Remove the JIT entitlement from gen_snapshot, take 2.

Push this down to VirtualMemory since some parts of the VM go there directly instead of through Page.

TEST=ci
Change-Id: Icc65242e9099e8785a38ba9e38311146d8b5845b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/510260
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>

runtime/tools/entitlements/gen_snapshot.plist

@@ -2,7 +2,5 @@
 <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
     <dict>
-        <key>com.apple.security.cs.allow-jit</key>
-        <true/>
     </dict>
 </plist>

runtime/tools/entitlements/gen_snapshot_product.plist

@@ -2,7 +2,5 @@
 <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
     <dict>
-        <key>com.apple.security.cs.allow-jit</key>
-        <true/>
     </dict>
 </plist>

runtime/vm/heap/page.cc

@@ -69,12 +69,7 @@ static intptr_t CacheIndex(uword flags) {
 }
 
 Page* Page::Allocate(intptr_t size, uword flags) {
-#if defined(DART_INCLUDE_SIMULATOR)
-  const bool using_simulator = FLAG_use_simulator;
-#else
-  const bool using_simulator = false;
-#endif
-  const bool executable = (flags & Page::kExecutable) != 0 && !using_simulator;
+  const bool executable = (flags & Page::kExecutable) != 0;
   const bool compressed = !executable;
   const char* name = executable ? "dart-code" : "dart-heap";
 
@@ -316,12 +311,7 @@ void Page::ResetProgressBar() {
 
 void Page::WriteProtect(bool read_only) {
   ASSERT(!is_image());
-#if defined(DART_INCLUDE_SIMULATOR)
-  const bool using_simulator = FLAG_use_simulator;
-#else
-  const bool using_simulator = false;
-#endif
-  if (is_executable() && read_only && !using_simulator) {
+  if (is_executable() && read_only) {
     // Handle making code executable in a special way.
     memory_->WriteProtectCode();
   } else {

runtime/vm/virtual_memory.h

@@ -76,10 +76,20 @@ class VirtualMemory {
 #endif
   }
 
+  DART_FORCE_INLINE static bool ExecutesGeneratedCode() {
+#if defined(DART_PRECOMPILER) && !defined(TESTING)
+    return false;  // I.e., gen_snapshot.
+#else
+    return true;
+#endif
+  }
+
   // Write protect a chunk of machine code which is currently writable.
   DART_FORCE_INLINE static void WriteProtectCode(void* address, intptr_t size) {
     Protect(address, size,
-            ShouldDualMapExecutablePages() ? kReadOnly : kReadExecute);
+            ShouldDualMapExecutablePages() || !ExecutesGeneratedCode()
+                ? kReadOnly
+                : kReadExecute);
   }
   DART_FORCE_INLINE void WriteProtectCode() const {
     WriteProtectCode(address(), size());

runtime/vm/virtual_memory_fuchsia.cc

@@ -151,6 +151,12 @@ VirtualMemory* VirtualMemory::AllocateAligned(intptr_t size,
   ASSERT(Utils::IsPowerOfTwo(alignment));
   ASSERT(Utils::IsAligned(alignment, page_size_));
 
+  // Ignore executable for gen_snapshot/simulator, but still let the heap
+  // track code and data pages separately.
+  if (!VirtualMemory::ExecutesGeneratedCode()) {
+    is_executable = false;
+  }
+
   const zx_vm_option_t align_flag = Utils::ShiftForPowerOfTwo(alignment)
                                     << ZX_VM_ALIGN_BASE;
   ASSERT((ZX_VM_ALIGN_1KB <= align_flag) && (align_flag <= ZX_VM_ALIGN_4GB));

runtime/vm/virtual_memory_posix.cc

@@ -621,6 +621,12 @@ VirtualMemory* VirtualMemory::AllocateAligned(intptr_t size,
   ASSERT(Utils::IsAligned(alignment, PageSize()));
   ASSERT(name != nullptr);
 
+  // Ignore executable for gen_snapshot/simulator, but still let the heap
+  // track code and data pages separately.
+  if (!VirtualMemory::ExecutesGeneratedCode()) {
+    is_executable = false;
+  }
+
 #if defined(DART_COMPRESSED_POINTERS)
   if (is_compressed) {
     RELEASE_ASSERT(!is_executable);

runtime/vm/virtual_memory_win.cc

@@ -139,6 +139,12 @@ VirtualMemory* VirtualMemory::AllocateAligned(intptr_t size,
   ASSERT(Utils::IsPowerOfTwo(alignment));
   ASSERT(Utils::IsAligned(alignment, PageSize()));
 
+  // Ignore executable for gen_snapshot/simulator, but still let the heap
+  // track code and data pages separately.
+  if (!VirtualMemory::ExecutesGeneratedCode()) {
+    is_executable = false;
+  }
+
 #if defined(DART_COMPRESSED_POINTERS)
   if (is_compressed) {
     RELEASE_ASSERT(!is_executable);