Handle importing globals in s2wasm (#843)

* Handle importing globals in s2wasm

* Make importedGlobals a set of Names, make Names hashable

* Revert "Make importedGlobals a set of Names, make Names hashable"

This reverts commit 1d0ca7a5e3839b15ca60593330979864c9c3ed60.

* Refactor relocation parsing to handle expressions directly

* PR Feedback

- Move comment where it belongs
- Add comment about ownership to addRelocation
- Remove do-nothing parseImportGlobal

* Reword "imported globals" to "imported objects"

- Flip isObjectImported to isObjectImplemented, for consistency

* Add tests for s2wasm globals.

Also implement import relocation expression handling

* Simplify globals.s test

* Fix memory leak of relocation

* Use unique_ptr instead of delete in getRelocatableExpression

2 files changed, 153 insertions, 0 deletions

diff --git a/test/dot_s/globals.s b/test/dot_s/globals.s
new file mode 100644
index 000000000..4ea8041a9
--- /dev/null
+++ b/test/dot_s/globals.s
@@ -0,0 +1,72 @@
+    .text
+    .globl globals
+    .type globals,@function
+globals:
+    i32.const   $push0=, 0
+    i32.const   $push1=, 7
+    i32.store   local_global($pop0), $pop1
+    i32.const   $push2=, 0
+    i32.load    $drop=, local_global($pop2)
+    i32.const   $drop=, local_global
+    .endfunc
+.Lfunc_end0:
+    .size   globals, .Lfunc_end0-globals
+
+    .globl import_globals
+    .type import_globals,@function
+import_globals:
+    i32.const   $push0=, 0
+    i32.const   $push1=, 7
+    i32.store   imported_global($pop0), $pop1
+    i32.const   $push2=, 0
+    i32.load    $drop=, imported_global($pop2)
+    i32.const   $drop=, imported_global
+    .endfunc
+.Lfunc_end0:
+    .size   import_globals, .Lfunc_end0-import_globals
+
+    .globl globals_offset
+    .type globals_offset,@function
+globals_offset:
+    i32.const   $push0=, 4
+    i32.const   $push1=, 7
+    i32.store   local_global+12($pop0), $pop1
+    i32.const   $push2=, 8
+    i32.load    $drop=, local_global-4($pop2)
+    i32.const   $drop=, local_global+16
+    .endfunc
+.Lfunc_end0:
+    .size   globals_offset, .Lfunc_end0-globals_offset
+
+    .globl import_globals_offset
+    .type import_globals_offset,@function
+import_globals_offset:
+    i32.const   $push0=, 4
+    i32.const   $push1=, 7
+    i32.store   imported_global+12($pop0), $pop1
+    i32.const   $push2=, 8
+    i32.load    $drop=, imported_global-4($pop2)
+    i32.const   $drop=, imported_global+16
+    .endfunc
+.Lfunc_end0:
+    .size   import_globals_offset, .Lfunc_end0-import_globals_offset
+
+    .type   local_global,@object
+    .p2align    2
+local_global:
+    .int32  17
+    .size   local_global, 4
+
+    .type   initialized_with_global,@object
+    .p2align    2
+initialized_with_global:
+    .int32  local_global
+    .size   initialized_with_global, 4
+
+    .type   initialized_with_global_offset,@object
+    .p2align    2
+initialized_with_global_offset:
+    .int32  local_global+2
+    .size   initialized_with_global_offset, 4
+
+    .import_global  imported_global
diff --git a/test/dot_s/globals.wast b/test/dot_s/globals.wast
new file mode 100644
index 000000000..d6a164de6
--- /dev/null
+++ b/test/dot_s/globals.wast
@@ -0,0 +1,81 @@
+(module
+  (import "env" "memory" (memory $0 1))
+  (import "env" "imported_global" (global $imported_global i32))
+  (table 0 anyfunc)
+  (data (i32.const 12) "\11\00\00\00")
+  (data (i32.const 16) "\0c\00\00\00")
+  (data (i32.const 20) "\0e\00\00\00")
+  (export "globals" (func $globals))
+  (export "import_globals" (func $import_globals))
+  (export "globals_offset" (func $globals_offset))
+  (export "import_globals_offset" (func $import_globals_offset))
+  (func $globals
+    (i32.store offset=12
+      (i32.const 0)
+      (i32.const 7)
+    )
+    (drop
+      (i32.load offset=12
+        (i32.const 0)
+      )
+    )
+    (drop
+      (i32.const 12)
+    )
+  )
+  (func $import_globals
+    (i32.store
+      (get_global $imported_global)
+      (i32.const 7)
+    )
+    (drop
+      (i32.load
+        (get_global $imported_global)
+      )
+    )
+    (drop
+      (get_global $imported_global)
+    )
+  )
+  (func $globals_offset
+    (i32.store offset=24
+      (i32.const 4)
+      (i32.const 7)
+    )
+    (drop
+      (i32.load offset=8
+        (i32.const 8)
+      )
+    )
+    (drop
+      (i32.const 28)
+    )
+  )
+  (func $import_globals_offset
+    (i32.store offset=12
+      (i32.add
+        (i32.const 4)
+        (get_global $imported_global)
+      )
+      (i32.const 7)
+    )
+    (drop
+      (i32.load
+        (i32.add
+          (i32.const 8)
+          (i32.add
+            (i32.const -4)
+            (get_global $imported_global)
+          )
+        )
+      )
+    )
+    (drop
+      (i32.add
+        (i32.const 16)
+        (get_global $imported_global)
+      )
+    )
+  )
+)
+;; METADATA: { "asmConsts": {},"staticBump": 24, "initializers": [] }