hmaptool: easier to generate input

* hmaptool: implement param files and drop unused options
            now it takes header right on the CLI so that
            it's easier to generate the input from bazel.
* hmap.bzl: remove flatten_headers and use namespace for the
            same purpose
            use ctx.actions.args() for header maps
* other:    fix case in the github actions yml files

.github/workflows/tests.yml

@@ -34,7 +34,7 @@ jobs:
         run: find . -type f \( -name 'WORKSPACE' -o -name '*.bzl' -o -name '*.bazel' \) | xargs buildifier -lint=fix && git diff --exit-code
   check_docs:
     name: Check Docs
-    runs-on: macOS-latest
+    runs-on: macos-latest
     steps:
       - uses: actions/checkout@v1
       - name: Select Xcode 11.2
@@ -43,7 +43,7 @@ jobs:
         run: bazelisk run docs --nocheck_visibility && git diff --exit-code docs
   xcodeproj_tests:
     name: .xcodeproj Tests
-    runs-on: macOS-latest
+    runs-on: macos-latest
     steps:
       - uses: actions/checkout@v1
       - name: Select Xcode 11.2

.vscode/settings.json

@@ -3,4 +3,4 @@
         "bazel-*": true
     },
     "editor.formatOnSave": true,
-}
+}

docs/hmap_doc.md

@@ -5,7 +5,7 @@
 ## headermap
 
 <pre>
-headermap(<a href="#headermap-name">name</a>, <a href="#headermap-direct_hdr_providers">direct_hdr_providers</a>, <a href="#headermap-flatten_headers">flatten_headers</a>, <a href="#headermap-hdrs">hdrs</a>, <a href="#headermap-namespace">namespace</a>)
+headermap(<a href="#headermap-name">name</a>, <a href="#headermap-direct_hdr_providers">direct_hdr_providers</a>, <a href="#headermap-hdrs">hdrs</a>, <a href="#headermap-namespace">namespace</a>)
 </pre>
 
 Creates a binary headermap file from the given headers,
@@ -22,9 +22,8 @@ regardless of the package structure being used.
 | :-------------: | :-------------: | :-------------: | :-------------: | :-------------: |
 | name |  A unique name for this target.   | <a href="https://bazel.build/docs/build-ref.html#name">Name</a> | required |  |
 | direct_hdr_providers |  Targets whose direct headers should be added to the list of hdrs   | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | optional | [] |
-| flatten_headers |  Whether headers should be importable with the namespace as a prefix   | Boolean | required |  |
 | hdrs |  The list of headers included in the headermap   | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | required |  |
-| namespace |  The prefix to be used for header imports when flatten_headers is true   | String | required |  |
+| namespace |  The prefix to be used for header imports   | String | optional | "" |
 
 
 <a name="#HeaderMapInfo"></a>

rules/framework.bzl

@@ -209,24 +209,19 @@ def _apple_framework_packaging_impl(ctx):
     else:
         ctx.actions.write(framework_manifest, "# Empty framework\n")
 
-    # headermap
-    mappings_file = ctx.actions.declare_file(framework_name + "_framework.hmap.txt")
-    mappings = []
-    for header in header_in + private_header_in:
-        mappings.append(framework_name + "/" + header.basename + "|" + header.path)
-
-    # write mapping for hmap tool
-    ctx.actions.write(
-        content = "\n".join(mappings) + "\n",
-        output = mappings_file,
-    )
+    hmap_file = ctx.actions.declare_file(framework_name + "_framework_public_hmap.hmap")
+    args = ctx.actions.args()
+    args.add("--output", hmap_file.path)
+    args.add("--namespace", framework_name)
+    args.add_all(header_in)
+    args.add_all(private_header_in)
+    args.set_param_file_format("multiline")
+    args.use_param_file("@%s", use_always = True)
 
     # write headermap
-    hmap_file = ctx.actions.declare_file(framework_name + "_framework_public_hmap.hmap")
     ctx.actions.run(
-        inputs = [mappings_file],
         mnemonic = "HmapCreate",
-        arguments = [mappings_file.path, hmap_file.path],
+        arguments = [args],
         executable = ctx.executable._headermap_builder,
         outputs = [hmap_file],
     )

rules/hmap.bzl

@@ -7,36 +7,6 @@ HeaderMapInfo = provider(
     },
 )
 
-def _make_headermap_input_file(namespace, hdrs, flatten_headers):
-    """Create a header map input file.
-
-    This function creates a string representing the mappings from headers to their
-    namespaced include versions. The format is
-
-    virtual_header_path|real_header_path
-
-    Note the separator is a pipe character.
-
-    :param namespace: 'foo' in #include <foo/bar.h>
-    :param hdrs: list of header that need to be mapped
-    :param flatten_headers: boolean value that if set, will "flatten"
-           the virtual heders. What this means is that the headers
-           will also be added without the namespace or any paths
-           (basename).
-
-    :return: string with all the headers in the above mentioned
-    format. This can be saved to a file and read by the hmapbuild tool
-    included here to create a header map file.
-    """
-
-    entries = []
-    for hdr in hdrs:
-        namespaced_key = namespace + "/" + hdr.basename
-        entries.append("{}|{}".format(hdr.basename, hdr.path))
-        if flatten_headers:
-            entries.append("{}|{}".format(namespaced_key, hdr.path))
-    return "\n".join(entries) + "\n"
-
 def _make_headermap_impl(ctx):
     """Implementation of the headermap() rule.
 
@@ -50,33 +20,31 @@ def _make_headermap_impl(ctx):
     :return: provider with the info for this rule
     """
 
-    # Write a file for *this* headermap, this is a temporary file
-    input_f = ctx.actions.declare_file(ctx.label.name + "_input.txt")
-    all_hdrs = list(ctx.files.hdrs)
+    # Add a list of headermaps in text or hmap format
+    args = ctx.actions.args()
+    if ctx.attr.namespace:
+        args.add("--namespace", ctx.attr.namespace)
+
+    args.add("--output", ctx.outputs.headermap.path)
+
+    args.add_all(ctx.files.hdrs)
     for provider in ctx.attr.direct_hdr_providers:
         if apple_common.Objc in provider:
-            all_hdrs += provider[apple_common.Objc].direct_headers
+            args.add_all(provider[apple_common.Objc].direct_headers)
         elif CcInfo in provider:
-            all_hdrs += provider[CcInfo].compilation_context.direct_headers
+            args.add_all(provider[CcInfo].compilation_context.direct_headers)
         else:
             fail("direct_hdr_provider %s must contain either 'CcInfo' or 'objc' provider" % provider)
 
-    out = _make_headermap_input_file(ctx.attr.namespace, all_hdrs, ctx.attr.flatten_headers)
-    ctx.actions.write(
-        content = out,
-        output = input_f,
-    )
-
-    # Add a list of headermaps in text or hmap format
-    inputs = [input_f]
-    args = [input_f.path, ctx.outputs.headermap.path]
+    args.set_param_file_format(format = "multiline")
+    args.use_param_file("@%s", use_always = True)
     ctx.actions.run(
-        inputs = inputs,
         mnemonic = "HmapCreate",
-        arguments = args,
+        arguments = [args],
         executable = ctx.executable._headermap_builder,
         outputs = [ctx.outputs.headermap],
     )
+
     objc_provider = apple_common.new_objc_provider(
         header = depset([ctx.outputs.headermap]),
     )
@@ -98,8 +66,8 @@ headermap = rule(
     output_to_genfiles = True,
     attrs = {
         "namespace": attr.string(
-            mandatory = True,
-            doc = "The prefix to be used for header imports when flatten_headers is true",
+            mandatory = False,
+            doc = "The prefix to be used for header imports",
         ),
         "hdrs": attr.label_list(
             mandatory = True,
@@ -110,10 +78,6 @@ headermap = rule(
             mandatory = False,
             doc = "Targets whose direct headers should be added to the list of hdrs",
         ),
-        "flatten_headers": attr.bool(
-            mandatory = True,
-            doc = "Whether headers should be importable with the namespace as a prefix",
-        ),
         "_headermap_builder": attr.label(
             executable = True,
             cfg = "host",

rules/hmap/BUILD.bazel

@@ -1,4 +1,4 @@
-load("@rules_cc//cc:defs.bzl", "cc_binary", "cc_test")
+load("@rules_cc//cc:defs.bzl", "cc_binary", "cc_library", "cc_test")
 
 HMAP_COPTS = [
     "-DHASH_FUNCTION=HASH_MUR",
@@ -18,6 +18,21 @@ cc_binary(
     ],
     copts = HMAP_COPTS,
     visibility = HMAP_VISIBILITY,
+    deps = [
+        ":lines",
+    ],
+)
+
+cc_library(
+    name = "lines",
+    srcs = [
+        "lines.c",
+    ],
+    hdrs = [
+        "lines.h",
+    ],
+    copts = ["-Wno-parentheses"],
+    visibility = HMAP_VISIBILITY,
 )
 
 cc_binary(