From c9c33d9db3c84646232ff23e51a4069dd5e92044 Mon Sep 17 00:00:00 2001
From: Ryan Macnak <rmacnak@google.com>
Date: Wed, 19 Oct 2016 16:36:01 -0700
Subject: [PATCH] Implement File::Map on Windows.

R=zra@google.com

Review URL: https://codereview.chromium.org/2430473002 .
---
 runtime/bin/file_win.cc | 40 +++++++++++++++++++++++++++++++++++++---
 runtime/bin/main.cc     | 26 ++++++++++++++++----------
 2 files changed, 53 insertions(+), 13 deletions(-)

diff --git a/runtime/bin/file_win.cc b/runtime/bin/file_win.cc
index 28788430ea6..d1e771948cf 100644
--- a/runtime/bin/file_win.cc
+++ b/runtime/bin/file_win.cc
@@ -74,9 +74,43 @@ bool File::IsClosed() {
 }
 
 
-void* File::Map(MapType type, int64_t position, int64_t length) {
-  UNIMPLEMENTED();
-  return NULL;
+void* File::Map(File::MapType type, int64_t position, int64_t length) {
+  DWORD prot_alloc;
+  DWORD prot_final;
+  switch (type) {
+    case File::kReadOnly:
+      prot_alloc = PAGE_READWRITE;
+      prot_final = PAGE_READONLY;
+      break;
+    case File::kReadExecute:
+      prot_alloc = PAGE_EXECUTE_READWRITE;
+      prot_final = PAGE_EXECUTE_READ;
+      break;
+    default:
+      return NULL;
+  }
+
+  void* addr = VirtualAlloc(NULL, length, MEM_COMMIT | MEM_RESERVE, prot_alloc);
+  if (addr == NULL) {
+    Log::PrintErr("VirtualAlloc failed %d\n", GetLastError());
+    return NULL;
+  }
+
+  SetPosition(position);
+  if (!ReadFully(addr, length)) {
+    Log::PrintErr("ReadFully failed %d\n", GetLastError());
+    VirtualFree(addr, 0, MEM_RELEASE);
+    return NULL;
+  }
+
+  DWORD old_prot;
+  bool result = VirtualProtect(addr, length, prot_final, &old_prot);
+  if (!result) {
+    Log::PrintErr("VirtualProtect failed %d\n", GetLastError());
+    VirtualFree(addr, 0, MEM_RELEASE);
+    return NULL;
+  }
+  return addr;
 }
 
 
diff --git a/runtime/bin/main.cc b/runtime/bin/main.cc
index d95a6073a25..f233837dfbb 100644
--- a/runtime/bin/main.cc
+++ b/runtime/bin/main.cc
@@ -1241,7 +1241,8 @@ static bool ReadAppSnapshotBlobs(const char* script_name,
     file->Map(File::kReadOnly, vmisolate_position,
               instructions_position - vmisolate_position);
   if (read_only_buffer == NULL) {
-    ErrorExit(kErrorExitCode, "Failed to memory map snapshot\n");
+    Log::PrintErr("Failed to memory map snapshot\n");
+    Platform::Exit(kErrorExitCode);
   }
 
   *vmisolate_buffer = reinterpret_cast<const uint8_t*>(read_only_buffer)
@@ -1261,7 +1262,8 @@ static bool ReadAppSnapshotBlobs(const char* script_name,
     *instructions_buffer = reinterpret_cast<const uint8_t*>(
         file->Map(File::kReadExecute, instructions_position, header[4]));
     if (*instructions_buffer == NULL) {
-      ErrorExit(kErrorExitCode, "Failed to memory map snapshot2\n");
+      Log::PrintErr("Failed to memory map snapshot\n");
+      Platform::Exit(kErrorExitCode);
     }
   }
 
@@ -1283,29 +1285,33 @@ static bool ReadAppSnapshotDynamicLibrary(const char* script_name,
   *vmisolate_buffer = reinterpret_cast<const uint8_t*>(
       Extensions::ResolveSymbol(library, kPrecompiledVMIsolateSymbolName));
   if (*vmisolate_buffer == NULL) {
-    ErrorExit(kErrorExitCode, "Failed to resolve symbol '%s'\n",
-              kPrecompiledVMIsolateSymbolName);
+    Log::PrintErr("Failed to resolve symbol '%s'\n",
+                  kPrecompiledVMIsolateSymbolName);
+    Platform::Exit(kErrorExitCode);
   }
 
   *isolate_buffer = reinterpret_cast<const uint8_t*>(
       Extensions::ResolveSymbol(library, kPrecompiledIsolateSymbolName));
   if (*isolate_buffer == NULL) {
-    ErrorExit(kErrorExitCode, "Failed to resolve symbol '%s'\n",
-              kPrecompiledIsolateSymbolName);
+    Log::PrintErr("Failed to resolve symbol '%s'\n",
+                  kPrecompiledIsolateSymbolName);
+    Platform::Exit(kErrorExitCode);
   }
 
   *instructions_buffer = reinterpret_cast<const uint8_t*>(
       Extensions::ResolveSymbol(library, kPrecompiledInstructionsSymbolName));
   if (*instructions_buffer == NULL) {
-    ErrorExit(kErrorExitCode, "Failed to resolve symbol '%s'\n",
-              kPrecompiledInstructionsSymbolName);
+    Log::PrintErr("Failed to resolve symbol '%s'\n",
+                  kPrecompiledInstructionsSymbolName);
+    Platform::Exit(kErrorExitCode);
   }
 
   *rodata_buffer = reinterpret_cast<const uint8_t*>(
       Extensions::ResolveSymbol(library, kPrecompiledDataSymbolName));
   if (*rodata_buffer == NULL) {
-    ErrorExit(kErrorExitCode, "Failed to resolve symbol '%s'\n",
-              kPrecompiledDataSymbolName);
+    Log::PrintErr("Failed to resolve symbol '%s'\n",
+                  kPrecompiledDataSymbolName);
+    Platform::Exit(kErrorExitCode);
   }
 
   return true;