Don't allow memory to be shared by default (#756)

Shared memory is only allowed with the `--enable-threads` flag.

1 files changed, 19 insertions, 18 deletions

diff --git a/src/validator.cc b/src/validator.cc
index 85715b47..717f39ee 100644
--- a/src/validator.cc
+++ b/src/validator.cc
@@ -129,9 +129,10 @@ class Validator {
                           Type expected_type,
                           const char* desc);
   void CheckGlobal(const Location* loc, const Global* global);
-  void CheckLimits(const Location* loc, const Limits* limits,
-                   uint64_t absolute_max, const char* desc,
-                   LimitsShareable sharing);
+  void CheckLimits(const Location* loc,
+                   const Limits* limits,
+                   uint64_t absolute_max,
+                   const char* desc);
   void CheckTable(const Location* loc, const Table* table);
   void CheckElemSegments(const Module* module);
   void CheckMemory(const Location* loc, const Memory* memory);
@@ -784,8 +785,7 @@ void Validator::CheckGlobal(const Location* loc, const Global* global) {
 }
 
 void Validator::CheckLimits(const Location* loc, const Limits* limits,
-                            uint64_t absolute_max, const char* desc,
-                            LimitsShareable sharing) {
+                            uint64_t absolute_max, const char* desc) {
   if (limits->initial > absolute_max) {
     PrintError(loc, "initial %s (%" PRIu64 ") must be <= (%" PRIu64 ")", desc,
                limits->initial, absolute_max);
@@ -803,23 +803,17 @@ void Validator::CheckLimits(const Location* loc, const Limits* limits,
                  desc, limits->max, desc, limits->initial);
     }
   }
-  if (limits->is_shared) {
-    if (sharing == LimitsShareable::NotAllowed) {
-      PrintError(loc, "tables may not be shared");
-      return;
-    }
-    if (!limits->has_max) {
-      PrintError(loc, "shared memories must have max sizes");
-    }
-  }
 }
 
 void Validator::CheckTable(const Location* loc, const Table* table) {
   if (current_table_index_ == 1) {
     PrintError(loc, "only one table allowed");
   }
-  CheckLimits(loc, &table->elem_limits, UINT32_MAX, "elems",
-              LimitsShareable::NotAllowed);
+  CheckLimits(loc, &table->elem_limits, UINT32_MAX, "elems");
+
+  if (table->elem_limits.is_shared) {
+    PrintError(loc, "tables may not be shared");
+  }
 }
 
 void Validator::CheckElemSegments(const Module* module) {
@@ -845,8 +839,15 @@ void Validator::CheckMemory(const Location* loc, const Memory* memory) {
   if (current_memory_index_ == 1) {
     PrintError(loc, "only one memory block allowed");
   }
-  CheckLimits(loc, &memory->page_limits, WABT_MAX_PAGES, "pages",
-              LimitsShareable::Allowed);
+  CheckLimits(loc, &memory->page_limits, WABT_MAX_PAGES, "pages");
+
+  if (memory->page_limits.is_shared) {
+    if (!options_->features.threads_enabled()) {
+      PrintError(loc, "memories may not be shared");
+    } else if (!memory->page_limits.has_max) {
+      PrintError(loc, "shared memories must have max sizes");
+    }
+  }
 }
 
 void Validator::CheckDataSegments(const Module* module) {