Expose soname field on rust_library

Summary: Requested by tmcguire-meta on https://fb.workplace.com/groups/rustonmobile/posts/3723752194537762 in order to allow including rust shared objects into gradle builds in arvr land.

Reviewed By: dtolnay

Differential Revision: D58200175

fbshipit-source-id: 27d6e8ed37a8c661475ca1c88db8d4269aed33d2

Author: capickett

prelude/decls/cxx_rules.bzl

@@ -519,18 +519,12 @@ cxx_library = prelude_rule(
         cxx_common.exported_post_platform_linker_flags_arg() |
         native_common.link_style() |
         native_common.link_whole(link_whole_type = attrs.option(attrs.bool(), default = None)) |
+        native_common.soname() |
         cxx_common.raw_headers_arg() |
         cxx_common.include_directories_arg() |
         cxx_common.public_include_directories_arg() |
         cxx_common.public_system_include_directories_arg() |
         {
-            "soname": attrs.option(attrs.string(), default = None, doc = """
-                Sets the soname ("shared object name") of any shared library produced from this rule.
-                 The default value is based on the full rule name.
-                 The macro `$(ext)` will be replaced with a platform-appropriate extension.
-                 An argument can be provided, which is a library version.
-                 For example `soname = 'libfoo.$(ext 2.3)'` will be `libfoo.2.3.dylib` on Mac and `libfoo.so.2.3` on Linux.
-            """),
             "used_by_wrap_script": attrs.bool(default = False, doc = """
                 When using an exopackage
                  Android, if this parameter is set to `True`, then the library is

prelude/decls/native_common.bzl

@@ -46,10 +46,22 @@ def _link_group_public_deps_label():
 """),
     }
 
+def _soname():
+    return {
+        "soname": attrs.option(attrs.string(), default = None, doc = """
+    Sets the soname ("shared object name") of any shared library produced from this rule.
+     The default value is based on the full rule name.
+     The macro `$(ext)` will be replaced with a platform-appropriate extension.
+     An argument can be provided, which is a library version.
+     For example `soname = 'libfoo.$(ext 2.3)'` will be `libfoo.2.3.dylib` on Mac and `libfoo.so.2.3` on Linux.
+"""),
+    }
+
 native_common = struct(
     link_group_deps = _link_group_deps,
     link_group_public_deps_label = _link_group_public_deps_label,
     link_style = _link_style,
     link_whole = _link_whole,
     preferred_linkage = _preferred_linkage,
+    soname = _soname,
 )

prelude/decls/rust_rules.bzl

@@ -186,6 +186,7 @@ rust_library = prelude_rule(
         rust_common.crate(crate_type = attrs.option(attrs.string(), default = None)) |
         rust_common.crate_root() |
         native_common.preferred_linkage(preferred_linkage_type = attrs.enum(Linkage.values(), default = "any")) |
+        native_common.soname() |
         _rust_common_attributes(is_binary = False) |
         {
             "crate_dynamic": attrs.option(attrs.dep(), default = None),

prelude/rust/build.bzl

@@ -24,7 +24,6 @@ load("@prelude//cxx:debug.bzl", "SplitDebugMode")
 load("@prelude//cxx:dwp.bzl", "dwp", "dwp_available")
 load(
     "@prelude//cxx:linker.bzl",
-    "get_default_shared_library_name",
     "get_shared_library_name_linker_flags",
 )
 load(
@@ -75,6 +74,7 @@ load(
     "RustLinkInfo",
     "attr_crate",
     "attr_simple_crate_for_filenames",
+    "attr_soname",
     "get_available_proc_macros",
     "inherited_external_debug_info",
     "inherited_merged_link_infos",
@@ -895,7 +895,7 @@ def _compute_common_args(
 
     if crate_type in [CrateType("cdylib"), CrateType("dylib")] and not is_check:
         linker_info = compile_ctx.cxx_toolchain_info.linker_info
-        shlib_name = get_default_shared_library_name(linker_info, ctx.label)
+        shlib_name = attr_soname(ctx)
         dep_args.add(cmd_args(
             get_shared_library_name_linker_flags(linker_info.type, shlib_name),
             format = "-Clink-arg={}",

prelude/rust/link_info.bzl

@@ -16,6 +16,7 @@ load(
     "@prelude//cxx:cxx.bzl",
     "get_auto_link_group_specs",
 )
+load("@prelude//cxx:cxx_context.bzl", "get_cxx_toolchain_info")
 load(
     "@prelude//cxx:cxx_library_utility.bzl",
     "cxx_is_gnu",
@@ -37,6 +38,11 @@ load(
     "@prelude//cxx:link_groups_types.bzl",
     "LinkGroupInfo",  # @unused Used as a type
 )
+load(
+    "@prelude//cxx:linker.bzl",
+    "get_default_shared_library_name",
+    "get_shared_library_name_for_param",
+)
 load(
     "@prelude//linking:link_groups.bzl",
     "LinkGroupLib",  # @unused Used as a type
@@ -584,3 +590,12 @@ def attr_crate(ctx: AnalysisContext) -> CrateName:
         simple = normalize_crate(ctx.attrs.crate or ctx.label.name),
         dynamic = dynamic,
     )
+
+def attr_soname(ctx: AnalysisContext) -> str:
+    """
+    Get the shared library name to set for the given rust library.
+    """
+    linker_info = get_cxx_toolchain_info(ctx).linker_info
+    if ctx.attrs.soname != None:
+        return get_shared_library_name_for_param(linker_info, ctx.attrs.soname)
+    return get_default_shared_library_name(linker_info, ctx.label)

prelude/rust/rust_library.bzl

@@ -18,7 +18,6 @@ load(
 load(
     "@prelude//cxx:linker.bzl",
     "PDB_SUB_TARGET",
-    "get_default_shared_library_name",
     "get_pdb_providers",
 )
 load(
@@ -92,6 +91,7 @@ load(
     "RustLinkStrategyInfo",
     "RustProcMacroMarker",  # @unused Used as a type
     "attr_crate",
+    "attr_soname",
     "inherited_exported_link_deps",
     "inherited_link_group_lib_infos",
     "inherited_linkable_graphs",
@@ -599,7 +599,7 @@ def _advanced_unstable_link_providers(
     solibs = {}
 
     # Add the shared library to the list of shared libs.
-    shlib_name = get_default_shared_library_name(linker_info, ctx.label)
+    shlib_name = attr_soname(ctx)
 
     shared_lib_params = lang_style_param[(LinkageLang("native-unbundled"), LibOutputStyle("shared_lib"))]
     shared_lib_output = native_param_artifact[shared_lib_params].output
@@ -786,7 +786,7 @@ def _native_link_providers(
     solibs = {}
 
     # Add the shared library to the list of shared libs.
-    shlib_name = get_default_shared_library_name(linker_info, ctx.label)
+    shlib_name = attr_soname(ctx)
 
     # Only add a shared library if we generated one.
     # TODO(cjhopman): This is strange. Normally (like in c++) the link_infos passed to create_merged_link_info above would only have