build: separate host and target Rust artifacts in cross builds

BUILDING.md

@@ -1067,6 +1067,19 @@ a warning is printed and Temporal support is disabled.
 
 Passing both options to `configure.py` is an error.
 
+For non-Windows cross builds with bundled Temporal, set the Rust target when
+configuring:
+
+```bash
+CARGO_BUILD_TARGET=riscv64gc-unknown-linux-gnu ./configure \
+  --cross-compiling --dest-os=linux --dest-cpu=riscv64
+```
+
+Configure saves this target and the host triple reported by `rustc -vV`.
+Install the target's Rust standard library and configure the cross linker
+separately. Re-run configure when changing targets. Cargo configuration-file
+targets and custom JSON targets are not supported by this detection.
+
 ## Building Node.js with external core modules
 
 It is possible to specify one or more JavaScript text files to be bundled in

configure.py

@@ -1957,6 +1957,31 @@ def configure_node(o):
     os.environ['GYP_CROSSCOMPILE'] = "1"
 
   o['variables']['want_separate_host_toolset'] = int(cross_compiling)
+  o['variables']['cargo_cross_compiling'] = 0
+  if (flavor != 'win' and cross_compiling and
+      not options.v8_disable_temporal_support and not options.shared_temporal_capi):
+    # Only bundled Temporal cross builds need explicit per-toolset Rust targets.
+    rust_target = os.environ.get('CARGO_BUILD_TARGET', '') or o['variables']['cargo_rust_target']
+    if not rust_target:
+      error('Cross compilation with bundled Temporal requires CARGO_BUILD_TARGET')
+    rust_host_target = ''
+    rustc = os.environ.get('RUSTC', 'rustc')
+    try:
+      version = subprocess.check_output(shlex.split(rustc) + ['-vV'],
+                                        stderr=subprocess.PIPE, text=True)
+    except (OSError, subprocess.CalledProcessError):
+      version = ''
+    match = re.search(r'^host: (\S+)$', version, re.MULTILINE)
+    if match:
+      rust_host_target = match.group(1)
+    if not rust_host_target:
+      error('Cannot determine the Rust host triple from rustc -vV')
+    for triple in (rust_host_target, rust_target):
+      if not re.fullmatch(r'[A-Za-z0-9_]+(?:-[A-Za-z0-9_]+)+', triple):
+        error('Rust targets must be target triples, not paths to target JSON files')
+    o['variables']['cargo_cross_compiling'] = 1
+    o['variables']['cargo_rust_target_target'] = rust_target
+    o['variables']['cargo_rust_target_host'] = rust_host_target
 
   if target_arch == 'arm64':
     o['variables']['arm_fpu'] = options.arm_fpu or 'neon'

deps/crates/crates.gyp

@@ -6,14 +6,19 @@
     'zoneinfo64_dir': 'zoneinfo64-v0_3',
     'temporal_zoneinfo64_data_output': '<(SHARED_INTERMEDIATE_DIR)/src/builtins/builtins-temporal-zoneinfo64-data.cc',
     'cargo_rust_target%': '',
+    'cargo_cross_compiling%': 0,
+    'cargo_rust_target_host%': '',
+    'cargo_rust_target_target%': '',
+    'node_shared_temporal_capi%': 'false',
   },
   'conditions': [
     ['build_type == "Release"', {
       'variables': {
         'cargo_build_flags': ['--release'],
+        'cargo_profile': 'release',
       },
       'conditions': [
-        ['cargo_rust_target!=""', {
+        ['cargo_rust_target!="" and cargo_cross_compiling==0', {
           'variables': {
             'cargo_build_flags': ['--target', '<(cargo_rust_target)'],
           }
@@ -31,6 +36,7 @@
     }, {
       'variables': {
         'cargo_build_flags': [],
+        'cargo_profile': 'debug',
       },
       'conditions': [
         ['OS=="win"', {
@@ -50,6 +56,17 @@
       'target_name': 'node_crates',
       'type': 'none',
       'toolsets': ['host', 'target'],
+      'variables': {
+        'cargo_output_dir': '<(SHARED_INTERMEDIATE_DIR)',
+        'cargo_cross_target_flags': [],
+        'conditions': [
+          ['cargo_cross_compiling==1', {
+            'cargo_output_dir': '<(SHARED_INTERMEDIATE_DIR)/cargo/<(_toolset)',
+            'cargo_cross_target_flags': ['--target', '<(cargo_rust_target_<(_toolset))'],
+            'node_crates_libpath': '<(SHARED_INTERMEDIATE_DIR)/cargo/<(_toolset)/<(cargo_rust_target_<(_toolset))/<(cargo_profile)/<(STATIC_LIB_PREFIX)node_crates<(STATIC_LIB_SUFFIX)',
+          }],
+        ],
+      },
       'hard_dependency': 1,
       'sources': [
         'Cargo.toml',
@@ -70,7 +87,7 @@
         ],
       },
       'conditions': [
-        ['OS=="win"', {
+        ['OS=="win" and node_shared_temporal_capi=="false"', {
           'actions': [
             {
               'action_name': 'cargo_build',
@@ -90,7 +107,8 @@
               ],
             }
           ],
-        }, {
+        }],
+        ['OS!="win" and node_shared_temporal_capi=="false"', {
           'actions': [
             {
               'action_name': 'cargo_build',
@@ -103,10 +121,11 @@
               'action': [
                 '<(cargo)',
                 'rustc',
+                '<@(cargo_cross_target_flags)',
                 '<@(cargo_build_flags)',
                 '--frozen',
                 '--target-dir',
-                '<(SHARED_INTERMEDIATE_DIR)'
+                '<(cargo_output_dir)'
               ],
             }
           ],
@@ -132,7 +151,7 @@
       # available to load it at runtime.
       'target_name': 'temporal_zoneinfo64_data',
       'type': 'none',
-      'toolsets': ['host', 'target'],
+      'toolsets': ['target'],
       'hard_dependency': 1,
       'direct_dependent_settings': {
         'sources': [

src/inspector/node_inspector.gypi

@@ -113,7 +113,7 @@
   ],
   'dependencies': [
     '<(protocol_tool_path)/inspector_protocol.gyp:crdtp',
-    '<(v8_gypfiles_dir)/v8.gyp:v8_inspector_headers',
+    '<(v8_gypfiles_dir)/v8.gyp:v8_inspector_headers#target',
   ],
   'actions': [
     {

tools/v8_gypfiles/d8.gyp

@@ -19,7 +19,7 @@
         'v8.gyp:v8',
         'v8.gyp:v8_libbase',
         'v8.gyp:v8_libplatform',
-        'v8.gyp:generate_bytecode_builtins_list',
+        'v8.gyp:generate_bytecode_builtins_list#target',
         'v8.gyp:fp16',
       ],
       # Generated source files need this explicitly:

tools/v8_gypfiles/v8.gyp

@@ -101,9 +101,11 @@
       ],
     },  # v8_pch
     {
+      # Shared generated sources have one producer for both toolsets. In cross
+      # builds, the executable used by this action still belongs to the host.
       'target_name': 'run_torque',
       'type': 'none',
-      'toolsets': ['host', 'target'],
+      'toolsets': ['target'],
       'conditions': [
         ['want_separate_host_toolset', {
           'dependencies': ['torque#host'],
@@ -191,8 +193,8 @@
       'toolsets': ['host', 'target'],
       'hard_dependency': 1,
       'dependencies': [
-        'generate_bytecode_builtins_list',
-        'run_torque',
+        'generate_bytecode_builtins_list#target',
+        'run_torque#target',
         'v8_base_without_compiler',
         'torque_runtime_support',
         'v8_maybe_icu',
@@ -214,8 +216,8 @@
       'toolsets': ['host', 'target'],
       'hard_dependency': 1,
       'dependencies': [
-        'generate_bytecode_builtins_list',
-        'run_torque',
+        'generate_bytecode_builtins_list#target',
+        'run_torque#target',
         'v8_internal_headers',
         'v8_libbase',
         'v8_maybe_icu',
@@ -236,7 +238,7 @@
       'target_name': 'generate_bytecode_builtins_list',
       'type': 'none',
       'hard_dependency': 1,
-      'toolsets': ['host', 'target'],
+      'toolsets': ['target'],
       'conditions': [
         ['want_separate_host_toolset', {
           'dependencies': ['bytecode_builtins_list_generator#host'],
@@ -277,8 +279,8 @@
       'type': 'static_library',
       'toolsets': ['host', 'target'],
       'dependencies': [
-        'generate_bytecode_builtins_list',
-        'run_torque',
+        'generate_bytecode_builtins_list#target',
+        'run_torque#target',
         'v8_base_without_compiler',
         'v8_initializers',
         'v8_maybe_icu',
@@ -497,8 +499,8 @@
         }],
         ['want_separate_host_toolset', {
           'dependencies': [
-            'generate_bytecode_builtins_list',
-            'run_torque',
+            'generate_bytecode_builtins_list#target',
+            'run_torque#target',
             'mksnapshot#host',
             'v8_maybe_icu',
             # [GYP] added explicitly, instead of inheriting from the other deps
@@ -509,8 +511,8 @@
           ]
         }, {
           'dependencies': [
-            'generate_bytecode_builtins_list',
-            'run_torque',
+            'generate_bytecode_builtins_list#target',
+            'run_torque#target',
             'mksnapshot',
             'v8_maybe_icu',
             # [GYP] added explicitly, instead of inheriting from the other deps
@@ -631,8 +633,8 @@
         'v8_maybe_icu',
         'v8_shared_internal_headers',
         'v8_heap_base_headers',
-        'generate_bytecode_builtins_list',
-        'run_torque',
+        'generate_bytecode_builtins_list#target',
+        'run_torque#target',
         'v8_libbase',
         'fp16',
       ],
@@ -961,8 +963,8 @@
       'type': 'static_library',
       'toolsets': ['host', 'target'],
       'dependencies': [
-        'generate_bytecode_builtins_list',
-        'run_torque',
+        'generate_bytecode_builtins_list#target',
+        'run_torque#target',
         'v8_maybe_icu',
         'v8_base_without_compiler',
         'v8_internal_headers',
@@ -983,8 +985,8 @@
       'type': 'static_library',
       'toolsets': ['host', 'target'],
       'dependencies': [
-        'generate_bytecode_builtins_list',
-        'run_torque',
+        'generate_bytecode_builtins_list#target',
+        'run_torque#target',
         'v8_internal_headers',
         'v8_maybe_icu',
         'v8_base_without_compiler',
@@ -1019,8 +1021,8 @@
       'toolsets': ['host', 'target'],
       'hard_dependency': 1,
       'dependencies': [
-        'generate_bytecode_builtins_list',
-        'run_torque',
+        'generate_bytecode_builtins_list#target',
+        'run_torque#target',
         'v8_maybe_icu',
       ],
       'conditions': [
@@ -1044,7 +1046,7 @@
     {
       'target_name': 'v8_inspector_headers',
       'type': 'none',
-      'toolsets': ['host', 'target'],
+      'toolsets': ['target'],
       'hard_dependency': 1,
       'includes': ['inspector.gypi'],
       'direct_dependent_settings': {
@@ -1102,13 +1104,13 @@
         'v8_bigint',
         'v8_headers',
         'v8_heap_base',
-        'v8_inspector_headers',
+        'v8_inspector_headers#target',
         'v8_libbase',
         'v8_shared_internal_headers',
         'v8_version',
         'cppgc_base',
-        'generate_bytecode_builtins_list',
-        'run_torque',
+        'generate_bytecode_builtins_list#target',
+        'run_torque#target',
         'v8_internal_headers',
         'v8_maybe_icu',
         'v8_zlib',
@@ -1155,7 +1157,7 @@
             }],
             ['v8_enable_i18n_support==0', {
               'dependencies': [
-                '../../deps/crates/crates.gyp:temporal_zoneinfo64_data',
+                '../../deps/crates/crates.gyp:temporal_zoneinfo64_data#target',
               ],
             }],
           ],
@@ -1369,7 +1371,7 @@
         }],
         ['v8_enable_i18n_support==1', {
           'dependencies': [
-            'run_gen-regexp-special-case',
+            'run_gen-regexp-special-case#target',
           ],
           'sources': [
             '<(SHARED_INTERMEDIATE_DIR)/src/regexp/special-case.cc',
@@ -2080,7 +2082,7 @@
     {
       'target_name': 'run_gen-regexp-special-case',
       'type': 'none',
-      'toolsets': ['host', 'target'],
+      'toolsets': ['target'],
       'conditions': [
         ['want_separate_host_toolset', {
           'dependencies': ['gen-regexp-special-case#host'],
@@ -2320,8 +2322,8 @@
     {
       'target_name': 'postmortem-metadata',
       'type': 'none',
-      'toolsets': ['host', 'target'],
-      'dependencies': ['run_torque'],
+      'toolsets': ['target'],
+      'dependencies': ['run_torque#target'],
       'variables': {
         'heapobject_files': [
           '<(SHARED_INTERMEDIATE_DIR)/torque-generated/instance-types.h',

tools/v8_gypfiles/v8_debug_helper.gyp

@@ -36,8 +36,8 @@
       'dependencies': [
         'gen_heap_constants',
 
-        'v8.gyp:generate_bytecode_builtins_list',
-        'v8.gyp:run_torque',
+        'v8.gyp:generate_bytecode_builtins_list#target',
+        'v8.gyp:run_torque#target',
         'v8.gyp:v8_maybe_icu',
         'v8.gyp:fp16',
         'v8.gyp:v8_libbase',
@@ -161,8 +161,8 @@
         'v8.gyp:v8_libplatform',
         'v8.gyp:v8_maybe_icu',
         'v8.gyp:fp16',
-        'v8.gyp:generate_bytecode_builtins_list',
-        'v8.gyp:run_torque',
+        'v8.gyp:generate_bytecode_builtins_list#target',
+        'v8.gyp:run_torque#target',
       ],
       'conditions': [
         ['node_shared_abseil=="false"', {