analyzer: only call get_diagnostic_tree when it's needed

impl_sm_context::get_diagnostic_tree could be expensive, and
I find myself needing to put a breakpoint on it to debug
PR analyzer/99771, so only call it if we're about to use
the result.

gcc/analyzer/ChangeLog:
	* sm-file.cc (fileptr_state_machine::on_stmt): Only call
	get_diagnostic_tree if the result will be used.
	* sm-malloc.cc (malloc_state_machine::on_stmt): Likewise.
	(malloc_state_machine::on_deallocator_call): Likewise.
	(malloc_state_machine::on_realloc_call): Likewise.
	(malloc_state_machine::on_realloc_call): Likewise.
	* sm-sensitive.cc
	(sensitive_state_machine::warn_for_any_exposure): Likewise.
	* sm-taint.cc (taint_state_machine::on_stmt): Likewise.

gcc/analyzer/sm-file.cc

@@ -344,7 +344,6 @@ fileptr_state_machine::on_stmt (sm_context *sm_ctxt,
 	if (is_named_call_p (callee_fndecl, "fclose", call, 1))
 	  {
 	    tree arg = gimple_call_arg (call, 0);
-	    tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
 
 	    sm_ctxt->on_transition (node, stmt, arg, m_start, m_closed);
 
@@ -356,6 +355,7 @@ fileptr_state_machine::on_stmt (sm_context *sm_ctxt,
 
 	    if (sm_ctxt->get_state (stmt, arg) == m_closed)
 	      {
+		tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
 		sm_ctxt->warn (node, stmt, arg,
 			       new double_fclose (*this, diag_arg));
 		sm_ctxt->set_next_state (stmt, arg, m_stop);

gcc/analyzer/sm-malloc.cc

@@ -1674,11 +1674,11 @@ malloc_state_machine::on_stmt (sm_context *sm_ctxt,
       if (TREE_CODE (op) == MEM_REF)
 	{
 	  tree arg = TREE_OPERAND (op, 0);
-	  tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
 
 	  state_t state = sm_ctxt->get_state (stmt, arg);
 	  if (unchecked_p (state))
 	    {
+	      tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
 	      sm_ctxt->warn (node, stmt, arg,
 			     new possible_null_deref (*this, diag_arg));
 	      const allocation_state *astate = as_a_allocation_state (state);
@@ -1686,12 +1686,14 @@ malloc_state_machine::on_stmt (sm_context *sm_ctxt,
 	    }
 	  else if (state == m_null)
 	    {
+	      tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
 	      sm_ctxt->warn (node, stmt, arg,
 			     new null_deref (*this, diag_arg));
 	      sm_ctxt->set_next_state (stmt, arg, m_stop);
 	    }
 	  else if (freed_p (state))
 	    {
+	      tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
 	      const allocation_state *astate = as_a_allocation_state (state);
 	      sm_ctxt->warn (node, stmt, arg,
 			     new use_after_free (*this, diag_arg,
@@ -1738,7 +1740,6 @@ malloc_state_machine::on_deallocator_call (sm_context *sm_ctxt,
   if (argno >= gimple_call_num_args (call))
     return;
   tree arg = gimple_call_arg (call, argno);
-  tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
 
   state_t state = sm_ctxt->get_state (call, arg);
 
@@ -1752,6 +1753,7 @@ malloc_state_machine::on_deallocator_call (sm_context *sm_ctxt,
       if (!astate->m_deallocators->contains_p (d))
 	{
 	  /* Wrong allocator.  */
+	  tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
 	  pending_diagnostic *pd
 	    = new mismatching_deallocation (*this, diag_arg,
 					    astate->m_deallocators,
@@ -1766,6 +1768,7 @@ malloc_state_machine::on_deallocator_call (sm_context *sm_ctxt,
   else if (state == d->m_freed)
     {
       /* freed -> stop, with warning.  */
+      tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
       sm_ctxt->warn (node, call, arg,
 		     new double_free (*this, diag_arg, d->m_name));
       sm_ctxt->set_next_state (call, arg, m_stop);
@@ -1773,6 +1776,7 @@ malloc_state_machine::on_deallocator_call (sm_context *sm_ctxt,
   else if (state == m_non_heap)
     {
       /* non-heap -> stop, with warning.  */
+      tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
       sm_ctxt->warn (node, call, arg,
 		     new free_of_non_heap (*this, diag_arg,
 					   d->m_name));
@@ -1806,7 +1810,6 @@ malloc_state_machine::on_realloc_call (sm_context *sm_ctxt,
 				       const gcall *call) const
 {
   tree ptr = gimple_call_arg (call, 0);
-  tree diag_ptr = sm_ctxt->get_diagnostic_tree (ptr);
 
   state_t state = sm_ctxt->get_state (call, ptr);
 
@@ -1818,6 +1821,7 @@ malloc_state_machine::on_realloc_call (sm_context *sm_ctxt,
       if (astate->m_deallocators != &m_free)
 	{
 	  /* Wrong allocator.  */
+	  tree diag_ptr = sm_ctxt->get_diagnostic_tree (ptr);
 	  pending_diagnostic *pd
 	    = new mismatching_deallocation (*this, diag_ptr,
 					    astate->m_deallocators,

gcc/analyzer/sm-sensitive.cc

@@ -174,10 +174,12 @@ sensitive_state_machine::warn_for_any_exposure (sm_context *sm_ctxt,
 						const gimple *stmt,
 						tree arg) const
 {
-  tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
   if (sm_ctxt->get_state (stmt, arg) == m_sensitive)
-    sm_ctxt->warn (node, stmt, arg,
+    {
-		   new exposure_through_output_file (*this, diag_arg));
+      tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
+      sm_ctxt->warn (node, stmt, arg,
+		     new exposure_through_output_file (*this, diag_arg));
+    }
 }
 
 /* Implementation of state_machine::on_stmt vfunc for

gcc/analyzer/sm-taint.cc

@@ -227,7 +227,6 @@ taint_state_machine::on_stmt (sm_context *sm_ctxt,
       if (op == ARRAY_REF)
 	{
 	  tree arg = TREE_OPERAND (rhs1, 1);
-	  tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
 
 	  /* Unsigned types have an implicit lower bound.  */
 	  bool is_unsigned = false;
@@ -239,6 +238,7 @@ taint_state_machine::on_stmt (sm_context *sm_ctxt,
 	  if (state == m_tainted)
 	    {
 	      /* Complain about missing bounds.  */
+	      tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
 	      pending_diagnostic *d
 		= new tainted_array_index (*this, diag_arg,
 					   is_unsigned
@@ -249,6 +249,7 @@ taint_state_machine::on_stmt (sm_context *sm_ctxt,
 	  else if (state == m_has_lb)
 	    {
 	      /* Complain about missing upper bound.  */
+	      tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
 	      sm_ctxt->warn (node, stmt, arg,
 			      new tainted_array_index (*this, diag_arg,
 						       BOUNDS_LOWER));
@@ -259,6 +260,7 @@ taint_state_machine::on_stmt (sm_context *sm_ctxt,
 	      /* Complain about missing lower bound.  */
 	      if (!is_unsigned)
 		{
+		  tree diag_arg = sm_ctxt->get_diagnostic_tree (arg);
 		  sm_ctxt->warn  (node, stmt, arg,
 				  new tainted_array_index (*this, diag_arg,
 							   BOUNDS_UPPER));