From patchwork Tue Jan 29 22:36:50 2013
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Subject: [Fortran] PR56138 - fix deferred-length character funcs w/o result
 variable
From: Tobias Burnus <burnus@net-b.de>
X-Patchwork-Id: 216678
Message-Id: <51084F02.6060903@net-b.de>
To: gcc patches <gcc-patches@gcc.gnu.org>, gfortran <fortran@gcc.gnu.org>
Date: Tue, 29 Jan 2013 23:36:50 +0100

For allocatable string lengths (deferred length strings), the current 
code generates a local integer variable to which the the length is assigned.

For some reason, that doesn't work for some functions which do not use a 
result variable - leading to failures as the pass-by-reference variable 
is not dereferenced. That's fixed by the attached patch. I have to admit 
that I do not understand why it works without the patch for the examples 
in gfortran.dg/allocatable_function_5.f90, where - for some tests - also 
no result variable is used.

Build and regtested on x86-64-gnu-linux.
OK for the trunk?

Tobias


2012-01-29  Tobias Burnus  <burnus@net-b.de>

	PR fortran/56138
	* trans-decl.c (gfc_trans_deferred_vars): Fix deferred-length
	results for functions without extra result variable.

2012-01-29  Tobias Burnus  <burnus@net-b.de>

	PR fortran/56138
	* gfortran.dg/allocatable_function_6.f90: New.

diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c
index 1d0919d..7732440 100644
--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -3775,7 +3775,7 @@ gfc_trans_deferred_vars (gfc_symbol * proc_sym, gfc_wrapped_block * block)
 					        null_pointer_node));
 		}
 
-	      if ((sym->attr.dummy ||sym->attr.result)
+	      if ((sym->attr.dummy || sym->attr.result || sym->result == sym)
 		    && sym->ts.type == BT_CHARACTER
 		    && sym->ts.deferred)
 		{
diff --git a/gcc/testsuite/gfortran.dg/allocatable_function_6.f90 b/gcc/testsuite/gfortran.dg/allocatable_function_6.f90
new file mode 100644
index 0000000..4255009
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/allocatable_function_6.f90
@@ -0,0 +1,22 @@
+! { dg-do run }
+!
+! PR fortran/56138
+!
+! Contributed by John Chludzinski, using the code of John Reid
+!
+implicit none
+CHARACTER(LEN=:),ALLOCATABLE :: str 
+if (s_to_c("ABCdef") /= "ABCdef" .or. len(s_to_c("ABCdef")) /= 6) call abort()
+str = s_to_c("ABCdef")
+if (str /= "ABCdef" .or. len(str) /= 6) call abort()
+str(1:3) = s_to_c("123")
+if (str /= "123def" .or. len(str) /= 6) call abort()
+
+contains
+
+PURE FUNCTION s_to_c(string) 
+  CHARACTER(LEN=*),INTENT(IN)   :: string 
+  CHARACTER(LEN=:),ALLOCATABLE :: s_to_c 
+  s_to_c = string
+ENDFUNCTION s_to_c 
+end