From 77c6be036bc954ebc879b04b749f69e4893d24c4 Mon Sep 17 00:00:00 2001
From: Cristiano Calcagno <cristianoc@users.noreply.github.com>
Date: Wed, 28 Sep 2022 04:46:31 +0200
Subject: [PATCH] Add example for dead code elimination for JSX v4.

DCE does not seem to be working: probably JSC call does not use proper location for the make function.
---
 .../examples/deadcode/expected/deadcode.txt    | 17 ++++++++++++++++-
 .../examples/deadcode/src/JsxV4.bs.js          | 18 ++++++++++++++++++
 .../reanalyze/examples/deadcode/src/JsxV4.res  |  7 +++++++
 3 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 analysis/reanalyze/examples/deadcode/src/JsxV4.bs.js
 create mode 100644 analysis/reanalyze/examples/deadcode/src/JsxV4.res

diff --git a/analysis/reanalyze/examples/deadcode/expected/deadcode.txt b/analysis/reanalyze/examples/deadcode/expected/deadcode.txt
index e14064bc7..c7ff7fc55 100644
--- a/analysis/reanalyze/examples/deadcode/expected/deadcode.txt
+++ b/analysis/reanalyze/examples/deadcode/expected/deadcode.txt
@@ -1101,6 +1101,9 @@
   addRecordLabelDeclaration text ImportMyBanner.res:5:16 path:+ImportMyBanner.message
   addValueReference ImportMyBanner.res:12:4 --> ImportMyBanner.res:7:0
   Scanning JSResource.cmt Source:JSResource.res
+  Scanning JsxV4.cmt Source:JsxV4.res
+  addValueDeclaration +make JsxV4.res:4:23 path:+JsxV4.C
+  addValueReference JsxV4.res:4:36 --> React.res:3:0
   Scanning LetPrivate.cmt Source:LetPrivate.res
   addValueDeclaration +y LetPrivate.res:7:4 path:+LetPrivate
   addValueDeclaration +x LetPrivate.res:3:6 path:+LetPrivate.local_1
@@ -1887,6 +1890,7 @@ File References
   ImportJsValue.res -->> 
   ImportMyBanner.res -->> 
   JSResource.res -->> 
+  JsxV4.res -->> React.res
   LetPrivate.res -->> 
   ModuleAliases.res -->> 
   ModuleAliases2.res -->> 
@@ -2121,6 +2125,7 @@ File References
   Dead Value +ImportMyBanner.+make: 0 references () [0]
   Live Value +ImportMyBanner.+make: 0 references () [0]
   Dead RecordLabel +ImportMyBanner.message.text: 0 references () [0]
+  Dead Value +JsxV4.C.+make: 0 references () [0]
   Live Value +LetPrivate.+y: 0 references () [0]
   Live Value +LetPrivate.local_1.+x: 1 references (LetPrivate.res:7:4) [0]
   Live Value +ModuleAliases.+testInner2: 0 references () [0]
@@ -3981,6 +3986,16 @@ File References
   <-- line 12
   @dead("make") let make = make
 
+  Warning Dead Module
+  File "JsxV4.res", line 3, characters 8-62
+  JsxV4.C is a dead module as all its items are dead.
+
+  Warning Dead Value
+  File "JsxV4.res", line 4, characters 20-47
+  C.make is never used
+  <-- line 4
+    @react.component @dead("C.make") let make = () => React.null
+
   Warning Dead Module
   File "ModuleAliases.res", line 2, characters 10-57
   ModuleAliases.Outer.Inner is a dead module as all its items are dead.
@@ -4505,4 +4520,4 @@ File References
   <-- line 96
   type variant1Object = | @dead("variant1Object.R") R(payload)
   
-  Analysis reported 334 issues (Incorrect Dead Annotation:1, Warning Dead Exception:2, Warning Dead Module:25, Warning Dead Type:89, Warning Dead Value:199, Warning Dead Value With Side Effects:2, Warning Redundant Optional Argument:5, Warning Unused Argument:11)
+  Analysis reported 336 issues (Incorrect Dead Annotation:1, Warning Dead Exception:2, Warning Dead Module:26, Warning Dead Type:89, Warning Dead Value:200, Warning Dead Value With Side Effects:2, Warning Redundant Optional Argument:5, Warning Unused Argument:11)
diff --git a/analysis/reanalyze/examples/deadcode/src/JsxV4.bs.js b/analysis/reanalyze/examples/deadcode/src/JsxV4.bs.js
new file mode 100644
index 000000000..c4f62837d
--- /dev/null
+++ b/analysis/reanalyze/examples/deadcode/src/JsxV4.bs.js
@@ -0,0 +1,18 @@
+// Generated by ReScript, PLEASE EDIT WITH CARE
+
+import * as React from "react";
+
+function JsxV4$C(props) {
+  return null;
+}
+
+var C = {
+  make: JsxV4$C
+};
+
+React.createElement(JsxV4$C, {});
+
+export {
+  C ,
+}
+/*  Not a pure module */
diff --git a/analysis/reanalyze/examples/deadcode/src/JsxV4.res b/analysis/reanalyze/examples/deadcode/src/JsxV4.res
new file mode 100644
index 000000000..e9edcb20e
--- /dev/null
+++ b/analysis/reanalyze/examples/deadcode/src/JsxV4.res
@@ -0,0 +1,7 @@
+@@jsxConfig({version: 4})
+
+module C = {
+  @react.component let make = () => React.null
+}
+
+let _ = <C />