[PATCH] PR fortran/87737 - ICE tree check: expected ssa_name, have addr_expr in remap_gimple_op_r, at tree-inline.c:923

[Harald Anlauf <anlauf@gmx.de>]

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Dear all,

the ICE in the original testcase does no longer occur but leads to an
error in a later stage of compilation, and we accepted invalid code.
(Cross-checked with other compilers, such as Intel and NAG).

F2018 states:

15.6.2.6  ENTRY statement

(3) ... If the characteristics of the result of the function named in the
ENTRY statement are the same as the characteristics of the result of the
function named in the FUNCTION statement, their result names identify the same
entity, although their names need not be the same. Otherwise, they are storage
associated and shall all be nonpointer, nonallocatable scalar variables that
are default integer, default real, double precision real, default complex, or
default logical.

We thus better reject the testcase example during resolution with an
appropriate error message.  (I hope the chosen one is fine enough.)

Regtested on x86_64-pc-linux-gnu.  OK for mainline?

Thanks,
Harald


Fortran - reject function entries with mismatched characteristics

gcc/fortran/ChangeLog:

	PR fortran/87737
	* resolve.c (resolve_entries): For functions of type CHARACTER
	tighten the checks for matching characteristics.

gcc/testsuite/ChangeLog:

	PR fortran/87737
	* gfortran.dg/entry_24.f90: New test.


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diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 5b9ba43780e..f641d0d4dae 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -804,6 +804,15 @@ resolve_entries (gfc_namespace *ns)
 	     the same string length, i.e. both len=*, or both len=4.
 	     Having both len=<variable> is also possible, but difficult to
 	     check at compile time.  */
+	  else if (ts->type == BT_CHARACTER
+		   && (el->sym->result->attr.allocatable
+		       != ns->entries->sym->result->attr.allocatable))
+	    {
+	      gfc_error ("Function %s at %L has entry %s with mismatched "
+			 "characteristics", ns->entries->sym->name,
+			 &ns->entries->sym->declared_at, el->sym->name);
+	      return;
+	    }
 	  else if (ts->type == BT_CHARACTER && ts->u.cl && fts->u.cl
 		   && (((ts->u.cl->length && !fts->u.cl->length)
 			||(!ts->u.cl->length && fts->u.cl->length))
diff --git a/gcc/testsuite/gfortran.dg/entry_24.f90 b/gcc/testsuite/gfortran.dg/entry_24.f90
new file mode 100644
index 00000000000..9773597f4e1
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/entry_24.f90
@@ -0,0 +1,20 @@
+! { dg-do compile }
+! PR fortran/87737 - improve check on function entry characteristics
+
+function f() ! { dg-error "mismatched characteristics" }
+  character(:), allocatable :: f
+  character(1)              :: g
+  f = 'f'
+  return
+entry g()
+  g = 'g'
+end
+
+function f2() ! { dg-error "mismatched characteristics" }
+  character(1)              :: f2
+  character(1), allocatable :: g2
+  f2 = 'f'
+  return
+entry g2()
+  g2 = 'g'
+end