[PATCH] analyzer: deal with -fshort-enums

[Alexandre Oliva <oliva@adacore.com>]

On platforms that enable -fshort-enums by default, various switch-enum
analyzer tests fail, because apply_constraints_for_gswitch doesn't
expect the integral promotion type cast.  I've arranged for the code
to cope with those casts.

Regstrapped on x86_64-linux-gnu, also tested on arm-eabi with default
cpu on trunk, and with tms570 on gcc-13.  Ok to install?


for  gcc/analyzer/ChangeLog

	* region-model.cc (has_nondefault_case_for_value_p): Take
	enumerate type as a parameter.
	(region_model::apply_constraints_for_gswitch): Cope with
	integral promotion type casts.
---
 gcc/analyzer/region-model.cc |   27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc
index dc83440652027..05f716cb7d663 100644
--- a/gcc/analyzer/region-model.cc
+++ b/gcc/analyzer/region-model.cc
@@ -5340,10 +5340,10 @@ has_nondefault_case_for_value_p (const gswitch *switch_stmt, tree int_cst)
    has nondefault cases handling all values in the enum.  */
 
 static bool
-has_nondefault_cases_for_all_enum_values_p (const gswitch *switch_stmt)
+has_nondefault_cases_for_all_enum_values_p (const gswitch *switch_stmt,
+					    tree type)
 {
   gcc_assert (switch_stmt);
-  tree type = TREE_TYPE (gimple_switch_index (switch_stmt));
   gcc_assert (TREE_CODE (type) == ENUMERAL_TYPE);
 
   for (tree enum_val_iter = TYPE_VALUES (type);
@@ -5379,6 +5379,23 @@ apply_constraints_for_gswitch (const switch_cfg_superedge &edge,
 {
   tree index  = gimple_switch_index (switch_stmt);
   const svalue *index_sval = get_rvalue (index, ctxt);
+  bool check_index_type = true;
+
+  /* With -fshort-enum, there may be a type cast.  */
+  if (ctxt && index_sval->get_kind () == SK_UNARYOP
+      && TREE_CODE (index_sval->get_type ()) == INTEGER_TYPE)
+    {
+      const unaryop_svalue *unaryop = as_a <const unaryop_svalue *> (index_sval);
+      if (unaryop->get_op () == NOP_EXPR
+	  && is_a <const initial_svalue *> (unaryop->get_arg ()))
+	if (const initial_svalue *initvalop = (as_a <const initial_svalue *>
+					       (unaryop->get_arg ())))
+	  if (TREE_CODE (initvalop->get_type ()) == ENUMERAL_TYPE)
+	    {
+	      index_sval = initvalop;
+	      check_index_type = false;
+	    }
+    }
 
   /* If we're switching based on an enum type, assume that the user is only
      working with values from the enum.  Hence if this is an
@@ -5390,12 +5407,14 @@ apply_constraints_for_gswitch (const switch_cfg_superedge &edge,
       ctxt
       /* Must be an enum value.  */
       && index_sval->get_type ()
-      && TREE_CODE (TREE_TYPE (index)) == ENUMERAL_TYPE
+      && (!check_index_type
+	  || TREE_CODE (TREE_TYPE (index)) == ENUMERAL_TYPE)
       && TREE_CODE (index_sval->get_type ()) == ENUMERAL_TYPE
       /* If we have a constant, then we can check it directly.  */
       && index_sval->get_kind () != SK_CONSTANT
       && edge.implicitly_created_default_p ()
-      && has_nondefault_cases_for_all_enum_values_p (switch_stmt)
+      && has_nondefault_cases_for_all_enum_values_p (switch_stmt,
+						     index_sval->get_type ())
       /* Don't do this if there's a chance that the index is
 	 attacker-controlled.  */
       && !ctxt->possibly_tainted_p (index_sval))

-- 
Alexandre Oliva, happy hacker            https://FSFLA.org/blogs/lxo/
   Free Software Activist                   GNU Toolchain Engineer
More tolerance and less prejudice are key for inclusion and diversity
Excluding neuro-others for not behaving ""normal"" is *not* inclusive