From 755c45ca48348bf05007e7d9672004d371c0eab8 Mon Sep 17 00:00:00 2001
From: Arne Welzel <arne.welzel@corelight.com>
Date: Fri, 26 Jan 2024 13:01:07 +0100
Subject: [PATCH] Deprecate &bit-order on bit ranges.

This does not appear to have any effect and allowing it may be
confusing to users. Deprecate it with the idea of eventual
removal.
---
 .../src/compiler/visitors/validator.cc          |  9 +++++++++
 .../spicy.types.bitfield.bit-bitorder/output    |  3 +++
 tests/spicy/types/bitfield/bit-bitorder.spicy   | 17 +++++++++++++++++
 3 files changed, 29 insertions(+)
 create mode 100644 tests/Baseline/spicy.types.bitfield.bit-bitorder/output
 create mode 100644 tests/spicy/types/bitfield/bit-bitorder.spicy

diff --git a/spicy/toolchain/src/compiler/visitors/validator.cc b/spicy/toolchain/src/compiler/visitors/validator.cc
index 8121ad357..5c6d12e60 100644
--- a/spicy/toolchain/src/compiler/visitors/validator.cc
+++ b/spicy/toolchain/src/compiler/visitors/validator.cc
@@ -752,6 +752,15 @@ struct VisitorPost : public hilti::visitor::PreOrder<void, VisitorPost>, public
                     error(fmt("'%s' can be used at most once", a), p);
             }
         }
+
+        if ( auto t = f.itemType().tryAs<type::Bitfield>() ) {
+            for ( const auto& b : t->bits() ) {
+                if ( AttributeSet::has(b.attributes(), "&bit-order") )
+                    hilti::logger().deprecated(fmt("&bit-order on bitfield item '%s' has no effect and is deprecated",
+                                                   b.id()),
+                                               b.meta().location());
+            }
+        }
     }
 
     void operator()(const spicy::type::unit::item::UnresolvedField& u, position_t p) {
diff --git a/tests/Baseline/spicy.types.bitfield.bit-bitorder/output b/tests/Baseline/spicy.types.bitfield.bit-bitorder/output
new file mode 100644
index 000000000..3abeb59bf
--- /dev/null
+++ b/tests/Baseline/spicy.types.bitfield.bit-bitorder/output
@@ -0,0 +1,3 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+[warning] <...>/bit-bitorder.spicy:14:5-14:56: &bit-order on bitfield item 'x1015_msb0' has no effect and is deprecated
+[warning] <...>/bit-bitorder.spicy:15:5-15:56: &bit-order on bitfield item 'x1015_lsb0' has no effect and is deprecated
diff --git a/tests/spicy/types/bitfield/bit-bitorder.spicy b/tests/spicy/types/bitfield/bit-bitorder.spicy
new file mode 100644
index 000000000..619b47267
--- /dev/null
+++ b/tests/spicy/types/bitfield/bit-bitorder.spicy
@@ -0,0 +1,17 @@
+# @TEST-EXEC: spicyc -p -o /dev/null %INPUT 2>output
+# @TEST-EXEC: btest-diff output
+#
+# @TEST-DOC: Test deprecated "&bit-order" attribute on bits emits deprecation warning.
+
+module Mini;
+
+import spicy;
+
+public type X = unit {
+  be16_lsb0: bitfield(16) {
+    x0: 0;
+    x1015: 10..15;
+    x1015_msb0: 10..15 &bit-order=spicy::BitOrder::MSB0;
+    x1015_lsb0: 10..15 &bit-order=spicy::BitOrder::LSB0;
+  };
+};