Bug 1723623 - Relax platform checks for wasm sandboxing. r=firefox-build-system-reviewers,andi

- Don't encode any platform dependency in the frontend itself, as that's
  dealt with by configure. Do check that there's a wasm compiler setup,
  though (also dealth with by configure).

- Allow to enable on any 64-bits platform when building with wasm2c
  instead of lucetc.

Differential Revision: https://phabricator.services.mozilla.com/D121582

python/mozbuild/mozbuild/frontend/data.py

@@ -17,10 +17,7 @@ structures.
 
 from __future__ import absolute_import, print_function, unicode_literals
 
-from mozbuild.frontend.context import (
-    ObjDirPath,
-    SourcePath,
-)
+from mozbuild.frontend.context import ObjDirPath, SourcePath
 from mozpack.chrome.manifest import ManifestEntry
 
 import mozpack.path as mozpath
@@ -131,11 +128,7 @@ class DirectoryTraversal(ContextDerived):
 class BaseConfigSubstitution(ContextDerived):
     """Base class describing autogenerated files as part of config.status."""
 
-    __slots__ = (
-        "input_path",
-        "output_path",
-        "relpath",
-    )
+    __slots__ = ("input_path", "output_path", "relpath")
 
     def __init__(self, context):
         ContextDerived.__init__(self, context)
@@ -193,10 +186,7 @@ class ComputedFlags(ContextDerived):
 class XPIDLModule(ContextDerived):
     """Describes an XPIDL module to be compiled."""
 
-    __slots__ = (
-        "name",
-        "idl_files",
-    )
+    __slots__ = ("name", "idl_files")
 
     def __init__(self, context, name, idl_files):
         ContextDerived.__init__(self, context)
@@ -502,12 +492,7 @@ class BaseProgram(Linkable):
 
     __slots__ = "program"
 
-    DICT_ATTRS = {
-        "install_target",
-        "KIND",
-        "program",
-        "relobjdir",
-    }
+    DICT_ATTRS = {"install_target", "KIND", "program", "relobjdir"}
 
     def __init__(self, context, program, is_unit_test=False):
         Linkable.__init__(self, context)
@@ -639,11 +624,7 @@ class HostRustProgram(BaseRustProgram):
 
 
 class RustTests(ContextDerived):
-    __slots__ = (
-        "names",
-        "features",
-        "output_category",
-    )
+    __slots__ = ("names", "features", "output_category")
 
     def __init__(self, context, names, features):
         ContextDerived.__init__(self, context)
@@ -655,12 +636,7 @@ class RustTests(ContextDerived):
 class BaseLibrary(Linkable):
     """Generic context derived container object for libraries."""
 
-    __slots__ = (
-        "basename",
-        "lib_name",
-        "import_name",
-        "refs",
-    )
+    __slots__ = ("basename", "lib_name", "import_name", "refs")
 
     def __init__(self, context, basename):
         Linkable.__init__(self, context)
@@ -698,10 +674,7 @@ class Library(BaseLibrary):
 class StaticLibrary(Library):
     """Context derived container object for a static library"""
 
-    __slots__ = (
-        "link_into",
-        "no_expand_lib",
-    )
+    __slots__ = ("link_into", "no_expand_lib")
 
     def __init__(
         self, context, basename, real_name=None, link_into=None, no_expand_lib=False
@@ -721,11 +694,9 @@ class SandboxedWasmLibrary(Library):
     def __init__(self, context, basename, real_name=None):
         Library.__init__(self, context, basename, real_name)
 
-        # TODO: WASM sandboxed libraries are in a weird place: they are
-        # built in a different way, but they should share some code with
-        # SharedLibrary.  This is the minimal configuration needed to work
-        # on the below platforms.
-        assert context.config.substs["OS_TARGET"] in ("Linux", "Darwin")
+        # Wasm libraries are not going to compile unless we have a compiler
+        # for them.
+        assert context.config.substs["WASM_CC"] and context.config.substs["WASM_CXX"]
 
         self.lib_name = "%s%s%s" % (
             context.config.dll_prefix,
@@ -1083,10 +1054,7 @@ class LocalInclude(ContextDerived):
 class PerSourceFlag(ContextDerived):
     """Describes compiler flags specified for individual source files."""
 
-    __slots__ = (
-        "file_name",
-        "flags",
-    )
+    __slots__ = ("file_name", "flags")
 
     def __init__(self, context, file_name, flags):
         ContextDerived.__init__(self, context)
@@ -1114,10 +1082,7 @@ class JARManifest(ContextDerived):
 class BaseSources(ContextDerived):
     """Base class for files to be compiled during the build."""
 
-    __slots__ = (
-        "files",
-        "canonical_suffix",
-    )
+    __slots__ = ("files", "canonical_suffix")
 
     def __init__(self, context, files, canonical_suffix):
         ContextDerived.__init__(self, context)
@@ -1415,10 +1380,7 @@ class GeneratedFile(ContextDerived):
 class ChromeManifestEntry(ContextDerived):
     """Represents a chrome.manifest entry."""
 
-    __slots__ = (
-        "path",
-        "entry",
-    )
+    __slots__ = ("path", "entry")
 
     def __init__(self, context, manifest_path, entry):
         ContextDerived.__init__(self, context)

python/mozbuild/mozbuild/test/frontend/test_emitter.py

@@ -1415,7 +1415,9 @@ class TestEmitterBasic(unittest.TestCase):
 
     def test_wasm_sources(self):
         """Test that WASM_SOURCES works properly."""
-        reader = self.reader("wasm-sources", extra_substs={"OS_TARGET": "Linux"})
+        reader = self.reader(
+            "wasm-sources", extra_substs={"WASM_CC": "clang", "WASM_CXX": "clang++"}
+        )
         objs = list(self.read_topsrcdir(reader))
 
         # The second to last object is a linkable.
@@ -1833,7 +1835,10 @@ class TestEmitterBasic(unittest.TestCase):
             self.read_topsrcdir(reader)
 
     def test_wasm_compile_flags(self):
-        reader = self.reader("wasm-compile-flags", extra_substs={"OS_TARGET": "Linux"})
+        reader = self.reader(
+            "wasm-compile-flags",
+            extra_substs={"WASM_CC": "clang", "WASM_CXX": "clang++"},
+        )
         flags = list(self.read_topsrcdir(reader))[2]
         self.assertIsInstance(flags, ComputedFlags)
         self.assertEqual(

toolkit/moz.configure

@@ -2253,19 +2253,22 @@ with only_when(requires_wasm_sandboxing & compile_environment):
     set_config("LUCETC_TARGET", rust_target_triple)
 
 
-@depends("--with-wasm-sandboxed-libraries", target)
-def wasm_sandboxing(libraries, target):
+@depends("--with-wasm-sandboxed-libraries", target, lucetc)
+def wasm_sandboxing(libraries, target, lucetc):
     if not libraries:
         return
 
     # Wasm sandboxing is only enabled on specific targets.
-    if not (
+    if lucetc and not (
         target.cpu in ("x86_64",)
         and (target.kernel == "Linux" and target.os != "Android")
         or target.kernel == "Darwin"
     ):
         die("wasm sandboxing is only enabled on x86-64 Linux and Mac")
 
+    if not lucetc and target.bitness != 64:
+        die("wasm sandboxing is only supported on 64-bits platforms")
+
     return namespace(**{name: True for name in libraries})