re PR c/61053 (_Alignas(long long) reduces alignment of long long)

	PR c/61053
c-family/
	* c-common.c (min_align_of_type): New function factored out from...
	(c_sizeof_or_alignof_type): ...here.
	* c-common.h (min_align_of_type): Declare.
c/
	* c-decl.c (grokdeclarator): Use min_align_of_type instead of
	TYPE_ALIGN_UNIT.
testsuite/
	* gcc.dg/pr61053.c: New test.

From-SVN: r210230

7 files changed, 116 insertions, 16 deletions

diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index 06a1b14..fc84f31 100644
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,5 +1,12 @@
 2014-05-08  Marek Polacek  <polacek@redhat.com>
 
+	PR c/61053
+	* c-common.c (min_align_of_type): New function factored out from...
+	(c_sizeof_or_alignof_type): ...here.
+	* c-common.h (min_align_of_type): Declare.
+
+2014-05-08  Marek Polacek  <polacek@redhat.com>
+
 	PR c/61077
 	* c-common.c (check_main_parameter_types): Warn for _Atomic-qualified
 	parameter type of main.
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 33ad250..d7c85fc 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -4938,6 +4938,26 @@ c_common_get_alias_set (tree t)
   return -1;
 }
 
+/* Return the least alignment required for type TYPE.  */
+
+unsigned int
+min_align_of_type (tree type)
+{
+  unsigned int align = TYPE_ALIGN (type);
+  align = MIN (align, BIGGEST_ALIGNMENT);
+#ifdef BIGGEST_FIELD_ALIGNMENT
+  align = MIN (align, BIGGEST_FIELD_ALIGNMENT);
+#endif
+  unsigned int field_align = align;
+#ifdef ADJUST_FIELD_ALIGN
+  tree field = build_decl (UNKNOWN_LOCATION, FIELD_DECL, NULL_TREE,
+			   type);
+  field_align = ADJUST_FIELD_ALIGN (field, field_align);
+#endif
+  align = MIN (align, field_align);
+  return align / BITS_PER_UNIT;
+}
+
 /* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where
    the IS_SIZEOF parameter indicates which operator is being applied.
    The COMPLAIN flag controls whether we should diagnose possibly
@@ -5016,21 +5036,7 @@ c_sizeof_or_alignof_type (location_t loc,
 				size_int (TYPE_PRECISION (char_type_node)
 					  / BITS_PER_UNIT));
       else if (min_alignof)
-	{
-	  unsigned int align = TYPE_ALIGN (type);
-	  align = MIN (align, BIGGEST_ALIGNMENT);
-#ifdef BIGGEST_FIELD_ALIGNMENT
-	  align = MIN (align, BIGGEST_FIELD_ALIGNMENT);
-#endif
-	  unsigned int field_align = align;
-#ifdef ADJUST_FIELD_ALIGN
-	  tree field = build_decl (UNKNOWN_LOCATION, FIELD_DECL, NULL_TREE,
-				   type);
-	  field_align = ADJUST_FIELD_ALIGN (field, field_align);
-#endif
-	  align = MIN (align, field_align);
-	  value = size_int (align / BITS_PER_UNIT);
-	}
+	value = size_int (min_align_of_type (type));
       else
 	value = size_int (TYPE_ALIGN_UNIT (type));
     }
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 57b7dce..d34d2bb 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -758,6 +758,7 @@ extern tree c_wrap_maybe_const (tree, bool);
 extern tree c_save_expr (tree);
 extern tree c_common_truthvalue_conversion (location_t, tree);
 extern void c_apply_type_quals_to_decl (int, tree);
+extern unsigned int min_align_of_type (tree);
 extern tree c_sizeof_or_alignof_type (location_t, tree, bool, bool, int);
 extern tree c_alignof_expr (location_t, tree);
 /* Print an error message for invalid operands to arith operation CODE.
diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index 8925371..1c8c435 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,5 +1,11 @@
 2014-05-08  Marek Polacek  <polacek@redhat.com>
 
+	PR c/61053
+	* c-decl.c (grokdeclarator): Use min_align_of_type instead of
+	TYPE_ALIGN_UNIT.
+
+2014-05-08  Marek Polacek  <polacek@redhat.com>
+
 	PR c/61077
 	* c-decl.c (start_function): Warn for _Atomic-qualified return type
 	of main.
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index d8631fc..d52dcc9 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -5931,7 +5931,7 @@ grokdeclarator (const struct c_declarator *declarator,
       else if (declspecs->align_log != -1)
 	{
 	  alignas_align = 1U << declspecs->align_log;
-	  if (alignas_align < TYPE_ALIGN_UNIT (type))
+	  if (alignas_align < min_align_of_type (type))
 	    {
 	      if (name)
 		error_at (loc, "%<_Alignas%> specifiers cannot reduce "
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index fe0683e..bbfb333b 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2014-05-08  Marek Polacek  <polacek@redhat.com>
 
+	PR c/61053
+	* gcc.dg/pr61053.c: New test.
+
+2014-05-08  Marek Polacek  <polacek@redhat.com>
+
 	PR c/61077
 	* gcc.dg/pr61077.c: New test.
 
diff --git a/gcc/testsuite/gcc.dg/pr61053.c b/gcc/testsuite/gcc.dg/pr61053.c
new file mode 100644
index 0000000..4fd5319
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr61053.c
@@ -0,0 +1,75 @@
+/* PR c/61053 */
+/* { dg-do compile { target i?86-*-* x86_64-*-* } } */
+/* { dg-options "-std=c11 -pedantic-errors" } */
+
+_Alignas (char) char cc;
+_Alignas (short int) char cs;
+_Alignas (int) char ci;
+_Alignas (long int) char cl;
+_Alignas (long long int) char cll;
+_Alignas (float) char cf;
+_Alignas (double) char cd;
+_Alignas (long double) char cld;
+
+_Alignas (char) short int sc; /* { dg-error "cannot reduce alignment" } */
+_Alignas (short int) short int ss;
+_Alignas (int) short int si;
+_Alignas (long int) short int sl;
+_Alignas (long long int) short int sll;
+_Alignas (float) short int sf;
+_Alignas (double) short int sd;
+_Alignas (long double) short int sld;
+
+_Alignas (char) int ic; /* { dg-error "cannot reduce alignment" } */
+_Alignas (short int) int is; /* { dg-error "cannot reduce alignment" } */
+_Alignas (int) int ii;
+_Alignas (long int) int il;
+_Alignas (long long int) int ill;
+_Alignas (float) int if_;
+_Alignas (double) int id;
+_Alignas (long double) int ild;
+
+_Alignas (char) long int lic; /* { dg-error "cannot reduce alignment" } */
+_Alignas (short int) long int lis; /* { dg-error "cannot reduce alignment" } */
+_Alignas (int) long int lii; /* { dg-error "cannot reduce alignment" "" { target { ! { ia32 } } } } */
+_Alignas (long int) long int lil;
+_Alignas (long long int) long int lill;
+_Alignas (float) long int lif; /* { dg-error "cannot reduce alignment" "" { target { ! { ia32 } } } } */
+_Alignas (double) long int lid;
+_Alignas (long double) long int lild;
+
+_Alignas (char) long long int llic; /* { dg-error "cannot reduce alignment" } */
+_Alignas (short int) long long int llis; /* { dg-error "cannot reduce alignment" } */
+_Alignas (int) long long int llii; /* { dg-error "cannot reduce alignment" "" { target { ! { ia32 } } } } */
+_Alignas (long int) long long int llil;
+_Alignas (long long int) long long int llill;
+_Alignas (float) long long int llif; /* { dg-error "cannot reduce alignment" "" { target { ! { ia32 } } } } */
+_Alignas (double) long long int llid;
+_Alignas (long double) long long int llild;
+
+_Alignas (char) float fc; /* { dg-error "cannot reduce alignment" } */
+_Alignas (short int) float fs; /* { dg-error "cannot reduce alignment" } */
+_Alignas (int) float fi;
+_Alignas (long int) float fl;
+_Alignas (long long int) float fll;
+_Alignas (float) float ff;
+_Alignas (double) float fd;
+_Alignas (long double) float fld;
+
+_Alignas (char) double dc; /* { dg-error "cannot reduce alignment" } */
+_Alignas (short int) double ds; /* { dg-error "cannot reduce alignment" } */
+_Alignas (int) double di; /* { dg-error "cannot reduce alignment" "" { target { ! { ia32 } } } } */
+_Alignas (long int) double dl;
+_Alignas (long long int) double dll;
+_Alignas (float) double df; /* { dg-error "cannot reduce alignment" "" { target { ! { ia32 } } } } */
+_Alignas (double) double dd;
+_Alignas (long double) double dld;
+
+_Alignas (char) long double ldc; /* { dg-error "cannot reduce alignment" } */
+_Alignas (short int) long double lds; /* { dg-error "cannot reduce alignment" } */
+_Alignas (int) long double ldi; /* { dg-error "cannot reduce alignment" "" { target { ! { ia32 } } } } */
+_Alignas (long int) long double ldl; /* { dg-error "cannot reduce alignment" "" { target { ! { ia32 } } } } */
+_Alignas (long long int) long double ldll; /* { dg-error "cannot reduce alignment" "" { target { ! { ia32 } } } } */
+_Alignas (float) long double ldf; /* { dg-error "cannot reduce alignment" "" { target { ! { ia32 } } } } */
+_Alignas (double) long double ldd; /* { dg-error "cannot reduce alignment" "" { target { ! { ia32 } } } } */
+_Alignas (long double) long double ldld;