+2016-02-23 Martin Sebor <msebor@redhat.com>
+
+ PR c/69759
+ * doc/extend.texi (Other Builtins): Document __builtin_alloca and
+ __builtin_alloca_with_align.
+
2016-02-23 Richard Henderson <rth@redhat.com>
* config/i386/i386-c.c (ix86_target_macros): Remove __SEG_TLS.
+2016-02-22 Martin Sebor <msebor@redhat.com>
+
+ PR middle-end/69780
+ * c-common.c (check_builtin_function_arguments): Validate and
+ reject invalid arguments to __builtin_alloca_with_align.
+
2016-02-20 Mark Wielaard <mjw@redhat.com>
PR c/28901
switch (DECL_FUNCTION_CODE (fndecl))
{
+ case BUILT_IN_ALLOCA_WITH_ALIGN:
+ {
+ /* Get the requested alignment (in bits) if it's a constant
+ integer expression. */
+ unsigned HOST_WIDE_INT align
+ = tree_fits_uhwi_p (args[1]) ? tree_to_uhwi (args[1]) : 0;
+
+ /* Determine if the requested alignment is a power of 2. */
+ if ((align & (align - 1)))
+ align = 0;
+
+ /* The maximum alignment in bits corresponding to the same
+ maximum in bytes enforced in check_user_alignment(). */
+ unsigned maxalign = (UINT_MAX >> 1) + 1;
+
+ /* Reject invalid alignments. */
+ if (align < BITS_PER_UNIT || maxalign < 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 %qu bits",
+ fndecl, BITS_PER_UNIT, maxalign);
+ return false;
+ }
+ return true;
+ }
+
case BUILT_IN_CONSTANT_P:
return builtin_function_validate_nargs (fndecl, nargs, 1);
@node Other Builtins
@section Other Built-in Functions Provided by GCC
@cindex built-in functions
+@findex __builtin_alloca
+@findex __builtin_alloca_with_align
@findex __builtin_call_with_static_chain
@findex __builtin_fpclassify
@findex __builtin_isfinite
@code{__builtin_} prefixed. The @code{isinf} and @code{isnan}
built-in functions appear both with and without the @code{__builtin_} prefix.
+@deftypefn {Built-in Function} void *__builtin_alloca (size_t size)
+The @code{__builtin_alloca} function must be called at block scope.
+The function allocates an object @var{size} bytes large on the stack
+of the calling function. The object is aligned on the default stack
+alignment boundary for the target determined by the
+@code{__BIGGEST_ALIGNMENT__} macro. The @code{__builtin_alloca}
+function returns a pointer to the first byte of the allocated object.
+The lifetime of the allocated object ends just before the calling
+function returns to its caller. This is so even when
+@code{__builtin_alloca} is called within a nested block.
+
+For example, the following function allocates eight objects of @code{n}
+bytes each on the stack, storing a pointer to each in consecutive elements
+of the array @code{a}. It then passes the array to function @code{g}
+which can safely use the storage pointed to by each of the array elements.
+
+@smallexample
+void f (unsigned n)
+@{
+ void *a [8];
+ for (int i = 0; i != 8; ++i)
+ a [i] = __builtin_alloca (n);
+
+ g (a, n); // @r{safe}
+@}
+@end smallexample
+
+Since the @code{__builtin_alloca} function doesn't validate its argument
+it is the responsibility of its caller to make sure the argument doesn't
+cause it to exceed the stack size limit.
+The @code{__builtin_alloca} function is provided to make it possible to
+allocate on the stack arrays of bytes with an upper bound that may be
+computed at run time. Since C99 @xref{Variable Length} Arrays offer
+similar functionality under a portable, more convenient, and safer
+interface they are recommended instead, in both C99 and C++ programs
+where GCC provides them as an extension.
+
+@end deftypefn
+
+@deftypefn {Built-in Function} void *__builtin_alloca_with_align (size_t size, size_t alignment)
+The @code{__builtin_alloca_with_align} function must be called at block
+scope. The function allocates an object @var{size} bytes large on
+the stack of the calling function. The allocated object is aligned on
+the boundary specified by the argument @var{alignment} whose unit is given
+in bits (not bytes). The @var{size} argument must be positive and not
+exceed the stack size limit. The @var{alignment} argument must be a constant
+integer expression that evaluates to a power of 2 greater than or equal to
+@code{CHAR_BIT} and less than some unspecified maximum. Invocations
+with other values are rejected with an error indicating the valid bounds.
+The function returns a pointer to the first byte of the allocated object.
+The lifetime of the allocated object ends at the end of the block in which
+the function was called. The allocated storage is released no later than
+just before the calling function returns to its caller, but may be released
+at the end of the block in which the function was called.
+
+For example, in the following function the call to @code{g} is unsafe
+because when @code{overalign} is non-zero, the space allocated by
+@code{__builtin_alloca_with_align} may have been released at the end
+of the @code{if} statement in which it was called.
+
+@smallexample
+void f (unsigned n, bool overalign)
+@{
+ void *p;
+ if (overalign)
+ p = __builtin_alloca_with_align (n, 64 /* bits */);
+ else
+ p = __builtin_alloc (n);
+
+ g (p, n); // @r{unsafe}
+@}
+@end smallexample
+
+Since the @code{__builtin_alloca_with_align} function doesn't validate its
+@var{size} argument it is the responsibility of its caller to make sure
+the argument doesn't cause it to exceed the stack size limit.
+The @code{__builtin_alloca_with_align} function is provided to make
+it possible to allocate on the stack overaligned arrays of bytes with
+an upper bound that may be computed at run time. Since C99
+@xref{Variable Length} Arrays offer the same functionality under
+a portable, more convenient, and safer interface they are recommended
+instead, in both C99 and C++ programs where GCC provides them as
+an extension.
+
+@end deftypefn
+
@deftypefn {Built-in Function} int __builtin_types_compatible_p (@var{type1}, @var{type2})
You can use the built-in function @code{__builtin_types_compatible_p} to
+2016-02-23 Martin Sebor <msebor@redhat.com>
+
+ PR middle-end/69780
+ * g++.dg/ext/builtin_alloca.C: New test.
+ * gcc.dg/builtins-68.c: New test.
+
2016-02-23 Richard Henderson <rth@redhat.com>
* gcc.target/i386/addr-space-3.c: Remove test.
--- /dev/null
+// 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)
+#define LONG_MAX __LONG_MAX__
+#define LLONG_MAX __LONG_LONG_MAX__
+
+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" }
+ p = __builtin_alloca_with_align (n, ~0U); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, LONG_MAX); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, ~0LU); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, 1LLU << 34); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, LLONG_MAX); // { dg-error "must be a constant integer" }
+ p = __builtin_alloca_with_align (n, ~0LLU); // { 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);
--- /dev/null
+/* 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 } */
+/* { dg-options "-Wno-long-long" } */
+
+#define CHAR_BIT __CHAR_BIT__
+#define INT_MAX __INT_MAX__
+#define INT_MIN (-INT_MAX - 1)
+#define LONG_MAX __LONG_MAX__
+#define LLONG_MAX __LONG_LONG_MAX__
+
+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 less than (1LLU << 32) 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" } */
+ p = __builtin_alloca_with_align (n, ~0U); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, LONG_MAX); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, ~0LU); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, 1LLU << 34); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, LLONG_MAX); /* { dg-error "must be a constant integer" } */
+ p = __builtin_alloca_with_align (n, ~0LLU); /* { dg-error "must be a constant integer" } */
+}
projects / platform / upstream / linaro-gcc.git / commitdiff