[committed] analyzer: fix ICE on unhandled tree codes in gassign [PR96640]

David Malcolm dmalcolm@redhat.com
Tue Aug 18 00:49:46 GMT 2020


PR analyzer/96640 reports a ICE within region_model::on_assignment when
failing to handle a WIDEN_MULT_EVEN_EXPR, and various other tree codes.

The old implementation of region_model::on_assignment gracefully handled
tree codes it didn't understand, returning "UNKNOWN", whereas the new
implementation (r11-2694-g808f4dfeb3a95f50f15e71148e5c1067f90a126d) had
a "sorry_at" and an assertion left over from development, leading to ICEs.

This patch restores the old behavior for these cases, and marks various
vector operations as leading to unknown results.

Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
Pushed to master as r11-2728-g1b0be822208349b2795381deace2352e998c1ad0.

gcc/analyzer/ChangeLog:
	PR analyzer/96640
	* region-model.cc (region_model::get_gassign_result): Handle various
	VEC_* tree codes by returning UNKNOWN.
	(region_model::on_assignment): Handle unrecognized tree codes by
	setting lhs to an unknown value, rather than issuing a "sorry" and
	asserting.
---
 gcc/analyzer/region-model.cc | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc
index 3c7ea40e8d8..cd74c0f6195 100644
--- a/gcc/analyzer/region-model.cc
+++ b/gcc/analyzer/region-model.cc
@@ -526,6 +526,22 @@ region_model::get_gassign_result (const gassign *assign,
     case VEC_SERIES_EXPR:
     case VEC_COND_EXPR:
     case VEC_PERM_EXPR:
+    case VEC_WIDEN_MULT_HI_EXPR:
+    case VEC_WIDEN_MULT_LO_EXPR:
+    case VEC_WIDEN_MULT_EVEN_EXPR:
+    case VEC_WIDEN_MULT_ODD_EXPR:
+    case VEC_UNPACK_HI_EXPR:
+    case VEC_UNPACK_LO_EXPR:
+    case VEC_UNPACK_FLOAT_HI_EXPR:
+    case VEC_UNPACK_FLOAT_LO_EXPR:
+    case VEC_UNPACK_FIX_TRUNC_HI_EXPR:
+    case VEC_UNPACK_FIX_TRUNC_LO_EXPR:
+    case VEC_PACK_TRUNC_EXPR:
+    case VEC_PACK_SAT_EXPR:
+    case VEC_PACK_FIX_TRUNC_EXPR:
+    case VEC_PACK_FLOAT_EXPR:
+    case VEC_WIDEN_LSHIFT_HI_EXPR:
+    case VEC_WIDEN_LSHIFT_LO_EXPR:
       return m_mgr->get_or_create_unknown_svalue (TREE_TYPE (lhs));
     }
 }
@@ -555,10 +571,12 @@ region_model::on_assignment (const gassign *assign, region_model_context *ctxt)
     {
     default:
       {
-	if (1)
+	if (0)
 	  sorry_at (assign->location, "unhandled assignment op: %qs",
 		    get_tree_code_name (op));
-	gcc_unreachable ();
+	const svalue *unknown_sval
+	  = m_mgr->get_or_create_unknown_svalue (TREE_TYPE (lhs));
+	set_value (lhs_reg, unknown_sval, ctxt);
       }
       break;
 
-- 
2.26.2



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