wasm-reduce tool (#1139)

Reduce an interesting wasm to a smaller still interesting wasm. This takes an arbitrary command to run, and reduces the wasm as much as it can while keeping the behavior of that command fixed. This can be used to reduce compiler bugs in an arbitrary VM, etc.

6 files changed, 112 insertions, 0 deletions

diff --git a/test/reduce/destructive.wast b/test/reduce/destructive.wast
new file mode 100644
index 000000000..65786502f
--- /dev/null
+++ b/test/reduce/destructive.wast
@@ -0,0 +1,10 @@
+(module
+  (export "x" (func $x))
+  (func $x (param $x i32) (result i32)
+    (if (i32.eq (get_local $x) (i32.const 98658746))
+      (unreachable) ;; this can be removed destructively, since we do not sent this param
+    )
+    (i32.const 100)
+  )
+)
+
diff --git a/test/reduce/destructive.wast.txt b/test/reduce/destructive.wast.txt
new file mode 100644
index 000000000..b5776b35e
--- /dev/null
+++ b/test/reduce/destructive.wast.txt
@@ -0,0 +1,9 @@
+(module
+ (type $0 (func (param i32) (result i32)))
+ (memory $0 0)
+ (export "x" (func $0))
+ (func $0 (type $0) (param $var$0 i32) (result i32)
+  (i32.const 100)
+ )
+)
+
diff --git a/test/reduce/memory_table.wast b/test/reduce/memory_table.wast
new file mode 100644
index 000000000..9e8ad4445
--- /dev/null
+++ b/test/reduce/memory_table.wast
@@ -0,0 +1,31 @@
+(module
+ (type $i (func (result i32)))
+ (memory $0 256 256)
+ (table 481 481 anyfunc)
+ (elem (i32.const 0) $f0 $f0 $f1 $f2 $f0 $f3 $f0)
+ (data (i32.const 0) "p\0bflkj")
+ (data (i32.const 10960) "1234hello")
+ (export "f1" (func $f1))
+ (export "f2" (func $f2))
+ (export "f4" (func $f4))
+ (func $f0 (result i32)
+  (i32.const 1234)
+ )
+ (func $f1
+  (i32.store (i32.const 1000) (i32.const 65530)) ;; dead store
+ )
+ (func $f2 (result i32)
+  (i32.store (i32.const 0) (i32.const 65530))
+  (i32.load (i32.const 0)) ;; load the written stuff
+ )
+ (func $f3 (result i32)
+  (i32.load (i32.const 10964)) ;; load the 'hell'
+ )
+ (func $f4 (result i32)
+  (i32.add
+   (call_indirect $i (i32.const 3))
+   (call_indirect $i (i32.const 0))
+  )
+ )
+)
+
diff --git a/test/reduce/memory_table.wast.txt b/test/reduce/memory_table.wast.txt
new file mode 100644
index 000000000..08918c9f3
--- /dev/null
+++ b/test/reduce/memory_table.wast.txt
@@ -0,0 +1,38 @@
+(module
+ (type $0 (func (result i32)))
+ (type $1 (func))
+ (table 481 481 anyfunc)
+ (elem (i32.const 0) $1 $1 $1 $3)
+ (memory $0 256 256)
+ (export "f1" (func $2))
+ (export "f2" (func $3))
+ (export "f4" (func $0))
+ (func $0 (type $0) (result i32)
+  (i32.add
+   (call_indirect $0
+    (i32.const 3)
+   )
+   (call_indirect $0
+    (i32.const 0)
+   )
+  )
+ )
+ (func $1 (type $0) (result i32)
+  (i32.const 1234)
+ )
+ (func $2 (type $1)
+  (nop)
+ )
+ (func $3 (type $0) (result i32)
+  (block $label$0 (result i32)
+   (i32.store
+    (i32.const 0)
+    (i32.const 65530)
+   )
+   (i32.load
+    (i32.const 0)
+   )
+  )
+ )
+)
+
diff --git a/test/reduce/simple.wast b/test/reduce/simple.wast
new file mode 100644
index 000000000..e54424190
--- /dev/null
+++ b/test/reduce/simple.wast
@@ -0,0 +1,15 @@
+(module
+  (export "x" (func $x))
+  (func $x (result i32)
+    (nop)
+    (nop)
+    (nop)
+    (drop (i32.const 1234))
+    (i32.const 5678) ;; easily reducible
+  )
+  (func $not-exported
+    (nop)
+    (unreachable)
+  )
+)
+
diff --git a/test/reduce/simple.wast.txt b/test/reduce/simple.wast.txt
new file mode 100644
index 000000000..b5209d1bc
--- /dev/null
+++ b/test/reduce/simple.wast.txt
@@ -0,0 +1,9 @@
+(module
+ (type $0 (func (result i32)))
+ (memory $0 0)
+ (export "x" (func $0))
+ (func $0 (type $0) (result i32)
+  (i32.const 5678)
+ )
+)
+