Add experimental "no-panic" feature.

When enabled, any "this should never happen" errors in dispatcher
and/or hostcalls will be logged, but the processing will continue
as if nothing happened, instead of panicking and trapping WasmVM.

Note that any execution past the "should have panicked" point
is mostly undefined, since the state of any objects might get
out-of-sync with the host when errors and/or events are being
ignored.

Signed-off-by: Piotr Sikora <code@piotrsikora.dev>

Author: PiotrSikora

BUILD

@@ -39,6 +39,20 @@ rust_library(
     ],
 )
 
+rust_library(
+    name = "proxy_wasm_no_panic",
+    srcs = glob(["src/*.rs"]),
+    crate_features = ["no-panic"],
+    crate_name = "proxy_wasm",
+    edition = "2018",
+    visibility = ["//visibility:public"],
+    deps = [
+        ":proxy_wasm_build_script",
+        "//bazel/cargo/remote:hashbrown",
+        "//bazel/cargo/remote:log",
+    ],
+)
+
 rust_binary(
     name = "http_auth_random",
     srcs = ["examples/http_auth_random/src/lib.rs"],

Cargo.toml

@@ -14,6 +14,10 @@ build = "build.rs"
 hashbrown = "0.15"
 log = "0.4"
 
+[features]
+default = []
+no-panic = []
+
 [profile.release]
 lto = true
 opt-level = 3

examples/http_auth_random/Cargo.toml

@@ -12,7 +12,7 @@ crate-type = ["cdylib"]
 
 [dependencies]
 log = "0.4"
-proxy-wasm = { path = "../../" }
+proxy-wasm = { path = "../../", features = ["no-panic"] }
 
 [profile.release]
 lto = true