The attached patch adds argument validation for
__builtin_alloca_with_align to reject arguments the middle end isn't
prepared to handle or that aren't meaningful for the API (constant
integers that aren't powers of 2 greater than or equal to 8).
Tested on x86_64-linux.
Martin
PR middle-end/69780 - [4.9/5/6 Regression] ICE on __builtin_alloca_with_align
with small alignment
gcc/testsuite/ChangeLog:
2016-02-14 Martin Sebor <mse...@redhat.com>
PR middle-end/69780
* g++.dg/ext/builtin_alloca.C: New test.
* gcc.dg/builtins-68.c: New test.
gcc/c-family/ChangeLog:
2016-02-14 Martin Sebor <mse...@redhat.com>
PR middle-end/69780
* c-common.c (check_builtin_function_arguments): Validate and reject
invalid arguments to __builtin_alloca_with_align.
Index: gcc/c-family/c-common.c
===================================================================
--- gcc/c-family/c-common.c (revision 233367)
+++ gcc/c-family/c-common.c (working copy)
@@ -9818,6 +9818,29 @@ check_builtin_function_arguments (tree f
switch (DECL_FUNCTION_CODE (fndecl))
{
+ case BUILT_IN_ALLOCA_WITH_ALIGN:
+ {
+ /* Get the requested alignment (in bits) if it's a constant
+ integer expression. */
+ HOST_WIDE_INT align =
+ TREE_CODE (args [1]) == INTEGER_CST ? tree_to_uhwi (args [1]) : 0;
+
+ /* Determine the exact power of 2 of the requested alignment. */
+ int alignpow = align ? tree_log2 (args [1]) : 0;
+
+ /* Reject invalid alignments. */
+ if (alignpow < 3 || MAX_STACK_ALIGNMENT < align)
+ {
+ error_at (EXPR_LOC_OR_LOC (args [1], input_location),
+ "second argument to function %qE must be a constant "
+ "integer power of 2 between %qi and %qwu bits",
+ fndecl, CHAR_TYPE_SIZE,
+ (unsigned HOST_WIDE_INT)MAX_STACK_ALIGNMENT);
+ return false;
+ }
+ return true;
+ }
+
case BUILT_IN_CONSTANT_P:
return builtin_function_validate_nargs (fndecl, nargs, 1);
Index: gcc/testsuite/g++.dg/ext/builtin_alloca.C
===================================================================
--- gcc/testsuite/g++.dg/ext/builtin_alloca.C (revision 0)
+++ gcc/testsuite/g++.dg/ext/builtin_alloca.C (working copy)
@@ -0,0 +1,183 @@
+// PR middle-end/69780 - [4.9/5/6 Regression] ICE on
+// __builtin_alloca_with_align with small alignment
+// { dg-require-effective-target alloca }
+// { dg-do compile }
+
+#define CHAR_BIT __CHAR_BIT__
+#define INT_MAX __INT_MAX__
+#define INT_MIN (-INT_MAX - 1)
+
+static void* p;
+
+// Verify that valid __builtin_alloca_with_align expressions are accepted.
+void test_valid (int n)
+{
+ enum {
+ A1 = CHAR_BIT * 1,
+ A2 = CHAR_BIT * 2,
+ A4 = CHAR_BIT * 4,
+ A8 = CHAR_BIT * 8,
+ A16 = CHAR_BIT * 16,
+ A32 = CHAR_BIT * 32
+ };
+
+ const int a1 = A1;
+ const int a2 = A2;
+ const int a4 = A4;
+ const int a8 = A8;
+ const int a16 = A16;
+ const int a32 = A32;
+
+ // Valid alignments are power of 2 positive multiples of CHAR_BIT.
+ p = __builtin_alloca_with_align (n, CHAR_BIT * 1);
+ p = __builtin_alloca_with_align (n, CHAR_BIT * 2);
+ p = __builtin_alloca_with_align (n, CHAR_BIT * 4);
+ p = __builtin_alloca_with_align (n, CHAR_BIT * 8);
+ p = __builtin_alloca_with_align (n, CHAR_BIT * 16);
+ p = __builtin_alloca_with_align (n, CHAR_BIT * 32);
+
+ p = __builtin_alloca_with_align (n, A1);
+ p = __builtin_alloca_with_align (n, A2);
+ p = __builtin_alloca_with_align (n, A4);
+ p = __builtin_alloca_with_align (n, A8);
+ p = __builtin_alloca_with_align (n, A16);
+ p = __builtin_alloca_with_align (n, A32);
+
+ p = __builtin_alloca_with_align (n, a1);
+ p = __builtin_alloca_with_align (n, a2);
+ p = __builtin_alloca_with_align (n, a4);
+ p = __builtin_alloca_with_align (n, a8);
+ p = __builtin_alloca_with_align (n, a16);
+ p = __builtin_alloca_with_align (n, a32);
+}
+
+template <int A> struct X { enum { Align = A }; };
+
+template <int A>
+void test_valid_template (int n)
+{
+ // Valid alignments are power of 2 positive multiples of CHAR_BIT.
+ p = __builtin_alloca_with_align (n, A);
+}
+
+template void test_valid_template<CHAR_BIT>(int);
+template void test_valid_template<CHAR_BIT * 2>(int);
+template void test_valid_template<CHAR_BIT * 4>(int);
+template void test_valid_template<CHAR_BIT * 8>(int);
+template void test_valid_template<CHAR_BIT * 16>(int);
+template void test_valid_template<CHAR_BIT * 32>(int);
+
+// Exercise the alignment in a dependent context.
+template <int A>
+void test_valid_template_dep (int n)
+{
+ // Valid alignments are power of 2 positive multiples of CHAR_BIT.
+ p = __builtin_alloca_with_align (n, X<A>::Align);
+}
+
+template void test_valid_template_dep<CHAR_BIT>(int);
+template void test_valid_template_dep<CHAR_BIT * 2>(int);
+template void test_valid_template_dep<CHAR_BIT * 4>(int);
+template void test_valid_template_dep<CHAR_BIT * 8>(int);
+template void test_valid_template_dep<CHAR_BIT * 16>(int);
+template void test_valid_template_dep<CHAR_BIT * 32>(int);
+
+// Invalid size must be rejected (and not cause an ICE).
+void test_arg1_non_int (int n)
+{
+ extern void f ();
+
+ p = __builtin_alloca_with_align ((void*)0, 32); // { dg-error "invalid conversion" }
+
+ p = __builtin_alloca_with_align ("", 32); // { dg-error "invalid conversion" }
+ p = __builtin_alloca_with_align (L"", 32); // { dg-error "invalid conversion" }
+ p = __builtin_alloca_with_align (f, 32); // { dg-error "invalid conversion" }
+}
+
+// Non-integer alignment must be rejected.
+void test_arg2_non_int (int n)
+{
+ // Verify the full text of the diagnostic just once.
+ p = __builtin_alloca_with_align (n, 0.0); // { dg-error "second argument to function .__builtin_alloca_with_align. must be a constant integer power of 2 between .8. and " }
+
+ p = __builtin_alloca_with_align (n, (void*)0); // { dg-error "invalid conversion|must be a constant integer" }
+ p = __builtin_alloca_with_align (n, ""); // { dg-error "invalid conversion|must be a constant integer" }
+ p = __builtin_alloca_with_align (n, L""); // { dg-error "invalid conversion|must be a constant integer" }
+}
+
+// Integer alignment that's not a constant expression must be rejected.
+void test_arg2_non_const (int n, int a1)
+{
+ extern const int a2;
+ static volatile const int a3 = CHAR_BIT;
+
+ p = __builtin_alloca_with_align (n, a1); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, a2); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, a3); // { dg-error "must be a constant integer" }
+}
+
+// Constant integer alignment that's not a power of 2 positive multiple
+// of CHAR_BIT must be rejected.
+void test_arg2_non_pow2 (int n)
+{
+ p = __builtin_alloca_with_align (n, INT_MIN); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, -1); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, !1); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, !0); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 0); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 1); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 2); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 3); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 4); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 5); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 6); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 7); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 9); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 10); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 11); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 12); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 13); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 14); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 15); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 17); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 31); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 33); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 63); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 65); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, INT_MAX); // { dg-error "must be a constant integer" }
+}
+
+// Exercise invalid alignment specified by a template argument.
+template <int A>
+void test_invalid_template_1 (int n)
+{
+ // Valid alignments are power of 2 positive multiples of CHAR_BIT.
+ p = __builtin_alloca_with_align (n, A); // { dg-error "must be a constant integer" }
+}
+
+template void test_invalid_template_1<1>(int);
+
+template <int A>
+void test_invalid_template_7 (int n)
+{
+ p = __builtin_alloca_with_align (n, A); // { dg-error "must be a constant integer" }
+}
+
+template void test_invalid_template_7<7>(int);
+
+template <int A>
+void test_invalid_template_9 (int n)
+{
+ p = __builtin_alloca_with_align (n, A); // { dg-error "must be a constant integer" }
+}
+
+template void test_invalid_template_9<9>(int);
+
+// Exercise invalid alignment specified by a template dependent argument.
+template <int A>
+void test_invalid_template_dep_1 (int n)
+{
+ p = __builtin_alloca_with_align (n, X<A>::Align); // { dg-error "must be a constant integer" }
+}
+
+template void test_invalid_template_dep_1<1>(int);
Index: gcc/testsuite/gcc.dg/builtins-68.c
===================================================================
--- gcc/testsuite/gcc.dg/builtins-68.c (revision 0)
+++ gcc/testsuite/gcc.dg/builtins-68.c (working copy)
@@ -0,0 +1,101 @@
+/* PR middle-end/69780 - [4.9/5/6 Regression] ICE on
+ __builtin_alloca_with_align with small alignment */
+/* { dg-require-effective-target alloca } */
+/* { dg-do compile } */
+
+#define CHAR_BIT __CHAR_BIT__
+#define INT_MAX __INT_MAX__
+#define INT_MIN (-INT_MAX - 1)
+
+static void* p;
+
+/* Verify that valid __builtin_alloca_with_align expressions are accepted. */
+void test_valid (int n)
+{
+ enum {
+ A1 = CHAR_BIT * 1,
+ A2 = CHAR_BIT * 2,
+ A4 = CHAR_BIT * 4,
+ A8 = CHAR_BIT * 8,
+ A16 = CHAR_BIT * 16,
+ A32 = CHAR_BIT * 32
+ };
+
+ /* Valid alignments are power of 2 positive multiples of CHAR_BIT. */
+ p = __builtin_alloca_with_align (n, CHAR_BIT * 1);
+ p = __builtin_alloca_with_align (n, CHAR_BIT * 2);
+ p = __builtin_alloca_with_align (n, CHAR_BIT * 4);
+ p = __builtin_alloca_with_align (n, CHAR_BIT * 8);
+ p = __builtin_alloca_with_align (n, CHAR_BIT * 16);
+ p = __builtin_alloca_with_align (n, CHAR_BIT * 32);
+
+ p = __builtin_alloca_with_align (n, A1);
+ p = __builtin_alloca_with_align (n, A2);
+ p = __builtin_alloca_with_align (n, A4);
+ p = __builtin_alloca_with_align (n, A8);
+ p = __builtin_alloca_with_align (n, A16);
+ p = __builtin_alloca_with_align (n, A32);
+}
+
+/* Non-integer alignments must be rejected. */
+void test_arg2_non_int (int n)
+{
+ /* Verify the full text of the diagnostic just once. */
+ p = __builtin_alloca_with_align (n, 0.0); /* { dg-error "second argument to function .__builtin_alloca_with_align. must be a constant integer power of 2 between .8. and " } */
+
+ /* Disable diagnostic complaining about converting void* to int that
+ preempts the "constant integer expression" error. */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wint-conversion"
+
+ p = __builtin_alloca_with_align (n, (void*)0); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, ""); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, L""); /* { dg-error "must be a constant integer" } */
+
+#pragma GCC diagnostic pop
+
+}
+
+/* Integer alignment that's not a constant expression must be rejected. */
+void test_arg2_non_const (int n, int a1)
+{
+ extern const int a2;
+ static const int a3 = CHAR_BIT;
+ static volatile const int a4 = CHAR_BIT;
+
+ p = __builtin_alloca_with_align (n, a1); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, a2); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, a3); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, a4); /* { dg-error "must be a constant integer" } */
+}
+
+/* Constant integer alignment that's not a power of 2 positive multiple
+ of CHAR_BIT must be rejected. */
+void test_arg2_non_pow2 (int n)
+{
+ p = __builtin_alloca_with_align (n, INT_MIN); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, -1); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, !1); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, !0); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 0); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 1); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 2); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 3); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 4); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 5); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 6); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 7); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 9); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 10); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 11); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 12); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 13); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 14); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 15); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 17); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 31); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 33); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 63); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 65); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, INT_MAX); /* { dg-error "must be a constant integer" } */
+}
