From 5e2cdebdada69393e6556fb3dcdb610fee6ee112 Mon Sep 17 00:00:00 2001
From: Cheng Shao <terrorjack@type.dance>
Date: Tue, 13 Dec 2022 11:23:14 +0000
Subject: [PATCH] Specify default exe extension on wasm32 to be .wasm

Specify default exe extension on wasm32 to be .wasm, following the convention in other WebAssembly toolchains.
---
 Cabal/src/Distribution/Simple/BuildPaths.hs | 5 +++--
 Cabal/src/Distribution/Simple/Utils.hs      | 7 ++++---
 changelog.d/pr-8633                         | 7 +++++++
 3 files changed, 14 insertions(+), 5 deletions(-)
 create mode 100644 changelog.d/pr-8633

diff --git a/Cabal/src/Distribution/Simple/BuildPaths.hs b/Cabal/src/Distribution/Simple/BuildPaths.hs
index 733953747c8..078633874d1 100644
--- a/Cabal/src/Distribution/Simple/BuildPaths.hs
+++ b/Cabal/src/Distribution/Simple/BuildPaths.hs
@@ -235,8 +235,9 @@ mkGenericSharedBundledLibName platform comp lib
 -- | Default extension for executable files on the current platform.
 -- (typically @\"\"@ on Unix and @\"exe\"@ on Windows or OS\/2)
 exeExtension :: Platform -> String
-exeExtension (Platform _arch os) = case os of
-                   Windows -> "exe"
+exeExtension platform = case platform of
+                   Platform _ Windows -> "exe"
+                   Platform Wasm32 _  -> "wasm"
                    _       -> ""
 
 -- | Extension for object files. For GHC the extension is @\"o\"@.
diff --git a/Cabal/src/Distribution/Simple/Utils.hs b/Cabal/src/Distribution/Simple/Utils.hs
index 6bf0729410a..3fb6f56c738 100644
--- a/Cabal/src/Distribution/Simple/Utils.hs
+++ b/Cabal/src/Distribution/Simple/Utils.hs
@@ -1535,12 +1535,13 @@ dropExeExtension filepath =
 -- | List of possible executable file extensions on the current build
 -- platform.
 exeExtensions :: [String]
-exeExtensions = case buildOS of
+exeExtensions = case (buildArch, buildOS) of
   -- Possible improvement: on Windows, read the list of extensions from the
   -- PATHEXT environment variable. By default PATHEXT is ".com; .exe; .bat;
   -- .cmd".
-  Windows -> ["", "exe"]
-  Ghcjs   -> ["", "exe"]
+  (_, Windows) -> ["", "exe"]
+  (_, Ghcjs)   -> ["", "exe"]
+  (Wasm32, _)  -> ["", "wasm"]
   _       -> [""]
 
 -- ------------------------------------------------------------
diff --git a/changelog.d/pr-8633 b/changelog.d/pr-8633
new file mode 100644
index 00000000000..2aafda9a837
--- /dev/null
+++ b/changelog.d/pr-8633
@@ -0,0 +1,7 @@
+synopsis: Specify default exe extension on wasm32 to be .wasm
+packages: Cabal
+prs: #8633
+issues:
+description: {
+  Specify default exe extension on wasm32 to be .wasm, following the convention in other WebAssembly toolchains.
+}