[meta-oe][PATCH v3 3/4] nodejs: Use qemu usermode to run target binaries during build

["Khem Raj" <raj.khem@gmail.com>]

So far, we have been trying to build nodejs-native and use the native
host binaries from there, which has worked out ok but always changes
when major upgrade is done, since more binaries or places are required
to be captured. This patch changes this approach to use qemu-user to run
these binaries under during cross build. This lets them run closer to
upstream build process and also removes dependency on nodejs-native

Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
 .../nodejs/0002-Using-native-binaries.patch   | 93 +++++++++----------
 .../recipes-devtools/nodejs/nodejs_14.16.1.bb | 34 ++++++-
 2 files changed, 74 insertions(+), 53 deletions(-)

diff --git a/meta-oe/recipes-devtools/nodejs/nodejs/0002-Using-native-binaries.patch b/meta-oe/recipes-devtools/nodejs/nodejs/0002-Using-native-binaries.patch
index b5142dc9c1..c6fc2dcd76 100644
--- a/meta-oe/recipes-devtools/nodejs/nodejs/0002-Using-native-binaries.patch
+++ b/meta-oe/recipes-devtools/nodejs/nodejs/0002-Using-native-binaries.patch
@@ -8,64 +8,55 @@ Subject: [PATCH] Using native binaries
  tools/v8_gypfiles/v8.gyp | 11 ++++-------
  2 files changed, 6 insertions(+), 9 deletions(-)
 
-diff --git a/node.gyp b/node.gyp
-index 8f4dc518..d9389190 100644
 --- a/node.gyp
 +++ b/node.gyp
-@@ -446,7 +446,7 @@
-                 '<(SHARED_INTERMEDIATE_DIR)/node_code_cache.cc',
+@@ -487,6 +487,7 @@
+               'action_name': 'run_mkcodecache',
+               'process_outputs_as_sources': 1,
+               'inputs': [
++                '<(PRODUCT_DIR)/v8-qemu-wrapper.sh',
+                 '<(mkcodecache_exec)',
                ],
-               'action': [
--                '<@(_inputs)',
-+                'mkcodecache',
-                 '<@(_outputs)',
+               'outputs': [
+@@ -512,6 +513,7 @@
+               'action_name': 'node_mksnapshot',
+               'process_outputs_as_sources': 1,
+               'inputs': [
++                '<(PRODUCT_DIR)/v8-qemu-wrapper.sh',
+                 '<(node_mksnapshot_exec)',
                ],
-             },
-@@ -471,7 +471,7 @@
-                 '<(SHARED_INTERMEDIATE_DIR)/node_snapshot.cc',
-               ],
-               'action': [
--                '<@(_inputs)',
-+                'node_mksnapshot',
-                 '<@(_outputs)',
-               ],
-             },
-diff --git a/tools/v8_gypfiles/v8.gyp b/tools/v8_gypfiles/v8.gyp
-index a506a67d..c91f7dde 100644
+               'outputs': [
 --- a/tools/v8_gypfiles/v8.gyp
 +++ b/tools/v8_gypfiles/v8.gyp
-@@ -140,7 +140,8 @@
-             '<@(torque_outputs)',
-           ],
-           'action': [
--            '<@(_inputs)',
-+            'torque',
-+            '<@(torque_files)',
-             '-o', '<(torque_output_root)/torque-generated',
-             '-v8-root', '<(V8_ROOT)'
+@@ -220,6 +220,7 @@
+         {
+           'action_name': 'run_torque_action',
+           'inputs': [  # Order matters.
++            '<(PRODUCT_DIR)/v8-qemu-wrapper.sh',
+             '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)torque<(EXECUTABLE_SUFFIX)',
+             '<@(torque_files)',
            ],
-@@ -247,9 +248,7 @@
-             '<(generate_bytecode_builtins_list_output)',
+@@ -351,6 +352,7 @@
+         {
+           'action_name': 'generate_bytecode_builtins_list_action',
+           'inputs': [
++            '<(PRODUCT_DIR)/v8-qemu-wrapper.sh',
+             '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)bytecode_builtins_list_generator<(EXECUTABLE_SUFFIX)',
            ],
-           'action': [
--            'python',
--            '<(V8_ROOT)/tools/run.py',
--            '<@(_inputs)',
-+            'bytecode_builtins_list_generator',
-             '<@(_outputs)',
+           'outputs': [
+@@ -533,6 +535,7 @@
+             ],
+           },
+           'inputs': [
++            '<(PRODUCT_DIR)/v8-qemu-wrapper.sh',
+             '<(mksnapshot_exec)',
            ],
-         },
-@@ -1396,9 +1395,7 @@
-             '<(SHARED_INTERMEDIATE_DIR)/src/regexp/special-case.cc',
+           'outputs': [
+@@ -1448,6 +1451,7 @@
+         {
+           'action_name': 'run_gen-regexp-special-case_action',
+           'inputs': [
++            '<(PRODUCT_DIR)/v8-qemu-wrapper.sh',
+             '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)gen-regexp-special-case<(EXECUTABLE_SUFFIX)',
            ],
-           'action': [
--            'python',
--            '<(V8_ROOT)/tools/run.py',
--            '<@(_inputs)',
-+            'gen-regexp-special-case',
-             '<@(_outputs)',
-           ],
-         },
--- 
-2.20.1
-
+           'outputs': [
diff --git a/meta-oe/recipes-devtools/nodejs/nodejs_14.16.1.bb b/meta-oe/recipes-devtools/nodejs/nodejs_14.16.1.bb
index 32bdd713b5..aef83cc31c 100644
--- a/meta-oe/recipes-devtools/nodejs/nodejs_14.16.1.bb
+++ b/meta-oe/recipes-devtools/nodejs/nodejs_14.16.1.bb
@@ -4,9 +4,9 @@ LICENSE = "MIT & BSD & Artistic-2.0"
 LIC_FILES_CHKSUM = "file://LICENSE;md5=85bf260d8b6de1588f57abc5dc66587c"
 
 DEPENDS = "openssl"
-DEPENDS_append_class-target = " nodejs-native"
+DEPENDS_append_class-target = " qemu-native"
 
-inherit pkgconfig python3native
+inherit pkgconfig python3native qemu
 
 COMPATIBLE_MACHINE_armv4 = "(!.*armv4).*"
 COMPATIBLE_MACHINE_armv5 = "(!.*armv5).*"
@@ -93,6 +93,35 @@ python do_unpack() {
         shutil.rmtree(d.getVar('S') + '/deps/zlib', True)
 }
 
+# V8's JIT infrastructure requires binaries such as mksnapshot and
+# mkpeephole to be run in the host during the build. However, these
+# binaries must have the same bit-width as the target (e.g. a x86_64
+# host targeting ARMv6 needs to produce a 32-bit binary). Instead of
+# depending on a third Yocto toolchain, we just build those binaries
+# for the target and run them on the host with QEMU.
+python do_create_v8_qemu_wrapper () {
+    """Creates a small wrapper that invokes QEMU to run some target V8 binaries
+    on the host."""
+    qemu_libdirs = [d.expand('${STAGING_DIR_HOST}${libdir}'),
+                    d.expand('${STAGING_DIR_HOST}${base_libdir}')]
+    qemu_cmd = qemu_wrapper_cmdline(d, d.getVar('STAGING_DIR_HOST', True),
+                                    qemu_libdirs)
+    wrapper_path = d.expand('${B}/v8-qemu-wrapper.sh')
+    with open(wrapper_path, 'w') as wrapper_file:
+        wrapper_file.write("""#!/bin/sh
+
+# This file has been generated automatically.
+# It invokes QEMU to run binaries built for the target in the host during the
+# build process.
+
+%s "$@"
+""" % qemu_cmd)
+    os.chmod(wrapper_path, 0o755)
+}
+
+do_create_v8_qemu_wrapper[dirs] = "${B}"
+addtask create_v8_qemu_wrapper after do_configure before do_compile
+
 # Node is way too cool to use proper autotools, so we install two wrappers to forcefully inject proper arch cflags to workaround gypi
 do_configure () {
     export LD="${CXX}"
@@ -110,6 +139,7 @@ do_configure () {
 
 do_compile () {
     export LD="${CXX}"
+    install -Dm 0755 ${B}/v8-qemu-wrapper.sh ${B}/out/Release/v8-qemu-wrapper.sh
     oe_runmake BUILDTYPE=Release
 }
 
-- 
2.31.1