Bug 1556668 - Move Wasm's MapFile from SpiderMonkey to Gecko to eliminate an NSPR dependency. r=luke

Differential Revision: https://phabricator.services.mozilla.com/D33605

--HG--
extra : moz-landing-system : lando

dom/indexedDB/ActorsChild.cpp

@@ -3017,6 +3017,39 @@ void BackgroundRequestChild::PreprocessHelper::RunOnOwningThread() {
   }
 }
 
+class MemUnmap {
+  uint32_t mSize = 0;
+
+ public:
+  MemUnmap() = default;
+  explicit MemUnmap(uint32_t aSize) : mSize(aSize) {}
+
+  void operator()(uint8_t* aP) {
+    MOZ_ASSERT(mSize);
+    PR_MemUnmap(aP, mSize);
+  }
+};
+
+using UniqueMapping = UniquePtr<uint8_t, MemUnmap>;
+
+static UniqueMapping MapFile(PRFileDesc* aFile, PRFileInfo* aInfo) {
+  if (PR_GetOpenFileInfo(aFile, aInfo) != PR_SUCCESS) {
+    return nullptr;
+  }
+
+  PRFileMap* map = PR_CreateFileMap(aFile, aInfo->size, PR_PROT_READONLY);
+  if (!map) {
+    return nullptr;
+  }
+
+  // PRFileMap objects do not need to be kept alive after the memory has been
+  // mapped, so unconditionally close the PRFileMap, regardless of whether
+  // PR_MemMap succeeds.
+  uint8_t* memory = (uint8_t*)PR_MemMap(map, 0, aInfo->size);
+  PR_CloseFileMap(map);
+  return UniqueMapping(memory, MemUnmap(aInfo->size));
+}
+
 void BackgroundRequestChild::PreprocessHelper::ProcessCurrentStream() {
   MOZ_ASSERT(!IsOnOwningThread());
   MOZ_ASSERT(!mStreams.IsEmpty());
@@ -3038,8 +3071,16 @@ void BackgroundRequestChild::PreprocessHelper::ProcessCurrentStream() {
 
   MOZ_ASSERT(mCurrentBytecodeFileDesc);
 
+  PRFileInfo bytecodeInfo;
+  UniqueMapping bytecodeMapping =
+      MapFile(mCurrentBytecodeFileDesc, &bytecodeInfo);
+  if (NS_WARN_IF(!bytecodeMapping)) {
+    ContinueWithStatus(NS_ERROR_FAILURE);
+    return;
+  }
+
   RefPtr<JS::WasmModule> module =
-      JS::DeserializeWasmModule(mCurrentBytecodeFileDesc, nullptr, 0);
+      JS::DeserializeWasmModule(bytecodeMapping.get(), bytecodeInfo.size);
   if (NS_WARN_IF(!module)) {
     ContinueWithStatus(NS_ERROR_FAILURE);
     return;

js/src/jsapi.cpp

@@ -5819,8 +5819,8 @@ JS_PUBLIC_API RefPtr<JS::WasmModule> JS::GetWasmModule(HandleObject obj) {
 }
 
 JS_PUBLIC_API RefPtr<JS::WasmModule> JS::DeserializeWasmModule(
-    PRFileDesc* bytecode, UniqueChars filename, unsigned line) {
-  return wasm::DeserializeModule(bytecode, std::move(filename), line);
+    const uint8_t* bytecode, size_t bytecodeLength) {
+  return wasm::DeserializeModule(bytecode, bytecodeLength);
 }
 
 JS_PUBLIC_API void JS::SetProcessLargeAllocationFailureCallback(

js/src/jsapi.h

@@ -3029,7 +3029,7 @@ extern JS_PUBLIC_API RefPtr<WasmModule> GetWasmModule(HandleObject obj);
  */
 
 extern JS_PUBLIC_API RefPtr<WasmModule> DeserializeWasmModule(
-    PRFileDesc* bytecode, JS::UniqueChars filename, unsigned line);
+    const uint8_t* bytecode, size_t bytecodeLength);
 
 /**
  * If a large allocation fails when calling pod_{calloc,realloc}CanGC, the JS

js/src/vm/PosixNSPR.cpp

@@ -14,29 +14,4 @@
 #  include <sys/time.h>
 #  include <time.h>
 
-int32_t PR_FileDesc2NativeHandle(PRFileDesc* fd) {
-  MOZ_CRASH("PR_FileDesc2NativeHandle");
-}
-
-PRStatus PR_GetOpenFileInfo(PRFileDesc* fd, PRFileInfo* info) {
-  MOZ_CRASH("PR_GetOpenFileInfo");
-}
-
-int32_t PR_Seek(PRFileDesc* fd, int32_t offset, PRSeekWhence whence) {
-  MOZ_CRASH("PR_Seek");
-}
-
-PRFileMap* PR_CreateFileMap(PRFileDesc* fd, int64_t size,
-                            PRFileMapProtect prot) {
-  MOZ_CRASH("PR_CreateFileMap");
-}
-
-void* PR_MemMap(PRFileMap* fmap, int64_t offset, uint32_t len) {
-  MOZ_CRASH("PR_MemMap");
-}
-
-PRStatus PR_MemUnmap(void* addr, uint32_t len) { MOZ_CRASH("PR_MemUnmap"); }
-
-PRStatus PR_CloseFileMap(PRFileMap* fmap) { MOZ_CRASH("PR_CloseFileMap"); }
-
 #endif /* JS_POSIX_NSPR */

js/src/vm/PosixNSPR.h

@@ -11,42 +11,6 @@
 
 #  include "jspubtd.h"
 
-int32_t PR_FileDesc2NativeHandle(PRFileDesc* fd);
-
-enum PRFileType { PR_FILE_FILE = 1, PR_FILE_DIRECTORY = 2, PR_FILE_OTHER = 3 };
-
-struct PRFileInfo {
-  PRFileType type;
-  int32_t size;
-  int64_t creationTime;
-  int64_t modifyTime;
-};
-
-typedef enum { PR_FAILURE = -1, PR_SUCCESS = 0 } PRStatus;
-
-PRStatus PR_GetOpenFileInfo(PRFileDesc* fd, PRFileInfo* info);
-
-enum PRSeekWhence { PR_SEEK_SET = 0, PR_SEEK_CUR = 1, PR_SEEK_END = 2 };
-
-int32_t PR_Seek(PRFileDesc* fd, int32_t offset, PRSeekWhence whence);
-
-enum PRFileMapProtect {
-  PR_PROT_READONLY,
-  PR_PROT_READWRITE,
-  PR_PROT_WRITECOPY
-};
-
-struct PRFileMap;
-
-PRFileMap* PR_CreateFileMap(PRFileDesc* fd, int64_t size,
-                            PRFileMapProtect prot);
-
-void* PR_MemMap(PRFileMap* fmap, int64_t offset, uint32_t len);
-
-PRStatus PR_MemUnmap(void* addr, uint32_t len);
-
-PRStatus PR_CloseFileMap(PRFileMap* fmap);
-
 #endif /* JS_POSIX_NSPR */
 
 #endif /* vm_PosixNSPR_h */

js/src/wasm/WasmModule.cpp

@@ -357,39 +357,8 @@ bool wasm::GetOptimizedEncodingBuildId(JS::BuildIdCharVector* buildId) {
   return true;
 }
 
-struct MemUnmap {
-  uint32_t size;
-  MemUnmap() : size(0) {}
-  explicit MemUnmap(uint32_t size) : size(size) {}
-  void operator()(uint8_t* p) {
-    MOZ_ASSERT(size);
-    PR_MemUnmap(p, size);
-  }
-};
-
-typedef UniquePtr<uint8_t, MemUnmap> UniqueMapping;
-
-static UniqueMapping MapFile(PRFileDesc* file, PRFileInfo* info) {
-  if (PR_GetOpenFileInfo(file, info) != PR_SUCCESS) {
-    return nullptr;
-  }
-
-  PRFileMap* map = PR_CreateFileMap(file, info->size, PR_PROT_READONLY);
-  if (!map) {
-    return nullptr;
-  }
-
-  // PRFileMap objects do not need to be kept alive after the memory has been
-  // mapped, so unconditionally close the PRFileMap, regardless of whether
-  // PR_MemMap succeeds.
-  uint8_t* memory = (uint8_t*)PR_MemMap(map, 0, info->size);
-  PR_CloseFileMap(map);
-  return UniqueMapping(memory, MemUnmap(info->size));
-}
-
-RefPtr<JS::WasmModule> wasm::DeserializeModule(PRFileDesc* bytecodeFile,
-                                               UniqueChars filename,
-                                               unsigned line) {
+RefPtr<JS::WasmModule> wasm::DeserializeModule(const uint8_t* bytecode,
+                                               size_t bytecodeLength) {
   // We have to compile new code here so if we're fundamentally unable to
   // compile, we have to fail. If you change this code, update the
   // MutableCompileArgs setting below.
@@ -397,23 +366,17 @@ RefPtr<JS::WasmModule> wasm::DeserializeModule(PRFileDesc* bytecodeFile,
     return nullptr;
   }
 
-  PRFileInfo bytecodeInfo;
-  UniqueMapping bytecodeMapping = MapFile(bytecodeFile, &bytecodeInfo);
-  if (!bytecodeMapping) {
+  MutableBytes bytecodeCopy = js_new<ShareableBytes>();
+  if (!bytecodeCopy ||
+      !bytecodeCopy->bytes.initLengthUninitialized(bytecodeLength)) {
     return nullptr;
   }
 
-  MutableBytes bytecode = js_new<ShareableBytes>();
-  if (!bytecode ||
-      !bytecode->bytes.initLengthUninitialized(bytecodeInfo.size)) {
-    return nullptr;
-  }
-
-  memcpy(bytecode->bytes.begin(), bytecodeMapping.get(), bytecodeInfo.size);
+  memcpy(bytecodeCopy->bytes.begin(), bytecode, bytecodeLength);
 
   ScriptedCaller scriptedCaller;
-  scriptedCaller.filename = std::move(filename);
-  scriptedCaller.line = line;
+  scriptedCaller.filename = nullptr;
+  scriptedCaller.line = 0;
 
   MutableCompileArgs args = js_new<CompileArgs>(std::move(scriptedCaller));
   if (!args) {
@@ -438,7 +401,7 @@ RefPtr<JS::WasmModule> wasm::DeserializeModule(PRFileDesc* bytecodeFile,
 
   UniqueChars error;
   UniqueCharsVector warnings;
-  SharedModule module = CompileBuffer(*args, *bytecode, &error, &warnings);
+  SharedModule module = CompileBuffer(*args, *bytecodeCopy, &error, &warnings);
   if (!module) {
     return nullptr;
   }

js/src/wasm/WasmModule.h

@@ -225,8 +225,8 @@ typedef RefPtr<const Module> SharedModule;
 
 MOZ_MUST_USE bool GetOptimizedEncodingBuildId(JS::BuildIdCharVector* buildId);
 
-RefPtr<JS::WasmModule> DeserializeModule(PRFileDesc* bytecode,
-                                         UniqueChars filename, unsigned line);
+RefPtr<JS::WasmModule> DeserializeModule(const uint8_t* bytecode,
+                                         size_t bytecodeLength);
 
 }  // namespace wasm
 }  // namespace js