From 85cf4b042a67706669a1f1edea582d885b787a93 Mon Sep 17 00:00:00 2001
From: Cameron Harris <cameronh63@gmail.com>
Date: Tue, 15 Feb 2022 20:23:02 +0200
Subject: [PATCH] Added 'add_fuel' command line option (#3792)

* Added 'add_fuel' command line option

* Added default value to 'add_fuel' config option

* Added 'add_fuel' to run command Store instantiation

* Added comment

* Added warning for add-fuel without consume-fuel

* Formatting

* Changed out --add-fuel and --consume-fuel to --fuel

* Formatting

* Update src/lib.rs

* Update src/commands/run.rs

Co-authored-by: Nick Fitzgerald <fitzgen@gmail.com>
---
 src/commands/run.rs | 6 ++++++
 src/lib.rs          | 9 ++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/commands/run.rs b/src/commands/run.rs
index ae228d480a..abd1e59a1d 100644
--- a/src/commands/run.rs
+++ b/src/commands/run.rs
@@ -164,6 +164,12 @@ impl RunCommand {
         let engine = Engine::new(&config)?;
         let mut store = Store::new(&engine, Host::default());
 
+        // If fuel has been configured, we want to add the configured
+        // fuel amount to this store.
+        if let Some(fuel) = self.common.fuel {
+            store.add_fuel(fuel)?;
+        }
+
         let preopen_sockets = self.compute_preopen_sockets()?;
 
         // Make wasi available by default.
diff --git a/src/lib.rs b/src/lib.rs
index b3cb8961f7..1a9b20c54f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -234,9 +234,8 @@ struct CommonOptions {
     #[structopt(long)]
     enable_cranelift_nan_canonicalization: bool,
 
-    /// Executing wasm code will consume fuel, limiting its execution.
     #[structopt(long)]
-    consume_fuel: bool,
+    fuel: Option<u64>,
 
     /// Executing wasm code will yield when a global epoch counter
     /// changes, allowing for async operation without blocking the
@@ -328,7 +327,11 @@ impl CommonOptions {
             config.dynamic_memory_guard_size(size);
         }
 
-        config.consume_fuel(self.consume_fuel);
+        // If fuel has been configured, set the `consume fuel` flag on the config.
+        if self.fuel.is_some() {
+            config.consume_fuel(true);
+        }
+
         config.epoch_interruption(self.epoch_interruption);
         config.generate_address_map(!self.disable_address_map);
         config.paged_memory_initialization(self.paged_memory_initialization);