From 8567160538a82110847b7a62a881ed222718881a Mon Sep 17 00:00:00 2001
From: Philip Herron <philip.herron@embecosm.com>
Date: Tue, 1 Dec 2020 12:11:06 +0000
Subject: [PATCH] Ensure the array index is of integer type.

The index expression must be validated to ensure it is an integer.

Addresses: #27 #55
---
 gcc/rust/analysis/rust-type-resolution.cc | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/gcc/rust/analysis/rust-type-resolution.cc b/gcc/rust/analysis/rust-type-resolution.cc
index 387f7fcda209a..98ff9187059fb 100644
--- a/gcc/rust/analysis/rust-type-resolution.cc
+++ b/gcc/rust/analysis/rust-type-resolution.cc
@@ -496,7 +496,15 @@ TypeResolution::visit (AST::ArrayIndexExpr &expr)
 
   // check the index_type should be an i32 which should really be
   // more permissive
-  // TODO
+  AST::Type *i32 = nullptr;
+  scope.LookupType ("i32", &i32);
+  rust_assert (i32 != nullptr);
+
+  if (!typesAreCompatible (array_index_type, i32,
+			   expr.get_index_expr ()->get_locus_slow ()))
+    {
+      return;
+    }
 
   // the the element type from the array_expr_type and it _must_ be an array
   AST::ArrayType *resolved = ArrayTypeVisitor::Resolve (array_expr_type);