add a --memory-base options to asm2wasm, to fix the memory base instead of depending on an import

6 files changed, 19 insertions, 4 deletions

diff --git a/auto_update_tests.py b/auto_update_tests.py
index 63590f6cc..f3671b5ce 100755
--- a/auto_update_tests.py
+++ b/auto_update_tests.py
@@ -25,6 +25,8 @@ for asm in sorted(os.listdir('test')):
           # test mem init importing
           open('a.mem', 'wb').write(asm)
           cmd += ['--mem-init=a.mem']
+          if asm[0] == 'e':
+            cmd += ['--mem-base=1024']
         if 'i64' in asm or 'wasm-only' in asm:
           cmd += ['--wasm-only']
         print '..', asm, wasm
diff --git a/check.py b/check.py
index df9633de8..67adea9ef 100755
--- a/check.py
+++ b/check.py
@@ -370,6 +370,8 @@ for asm in tests:
           # test mem init importing
           open('a.mem', 'wb').write(asm)
           cmd += ['--mem-init=a.mem']
+          if asm[0] == 'e':
+            cmd += ['--mem-base=1024']
         if 'i64' in asm or 'wasm-only' in asm:
           cmd += ['--wasm-only']
         wasm = os.path.join(options.binaryen_test, wasm)
diff --git a/src/tools/asm2wasm.cpp b/src/tools/asm2wasm.cpp
index def361066..6761ed28a 100644
--- a/src/tools/asm2wasm.cpp
+++ b/src/tools/asm2wasm.cpp
@@ -51,6 +51,10 @@ int main(int argc, const char *argv[]) {
            [](Options *o, const std::string &argument) {
              o->extra["mem init"] = argument;
            })
+      .add("--mem-base", "-mb", "Set the location to write the memory initialization (--mem-init) file (GLOBAL_BASE in emscripten). If not provided, the memoryBase global import is used.", Options::Arguments::One,
+           [](Options *o, const std::string &argument) {
+             o->extra["mem base"] = argument;
+           })
       .add("--total-memory", "-m", "Total memory size", Options::Arguments::One,
            [](Options *o, const std::string &argument) {
              o->extra["total memory"] = argument;
@@ -104,7 +108,14 @@ int main(int argc, const char *argv[]) {
     auto filename = memInit->second.c_str();
     auto data(read_file<std::vector<char>>(filename, Flags::Binary, options.debug ? Flags::Debug : Flags::Release));
     // create the memory segment
-    wasm.memory.segments.emplace_back(Builder(wasm).makeGetGlobal(Name("memoryBase"), i32), data);
+    Expression* init;
+    const auto &memBase = options.extra.find("mem base");
+    if (memBase == options.extra.end()) {
+      init = Builder(wasm).makeGetGlobal(Name("memoryBase"), i32);
+    } else {
+      init = Builder(wasm).makeConst(Literal(int32_t(atoi(memBase->second.c_str()))));
+    }
+    wasm.memory.segments.emplace_back(init, data);
   }
 
   if (options.debug) std::cerr << "printing..." << std::endl;
diff --git a/test/emcc_O2_hello_world.fromasm b/test/emcc_O2_hello_world.fromasm
index 9646d4d62..70ff7a09e 100644
--- a/test/emcc_O2_hello_world.fromasm
+++ b/test/emcc_O2_hello_world.fromasm
@@ -33,7 +33,7 @@
   (import "env" "memoryBase" (global $memoryBase i32))
   (import "env" "tableBase" (global $tableBase i32))
   (elem (i32.const 0) $b0 $___stdio_close $b1 $b1 $___stdout_write $___stdio_seek $b1 $___stdio_write $b1 $b1 $b2 $b2 $b2 $b2 $_cleanup_418 $b2 $b2 $b2)
-  (data (get_global $memoryBase) "emcc_O2_hello_world.asm.js")
+  (data (i32.const 1024) "emcc_O2_hello_world.asm.js")
   (global $STACKTOP (mut i32) (get_global $STACKTOP$asm2wasm$import))
   (global $STACK_MAX (mut i32) (get_global $STACK_MAX$asm2wasm$import))
   (global $tempDoublePtr (mut i32) (get_global $tempDoublePtr$asm2wasm$import))
diff --git a/test/emcc_hello_world.fromasm b/test/emcc_hello_world.fromasm
index 01a30d8eb..043ad0d96 100644
--- a/test/emcc_hello_world.fromasm
+++ b/test/emcc_hello_world.fromasm
@@ -42,7 +42,7 @@
   (import "env" "memoryBase" (global $memoryBase i32))
   (import "env" "tableBase" (global $tableBase i32))
   (elem (i32.const 0) $b0 $___stdio_close $b1 $b1 $___stdout_write $___stdio_seek $___stdio_write $b1 $b1 $b1 $b2 $b2 $b2 $b2 $b2 $_cleanup $b2 $b2)
-  (data (get_global $memoryBase) "emcc_hello_world.asm.js")
+  (data (i32.const 1024) "emcc_hello_world.asm.js")
   (global $STACKTOP (mut i32) (get_global $STACKTOP$asm2wasm$import))
   (global $STACK_MAX (mut i32) (get_global $STACK_MAX$asm2wasm$import))
   (global $tempDoublePtr (mut i32) (get_global $tempDoublePtr$asm2wasm$import))
diff --git a/test/empty.fromasm b/test/empty.fromasm
index a8d289e29..a88b44007 100644
--- a/test/empty.fromasm
+++ b/test/empty.fromasm
@@ -3,5 +3,5 @@
   (import "env" "table" (table 0 0 anyfunc))
   (import "env" "memoryBase" (global $memoryBase i32))
   (import "env" "tableBase" (global $tableBase i32))
-  (data (get_global $memoryBase) "empty.asm.js")
+  (data (i32.const 1024) "empty.asm.js")
 )