deps: cherry-pick fc0ddf5 from upstream V8

addaleax · targos · commit 1ccca91ee72e · 2019-01-31T19:28:45.000+01:00
Original commit message: [snapshot] Always align embedded blob code pointer and size Other platforms besides ARM64 Windows may also have alignment requirements, e.g. PPC and s390. These requirements may affect both the code pointer field and the size field, and so they each need alignment directives because they are stored in different sections. Since aligning wastes a handful of bytes at most, not making alignment conditional on the platform type seems like a good idea. Refs: nodejs#24875 Change-Id: I1f58606af294be65e74a1f107cd05fc21e032704 Reviewed-on: https://chromium-review.googlesource.com/c/1433778 Commit-Queue: Jakob Gruber <jgruber@chromium.org> Reviewed-by: Jakob Gruber <jgruber@chromium.org> Cr-Commit-Position: refs/heads/master@{#59058} Refs: v8/v8@fc0ddf5
diff --git a/common.gypi b/common.gypi
@@ -38,7 +38,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.0',
+    'v8_embedder_string': '-node.1',
 
     ##### V8 defaults for Node.js #####
 
diff --git a/deps/v8/src/snapshot/embedded-file-writer.cc b/deps/v8/src/snapshot/embedded-file-writer.cc
@@ -553,13 +553,11 @@ void PlatformDependentEmbeddedFileWriter::AlignToCodeAlignment() {
 }
 
 void PlatformDependentEmbeddedFileWriter::AlignToDataAlignment() {
-#if defined(V8_OS_WIN) && defined(V8_TARGET_ARCH_ARM64)
-  // On Windows ARM64, instruction "ldr xt,[xn,v8_Default_embedded_blob_]" is
-  // generated by clang-cl to load elements in v8_Default_embedded_blob_.
-  // The generated instruction has scale 3 which requires the load target to be
-  // aligned at 8 bytes (2^3).
+  // On Windows ARM64, s390, PPC and possibly more platforms, aligned load
+  // instructions are used to retrieve v8_Default_embedded_blob_ and/or
+  // v8_Default_embedded_blob_size_. The generated instructions require the
+  // load target to be aligned at 8 bytes (2^3).
   fprintf(fp_, ".balign 8\n");
-#endif
 }
 
 void PlatformDependentEmbeddedFileWriter::Comment(const char* string) {
diff --git a/deps/v8/src/snapshot/embedded-file-writer.h b/deps/v8/src/snapshot/embedded-file-writer.h
@@ -286,6 +286,7 @@ class EmbeddedFileWriter : public EmbeddedFileWriterInterface {
 
       w->Comment("The size of the embedded blob in bytes.");
       w->SectionRoData();
+      w->AlignToDataAlignment();
       w->DeclareUint32(embedded_blob_size_symbol, blob->size());
       w->Newline();
     }

Original file line number	Diff line number	Diff line change
`@@ -286,6 +286,7 @@ class EmbeddedFileWriter : public EmbeddedFileWriterInterface {`
`286`	`286`
`287`	`287`	`w->Comment("The size of the embedded blob in bytes.");`
`288`	`288`	`w->SectionRoData();`
	`289`	`+ w->AlignToDataAlignment();`
`289`	`290`	`w->DeclareUint32(embedded_blob_size_symbol, blob->size());`
`290`	`291`	`w->Newline();`
`291`	`292`	`}`