[gcc r13-2023] analyzer: fix ICE casued by dup2 in sm-fd.cc[PR106551]

[Immad Mir <mir@gcc.gnu.org>]

https://gcc.gnu.org/g:837142257cbde3cc03ee0dacd1d7b2fb4fa48bae

commit r13-2023-g837142257cbde3cc03ee0dacd1d7b2fb4fa48bae
Author: Immad Mir <mirimmad@outlook.com>
Date:   Thu Aug 11 21:45:54 2022 +0530

    analyzer: fix ICE casued by dup2 in sm-fd.cc[PR106551]
    
    This patch fixes the ICE caused by valid_to_unchecked_state,
    at analyzer/sm-fd.cc by handling the m_start state in
    check_for_dup.
    
    Tested lightly on x86_64.
    
    gcc/analyzer/ChangeLog:
            PR analyzer/106551
            * sm-fd.cc (check_for_dup): handle the m_start
            state when transitioning the state of LHS
            of dup, dup2 and dup3 call.
    
    gcc/testsuite/ChangeLog:
            * gcc.dg/analyzer/fd-dup-1.c: New testcases.
            * gcc.dg/analyzer/fd-uninit-1.c: Remove bogus
            warning.
    Signed-off-by: Immad Mir <mirimmad@outlook.com>

Diff:
---
 gcc/analyzer/sm-fd.cc                       | 10 ++++++----
 gcc/testsuite/gcc.dg/analyzer/fd-dup-1.c    | 27 ++++++++++++++++++++++++++-
 gcc/testsuite/gcc.dg/analyzer/fd-uninit-1.c |  2 --
 3 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/gcc/analyzer/sm-fd.cc b/gcc/analyzer/sm-fd.cc
index 8bb76d72b05..e02b86baad1 100644
--- a/gcc/analyzer/sm-fd.cc
+++ b/gcc/analyzer/sm-fd.cc
@@ -971,7 +971,8 @@ fd_state_machine::check_for_dup (sm_context *sm_ctxt, const supernode *node,
   state_t state_arg_1 = sm_ctxt->get_state (stmt, arg_1);
   if (state_arg_1 == m_stop)
     return;
-  if (!(is_constant_fd_p (state_arg_1) || is_valid_fd_p (state_arg_1)))
+  if (!(is_constant_fd_p (state_arg_1) || is_valid_fd_p (state_arg_1)
+	|| state_arg_1 == m_start))
     {
       check_for_open_fd (sm_ctxt, node, stmt, call, callee_fndecl,
 			 DIRS_READ_WRITE);
@@ -983,7 +984,7 @@ fd_state_machine::check_for_dup (sm_context *sm_ctxt, const supernode *node,
     case DUP_1:
       if (lhs)
 	{
-	  if (is_constant_fd_p (state_arg_1))
+	  if (is_constant_fd_p (state_arg_1) || state_arg_1 == m_start)
 	    sm_ctxt->set_next_state (stmt, lhs, m_unchecked_read_write);
 	  else
 	    sm_ctxt->set_next_state (stmt, lhs,
@@ -999,7 +1000,8 @@ fd_state_machine::check_for_dup (sm_context *sm_ctxt, const supernode *node,
       if (state_arg_2 == m_stop)
 	return;
       /* Check if -1 was passed as second argument to dup2.  */
-      if (!(is_constant_fd_p (state_arg_2) || is_valid_fd_p (state_arg_2)))
+      if (!(is_constant_fd_p (state_arg_2) || is_valid_fd_p (state_arg_2)
+	    || state_arg_2 == m_start))
 	{
 	  sm_ctxt->warn (
 	      node, stmt, arg_2,
@@ -1011,7 +1013,7 @@ fd_state_machine::check_for_dup (sm_context *sm_ctxt, const supernode *node,
       file descriptor i.e the first argument.  */
       if (lhs)
 	{
-	  if (is_constant_fd_p (state_arg_1))
+	  if (is_constant_fd_p (state_arg_1) || state_arg_1 == m_start)
 	    sm_ctxt->set_next_state (stmt, lhs, m_unchecked_read_write);
 	  else
 	    sm_ctxt->set_next_state (stmt, lhs,
diff --git a/gcc/testsuite/gcc.dg/analyzer/fd-dup-1.c b/gcc/testsuite/gcc.dg/analyzer/fd-dup-1.c
index eba2570568f..b971d31b1c7 100644
--- a/gcc/testsuite/gcc.dg/analyzer/fd-dup-1.c
+++ b/gcc/testsuite/gcc.dg/analyzer/fd-dup-1.c
@@ -220,4 +220,29 @@ test_19 (const char *path, void *buf)
         close (fd);
     }
     
-}
\ No newline at end of file
+}
+
+extern int m;
+
+void
+test_20 ()
+{
+    int fd = dup (m); 
+    close (fd);
+}
+
+void
+test_21 ()
+{
+    int fd = dup2 (m, 1); 
+    close (fd);
+}
+
+void
+test_22 (int flags)
+{
+    int fd = dup3 (m, 1, flags);
+    close (fd);
+}
+
+
diff --git a/gcc/testsuite/gcc.dg/analyzer/fd-uninit-1.c b/gcc/testsuite/gcc.dg/analyzer/fd-uninit-1.c
index b5b189ece98..1084d1b4da2 100644
--- a/gcc/testsuite/gcc.dg/analyzer/fd-uninit-1.c
+++ b/gcc/testsuite/gcc.dg/analyzer/fd-uninit-1.c
@@ -9,8 +9,6 @@ test_1 ()
 {
   int m;
   return dup (m); /* { dg-warning "use of uninitialized value 'm'" "uninit" } */
-  /* { dg-bogus "'dup' on possibly invalid file descriptor 'm'" "invalid fd false +ve" { xfail *-*-* } .-1 } */
-  /* XFAIL: probably covered by fix for PR analyzer/106551.  */
 }
 
 int