From 5d4483674f25fddf87c0842ac37afcd0fd0b64cb Mon Sep 17 00:00:00 2001
From: Tyler Rockwood <rockwood@redpanda.com>
Date: Tue, 19 Sep 2023 15:57:13 -0500
Subject: [PATCH] c-api: Expose image_range for modules

We're using this to monitor the amount of executable memory each module
needs.

Signed-off-by: Tyler Rockwood <rockwood@redpanda.com>
---
 crates/c-api/include/wasmtime/module.h | 15 +++++++++++++++
 crates/c-api/src/module.rs             | 11 +++++++++++
 2 files changed, 26 insertions(+)

diff --git a/crates/c-api/include/wasmtime/module.h b/crates/c-api/include/wasmtime/module.h
index deb6bcec1efa..8eca72a4899e 100644
--- a/crates/c-api/include/wasmtime/module.h
+++ b/crates/c-api/include/wasmtime/module.h
@@ -148,6 +148,21 @@ WASM_API_EXTERN wasmtime_error_t *wasmtime_module_deserialize_file(
     wasmtime_module_t **ret
 );
 
+
+/**
+ * \brief Returns the range of bytes in memory where this module’s compilation image resides.
+ *
+ * The compilation image for a module contains executable code, data, debug information, etc. 
+ * This is roughly the same as the wasmtime_module_serialize but not the exact same.
+ *
+ * For more details see: https://docs.wasmtime.dev/api/wasmtime/struct.Module.html#method.image_range
+ */
+WASM_API_EXTERN void wasmtime_module_image_range(
+    const wasm_module_t *module,
+    size_t *start,
+    size_t *end
+);
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif
diff --git a/crates/c-api/src/module.rs b/crates/c-api/src/module.rs
index a1dce264931d..3a1a6e6664cc 100644
--- a/crates/c-api/src/module.rs
+++ b/crates/c-api/src/module.rs
@@ -183,6 +183,17 @@ pub extern "C" fn wasmtime_module_serialize(
     handle_result(module.module.serialize(), |buf| ret.set_buffer(buf))
 }
 
+#[no_mangle]
+pub extern "C" fn wasmtime_module_image_range(
+    module: &wasmtime_module_t,
+    start: &mut usize,
+    end: &mut usize,
+) {
+    let range = module.module.image_range();
+    *start = range.start;
+    *end = range.end;
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn wasmtime_module_deserialize(
     engine: &wasm_engine_t,