PR c++/92745 - bogus error when initializing array of vectors.

In r268428 I changed reshape_init_r in such a way that when it sees
a nested { } in a CONSTRUCTOR with missing braces, it just returns
the initializer:
+     else if (COMPOUND_LITERAL_P (stripped_init)
...
+         ++d->cur;
+         gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (stripped_init));
+         return init;

But as this test shows, that's incorrect: if TYPE is an array, we need
to proceed to reshape_init_array_1 which will iterate over the array
initializers:
 6006   /* Loop until there are no more initializers.  */
 6007   for (index = 0;
 6008        d->cur != d->end && (!sized_array_p || index <= max_index_cst);
 6009        ++index)
 6010     {
and update d.cur accordingly.  In other words, when reshape_init gets

{{col[0][0], col[1][0], col[2][0], col[3][0]},
 {col[0][1], col[1][1], col[2][1], col[3][1]},
 {col[0][2], col[1][2], col[2][2], col[3][2]},
 {col[0][3], col[1][3], col[2][3], col[3][3]}}

we recurse on the first element:
  {col[0][0], col[1][0], col[2][0], col[3][0]}
and we can't just move d.cur to point to
  {col[0][1], col[1][1], col[2][1], col[3][1]}
and return; we need to iterate, so that d.cur ends up being properly
updated, and after all initializers have been seen, points to d.end.
Currently we skip the loop, wherefore we hit this:

 6502   /* Make sure all the element of the constructor were used. Otherwise,
 6503      issue an error about exceeding initializers.  */
 6504   if (d.cur != d.end)
 6505     {
 6506       if (complain & tf_error)
 6507         error ("too many initializers for %qT", type);
 6508       return error_mark_node;
 6509     }

	* decl.c (reshape_init_r): For a nested compound literal, do
	call reshape_init_{class,array,vector}.

	* g++.dg/cpp0x/initlist118.C: New test.

From-SVN: r279686

4 files changed, 39 insertions, 8 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 1552b3e..b047dbf 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2019-12-19  Marek Polacek  <polacek@redhat.com>
 
+	PR c++/92745 - bogus error when initializing array of vectors.
+	* decl.c (reshape_init_r): For a nested compound literal, do
+	call reshape_init_{class,array,vector}.
+
 	PR c++/92974 - bogus location for enum and non-enum in ?: warning.
 	* tree.c (build_min_non_dep): Use the location of NON_DEP when
 	building the expression.
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 7d4c947..c15cbfa 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -6399,14 +6399,13 @@ reshape_init_r (tree type, reshape_iter *d, bool first_initializer_p,
 	       by the front end.  Here we have e.g. {.__pfn=0B, .__delta=0},
 	       which is missing outermost braces.  We should warn below, and
 	       one of the routines below will wrap it in additional { }.  */;
-	  /* For a nested compound literal, there is no need to reshape since
-	     we called reshape_init in finish_compound_literal, before calling
-	     digest_init.  */
-	  else if (COMPOUND_LITERAL_P (stripped_init)
-		   /* Similarly, a CONSTRUCTOR of the target's type is a
-		      previously digested initializer.  */
-		   || same_type_ignoring_top_level_qualifiers_p (type,
-								 init_type))
+	  /* For a nested compound literal, proceed to specialized routines,
+	     to handle initialization of arrays and similar.  */
+	  else if (COMPOUND_LITERAL_P (stripped_init))
+	    gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (stripped_init));
+	  /* A CONSTRUCTOR of the target's type is a previously
+	     digested initializer.  */
+	  else if (same_type_ignoring_top_level_qualifiers_p (type, init_type))
 	    {
 	      ++d->cur;
 	      gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (stripped_init));
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a7835db..207d64a 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2019-12-19  Marek Polacek  <polacek@redhat.com>
 
+	PR c++/92745 - bogus error when initializing array of vectors.
+	* g++.dg/cpp0x/initlist118.C: New test.
+
 	PR c++/92974 - bogus location for enum and non-enum in ?: warning.
 	* g++.dg/diagnostic/enum1.C: New test.
 	* g++.dg/gomp/loop-2.C: Adjust dg-error.
diff --git a/gcc/testsuite/g++.dg/cpp0x/initlist118.C b/gcc/testsuite/g++.dg/cpp0x/initlist118.C
new file mode 100644
index 0000000..2e1b969
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/initlist118.C
@@ -0,0 +1,25 @@
+// PR c++/92745 - bogus error when initializing array of vectors.
+// { dg-do compile { target c++11 } }
+
+template <typename a, int b> struct c {
+  typedef a d[b];
+};
+
+template <typename a, int b> struct array {
+  typename c<a, b>::d e;
+  a operator[](long);
+};
+
+template<class T>
+using vec4_t __attribute__((vector_size(4*sizeof(T)))) = float;
+
+array<vec4_t<float>, 4>
+transpose(array<vec4_t<float>, 4> col)
+{
+  array<vec4_t<float>, 4>
+    ret{vec4_t<float>{col[0][0], col[1][0], col[2][0], col[3][0]},
+        vec4_t<float>{col[0][1], col[1][1], col[2][1], col[3][1]},
+        vec4_t<float>{col[0][2], col[1][2], col[2][2], col[3][2]},
+        vec4_t<float>{col[0][3], col[1][3], col[2][3], col[3][3]}};
+  return ret;
+}