Add C and JS API functions for accessing memory info (#4682)

Based on #3573 plus minor fixes

5 files changed, 101 insertions, 2 deletions

diff --git a/src/binaryen-c.cpp b/src/binaryen-c.cpp
index 709672aa4..44f323339 100644
--- a/src/binaryen-c.cpp
+++ b/src/binaryen-c.cpp
@@ -3812,6 +3812,37 @@ uint32_t BinaryenGetMemorySegmentByteOffset(BinaryenModuleRef module,
   Fatal() << "non-constant offsets aren't supported yet";
   return 0;
 }
+bool BinaryenHasMemory(BinaryenModuleRef module) {
+  return ((Module*)module)->memory.exists;
+}
+BinaryenIndex BinaryenMemoryGetInitial(BinaryenModuleRef module) {
+  return ((Module*)module)->memory.initial;
+}
+bool BinaryenMemoryHasMax(BinaryenModuleRef module) {
+  return ((Module*)module)->memory.hasMax();
+}
+BinaryenIndex BinaryenMemoryGetMax(BinaryenModuleRef module) {
+  return ((Module*)module)->memory.max;
+}
+const char* BinaryenMemoryImportGetModule(BinaryenModuleRef module) {
+  auto& memory = ((Module*)module)->memory;
+  if (memory.imported()) {
+    return memory.module.c_str();
+  } else {
+    return "";
+  }
+}
+const char* BinaryenMemoryImportGetBase(BinaryenModuleRef module) {
+  auto& memory = ((Module*)module)->memory;
+  if (memory.imported()) {
+    return memory.base.c_str();
+  } else {
+    return "";
+  }
+}
+bool BinaryenMemoryIsShared(BinaryenModuleRef module) {
+  return ((Module*)module)->memory.shared;
+}
 size_t BinaryenGetMemorySegmentByteLength(BinaryenModuleRef module,
                                           BinaryenIndex id) {
   const auto& segments = ((Module*)module)->memory.segments;
diff --git a/src/binaryen-c.h b/src/binaryen-c.h
index ed0f01f1c..715b08880 100644
--- a/src/binaryen-c.h
+++ b/src/binaryen-c.h
@@ -2285,6 +2285,15 @@ BINARYEN_API void BinaryenSetMemory(BinaryenModuleRef module,
                                     BinaryenIndex numSegments,
                                     bool shared);
 
+BINARYEN_API bool BinaryenHasMemory(BinaryenModuleRef module);
+BINARYEN_API BinaryenIndex BinaryenMemoryGetInitial(BinaryenModuleRef module);
+BINARYEN_API bool BinaryenMemoryHasMax(BinaryenModuleRef module);
+BINARYEN_API BinaryenIndex BinaryenMemoryGetMax(BinaryenModuleRef module);
+BINARYEN_API const char*
+BinaryenMemoryImportGetModule(BinaryenModuleRef module);
+BINARYEN_API const char* BinaryenMemoryImportGetBase(BinaryenModuleRef module);
+BINARYEN_API bool BinaryenMemoryIsShared(BinaryenModuleRef module);
+
 // Memory segments. Query utilities.
 
 BINARYEN_API uint32_t BinaryenGetNumMemorySegments(BinaryenModuleRef module);
diff --git a/src/js/binaryen.js-post.js b/src/js/binaryen.js-post.js
index 28f5b6258..b6ea7dee1 100644
--- a/src/js/binaryen.js-post.js
+++ b/src/js/binaryen.js-post.js
@@ -2500,9 +2500,24 @@ function wrapModule(module, self = {}) {
       );
     });
   };
+  self['hasMemory'] = function() {
+    return Boolean(Module['_BinaryenHasMemory'](module));
+  };
+  self['getMemoryInfo'] = function() {
+    var memoryInfo = {
+      'module': UTF8ToString(Module['_BinaryenMemoryImportGetModule'](module)),
+      'base': UTF8ToString(Module['_BinaryenMemoryImportGetBase'](module)),
+      'initial': Module['_BinaryenMemoryGetInitial'](module),
+      'shared': Boolean(Module['_BinaryenMemoryIsShared'](module))
+    };
+    if (Module['_BinaryenMemoryHasMax'](module)) {
+      memoryInfo['max'] = Module['_BinaryenMemoryGetMax'](module);
+    }
+    return memoryInfo;
+  };
   self['getNumMemorySegments'] = function() {
     return Module['_BinaryenGetNumMemorySegments'](module);
-  }
+  };
   self['getMemorySegmentInfoByIndex'] = function(id) {
     return {
       'offset': Module['_BinaryenGetMemorySegmentByteOffset'](module, id),
@@ -2517,7 +2532,7 @@ function wrapModule(module, self = {}) {
       })(),
       'passive': Boolean(Module['_BinaryenGetMemorySegmentPassive'](module, id))
     };
-  }
+  };
   self['setStart'] = function(start) {
     return Module['_BinaryenSetStart'](module, start);
   };
diff --git a/test/binaryen.js/memory-info.js b/test/binaryen.js/memory-info.js
new file mode 100644
index 000000000..16ec86753
--- /dev/null
+++ b/test/binaryen.js/memory-info.js
@@ -0,0 +1,35 @@
+var module = new binaryen.Module();
+assert(module.validate());
+console.log(JSON.stringify(module.hasMemory()));
+
+var initial = 1, maximum = 64;
+
+// Not shared
+module = new binaryen.Module();
+module.setMemory(initial, maximum, '');
+assert(module.validate());
+console.log(JSON.stringify(module.hasMemory()));
+console.log(JSON.stringify(module.getMemoryInfo()));
+
+// Shared
+module = new binaryen.Module();
+module.setFeatures(binaryen.Features.MVP | binaryen.Features.Atomics);
+module.setMemory(initial, maximum, '', [], true);
+assert(module.validate());
+console.log(JSON.stringify(module.hasMemory()));
+console.log(JSON.stringify(module.getMemoryInfo()));
+
+// Imported, not shared
+module = new binaryen.Module();
+module.addMemoryImport('my_mem', 'env', 'memory', false);
+assert(module.validate());
+console.log(JSON.stringify(module.hasMemory()));
+console.log(JSON.stringify(module.getMemoryInfo()));
+
+// Imported, shared
+module = new binaryen.Module();
+module.setFeatures(binaryen.Features.MVP | binaryen.Features.Atomics);
+module.addMemoryImport('my_mem', 'env', 'memory', true);
+assert(module.validate());
+console.log(JSON.stringify(module.hasMemory()));
+console.log(JSON.stringify(module.getMemoryInfo()));
diff --git a/test/binaryen.js/memory-info.js.txt b/test/binaryen.js/memory-info.js.txt
new file mode 100644
index 000000000..39d1290ae
--- /dev/null
+++ b/test/binaryen.js/memory-info.js.txt
@@ -0,0 +1,9 @@
+false
+true
+{"module":"","base":"","initial":1,"shared":false,"max":64}
+true
+{"module":"","base":"","initial":1,"shared":true,"max":64}
+false
+{"module":"env","base":"memory","initial":0,"shared":false,"max":65536}
+false
+{"module":"env","base":"memory","initial":0,"shared":true,"max":65536}