Revert "Add an --os=fuchsia option to build.py:"

This reverts commit 4ce18ab.

Reason for revert: bad merge, caused build breakages in flutter/engine

Original change's description:
> Add an --os=fuchsia option to build.py:
> 
> tools/build.py --os=fuchsia runtime create_sdk
> 
> This is analogous to --os=android. It cross compiles from Linux x64 to
> Fuchsia.
> 
> A lot of the build rules are just slightly different between the existing
> Fuchsia build rules used by Flutter, and the ones added by GN SDK. For
> example "$fuchsia_sdk_root/pkg:fdio" is now "$fuchsia_sdk_root/pkg/fdio".
> So to support this I had to add a new variable, using_fuchsia_gn_sdk,
> analogous to using_fuchsia_sdk. Flutter will need to set this to false.
> 
> Change-Id: Ief275d65f30a42a801607de93cf2d27a1fe825dd
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/150689
> Reviewed-by: Ryan Macnak <[email protected]>
> Commit-Queue: Liam Appelbe <[email protected]>

[email protected],[email protected],[email protected],[email protected],[email protected]

Change-Id: If01ee34eba906c55f2d56ba650748a86e81e701c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/151321
Auto-Submit: George Wright <[email protected]>
Commit-Queue: Liam Appelbe <[email protected]>
Reviewed-by: Liam Appelbe <[email protected]>

Author: George Wright

DEPS

@@ -470,17 +470,6 @@ deps = {
       "dep_type": "cipd",
   },
 
-  Var("dart_root") + "/third_party/fuchsia/sdk/linux": {
-    "packages": [
-      {
-      "package": "fuchsia/sdk/gn/linux-amd64",
-      "version": "git_revision:8d5242d4f6ff8b7634b492700e60b0fd09abefa3"
-      }
-    ],
-    "condition": 'host_os == "linux" and host_cpu == "x64"',
-    "dep_type": "cipd",
-  },
-
   Var("dart_root") + "/pkg/front_end/test/fasta/types/benchmark_data": {
     "packages": [
       {

build/config/BUILDCONFIG.gn

@@ -196,16 +196,6 @@ if (current_os == "win") {
   is_nacl = false
   is_posix = true
   is_win = false
-} else if (current_os == "fuchsia") {
-  is_android = false
-  is_chromeos = false
-  is_fuchsia = true
-  is_ios = false
-  is_linux = false
-  is_mac = false
-  is_nacl = false
-  is_posix = true
-  is_win = false
 }
 
 # =============================================================================
@@ -394,11 +384,6 @@ if (is_win) {
 } else if (is_mac) {
   host_toolchain = "//build/toolchain/mac:clang_x64"
   set_default_toolchain(host_toolchain)
-} else if (is_fuchsia) {
-  assert(host_os == "linux")
-  assert(host_cpu == "x64")
-  host_toolchain = "//build/toolchain/linux:clang_$host_cpu"
-  set_default_toolchain("//build/toolchain/fuchsia")
 }
 
 # ==============================================================================

build/config/compiler/BUILD.gn

@@ -243,7 +243,7 @@ config("compiler") {
   # 3. When using the sanitizers.
   # Otherwise there is a performance hit, in particular on ia32.
   if (is_android || is_asan || is_lsan || is_msan || is_tsan || is_ubsan ||
-      (is_linux && current_cpu != "x86") || is_fuchsia) {
+      (is_linux && current_cpu != "x86")) {
     cflags += [ "-fPIC" ]
     ldflags += [ "-fPIC" ]
   }
@@ -276,8 +276,6 @@ config("compiler") {
   if (is_win) {
     # Up-to-date toolchain MSVC doesn't support c++11 flag any longer.
     cc_std = [ "/std:c++14" ]
-  } else if (is_fuchsia) {
-    cc_std = [ "-std=c++17" ]
   } else {
     cc_std = [ "-std=c++11" ]
   }

build/fuchsia/sdk.gni

@@ -136,10 +136,7 @@ config("dart_config") {
   }
 
   if (is_fuchsia) {
-    if (using_fuchsia_gn_sdk) {
-      lib_dirs = [ "../out/DebugFuchsiaX64/lib" ]
-    }
-    if (using_fuchsia_gn_sdk || using_fuchsia_sdk) {
+    if (using_fuchsia_sdk) {
       # TODO(chinmaygarde): Currenty these targets need to be build in the
       # Fuchsia tree as well as outside it using the SDK. However, not all
       # Fuchsia features are available in the SDK. As these features are added,
@@ -226,12 +223,7 @@ library_for_all_configs("libdart") {
     defines = [ "DART_ENABLE_WASM" ]
   }
   if (is_fuchsia) {
-    if (using_fuchsia_gn_sdk) {
-      extra_deps += [
-        "$fuchsia_sdk_root/pkg/fdio",
-        "$fuchsia_sdk_root/pkg/trace-engine",
-      ]
-    } else if (using_fuchsia_sdk) {
+    if (using_fuchsia_sdk) {
       extra_deps += [
         "$fuchsia_sdk_root/pkg:fdio",
         "$fuchsia_sdk_root/pkg:trace-engine",

build/toolchain/fuchsia/BUILD.gn

@@ -42,9 +42,7 @@ template("build_libdart_builtin") {
     public_configs = [ ":libdart_builtin_config" ]
     deps = []
     if (is_fuchsia) {
-      if (using_fuchsia_gn_sdk) {
-        public_deps = [ "$fuchsia_sdk_root/pkg/fdio" ]
-      } else if (using_fuchsia_sdk) {
+      if (using_fuchsia_sdk) {
         public_deps = [ "$fuchsia_sdk_root/pkg:fdio" ]
       } else {
         public_deps = [ "//zircon/public/lib/fdio" ]
@@ -320,13 +318,7 @@ template("build_gen_snapshot_dart_io") {
     deps = []
 
     if (is_fuchsia) {
-      if (using_fuchsia_gn_sdk) {
-        deps += [
-          "$fuchsia_sdk_root/fidl/fuchsia.netstack",
-          "$fuchsia_sdk_root/pkg/sys_cpp",
-        ]
-        public_deps = [ "$fuchsia_sdk_root/pkg/fdio" ]
-      } else if (using_fuchsia_sdk) {
+      if (using_fuchsia_sdk) {
         deps += [
           "$fuchsia_sdk_root/fidl:fuchsia.netstack",
           "$fuchsia_sdk_root/pkg:sys_cpp",
@@ -462,13 +454,7 @@ template("dart_io") {
     deps += [ "//third_party/boringssl" ]
 
     if (is_fuchsia) {
-      if (using_fuchsia_gn_sdk) {
-        deps += [
-          "$fuchsia_sdk_root/fidl/fuchsia.netstack",
-          "$fuchsia_sdk_root/pkg/sys_cpp",
-        ]
-        public_deps = [ "$fuchsia_sdk_root/pkg/fdio" ]
-      } else if (using_fuchsia_sdk) {
+      if (using_fuchsia_sdk) {
         deps += [
           "$fuchsia_sdk_root/fidl:fuchsia.netstack",
           "$fuchsia_sdk_root/pkg:sys_cpp",
@@ -802,9 +788,7 @@ template("dart_executable") {
       # have them. They are needed for running Fuchsia binaries built for the
       # host.
       if (is_linux) {
-        # TODO(liama): Commenting this line out because it causes problems for
-        # --os=fuchsia. If no one complains, remove it.
-        # configs += [ "../../build/config/gcc:executable_ldconfig" ]
+        configs += [ "../../build/config/gcc:executable_ldconfig" ]
       } else if (is_mac) {
         configs += [ "../../build/config/mac:mac_dynamic_flags" ]
       }
@@ -1028,11 +1012,7 @@ executable("run_vm_tests") {
   }
 
   if (is_fuchsia) {
-    if (using_fuchsia_gn_sdk) {
-      include_dirs += [ "$fuchsia_sdk_path/pkg/trace-engine/include" ]
-      libs = [ "zircon" ]
-    }
-    if (!using_fuchsia_gn_sdk && !using_fuchsia_sdk) {
+    if (!using_fuchsia_sdk) {
       deps += [ "//zircon/system/ulib/trace" ]
     }
   }

runtime/BUILD.gn

@@ -744,20 +744,16 @@ class ProcessStarter {
     }
     actions[3] = {
       .action = FDIO_SPAWN_ACTION_SET_NAME,
-      .name = {
-        .data = program_arguments_[0],
-      },
+      .name.data = program_arguments_[0],
     };
 
     // Then fill in the namespace actions.
     if (ns != nullptr) {
       for (size_t i = 0; i < flat_ns->count; i++) {
         actions[fixed_actions_cnt + i] = {
           .action = FDIO_SPAWN_ACTION_ADD_NS_ENTRY,
-          .ns = {
-            .prefix = flat_ns->path[i],
-            .handle = flat_ns->handle[i],
-          },
+          .ns.prefix = flat_ns->path[i],
+          .ns.handle = flat_ns->handle[i],
         };
       }
       free(flat_ns);

runtime/bin/BUILD.gn

@@ -201,9 +201,7 @@ static AppSnapshot* TryReadAppSnapshotElf(
                 *isolate_data_buffer = nullptr,
                 *isolate_instructions_buffer = nullptr;
   Dart_LoadedElf* handle = nullptr;
-#if !defined(HOST_OS_FUCHSIA)
   if (force_load_elf_from_memory) {
-#endif
     File* const file =
         File::Open(/*namespc=*/nullptr, script_name, File::kRead);
     if (file == nullptr) return nullptr;
@@ -218,13 +216,11 @@ static AppSnapshot* TryReadAppSnapshotElf(
                             &isolate_data_buffer, &isolate_instructions_buffer);
     delete memory;
     file->Release();
-#if !defined(HOST_OS_FUCHSIA)
   } else {
     handle = Dart_LoadELF(script_name, file_offset, &error, &vm_data_buffer,
                           &vm_instructions_buffer, &isolate_data_buffer,
                           &isolate_instructions_buffer);
   }
-#endif
   if (handle == nullptr) {
     Syslog::PrintErr("Loading failed: %s\n", error);
     return nullptr;

runtime/bin/process_fuchsia.cc

@@ -17,9 +17,7 @@ library_for_all_configs("libdart_platform") {
   extra_deps = []
 
   if (is_fuchsia) {
-    if (using_fuchsia_gn_sdk) {
-      extra_deps += [ "$fuchsia_sdk_root/pkg/sys_cpp" ]
-    } else if (using_fuchsia_sdk) {
+    if (using_fuchsia_sdk) {
       extra_deps += [ "$fuchsia_sdk_root/pkg:sys_cpp" ]
     } else {
       extra_deps += [ "//sdk/lib/sys/cpp" ]