Cleanup some cgo handling

Author: dzbarsky

go/private/actions/archive.bzl

@@ -144,7 +144,7 @@ def emit_archive(go, source = None, _recompile_suffix = "", recompile_internal_d
             is_external_pkg = is_external_pkg,
         )
     else:
-        cgo_deps = depset()
+        cgo_deps = []
         emit_compilepkg(
             go,
             sources = source.srcs,
@@ -204,26 +204,21 @@ def emit_archive(go, source = None, _recompile_suffix = "", recompile_internal_d
         runfiles = source.runfiles,
         _validation_output = out_nogo_validation,
         _nogo_diagnostics = out_diagnostics,
-        _cgo_deps = cgo_deps,
+        _cgo_deps = depset(cgo_deps),
     )
     x_defs = dict(source.x_defs)
     for a in direct:
         x_defs.update(a.x_defs)
 
-    # Ensure that the _cgo_export.h of the current target comes first when cgo_exports is iterated
-    # by prepending it and specifying the order explicitly. This is required as the CcInfo attached
-    # to the archive only exposes a single header rather than combining all headers.
-    cgo_exports_direct = [out_cgo_export_h] if out_cgo_export_h else []
-    cgo_exports = depset(direct = cgo_exports_direct, transitive = [a.cgo_exports for a in direct], order = "preorder")
     return GoArchive(
         source = source,
         data = data,
         direct = direct,
         libs = depset(direct = [out_lib], transitive = [a.libs for a in direct]),
         transitive = depset([data], transitive = [a.transitive for a in direct]),
         x_defs = x_defs,
-        cgo_deps = depset(transitive = [cgo_deps] + [a.cgo_deps for a in direct]),
-        cgo_exports = cgo_exports,
+        cgo_deps = depset(cgo_deps, transitive = [a.cgo_deps for a in direct]),
+        cgo_export = out_cgo_export_h,
         runfiles = runfiles,
         _headers = headers,
     )

go/private/rules/binary.bzl

@@ -49,8 +49,6 @@ load(
     "non_go_transition",
 )
 
-_EMPTY_DEPSET = depset([])
-
 def _include_path(hdr):
     if not hdr.root.path:
         fail("Expected hdr to be a generated file, got source file: " + hdr.path)
@@ -66,9 +64,10 @@ def _include_path(hdr):
 
 def new_cc_import(
         go,
-        hdrs = _EMPTY_DEPSET,
-        defines = _EMPTY_DEPSET,
-        local_defines = _EMPTY_DEPSET,
+        headers = None,
+        includes = None,
+        defines = None,
+        local_defines = None,
         dynamic_library = None,
         static_library = None,
         alwayslink = False,
@@ -77,8 +76,8 @@ def new_cc_import(
         compilation_context = cc_common.create_compilation_context(
             defines = defines,
             local_defines = local_defines,
-            headers = hdrs,
-            includes = depset([_include_path(hdr) for hdr in hdrs.to_list()]),
+            headers = headers,
+            includes = includes,
         ),
         linking_context = cc_common.create_linking_context(
             linker_inputs = depset([
@@ -137,9 +136,7 @@ def _go_binary_impl(ctx):
         importable = False,
         is_main = is_main,
     )
-    name = ctx.attr.basename
-    if not name:
-        name = ctx.label.name
+    name = ctx.attr.basename or ctx.label.name
     executable = None
     if ctx.attr.out:
         # Use declare_file instead of attr.output(). When users set output files
@@ -161,7 +158,7 @@ def _go_binary_impl(ctx):
     providers = [
         archive,
         OutputGroupInfo(
-            cgo_exports = archive.cgo_exports,
+            cgo_exports = [archive.cgo_export] if archive.cgo_export else [],
             compilation_outputs = [archive.data.file],
             nogo_fix = [nogo_diagnostics] if nogo_diagnostics else [],
             _validation = [validation_output] if validation_output else [],
@@ -202,14 +199,14 @@ def _go_binary_impl(ctx):
                 "windows": ["-mthreads"],
             }.get(go.mode.goos, ["-pthread"]),
         }
-        cgo_exports = archive.cgo_exports.to_list()
-        if cgo_exports:
+        if archive.cgo_export:
             header = ctx.actions.declare_file("{}.h".format(name))
             ctx.actions.symlink(
                 output = header,
-                target_file = cgo_exports[0],
+                target_file = archive.cgo_export,
             )
-            cc_import_kwargs["hdrs"] = depset([header])
+            cc_import_kwargs["headers"] = depset([header])
+            cc_import_kwargs["includes"] = depset([_include_path(header)])
         if go.mode.linkmode == LINKMODE_C_SHARED:
             cc_import_kwargs["dynamic_library"] = executable
         elif go.mode.linkmode == LINKMODE_C_ARCHIVE:

go/private/rules/cgo.bzl

@@ -89,7 +89,7 @@ def cgo_configure(go, srcs, cdeps, cppopts, copts, cxxopts, clinkopts):
 
     inputs_direct = []
     inputs_transitive = []
-    deps_direct = []
+    deps = []
     lib_opts = []
     runfiles = go._ctx.runfiles(collect_data = True)
     seen_alwayslink_libs = {}
@@ -104,7 +104,7 @@ def cgo_configure(go, srcs, cdeps, cppopts, copts, cxxopts, clinkopts):
             inputs_transitive.append(cc_transitive_headers)
             cc_libs, cc_link_flags = _cc_libs_and_flags(d)
             inputs_direct.extend(cc_libs)
-            deps_direct.extend(cc_libs)
+            deps.extend(cc_libs)
             cc_defines = d[CcInfo].compilation_context.defines.to_list()
             cppopts.extend(["-D" + define for define in cc_defines])
             cc_includes = d[CcInfo].compilation_context.includes.to_list()
@@ -170,7 +170,6 @@ def cgo_configure(go, srcs, cdeps, cppopts, copts, cxxopts, clinkopts):
             fail("unknown library has neither cc nor objc providers: %s" % d.label)
 
     inputs = depset(direct = inputs_direct, transitive = inputs_transitive)
-    deps = depset(direct = deps_direct)
 
     # HACK: some C/C++ toolchains will ignore libraries (including dynamic libs
     # specified with -l flags) unless they appear after .o or .a files with

go/private/rules/library.bzl

@@ -67,7 +67,7 @@ def _go_library_impl(ctx):
             extensions = ["go"],
         ),
         OutputGroupInfo(
-            cgo_exports = archive.cgo_exports,
+            cgo_exports = [archive.cgo_export] if archive.cgo_export else [],
             compilation_outputs = [archive.data.file],
             nogo_fix = [nogo_diagnostics] if nogo_diagnostics else [],
             _validation = [validation_output] if validation_output else [],

go/private/rules/test.bzl

@@ -737,7 +737,6 @@ def _recompile_external_deps(go, external_go_info, internal_archive, library_lab
                 transitive = depset(direct = [arc_data], transitive = [a.transitive for a in deps]),
                 x_defs = go_info.x_defs,
                 cgo_deps = depset(transitive = [arc_data._cgo_deps] + [a.cgo_deps for a in deps]),
-                cgo_exports = depset(transitive = [a.cgo_exports for a in deps]),
                 runfiles = go_info.runfiles,
                 mode = go.mode,
                 _headers = internal_archive._headers,

go/providers.rst

@@ -285,9 +285,9 @@ which is available through the :param:`data` field.
 | The direct cgo dependencies of this library.                                                     |
 | This has the same constraints as things that can appear in the deps of a cc_library_.            |
 +--------------------------------+-----------------------------------------------------------------+
-| :param:`cgo_exports`           | :type:`depset of GoInfo`                                        |
+| :param:`cgo_export`           | :type:`File`                                                     |
 +--------------------------------+-----------------------------------------------------------------+
-| The transitive set of c headers needed to reference exports of this archive.                     |
+| The c headers needed to reference exports of this archive.                                       |
 +--------------------------------+-----------------------------------------------------------------+
 | :param:`runfiles`              | runfiles_                                                       |
 +--------------------------------+-----------------------------------------------------------------+