re PR fortran/60458 (Error message on associate: deferred type parameter and requires either the pointer or allocatable attribute)

2017-10-04  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/60458
	PR fortran/77296
	* resolve.c (resolve_assoc_var): Deferred character type
	associate names must not receive an integer conatant length.
	* symbol.c (gfc_is_associate_pointer): Deferred character
	length functions also require an associate pointer.
	* trans-decl.c (gfc_get_symbol_decl): Deferred character
	length functions or derived type components require the assoc
	name to have variable string length.
	* trans-stmt.c (trans_associate_var): Set the string length of
	deferred string length associate names. The address expression
	is not needed for allocatable, pointer or dummy targets. Change
	the comment about defered string length targets.

2017-10-04  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/77296
	* gfortran.dg/associate_32.f03 : New test.

From-SVN: r253400

7 files changed, 171 insertions, 4 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 6f904b1..c38b34b 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,19 @@
+2017-10-04  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/60458
+	PR fortran/77296
+	* resolve.c (resolve_assoc_var): Deferred character type
+	associate names must not receive an integer conatant length.
+	* symbol.c (gfc_is_associate_pointer): Deferred character
+	length functions also require an associate pointer.
+	* trans-decl.c (gfc_get_symbol_decl): Deferred character
+	length functions or derived type components require the assoc
+	name to have variable string length.
+	* trans-stmt.c (trans_associate_var): Set the string length of
+	deferred string length associate names. The address expression
+	is not needed for allocatable, pointer or dummy targets. Change
+	the comment about defered string length targets.
+
 2017-10-03  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	* io.c (match_wait_element): Correctly match END and EOR tags.
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 698cf6d..e6f95d5 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -8530,7 +8530,7 @@ resolve_assoc_var (gfc_symbol* sym, bool resolve_target)
       if (!sym->ts.u.cl)
 	sym->ts.u.cl = target->ts.u.cl;
 
-      if (!sym->ts.u.cl->length)
+      if (!sym->ts.u.cl->length && !sym->ts.deferred)
 	sym->ts.u.cl->length
 	  = gfc_get_int_expr (gfc_default_integer_kind,
 			      NULL, target->value.character.length);
diff --git a/gcc/fortran/symbol.c b/gcc/fortran/symbol.c
index 68a76c4..4c109fd 100644
--- a/gcc/fortran/symbol.c
+++ b/gcc/fortran/symbol.c
@@ -5054,6 +5054,12 @@ gfc_is_associate_pointer (gfc_symbol* sym)
   if (sym->ts.type == BT_CLASS)
     return true;
 
+  if (sym->ts.type == BT_CHARACTER
+      && sym->ts.deferred
+      && sym->assoc->target
+      && sym->assoc->target->expr_type == EXPR_FUNCTION)
+    return true;
+
   if (!sym->assoc->variable)
     return false;
 
diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c
index d227d51..b4f515f 100644
--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -1695,6 +1695,14 @@ gfc_get_symbol_decl (gfc_symbol * sym)
   if (sym->ts.type == BT_CHARACTER)
     {
       if (sym->attr.associate_var
+	  && sym->ts.deferred
+	  && sym->assoc && sym->assoc->target
+	  && ((sym->assoc->target->expr_type == EXPR_VARIABLE
+	       && sym->assoc->target->symtree->n.sym->ts.type != BT_CHARACTER)
+	      || sym->assoc->target->expr_type == EXPR_FUNCTION))
+	sym->ts.u.cl->backend_decl = NULL_TREE;
+
+      if (sym->attr.associate_var
 	  && sym->ts.u.cl->backend_decl
 	  && VAR_P (sym->ts.u.cl->backend_decl))
 	length = gfc_index_zero_node;
diff --git a/gcc/fortran/trans-stmt.c b/gcc/fortran/trans-stmt.c
index 925ea63..7a76b8e 100644
--- a/gcc/fortran/trans-stmt.c
+++ b/gcc/fortran/trans-stmt.c
@@ -1533,6 +1533,7 @@ trans_associate_var (gfc_symbol *sym, gfc_wrapped_block *block)
   bool need_len_assign;
   bool whole_array = true;
   gfc_ref *ref;
+  symbol_attribute attr;
 
   gcc_assert (sym->assoc);
   e = sym->assoc->target;
@@ -1592,6 +1593,17 @@ trans_associate_var (gfc_symbol *sym, gfc_wrapped_block *block)
 
       gfc_conv_expr_descriptor (&se, e);
 
+      if (sym->ts.type == BT_CHARACTER
+	  && sym->ts.deferred
+	  && !sym->attr.select_type_temporary
+	  && VAR_P (sym->ts.u.cl->backend_decl)
+	  && se.string_length != sym->ts.u.cl->backend_decl)
+	{
+	  gfc_add_modify (&se.pre, sym->ts.u.cl->backend_decl,
+			  fold_convert (gfc_charlen_type_node,
+					se.string_length));
+	}
+
       /* If we didn't already do the pointer assignment, set associate-name
 	 descriptor to the one generated for the temporary.  */
       if ((!sym->assoc->variable && !cst_array_ctor)
@@ -1758,8 +1770,35 @@ trans_associate_var (gfc_symbol *sym, gfc_wrapped_block *block)
 	  need_len_assign = need_len_assign && sym->ts.type == BT_CHARACTER;
 	}
 
-      tmp = TREE_TYPE (sym->backend_decl);
-      tmp = gfc_build_addr_expr (tmp, se.expr);
+      if (sym->ts.type == BT_CHARACTER
+	  && sym->ts.deferred
+	  && !sym->attr.select_type_temporary
+	  && VAR_P (sym->ts.u.cl->backend_decl)
+	  && se.string_length != sym->ts.u.cl->backend_decl)
+	{
+	  gfc_add_modify (&se.pre, sym->ts.u.cl->backend_decl,
+			  fold_convert (gfc_charlen_type_node,
+					se.string_length));
+	  if (e->expr_type == EXPR_FUNCTION)
+	    {
+	      tmp = gfc_call_free (sym->backend_decl);
+	      gfc_add_expr_to_block (&se.post, tmp);
+	    }
+	}
+
+      attr = gfc_expr_attr (e);
+      if (sym->ts.type == BT_CHARACTER && e->ts.type == BT_CHARACTER
+	  && (attr.allocatable || attr.pointer || attr.dummy))
+	{
+	  /* These are pointer types already.  */
+	  tmp = fold_convert (TREE_TYPE (sym->backend_decl), se.expr);
+	}
+      else
+	{
+          tmp = TREE_TYPE (sym->backend_decl);
+          tmp = gfc_build_addr_expr (tmp, se.expr);
+	}
+
       gfc_add_modify (&se.pre, sym->backend_decl, tmp);
 
       gfc_add_init_cleanup (block, gfc_finish_block( &se.pre),
@@ -1784,7 +1823,7 @@ trans_associate_var (gfc_symbol *sym, gfc_wrapped_block *block)
       gfc_init_se (&se, NULL);
       if (e->symtree->n.sym->ts.type == BT_CHARACTER)
 	{
-	  /* What about deferred strings?  */
+	  /* Deferred strings are dealt with in the preceeding.  */
 	  gcc_assert (!e->symtree->n.sym->ts.deferred);
 	  tmp = e->symtree->n.sym->ts.u.cl->backend_decl;
 	}
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 192fac7..883392f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-10-04  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/77296
+	* gfortran.dg/associate_32.f03 : New test.
+
 2017-10-04  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/78816
diff --git a/gcc/testsuite/gfortran.dg/associate_32.f03 b/gcc/testsuite/gfortran.dg/associate_32.f03
new file mode 100644
index 0000000..9a1f598
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/associate_32.f03
@@ -0,0 +1,93 @@
+! { dg-do run }
+!
+! Tests fix for PR77296 and other bugs found on the way.
+!
+! Contributed by Matt Thompson  <matthew.thompson@nasa.gov>
+!
+program test
+
+   implicit none
+   type :: str_type
+     character(len=:), allocatable :: str
+   end type
+
+   character(len=:), allocatable :: s, sd(:)
+   character(len=2), allocatable :: sf, sfd(:)
+   character(len=6) :: str
+   type(str_type) :: string
+
+   s = 'ab'
+   associate(ss => s)
+     if (ss .ne. 'ab') call abort ! This is the original bug.
+     ss = 'c'
+   end associate
+   if (s .ne. 'c ') call abort ! No reallocation within ASSOCIATE block!
+
+   sf = 'c'
+   associate(ss => sf)
+     if (ss .ne. 'c ') call abort ! This the bug in comment #2 of the PR.
+     ss = 'cd'
+   end associate
+
+   sd = [s, sf]
+   associate(ss => sd)
+     if (any (ss .ne. ['c ','cd'])) call abort
+   end associate
+
+   sfd = [sd,'ef']
+   associate(ss => sfd)
+     if (any (ss .ne. ['c ','cd','ef'])) call abort
+     ss = ['gh']
+   end associate
+     if (any (sfd .ne. ['gh','cd','ef'])) call abort ! No reallocation!
+
+   string%str = 'xyz'
+   associate(ss => string%str)
+     if (ss .ne. 'xyz') call abort
+     ss = 'c'
+   end associate
+   if (string%str .ne. 'c  ') call abort ! No reallocation!
+
+   str = "foobar"
+   call test_char (5 , str)
+   IF (str /= "abcder") call abort
+
+   associate(ss => foo())
+     if (ss .ne. 'pqrst') call abort
+   end associate
+
+   associate(ss => bar())
+     if (ss(2) .ne. 'uvwxy') call abort
+   end associate
+
+! The deallocation is not strictly necessary but it does allow
+! other memory leakage to be tested for.
+   deallocate (s, sd, sf, sfd, string%str)
+contains
+
+! This is a modified version of the subroutine in associate_1.f03.
+! 'str' is now a dummy.
+  SUBROUTINE test_char (n, str)
+    INTEGER, INTENT(IN) :: n
+
+    CHARACTER(LEN=n) :: str
+
+    ASSOCIATE (my => str)
+      IF (LEN (my) /= n) call abort
+      IF (my /= "fooba") call abort
+      my = "abcde"
+    END ASSOCIATE
+    IF (str /= "abcde") call abort
+  END SUBROUTINE test_char
+
+   function foo() result(res)
+     character (len=:), pointer :: res
+     allocate (res, source = 'pqrst')
+   end function
+
+   function bar() result(res)
+     character (len=:), allocatable :: res(:)
+     allocate (res, source = ['pqrst','uvwxy'])
+   end function
+
+end program test