re PR fortran/50627 (Error recovery: ICE in gfc_free_namespace after diagnosing missing end of construct)

2013-02-02  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/50627
	PR fortran/56054
	* decl.c (gfc_match_end):  Remove half-ready namespace
	from parent if the end of a block is missing.
	* parse.c (parse_module):  Do not put namespace into
	gsymbol on error.

2013-02-02  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/50627
	PR fortran/56054
	* gfortran.dg/block_12.f90:  New test.
	* gfortran.dg/module_error_1.f90:  New test.

From-SVN: r195684

6 files changed, 64 insertions, 1 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index bef16a5..47be01f 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,12 @@
+2013-02-02  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/50627
+	PR fortran/56054
+	* decl.c (gfc_match_end):  Remove half-ready namespace
+	from parent if the end of a block is missing.
+	* parse.c (parse_module):  Do not put namespace into
+	gsymbol on error.
+
 2012-01-30  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/56138
diff --git a/gcc/fortran/decl.c b/gcc/fortran/decl.c
index 2a6342c..72c511c 100644
--- a/gcc/fortran/decl.c
+++ b/gcc/fortran/decl.c
@@ -5955,6 +5955,8 @@ gfc_match_end (gfc_statement *st)
   const char *target;
   int eos_ok;
   match m;
+  gfc_namespace *parent_ns, *ns, *prev_ns;
+  gfc_namespace **nsp;
 
   old_loc = gfc_current_locus;
   if (gfc_match ("end") != MATCH_YES)
@@ -6180,6 +6182,35 @@ syntax:
 
 cleanup:
   gfc_current_locus = old_loc;
+
+  /* If we are missing an END BLOCK, we created a half-ready namespace.
+     Remove it from the parent namespace's sibling list.  */
+
+  if (state == COMP_BLOCK)
+    {
+      parent_ns = gfc_current_ns->parent;
+
+      nsp = &(gfc_state_stack->previous->tail->ext.block.ns);
+
+      prev_ns = NULL;
+      ns = *nsp;
+      while (ns)
+	{
+	  if (ns == gfc_current_ns)
+	    {
+	      if (prev_ns == NULL)
+		*nsp = NULL;
+	      else
+		prev_ns->sibling = ns->sibling;
+	    }
+	  prev_ns = ns;
+	  ns = ns->sibling;
+	}
+  
+      gfc_free_namespace (gfc_current_ns);
+      gfc_current_ns = parent_ns;
+    }
+
   return MATCH_ERROR;
 }
 
diff --git a/gcc/fortran/parse.c b/gcc/fortran/parse.c
index 94d204c..6ee7b7f 100644
--- a/gcc/fortran/parse.c
+++ b/gcc/fortran/parse.c
@@ -4291,6 +4291,7 @@ parse_module (void)
 {
   gfc_statement st;
   gfc_gsymbol *s;
+  bool error;
 
   s = gfc_get_gsymbol (gfc_new_block->name);
   if (s->defined || (s->type != GSYM_UNKNOWN && s->type != GSYM_MODULE))
@@ -4304,6 +4305,7 @@ parse_module (void)
 
   st = parse_spec (ST_NONE);
 
+  error = false;
 loop:
   switch (st)
     {
@@ -4322,12 +4324,15 @@ loop:
       gfc_error ("Unexpected %s statement in MODULE at %C",
 		 gfc_ascii_statement (st));
 
+      error = true;
       reject_statement ();
       st = next_statement ();
       goto loop;
     }
 
-  s->ns = gfc_current_ns;
+  /* Make sure not to free the namespace twice on error.  */
+  if (!error)
+    s->ns = gfc_current_ns;
 }
 
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 50798c7..c765743 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2013-02-02  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/50627
+	PR fortran/56054
+	* gfortran.dg/block_12.f90:  New test.
+	* gfortran.dg/module_error_1.f90:  New test.
+
 2013-02-02  Richard Sandiford  <rdsandiford@googlemail.com>
 
 	* lib/target-supports.exp (check_effective_target_vect_float)
diff --git a/gcc/testsuite/gfortran.dg/block_12.f90 b/gcc/testsuite/gfortran.dg/block_12.f90
new file mode 100644
index 0000000..a7e9c10
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/block_12.f90
@@ -0,0 +1,6 @@
+! { dg-do compile }
+! PR 50627 - this used to free a namespace twice.
+program main
+  block
+end program main ! { dg-error "END BLOCK" }
+! { dg-prune-output "Unexpected end of file" }
diff --git a/gcc/testsuite/gfortran.dg/module_error_1.f90 b/gcc/testsuite/gfortran.dg/module_error_1.f90
new file mode 100644
index 0000000..84decc0
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/module_error_1.f90
@@ -0,0 +1,5 @@
+! { dg-do compile }
+! PR fortran/50627
+module kernels
+      select type (args) ! { dg-error "Unexpected SELECT TYPE" }
+end module kernels