v8.patch

# 1. Disable pointer compression (limits the maximum number of WasmVMs).
# 2. Don't expose Wasm C API (only Wasm C++ API).
# 3. Revert v8 commit b26554ec368e9553782012c96aa5e99b163eaff2, which removed
#    use of _allowlist_function_transition from v8 bazel/defs.bzl, since it is
#    still required by the version of Bazel we currently use (6.5.0).
# 4. Tweak where v8 looks for its fp16 dependency, since it isn't downloaded by
#    gn.
# 5. Set torque generator path to location where Bazel can find outputs.
# 6. Compile v8 with -Wno-deprecated-declarations
# 7. Cherrypick V8 commit 35888fee7bbaaaf1f02ccc88a95c9a336fc790bc to fix gcc
#    build error.

diff --git a/BUILD.bazel b/BUILD.bazel
index 30be47fa333..72de2d422ca 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -220,7 +220,7 @@ v8_int(
 # If no explicit value for v8_enable_pointer_compression, we set it to 'none'.
 v8_string(
     name = "v8_enable_pointer_compression",
-    default = "none",
+    default = "False",
 )
 
 # Default setting for v8_enable_pointer_compression.
@@ -3698,14 +3698,22 @@ filegroup(
 
 v8_library(
   name = "lib_fp16",
-  srcs = ["third_party/fp16/src/include/fp16.h"],
-  hdrs = [
-    "third_party/fp16/src/include/fp16/fp16.h",
-    "third_party/fp16/src/include/fp16/bitcasts.h",
+  hdrs = ["@fp16//:include/fp16.h"],
+  srcs = [],
+  include_prefix = "third_party/fp16/src",
+  deps = [
+    "lib_fp16_includes",
   ],
-  includes = [
-    "third_party/fp16/src/include",
+)
+
+v8_library(
+  name = "lib_fp16_includes",
+  hdrs = [
+    "@fp16//:include/fp16/fp16.h",
+    "@fp16//:include/fp16/bitcasts.h",
   ],
+  srcs = [],
+  strip_include_prefix = "include",
 )
 
 filegroup(
diff --git a/bazel/defs.bzl b/bazel/defs.bzl
index 520a311595e..64b4928abe5 100644
--- a/bazel/defs.bzl
+++ b/bazel/defs.bzl
@@ -102,7 +102,9 @@ def _default_args():
             ],
             "//conditions:default": [],
         }),
-        copts = select({
+        copts = [
+            "-Wno-deprecated-declarations",
+        ] + select({
             "@v8//bazel/config:is_posix": [
                 "-fPIC",
                 "-fno-strict-aliasing",
@@ -131,7 +133,6 @@ def _default_args():
                 "-Wno-array-bounds",
                 "-Wno-class-memaccess",
                 "-Wno-comments",
-                "-Wno-deprecated-declarations",
                 "-Wno-implicit-fallthrough",
                 "-Wno-int-in-bool-context",
                 "-Wno-maybe-uninitialized",
@@ -316,7 +317,7 @@ def v8_library(
 # split the set of outputs by using OutputGroupInfo, that way we do not need to
 # run the torque generator twice.
 def _torque_files_impl(ctx):
-    v8root = "."
+    v8root = "external/v8"
 
     # Arguments
     args = []
@@ -480,6 +481,9 @@ _v8_mksnapshot = rule(
             cfg = "exec",
         ),
         "target_os": attr.string(mandatory = True),
+        "_allowlist_function_transition": attr.label(
+            default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
+        ),
         "prefix": attr.string(mandatory = True),
         "suffix": attr.string(mandatory = True),
     },
diff --git a/bazel/v8-non-pointer-compression.bzl b/bazel/v8-non-pointer-compression.bzl
index 8c929454840..57336154cf7 100644
--- a/bazel/v8-non-pointer-compression.bzl
+++ b/bazel/v8-non-pointer-compression.bzl
@@ -47,6 +47,17 @@ v8_binary_non_pointer_compression = rule(
         # Note specificaly how it's configured with v8_target_cpu_transition, which
         # ensures that setting propagates down the graph.
         "binary": attr.label(cfg = v8_disable_pointer_compression),
+        # This is a stock Bazel requirement for any rule that uses Starlark
+        # transitions. It's okay to copy the below verbatim for all such rules.
+        #
+        # The purpose of this requirement is to give the ability to restrict
+        # which packages can invoke these rules, since Starlark transitions
+        # make much larger graphs possible that can have memory and performance
+        # consequences for your build. The whitelist defaults to "everything".
+        # But you can redefine it more strictly if you feel that's prudent.
+        "_allowlist_function_transition": attr.label(
+            default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
+        ),
     },
     # Making this executable means it works with "$ bazel run".
     executable = True,
diff --git a/src/base/macros.h b/src/base/macros.h
index 794505278e1..890365bf3ae 100644
--- a/src/base/macros.h
+++ b/src/base/macros.h
@@ -182,7 +182,7 @@ namespace base {
 // base::is_trivially_copyable will differ for these cases.
 template <typename T>
 struct is_trivially_copyable {
-#if V8_CC_MSVC
+#if V8_CC_MSVC || (__GNUC__ == 12 && __GNUC_MINOR__ <= 2)
   // Unfortunately, MSVC 2015 is broken in that std::is_trivially_copyable can
   // be false even though it should be true according to the standard.
   // (status at 2018-02-26, observed on the msvc waterfall bot).
@@ -190,6 +190,11 @@ struct is_trivially_copyable {
   // intended, so we reimplement this according to the standard.
   // See also https://developercommunity.visualstudio.com/content/problem/
   //          170883/msvc-type-traits-stdis-trivial-is-bugged.html.
+  //
+  // GCC 12.1 and 12.2 are broken too, they are shipped by some stable Linux
+  // distributions, so the same polyfill is also used.
+  // See
+  // https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=aeba3e009b0abfccaf01797556445dbf891cc8dc
   static constexpr bool value =
       // Copy constructor is trivial or deleted.
       (std::is_trivially_copy_constructible<T>::value ||
diff --git a/src/wasm/c-api.cc b/src/wasm/c-api.cc
index 2d6d0f6c270..61d071acd52 100644
--- a/src/wasm/c-api.cc
+++ b/src/wasm/c-api.cc
@@ -2360,6 +2360,8 @@ auto Instance::exports() const -> ownvec<Extern> {
 
 }  // namespace wasm
 
+#if 0
+
 // BEGIN FILE wasm-c.cc
 
 extern "C" {
@@ -3386,3 +3388,5 @@ wasm_instance_t* wasm_frame_instance(const wasm_frame_t* frame) {
 #undef WASM_DEFINE_SHARABLE_REF
 
 }  // extern "C"
+
+#endif