[Patch, Fortran] Prevent segfault on illegal input

[Patch, Fortran] Prevent segfault on illegal input

[Andre Vehreschild]

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Hi all,

during debugging I found a segfault of gfortran, when it encounters an illegal
fortran code. The mistake in Fortran is flagged correctly, but later gfortran
crashes. This patch prevents the crash.

Bootstraps and regtest ok on x86_64-linux-gnu.

Ok for trunk?

Regards,
	Andre
-- 
Andre Vehreschild * Email: vehre ad gmx dot de 

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gcc/fortran/ChangeLog:

2015-03-13  Andre Vehreschild  <vehre@gmx.de>

	* resolve.c: Prevent segfault on illegal input.

gcc/testsuite/ChangeLog:

2015-03-13  Andre Vehreschild  <vehre@gmx.de>

	* gfortran.dg/pointer_2.f90: New test.



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diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 942a9ad..465cf2b 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -2639,6 +2639,10 @@ found:
     expr->ts = sym->ts;
   expr->value.function.name = sym->name;
   expr->value.function.esym = sym;
+  /* Prevent crash when sym->ts.u.derived->components is not set due to previous
+     error(s).  */
+  if (sym->ts.type == BT_CLASS && !CLASS_DATA (sym))
+    return MATCH_ERROR;
   if (sym->ts.type == BT_CLASS && CLASS_DATA (sym)->as)
     expr->rank = CLASS_DATA (sym)->as->rank;
   else if (sym->as != NULL)
diff --git a/gcc/testsuite/gfortran.dg/pointer_2.f90 b/gcc/testsuite/gfortran.dg/pointer_2.f90
new file mode 100644
index 0000000..d3b95d6
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pointer_2.f90
@@ -0,0 +1,18 @@
+! { dg-do compile }
+! Check that the compiler reports the errors, but does not segfault.
+! Contributed by: Andre Vehreschild  <vehre@gcc.gnu.org>
+!
+program test
+    implicit none
+    class(*), pointer :: P
+    class(*), allocatable :: P2
+
+    allocate(P2, source=convertType(P))
+
+contains
+
+  function convertType(in) ! { dg-error "must be dummy, allocatable or pointer" }
+    class(*), intent(in) :: in
+    class(*) :: convertType
+  end function
+end program test

Re: [Patch, Fortran] Prevent segfault on illegal input

[Tobias Burnus]

Andre Vehreschild wrote:
> during debugging I found a segfault of gfortran, when it encounters an illegal
> fortran code. The mistake in Fortran is flagged correctly, but later gfortran
> crashes. This patch prevents the crash.
>
> Bootstraps and regtest ok on x86_64-linux-gnu.
> Ok for trunk?

OK. Thanks for the patch.

Tobias

Re: [Patch, Fortran] Prevent segfault on illegal input

[Andre Vehreschild]

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Hi Tobias, hi all,

thanks for the review. Commited as r221455:

r221455 | vehre | 2015-03-16 11:29:59 +0100 (Mo, 16. Mär 2015) | 13 Zeilen

gcc/fortran/ChangeLog:

2015-03-16  Andre Vehreschild  <vehre@gmx.de>

	* resolve.c: Prevent segfault on illegal input.

gcc/testsuite/ChangeLog:

2015-03-16  Andre Vehreschild  <vehre@gmx.de>

	* gfortran.dg/pointer_2.f90: New test.

Regards,
	Andre

On Fri, 13 Mar 2015 14:05:00 +0100
Tobias Burnus <tobias.burnus@physik.fu-berlin.de> wrote:

> Andre Vehreschild wrote:
> > during debugging I found a segfault of gfortran, when it encounters an
> > illegal fortran code. The mistake in Fortran is flagged correctly, but
> > later gfortran crashes. This patch prevents the crash.
> >
> > Bootstraps and regtest ok on x86_64-linux-gnu.
> > Ok for trunk?
> 
> OK. Thanks for the patch.
> 
> Tobias


-- 
Andre Vehreschild * Email: vehre ad gmx dot de 

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Index: gcc/fortran/ChangeLog
===================================================================
--- gcc/fortran/ChangeLog	(Revision 221454)
+++ gcc/fortran/ChangeLog	(Arbeitskopie)
@@ -1,3 +1,7 @@
+2015-03-16  Andre Vehreschild  <vehre@gmx.de>
+
+	* resolve.c: Prevent segfault on illegal input.
+
 2015-03-14  Mikael Morin  <mikael@gcc.gnu.org>
 
 	PR fortran/61138
Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c	(Revision 221454)
+++ gcc/fortran/resolve.c	(Arbeitskopie)
@@ -2639,6 +2639,10 @@
     expr->ts = sym->ts;
   expr->value.function.name = sym->name;
   expr->value.function.esym = sym;
+  /* Prevent crash when sym->ts.u.derived->components is not set due to previous
+     error(s).  */
+  if (sym->ts.type == BT_CLASS && !CLASS_DATA (sym))
+    return MATCH_ERROR;
   if (sym->ts.type == BT_CLASS && CLASS_DATA (sym)->as)
     expr->rank = CLASS_DATA (sym)->as->rank;
   else if (sym->as != NULL)
Index: gcc/testsuite/gfortran.dg/pointer_2.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pointer_2.f90	(Revision 0)
+++ gcc/testsuite/gfortran.dg/pointer_2.f90	(Revision 221455)
@@ -0,0 +1,18 @@
+! { dg-do compile }
+! Check that the compiler reports the errors, but does not segfault.
+! Contributed by: Andre Vehreschild  <vehre@gcc.gnu.org>
+!
+program test
+    implicit none
+    class(*), pointer :: P
+    class(*), allocatable :: P2
+
+    allocate(P2, source=convertType(P))
+
+contains
+
+  function convertType(in) ! { dg-error "must be dummy, allocatable or pointer" }
+    class(*), intent(in) :: in
+    class(*) :: convertType
+  end function
+end program test
Index: gcc/testsuite/ChangeLog
===================================================================
--- gcc/testsuite/ChangeLog	(Revision 221454)
+++ gcc/testsuite/ChangeLog	(Arbeitskopie)
@@ -1,3 +1,7 @@
+2015-03-16  Andre Vehreschild  <vehre@gmx.de>
+
+	* gfortran.dg/pointer_2.f90: New test.
+
 2015-03-16  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* testsuite/g++.dg/pr65049.C: New test.