Use 3 modes for potentially trapping ops in asm2wasm (#929)

* use 3 modes for potentially trapping ops in asm2wasm: allow (just emit a potentially trapping op), js (do exactly what js does, even if it takes a slow ffi to do it), and clamp (avoid the trap by clamping as necessary)

1 files changed, 77 insertions, 0 deletions

diff --git a/test/dynamicLibrary.fromasm.clamp b/test/dynamicLibrary.fromasm.clamp
new file mode 100644
index 000000000..68cea0677
--- /dev/null
+++ b/test/dynamicLibrary.fromasm.clamp
@@ -0,0 +1,77 @@
+(module
+  (type $FUNCSIG$vi (func (param i32)))
+  (type $FUNCSIG$ii (func (param i32) (result i32)))
+  (import "env" "memoryBase" (global $memoryBase i32))
+  (import "env" "abortStackOverflow" (func $abortStackOverflow (param i32)))
+  (import "env" "_puts" (func $_puts (param i32) (result i32)))
+  (import "env" "memory" (memory $0 256 256))
+  (import "env" "table" (table 0 0 anyfunc))
+  (import "env" "tableBase" (global $tableBase i32))
+  (global $STACKTOP (mut i32) (i32.const 0))
+  (global $STACK_MAX (mut i32) (i32.const 0))
+  (global $_global i32 (i32.const 5242912))
+  (data (get_global $memoryBase) "dynamicLibrary.asm.js")
+  (export "__ZN3FooC2Ev" (func $__ZN3FooC2Ev))
+  (export "__post_instantiate" (func $__post_instantiate))
+  (export "runPostSets" (func $runPostSets))
+  (export "_global" (global $_global))
+  (func $___cxx_global_var_init
+    (call $__ZN3FooC2Ev
+      (i32.add
+        (get_global $memoryBase)
+        (i32.const 5242912)
+      )
+    )
+  )
+  (func $__ZN3FooC2Ev (param $0 i32)
+    (local $1 i32)
+    (set_local $1
+      (get_global $STACKTOP)
+    )
+    (set_global $STACKTOP
+      (i32.add
+        (get_global $STACKTOP)
+        (i32.const 16)
+      )
+    )
+    (if
+      (i32.ge_s
+        (get_global $STACKTOP)
+        (get_global $STACK_MAX)
+      )
+      (call $abortStackOverflow
+        (i32.const 16)
+      )
+    )
+    (drop
+      (call $_puts
+        (get_global $memoryBase)
+      )
+    )
+    (set_global $STACKTOP
+      (get_local $1)
+    )
+  )
+  (func $__GLOBAL__sub_I_liblib_cpp
+    (call $___cxx_global_var_init)
+  )
+  (func $runPostSets
+    (nop)
+  )
+  (func $__post_instantiate
+    (set_global $STACKTOP
+      (i32.add
+        (get_global $memoryBase)
+        (i32.const 32)
+      )
+    )
+    (set_global $STACK_MAX
+      (i32.add
+        (get_global $STACKTOP)
+        (i32.const 5242880)
+      )
+    )
+    (call $runPostSets)
+    (call $__GLOBAL__sub_I_liblib_cpp)
+  )
+)