From: Harald Anlauf <anlauf@gmx.de>
Date: Wed, 16 Jun 2021 20:04:22 +0000 (+0200)
Subject: Fortran - ICE in gfc_check_do_variable, at fortran/parse.c:4446
X-Git-Tag: basepoints/gcc-13~6771
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cfe0a2ec26867b290eb84af00317e60f8b67455c;p=thirdparty%2Fgcc.git

Fortran - ICE in gfc_check_do_variable, at fortran/parse.c:4446

Avoid NULL pointer dereferences during error recovery.

gcc/fortran/ChangeLog:

	PR fortran/95501
	PR fortran/95502
	* expr.c (gfc_check_pointer_assign): Avoid NULL pointer
	dereference.
	* match.c (gfc_match_pointer_assignment): Likewise.
	* parse.c (gfc_check_do_variable): Avoid comparison with NULL
	symtree.

gcc/testsuite/ChangeLog:

	PR fortran/95501
	PR fortran/95502
	* gfortran.dg/pr95502.f90: New test.
---

diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
index 956003ec605e..b11ae7ce5c5c 100644
--- a/gcc/fortran/expr.c
+++ b/gcc/fortran/expr.c
@@ -3815,6 +3815,9 @@ gfc_check_pointer_assign (gfc_expr *lvalue, gfc_expr *rvalue,
   int proc_pointer;
   bool same_rank;
 
+  if (!lvalue->symtree)
+    return false;
+
   lhs_attr = gfc_expr_attr (lvalue);
   if (lvalue->ts.type == BT_UNKNOWN && !lhs_attr.proc_pointer)
     {
diff --git a/gcc/fortran/match.c b/gcc/fortran/match.c
index 294620130387..d148de3e3b53 100644
--- a/gcc/fortran/match.c
+++ b/gcc/fortran/match.c
@@ -1409,7 +1409,7 @@ gfc_match_pointer_assignment (void)
   gfc_matching_procptr_assignment = 0;
 
   m = gfc_match (" %v =>", &lvalue);
-  if (m != MATCH_YES)
+  if (m != MATCH_YES || !lvalue->symtree)
     {
       m = MATCH_NO;
       goto cleanup;
diff --git a/gcc/fortran/parse.c b/gcc/fortran/parse.c
index 0522b3913935..6d7845e8517b 100644
--- a/gcc/fortran/parse.c
+++ b/gcc/fortran/parse.c
@@ -4588,6 +4588,9 @@ gfc_check_do_variable (gfc_symtree *st)
 {
   gfc_state_data *s;
 
+  if (!st)
+    return 0;
+
   for (s=gfc_state_stack; s; s = s->previous)
     if (s->do_variable == st)
       {
diff --git a/gcc/testsuite/gfortran.dg/pr95502.f90 b/gcc/testsuite/gfortran.dg/pr95502.f90
new file mode 100644
index 000000000000..d40fd9a55080
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr95502.f90
@@ -0,0 +1,8 @@
+! { dg-do compile }
+! PR fortran/95502 - ICE in gfc_check_do_variable, at fortran/parse.c:4446
+
+program p
+  integer, pointer :: z
+  nullify (z%kind)  ! { dg-error "in variable definition context" }
+  z%kind => NULL()  ! { dg-error "constant expression" }
+end