_set_fntype (new_call, TREE_TYPE (new_decl));
+      /* In case of a type cast we should modify used function
+        type instead of using type of new fndecl.  */
+      if (gimple_call_fntype (call) != TREE_TYPE (fndecl))
+       {
+         tree type = gimple_call_fntype (call);
+         type = chkp_copy_function_type_adding_bounds (type);
+         gimple_call_set_fntype (new_call, type);
+       }
+      else
+       gimple_call_set_fntype (new_call, TREE_TYPE (new_decl));
     }
   /* For indirect call we should fix function pointer type if
      pass some bounds.  */