4 files changed, 84 insertions, 0 deletions
diff --git a/test/ctor-eval/ignore-external-input.wast b/test/ctor-eval/ignore-external-input.wast
new file mode 100644
index 000000000..0849c67ab
--- /dev/null
+++ b/test/ctor-eval/ignore-external-input.wast
@@ -0,0 +1,63 @@
+(module
+  (import "wasi_snapshot_preview1" "environ_sizes_get" (func $wasi_environ_sizes_get (param i32 i32) (result i32)))
+  (import "wasi_snapshot_preview1" "environ_get" (func $wasi_environ_get (param i32 i32) (result i32)))
+
+  (import "wasi_snapshot_preview1" "args_sizes_get" (func $wasi_args_sizes_get (param i32 i32) (result i32)))
+  (import "wasi_snapshot_preview1" "args_get" (func $wasi_args_get (param i32 i32) (result i32)))
+
+  (import "wasi_snapshot_preview1" "something_else" (func $wasi_something_else (result i32)))
+
+  (memory 256 256)
+  (data (i32.const 0) "aaaaaaaaaaaaaaaaaaaaaaaaaaaa") ;; the final 4 'a's will remain
+
+  (func "test1"
+    ;; This is ok to call: when ignoring external input we assume there is no
+    ;; environment to read.
+    (i32.store
+      (i32.const 0) ;; the result (0) will be written to address 0
+      (call $wasi_environ_sizes_get
+        (i32.const 4) ;; count (0) will be written to address 4
+        (i32.const 0)
+      )
+    )
+    (i32.store
+      (i32.const 8) ;; the result (0) will be written to address 8
+      (call $wasi_environ_get
+        (i32.const 0)
+        (i32.const 0)
+      )
+    )
+  )
+
+  (func "test2"
+    ;; This is also ok to call: when ignoring external input we assume there are
+    ;; not args passed to main.
+    (i32.store
+      (i32.const 12) ;; the result (0) will be written to address 12
+      (call $wasi_args_sizes_get
+        (i32.const 16) ;; argc (0) will be written to address 16
+        (i32.const 0)
+      )
+    )
+    (i32.store
+      (i32.const 20) ;; the result (0) will be written to address 20
+      (call $wasi_args_get
+        (i32.const 0)
+        (i32.const 0)
+      )
+    )
+  )
+
+  (func "test3"
+    ;; This is *not* ok to call, and we will *not* reach the final store after
+    ;; this call. This function will not be evalled and will remain in the
+    ;; output.
+    (drop
+      (call $wasi_something_else)
+    )
+    (i32.store
+      (i32.const 24)
+      (i32.const 100)
+    )
+  )
+)
diff --git a/test/ctor-eval/ignore-external-input.wast.ctors b/test/ctor-eval/ignore-external-input.wast.ctors
new file mode 100644
index 000000000..c7060ede5
--- /dev/null
+++ b/test/ctor-eval/ignore-external-input.wast.ctors
@@ -0,0 +1 @@
+test1,test2,test3
diff --git a/test/ctor-eval/ignore-external-input.wast.out b/test/ctor-eval/ignore-external-input.wast.out
new file mode 100644
index 000000000..f728afd0e
--- /dev/null
+++ b/test/ctor-eval/ignore-external-input.wast.out
@@ -0,0 +1,17 @@
+(module
+ (type $none_=>_i32 (func (result i32)))
+ (type $none_=>_none (func))
+ (import "wasi_snapshot_preview1" "something_else" (func $wasi_something_else (result i32)))
+ (memory $0 256 256)
+ (data (i32.const 24) "aaaa")
+ (export "test3" (func $2))
+ (func $2
+  (drop
+   (call $wasi_something_else)
+  )
+  (i32.store
+   (i32.const 24)
+   (i32.const 100)
+  )
+ )
+)
diff --git a/test/lit/help/wasm-ctor-eval.test b/test/lit/help/wasm-ctor-eval.test
index cf0671c81..364ac5d4c 100644
--- a/test/lit/help/wasm-ctor-eval.test
+++ b/test/lit/help/wasm-ctor-eval.test
@@ -19,6 +19,9 @@
 ;; CHECK-NEXT:   --ctors,-c                           Comma-separated list of global
 ;; CHECK-NEXT:                                        constructor functions to evaluate
 ;; CHECK-NEXT:
+;; CHECK-NEXT:   --ignore-external-input,-ipi         Assumes no env vars are to be read, stdin
+;; CHECK-NEXT:                                        is empty, etc.
+;; CHECK-NEXT:
 ;; CHECK-NEXT:
 ;; CHECK-NEXT: Tool options:
 ;; CHECK-NEXT: -------------