From a48d76321e4cddfd2e0e66a72611fa104687cf29 Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Sun, 24 Dec 2023 00:39:57 -0500
Subject: [PATCH] Building basic wasm.

---
 Cargo.toml      | 12 ++++++++++++
 Makefile        |  4 ++++
 src/bin_wasm.rs |  6 ++++++
 3 files changed, 22 insertions(+)
 create mode 100644 src/bin_wasm.rs

diff --git a/Cargo.toml b/Cargo.toml
index e2b1052..888c739 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -39,12 +39,18 @@ path = "src/lib.rs"
   path = "src/bin_foreign_document_test.rs"
   required-features = ["foreign_document_test"]
 
+[[bin]]
+  name = "wasm"
+  path = "src/bin_wasm.rs"
+  required-features = ["wasm"]
+
 [dependencies]
 futures = { version = "0.3.28", optional = true }
 nom = "7.1.1"
 opentelemetry = { version = "0.20.0", optional = true, default-features = false, features = ["trace", "rt-tokio"] }
 opentelemetry-otlp = { version = "0.13.0", optional = true }
 opentelemetry-semantic-conventions = { version = "0.12.0", optional = true }
+serde = { version = "1.0.193", optional = true, features = ["derive"] }
 tokio = { version = "1.30.0", optional = true, default-features = false, features = ["rt", "rt-multi-thread"] }
 tracing = { version = "0.1.37", optional = true }
 tracing-opentelemetry = { version = "0.20.0", optional = true }
@@ -60,6 +66,7 @@ compare = ["tokio/process", "tokio/macros"]
 foreign_document_test = ["compare", "dep:futures", "tokio/sync", "dep:walkdir", "tokio/process"]
 tracing = ["dep:opentelemetry", "dep:opentelemetry-otlp", "dep:opentelemetry-semantic-conventions", "dep:tokio", "dep:tracing", "dep:tracing-opentelemetry", "dep:tracing-subscriber"]
 event_count = []
+wasm = ["dep:serde"]
 
 # Optimized build for any sort of release.
 [profile.release-lto]
@@ -79,3 +86,8 @@ strip = "symbols"
 inherits = "release"
 lto = true
 debug = true
+
+[profile.wasm]
+inherits = "release"
+lto = true
+strip = true
diff --git a/Makefile b/Makefile
index 67a8fc9..939dec8 100644
--- a/Makefile
+++ b/Makefile
@@ -29,6 +29,10 @@ build:
 release:
 > cargo build --release $(RELEASEFLAGS)
 
+.PHONY: wasm
+wasm:
+> cargo build --target=wasm32-unknown-unknown --profile wasm --bin wasm --features wasm
+
 .PHONY: clean
 clean:
 > cargo clean
diff --git a/src/bin_wasm.rs b/src/bin_wasm.rs
new file mode 100644
index 0000000..2496df2
--- /dev/null
+++ b/src/bin_wasm.rs
@@ -0,0 +1,6 @@
+#![no_main]
+
+#[no_mangle]
+pub extern "C" fn add(left: usize, right: usize) -> usize {
+    left + right
+}