cc: Add local_includes attribute to swift_cc*

cc/defs.bzl

@@ -10,6 +10,8 @@
 
 """Swift wrappers for native cc rules."""
 
+load(":utils.bzl", "construct_local_include")
+
 # Name for a unit test
 UNIT = "unit"
 
@@ -74,6 +76,9 @@ def _common_c_opts(nocopts, pedantic = False):
 
     return copts
 
+def _construct_local_includes(local_includes):
+    return [construct_local_include(path) for path in local_includes]
+
 def swift_cc_library(**kwargs):
     """Wraps cc_library to enforce standards for a production library.
 
@@ -85,13 +90,21 @@ def swift_cc_library(**kwargs):
     Args:
         **kwargs: See https://bazel.build/reference/be/c-cpp#cc_library
 
-            An additional attribute nocopts is supported. This
-            attribute takes a list of flags to remove from the
-            default compiler options. Use judiciously.
+            The following additional attributes are supported:
+
+            local_includes: List of local (non-public) include paths. Prefer
+            this to passing local includes using copts. Paths are expected to
+            be relative to the package this macro is called from.
+
+            nocopts: List of flags to remove from the default compile
+            options. Use judiciously.
     """
+    local_includes = _construct_local_includes(kwargs.pop("local_includes", []))
+
     nocopts = kwargs.pop("nocopts", [])  # pop because nocopts is a deprecated cc* attr.
 
     copts = _common_c_opts(nocopts, pedantic = True)
+    copts = local_includes + copts
     kwargs["copts"] = (kwargs["copts"] if "copts" in kwargs else []) + copts
 
     native.cc_library(**kwargs)
@@ -108,13 +121,21 @@ def swift_cc_tool_library(**kwargs):
     Args:
         **kwargs: See https://bazel.build/reference/be/c-cpp#cc_library
 
-            An additional attribute nocopts is supported. This
-            attribute takes a list of flags to remove from the
-            default compiler options. Use judiciously.
+            The following additional attributes are supported:
+
+            local_includes: List of local (non-public) include paths. Prefer
+            this to passing local includes using copts. Paths are expected to
+            be relative to the package this macro is called from.
+
+            nocopts: List of flags to remove from the default compile
+            options. Use judiciously.
     """
+    local_includes = _construct_local_includes(kwargs.pop("local_includes", []))
+
     nocopts = kwargs.pop("nocopts", [])
 
     copts = _common_c_opts(nocopts, pedantic = False)
+    copts = local_includes + copts
     kwargs["copts"] = (kwargs["copts"] if "copts" in kwargs else []) + copts
 
     native.cc_library(**kwargs)
@@ -130,13 +151,21 @@ def swift_cc_binary(**kwargs):
     Args:
         **kwargs: See https://bazel.build/reference/be/c-cpp#cc_binary
 
-            An additional attribute nocopts is supported. This
-            attribute takes a list of flags to remove from the
-            default compiler options. Use judiciously.
+            The following additional attributes are supported:
+
+            local_includes: List of local (non-public) include paths. Prefer
+            this to passing local includes using copts. Paths are expected to
+            be relative to the package this macro is called from.
+
+            nocopts: List of flags to remove from the default compile
+            options. Use judiciously.
     """
+    local_includes = _construct_local_includes(kwargs.pop("local_includes", []))
+
     nocopts = kwargs.pop("nocopts", [])
 
     copts = _common_c_opts(nocopts, pedantic = True)
+    copts = local_includes + copts
     kwargs["copts"] = (kwargs["copts"] if "copts" in kwargs else []) + copts
 
     native.cc_binary(**kwargs)
@@ -153,9 +182,14 @@ def swift_cc_tool(**kwargs):
     Args:
         **kwargs: See https://bazel.build/reference/be/c-cpp#cc_binary
 
-            An additional attribute nocopts is supported. This
-            attribute takes a list of flags to remove from the
-            default compiler options. Use judiciously.
+            The following additional attributes are supported:
+
+            local_includes: List of local (non-public) include paths. Prefer
+            this to passing local includes using copts. Paths are expected to
+            be relative to the package this macro is called from.
+
+            nocopts: List of flags to remove from the default compile
+            options. Use judiciously.
     """
     nocopts = kwargs.pop("nocopts", [])
 
@@ -169,7 +203,16 @@ def swift_cc_test_library(**kwargs):
 
     Args:
         **kwargs: See https://bazel.build/reference/be/c-cpp#cc_test
+
+            The following additional attributes are supported:
+
+            local_includes: List of local (non-public) include paths. Prefer
+            this to passing local includes using copts. Paths are expected to
+            be relative to the package this macro is called from.
     """
+    local_includes = _construct_local_includes(kwargs.pop("local_includes", []))
+
+    kwargs["copts"] = (kwargs["copts"] if "copts" in kwargs else []) + local_includes
     native.cc_library(**kwargs)
 
 def swift_cc_test(name, type, **kwargs):
@@ -183,11 +226,20 @@ def swift_cc_test(name, type, **kwargs):
             these test types seperately: `bazel test --test_tag_filters=unit //...`
 
         **kwargs: See https://bazel.build/reference/be/c-cpp#cc_test
+
+            The following additional attributes are supported:
+
+            local_includes: List of local (non-public) include paths. Prefer
+            this to passing local includes using copts. Paths are expected to
+            be relative to the package this macro is called from.
     """
 
     if not (type == UNIT or type == INTEGRATION):
         fail("The 'type' attribute must be either UNIT or INTEGRATION")
 
+    local_includes = _construct_local_includes(kwargs.pop("local_includes", []))
+
+    kwargs["copts"] = (kwargs["copts"] if "copts" in kwargs else []) + local_includes
     kwargs["name"] = name
     kwargs["tags"] = (kwargs["tags"] if "tags" in kwargs else []) + [type]
     native.cc_test(**kwargs)

cc/utils.bzl

@@ -0,0 +1,35 @@
+# Copyright (C) 2022 Swift Navigation Inc.
+# Contact: Swift Navigation <dev@swift-nav.com>
+#
+# This source is subject to the license found in the file 'LICENSE' which must
+# be be distributed together with this source. All other rights reserved.
+#
+# THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
+# EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
+
+def construct_local_include(path):
+    """Helper to correctly set up local (non-public) include paths.
+
+    When a bazel workspace is consumed externally, (i.e. via local_repository),
+    its sources are placed under <execroot>/external/<workspace_root>/. This
+    typically breaks local include paths defined using -I.
+
+    This macro ensures that the include path is constructed correctly both when
+    building a workpace standalone, and externally.
+
+    Args:
+        path: The include path relative to the package this macro is called from
+
+            Use the special argument $(GENDIR) to construct an include path for
+            any generated files the build depends on. Assumes these files are
+            not generated into a subdirectory.
+    """
+    root = Label(native.repository_name() + "//:WORKSPACE").workspace_root or "."
+    package = native.package_name()
+
+    # Generated files are placed in $(GENDIR)/external/<workspace_root>
+    if path == "$(GENDIR)":
+        return "-I" + path + "/" + root + "/" + package + "/"
+    else:
+        return "-I" + root + "/" + package + "/" + path + "/"