Support for self-referencing -include_lib directives

in the erlang_bytecode rule

The erlang_app macro will invoke erlang_bytecode in the correct manner
to support this

erlang_bytecode in general need not be called specifically in the
context of an application, so in this case the old behavior remains

Author: HoloRin

erlang_app.bzl

@@ -62,6 +62,7 @@ def erlang_app(
 
     erlang_bytecode(
         name = "beam_files",
+        app_name = app_name,
         hdrs = hdrs,
         srcs = srcs,
         erlc_opts = erlc_opts,
@@ -143,6 +144,7 @@ def test_erlang_app(
 
     erlang_bytecode(
         name = "test_beam_files",
+        app_name = app_name,
         hdrs = hdrs,
         srcs = srcs,
         erlc_opts = erlc_opts,

private/erlang_bytecode.bzl

@@ -25,8 +25,16 @@ def _dirname(path):
 def _impl(ctx):
     erl_libs_dir = ctx.label.name + "_deps"
 
+    target = None
+    if ctx.attr.app_name != "":
+        target = ErlangAppInfo(
+            app_name = ctx.attr.app_name,
+            include = ctx.files.hdrs,
+        )
+
     erl_libs_files = erl_libs_contents(
         ctx,
+        target_info = target,
         transitive = False,
         headers = True,
         dir = erl_libs_dir,
@@ -49,6 +57,8 @@ def _impl(ctx):
     dest_dir = beam_files[0].dirname
 
     include_args = []
+    if erl_libs_path != "":
+        include_args.extend(["-I", erl_libs_path])
     for dir in unique_dirnames(ctx.files.hdrs):
         include_args.extend(["-I", dir])
 
@@ -86,14 +96,17 @@ fi
 
 if [ -n "$FIRST" ]; then
     "{erlang_home}"/bin/erlc \\
-        -v {include_args} {pa_args} -o {out_dir} {erlc_opts} \\
+        -v {include_args} {pa_args} \\
+        -o {out_dir} {erlc_opts} \\
         $FIRST
     "{erlang_home}"/bin/erlc \\
-        -v {include_args} {pa_args} -pa {out_dir} -o {out_dir} {erlc_opts} \\
+        -v {include_args} {pa_args} -pa {out_dir} \\
+        -o {out_dir} {erlc_opts} \\
         $@
 else
     "{erlang_home}"/bin/erlc \\
-        -v {include_args} {pa_args} -o {out_dir} {erlc_opts} \\
+        -v {include_args} {pa_args} \\
+        -o {out_dir} {erlc_opts} \\
         $@
 fi
     """.format(
@@ -136,6 +149,7 @@ erlang_bytecode = rule(
             # rule.
             cfg = "target",
         ),
+        "app_name": attr.string(),
         "hdrs": attr.label_list(
             allow_files = [".hrl"],
         ),

private/util.bzl

@@ -21,8 +21,14 @@ def additional_file_dest_relative_path(dep_label, f):
     else:
         return f.short_path
 
-def erl_libs_contents2(ctx, deps = [], headers = False, dir = _DEFAULT_ERL_LIBS_DIR):
+def erl_libs_contents2(ctx, target_info = None, deps = [], headers = False, dir = _DEFAULT_ERL_LIBS_DIR):
     erl_libs_files = []
+    if headers and target_info != None:
+        dep_path = path_join(dir, target_info.app_name)
+        for hdr in target_info.include:
+            dest = ctx.actions.declare_file(path_join(dep_path, hdr.path))
+            ctx.actions.symlink(output = dest, target_file = hdr)
+            erl_libs_files.append(dest)
     for dep in deps:
         lib_info = dep[ErlangAppInfo]
         dep_path = path_join(dir, lib_info.app_name)