PR fortran/95500 - Segfault compiling extra interface on intrinsic

Converting an expression so that it can be passed by reference could
result in a NULL pointer dereference.

2020-06-04  Steven G. Kargl  <kargl@gcc.gnu.org>
	    Harald Anlauf  <anlauf@gmx.de>

gcc/fortran/
	PR fortran/95500
	* trans-expr.c (gfc_conv_expr_reference): Do not dereference NULL
	pointer.

gcc/testsuite/
	PR fortran/95500
	* gfortran.dg/pr95500.f90: New test.

(cherry picked from commit 8c727bdf4acf28c8315b119a1c8f6d6af745c2af)

diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
index 33fc061d89b8eb9cd712d1597d265ffcd0ada1d5..69147c4b81c257e6471d58bdc756bfeb18f4cacb 100644 (file)
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -8810,6 +8810,7 @@ gfc_conv_expr_reference (gfc_se * se, gfc_expr * expr, bool add_clobber)
 
   if (expr->expr_type == EXPR_FUNCTION
       && ((expr->value.function.esym
+          && expr->value.function.esym->result
           && expr->value.function.esym->result->attr.pointer
           && !expr->value.function.esym->result->attr.dimension)
          || (!expr->value.function.esym && !expr->ref

diff --git a/gcc/testsuite/gfortran.dg/pr95500.f90 b/gcc/testsuite/gfortran.dg/pr95500.f90
new file mode 100644 (file)
index 0000000..e9eb7c6
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr95500.f90
@@ -0,0 +1,15 @@
+! { dg-do compile }
+! PR fortran/95500 - ICE compiling extra interface on intrinsic
+
+program test_intrinsic
+  implicit none
+  intrinsic :: alog
+  intrinsic :: dlog
+  real (4), parameter :: one = 1
+
+  interface ln
+     procedure :: alog, dlog
+  end interface ln
+
+  write (*,*) 'ln  1', ln (one)
+end program test_intrinsic