From 24036c6c817680007ad76ebf308bbfff59877179 Mon Sep 17 00:00:00 2001
From: Kyle Cripps <kyle@pensando.io>
Date: Mon, 7 Oct 2024 09:35:47 -0700
Subject: [PATCH 1/3] Do not print confusing warning when a parser state
 contains an assignment to an l-value slice

Signed-off-by: Kyle Cripps <kyle@pensando.io>
---
 midend/interpreter.cpp                           | 10 +++++++---
 .../parser-unroll-slice-assignment.p4            | 16 ++++++++++++++++
 .../parser-unroll-slice-assignment-first.p4      | 16 ++++++++++++++++
 .../parser-unroll-slice-assignment-frontend.p4   | 16 ++++++++++++++++
 .../parser-unroll-slice-assignment-midend.p4     | 16 ++++++++++++++++
 .../parser-unroll-slice-assignment.p4            | 16 ++++++++++++++++
 .../parser-unroll-slice-assignment.p4-stderr     |  3 +++
 .../parser-unroll-slice-assignment-first.p4      | 16 ++++++++++++++++
 .../parser-unroll-slice-assignment-frontend.p4   | 16 ++++++++++++++++
 .../parser-unroll-slice-assignment-midend.p4     | 16 ++++++++++++++++
 .../parser-unroll-slice-assignment.p4            | 16 ++++++++++++++++
 .../parser-unroll-slice-assignment.p4-stderr     |  3 +++
 12 files changed, 157 insertions(+), 3 deletions(-)
 create mode 100644 testdata/p4_16_samples/parser-unroll-slice-assignment.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-first.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-frontend.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-midend.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4-stderr
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-first.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-frontend.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-midend.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4-stderr

diff --git a/midend/interpreter.cpp b/midend/interpreter.cpp
index 6f845b4a662..96cafedcac0 100644
--- a/midend/interpreter.cpp
+++ b/midend/interpreter.cpp
@@ -741,9 +741,13 @@ void ExpressionEvaluator::postorder(const IR::Operation_Ternary *expression) {
     auto e1i = e1->to<ScalarValue>();
     auto e2i = e2->to<ScalarValue>();
     if (e0i->isUninitialized()) {
-        auto result = new SymbolicStaticError(expression->e0, "Uninitialized");
-        set(expression, result);
-        return;
+        // This cannot be an uninitialized read if 'expression' is the LHS of
+        // an assignment to a sliced l-value.
+        if (!evaluatingLeftValue) {
+            auto result = new SymbolicStaticError(expression->e0, "Uninitialized");
+            set(expression, result);
+            return;
+        }
     } else if (e1i->isUninitialized()) {
         auto result = new SymbolicStaticError(expression->e1, "Uninitialized");
         set(expression, result);
diff --git a/testdata/p4_16_samples/parser-unroll-slice-assignment.p4 b/testdata/p4_16_samples/parser-unroll-slice-assignment.p4
new file mode 100644
index 00000000000..123b0c3de1e
--- /dev/null
+++ b/testdata/p4_16_samples/parser-unroll-slice-assignment.p4
@@ -0,0 +1,16 @@
+#include <core.p4>
+
+struct S {
+    bit<8> f;
+}
+
+parser p(packet_in packet, out S s) {
+    state start {
+        s.f[3:0] = 2;
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out S s);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-first.p4 b/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-first.p4
new file mode 100644
index 00000000000..53d755e7307
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-first.p4
@@ -0,0 +1,16 @@
+#include <core.p4>
+
+struct S {
+    bit<8> f;
+}
+
+parser p(packet_in packet, out S s) {
+    state start {
+        s.f[3:0] = 4w2;
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out S s);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-frontend.p4 b/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-frontend.p4
new file mode 100644
index 00000000000..53d755e7307
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-frontend.p4
@@ -0,0 +1,16 @@
+#include <core.p4>
+
+struct S {
+    bit<8> f;
+}
+
+parser p(packet_in packet, out S s) {
+    state start {
+        s.f[3:0] = 4w2;
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out S s);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-midend.p4 b/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-midend.p4
new file mode 100644
index 00000000000..53d755e7307
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-midend.p4
@@ -0,0 +1,16 @@
+#include <core.p4>
+
+struct S {
+    bit<8> f;
+}
+
+parser p(packet_in packet, out S s) {
+    state start {
+        s.f[3:0] = 4w2;
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out S s);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4 b/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4
new file mode 100644
index 00000000000..123b0c3de1e
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4
@@ -0,0 +1,16 @@
+#include <core.p4>
+
+struct S {
+    bit<8> f;
+}
+
+parser p(packet_in packet, out S s) {
+    state start {
+        s.f[3:0] = 2;
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out S s);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4-stderr b/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4-stderr
new file mode 100644
index 00000000000..be5cd84505a
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4-stderr
@@ -0,0 +1,3 @@
+parser-unroll-slice-assignment.p4(9): [--Wwarn=uninitialized_use] warning: s.f may be uninitialized
+        s.f[3:0] = 2;
+        ^^^
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-first.p4 b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-first.p4
new file mode 100644
index 00000000000..53d755e7307
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-first.p4
@@ -0,0 +1,16 @@
+#include <core.p4>
+
+struct S {
+    bit<8> f;
+}
+
+parser p(packet_in packet, out S s) {
+    state start {
+        s.f[3:0] = 4w2;
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out S s);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-frontend.p4 b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-frontend.p4
new file mode 100644
index 00000000000..53d755e7307
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-frontend.p4
@@ -0,0 +1,16 @@
+#include <core.p4>
+
+struct S {
+    bit<8> f;
+}
+
+parser p(packet_in packet, out S s) {
+    state start {
+        s.f[3:0] = 4w2;
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out S s);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-midend.p4 b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-midend.p4
new file mode 100644
index 00000000000..53d755e7307
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-midend.p4
@@ -0,0 +1,16 @@
+#include <core.p4>
+
+struct S {
+    bit<8> f;
+}
+
+parser p(packet_in packet, out S s) {
+    state start {
+        s.f[3:0] = 4w2;
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out S s);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4 b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4
new file mode 100644
index 00000000000..123b0c3de1e
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4
@@ -0,0 +1,16 @@
+#include <core.p4>
+
+struct S {
+    bit<8> f;
+}
+
+parser p(packet_in packet, out S s) {
+    state start {
+        s.f[3:0] = 2;
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out S s);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4-stderr b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4-stderr
new file mode 100644
index 00000000000..be5cd84505a
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4-stderr
@@ -0,0 +1,3 @@
+parser-unroll-slice-assignment.p4(9): [--Wwarn=uninitialized_use] warning: s.f may be uninitialized
+        s.f[3:0] = 2;
+        ^^^

From 47f774716d6fee96163283e3fe0e167c9cf8d9ad Mon Sep 17 00:00:00 2001
From: Kyle Cripps <kyle@pensando.io>
Date: Mon, 7 Oct 2024 10:02:06 -0700
Subject: [PATCH 2/3] Add additional test case

Signed-off-by: Kyle Cripps <kyle@pensando.io>
---
 .../parser-unroll-uninitialized-slice-read.p4        | 12 ++++++++++++
 .../parser-unroll-uninitialized-slice-read-first.p4  | 12 ++++++++++++
 ...arser-unroll-uninitialized-slice-read-frontend.p4 | 12 ++++++++++++
 .../parser-unroll-uninitialized-slice-read-midend.p4 | 12 ++++++++++++
 .../parser-unroll-uninitialized-slice-read.p4        | 12 ++++++++++++
 .../parser-unroll-uninitialized-slice-read.p4-stderr |  9 +++++++++
 .../parser-unroll-uninitialized-slice-read-first.p4  | 12 ++++++++++++
 ...arser-unroll-uninitialized-slice-read-frontend.p4 | 12 ++++++++++++
 .../parser-unroll-uninitialized-slice-read-midend.p4 | 12 ++++++++++++
 .../parser-unroll-uninitialized-slice-read.p4        | 12 ++++++++++++
 .../parser-unroll-uninitialized-slice-read.p4-stderr | 12 ++++++++++++
 11 files changed, 129 insertions(+)
 create mode 100644 testdata/p4_16_samples/parser-unroll-uninitialized-slice-read.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read-first.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read-frontend.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read-midend.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read.p4-stderr
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read-first.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read-frontend.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read-midend.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read.p4
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read.p4-stderr

diff --git a/testdata/p4_16_samples/parser-unroll-uninitialized-slice-read.p4 b/testdata/p4_16_samples/parser-unroll-uninitialized-slice-read.p4
new file mode 100644
index 00000000000..10d44be16b6
--- /dev/null
+++ b/testdata/p4_16_samples/parser-unroll-uninitialized-slice-read.p4
@@ -0,0 +1,12 @@
+#include <core.p4>
+
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+    state start {
+        g = f[3:0];
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out bit<8> f, out bit<4> g);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read-first.p4 b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read-first.p4
new file mode 100644
index 00000000000..10d44be16b6
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read-first.p4
@@ -0,0 +1,12 @@
+#include <core.p4>
+
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+    state start {
+        g = f[3:0];
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out bit<8> f, out bit<4> g);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read-frontend.p4 b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read-frontend.p4
new file mode 100644
index 00000000000..10d44be16b6
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read-frontend.p4
@@ -0,0 +1,12 @@
+#include <core.p4>
+
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+    state start {
+        g = f[3:0];
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out bit<8> f, out bit<4> g);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read-midend.p4 b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read-midend.p4
new file mode 100644
index 00000000000..10d44be16b6
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read-midend.p4
@@ -0,0 +1,12 @@
+#include <core.p4>
+
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+    state start {
+        g = f[3:0];
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out bit<8> f, out bit<4> g);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read.p4 b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read.p4
new file mode 100644
index 00000000000..10d44be16b6
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read.p4
@@ -0,0 +1,12 @@
+#include <core.p4>
+
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+    state start {
+        g = f[3:0];
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out bit<8> f, out bit<4> g);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read.p4-stderr b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read.p4-stderr
new file mode 100644
index 00000000000..52dd3c8a0f4
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-read.p4-stderr
@@ -0,0 +1,9 @@
+parser-unroll-uninitialized-slice-read.p4(5): [--Wwarn=uninitialized_use] warning: f may be uninitialized
+        g = f[3:0];
+            ^
+parser-unroll-uninitialized-slice-read.p4(3): [--Wwarn=uninitialized_out_param] warning: out parameter 'f' may be uninitialized when 'p' terminates
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+                                      ^
+parser-unroll-uninitialized-slice-read.p4(3)
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+       ^
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read-first.p4 b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read-first.p4
new file mode 100644
index 00000000000..10d44be16b6
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read-first.p4
@@ -0,0 +1,12 @@
+#include <core.p4>
+
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+    state start {
+        g = f[3:0];
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out bit<8> f, out bit<4> g);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read-frontend.p4 b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read-frontend.p4
new file mode 100644
index 00000000000..10d44be16b6
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read-frontend.p4
@@ -0,0 +1,12 @@
+#include <core.p4>
+
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+    state start {
+        g = f[3:0];
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out bit<8> f, out bit<4> g);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read-midend.p4 b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read-midend.p4
new file mode 100644
index 00000000000..10d44be16b6
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read-midend.p4
@@ -0,0 +1,12 @@
+#include <core.p4>
+
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+    state start {
+        g = f[3:0];
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out bit<8> f, out bit<4> g);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read.p4 b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read.p4
new file mode 100644
index 00000000000..10d44be16b6
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read.p4
@@ -0,0 +1,12 @@
+#include <core.p4>
+
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+    state start {
+        g = f[3:0];
+        transition accept;
+    }
+}
+
+parser simple(packet_in packet, out bit<8> f, out bit<4> g);
+package top(simple e);
+top(p()) main;
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read.p4-stderr b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read.p4-stderr
new file mode 100644
index 00000000000..c2e7e3cd08c
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-read.p4-stderr
@@ -0,0 +1,12 @@
+parser-unroll-uninitialized-slice-read.p4(5): [--Wwarn=uninitialized_use] warning: f may be uninitialized
+        g = f[3:0];
+            ^
+parser-unroll-uninitialized-slice-read.p4(3): [--Wwarn=uninitialized_out_param] warning: out parameter 'f' may be uninitialized when 'p' terminates
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+                                      ^
+parser-unroll-uninitialized-slice-read.p4(3)
+parser p(packet_in packet, out bit<8> f, out bit<4> g) {
+       ^
+parser-unroll-uninitialized-slice-read.p4(5): [--Wwarn=ignore-prop] warning: Result of 'g = f[3:0]' is not defined: Error: Uninitialized
+        g = f[3:0];
+          ^

From 364b582759671c3bb5fda4deb8cf392b43b870a8 Mon Sep 17 00:00:00 2001
From: Kyle Cripps <kyle@pensando.io>
Date: Mon, 7 Oct 2024 10:05:43 -0700
Subject: [PATCH 3/3] rename test

Signed-off-by: Kyle Cripps <kyle@pensando.io>
---
 ...ssignment.p4 => parser-unroll-uninitialized-slice-write.p4} | 0
 .../parser-unroll-slice-assignment.p4-stderr                   | 3 ---
 ...rst.p4 => parser-unroll-uninitialized-slice-write-first.p4} | 0
 ....p4 => parser-unroll-uninitialized-slice-write-frontend.p4} | 0
 ...nd.p4 => parser-unroll-uninitialized-slice-write-midend.p4} | 0
 ...ssignment.p4 => parser-unroll-uninitialized-slice-write.p4} | 0
 .../parser-unroll-uninitialized-slice-write.p4-stderr          | 3 +++
 .../parser-unroll/parser-unroll-slice-assignment.p4-stderr     | 3 ---
 ...rst.p4 => parser-unroll-uninitialized-slice-write-first.p4} | 0
 ....p4 => parser-unroll-uninitialized-slice-write-frontend.p4} | 0
 ...nd.p4 => parser-unroll-uninitialized-slice-write-midend.p4} | 0
 ...ssignment.p4 => parser-unroll-uninitialized-slice-write.p4} | 0
 .../parser-unroll-uninitialized-slice-write.p4-stderr          | 3 +++
 13 files changed, 6 insertions(+), 6 deletions(-)
 rename testdata/p4_16_samples/{parser-unroll-slice-assignment.p4 => parser-unroll-uninitialized-slice-write.p4} (100%)
 delete mode 100644 testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4-stderr
 rename testdata/p4_16_samples_outputs/{parser-unroll-slice-assignment-first.p4 => parser-unroll-uninitialized-slice-write-first.p4} (100%)
 rename testdata/p4_16_samples_outputs/{parser-unroll-slice-assignment-frontend.p4 => parser-unroll-uninitialized-slice-write-frontend.p4} (100%)
 rename testdata/p4_16_samples_outputs/{parser-unroll-slice-assignment-midend.p4 => parser-unroll-uninitialized-slice-write-midend.p4} (100%)
 rename testdata/p4_16_samples_outputs/{parser-unroll-slice-assignment.p4 => parser-unroll-uninitialized-slice-write.p4} (100%)
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-write.p4-stderr
 delete mode 100644 testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4-stderr
 rename testdata/p4_16_samples_outputs/parser-unroll/{parser-unroll-slice-assignment-first.p4 => parser-unroll-uninitialized-slice-write-first.p4} (100%)
 rename testdata/p4_16_samples_outputs/parser-unroll/{parser-unroll-slice-assignment-frontend.p4 => parser-unroll-uninitialized-slice-write-frontend.p4} (100%)
 rename testdata/p4_16_samples_outputs/parser-unroll/{parser-unroll-slice-assignment-midend.p4 => parser-unroll-uninitialized-slice-write-midend.p4} (100%)
 rename testdata/p4_16_samples_outputs/parser-unroll/{parser-unroll-slice-assignment.p4 => parser-unroll-uninitialized-slice-write.p4} (100%)
 create mode 100644 testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-write.p4-stderr

diff --git a/testdata/p4_16_samples/parser-unroll-slice-assignment.p4 b/testdata/p4_16_samples/parser-unroll-uninitialized-slice-write.p4
similarity index 100%
rename from testdata/p4_16_samples/parser-unroll-slice-assignment.p4
rename to testdata/p4_16_samples/parser-unroll-uninitialized-slice-write.p4
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4-stderr b/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4-stderr
deleted file mode 100644
index be5cd84505a..00000000000
--- a/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4-stderr
+++ /dev/null
@@ -1,3 +0,0 @@
-parser-unroll-slice-assignment.p4(9): [--Wwarn=uninitialized_use] warning: s.f may be uninitialized
-        s.f[3:0] = 2;
-        ^^^
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-first.p4 b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-write-first.p4
similarity index 100%
rename from testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-first.p4
rename to testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-write-first.p4
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-frontend.p4 b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-write-frontend.p4
similarity index 100%
rename from testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-frontend.p4
rename to testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-write-frontend.p4
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-midend.p4 b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-write-midend.p4
similarity index 100%
rename from testdata/p4_16_samples_outputs/parser-unroll-slice-assignment-midend.p4
rename to testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-write-midend.p4
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4 b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-write.p4
similarity index 100%
rename from testdata/p4_16_samples_outputs/parser-unroll-slice-assignment.p4
rename to testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-write.p4
diff --git a/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-write.p4-stderr b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-write.p4-stderr
new file mode 100644
index 00000000000..b5834510440
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll-uninitialized-slice-write.p4-stderr
@@ -0,0 +1,3 @@
+parser-unroll-uninitialized-slice-write.p4(9): [--Wwarn=uninitialized_use] warning: s.f may be uninitialized
+        s.f[3:0] = 2;
+        ^^^
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4-stderr b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4-stderr
deleted file mode 100644
index be5cd84505a..00000000000
--- a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4-stderr
+++ /dev/null
@@ -1,3 +0,0 @@
-parser-unroll-slice-assignment.p4(9): [--Wwarn=uninitialized_use] warning: s.f may be uninitialized
-        s.f[3:0] = 2;
-        ^^^
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-first.p4 b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-write-first.p4
similarity index 100%
rename from testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-first.p4
rename to testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-write-first.p4
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-frontend.p4 b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-write-frontend.p4
similarity index 100%
rename from testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-frontend.p4
rename to testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-write-frontend.p4
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-midend.p4 b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-write-midend.p4
similarity index 100%
rename from testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment-midend.p4
rename to testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-write-midend.p4
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4 b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-write.p4
similarity index 100%
rename from testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-slice-assignment.p4
rename to testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-write.p4
diff --git a/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-write.p4-stderr b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-write.p4-stderr
new file mode 100644
index 00000000000..b5834510440
--- /dev/null
+++ b/testdata/p4_16_samples_outputs/parser-unroll/parser-unroll-uninitialized-slice-write.p4-stderr
@@ -0,0 +1,3 @@
+parser-unroll-uninitialized-slice-write.p4(9): [--Wwarn=uninitialized_use] warning: s.f may be uninitialized
+        s.f[3:0] = 2;
+        ^^^