Add support for direct CASAPI access from libToolchainCASPlugin.dylib

Package.swift

@@ -46,13 +46,18 @@ let package = Package(
     .target(name: "CSwiftScan",
             exclude: [ "CMakeLists.txt" ]),
 
+    /// C modules wrapper for ToolchainCASPlugin.
+    .target(name: "CToolchainCASPlugin",
+            exclude: [ "CMakeLists.txt" ]),
+
     /// The driver library.
     .target(
       name: "SwiftDriver",
       dependencies: [
         "SwiftOptions",
         .product(name: "SwiftToolsSupport-auto", package: "swift-tools-support-core"),
         "CSwiftScan",
+        "CToolchainCASPlugin",
         .product(name: "Yams", package: "yams"),
       ],
       exclude: ["CMakeLists.txt"]),

Sources/CMakeLists.txt

@@ -7,6 +7,7 @@
 # See http://swift.org/CONTRIBUTORS.txt for Swift project authors
 
 add_subdirectory(CSwiftScan)
+add_subdirectory(CToolchainCASPlugin)
 add_subdirectory(SwiftOptions)
 add_subdirectory(SwiftDriver)
 add_subdirectory(SwiftDriverExecution)

Sources/CSwiftScan/include/swiftscan_header.h

@@ -275,6 +275,11 @@ typedef struct {
 
   //=== Scanner CAS Operations ----------------------------------------------===//
   swiftscan_cas_t (*swiftscan_cas_create)(const char *path);
+  swiftscan_cas_t (*swiftscan_cas_create_from_plugin)(const char *plugin_path,
+                                                      const char *ondisk_path,
+                                                      int argc,
+                                                      const char **keys,
+                                                      const char **values);
   void (*swiftscan_cas_dispose)(swiftscan_cas_t cas);
   swiftscan_string_ref_t (*swiftscan_cas_store)(swiftscan_cas_t cas,
                                                 uint8_t *data, unsigned size);

Sources/CToolchainCASPlugin/CMakeLists.txt

@@ -0,0 +1,10 @@
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See http://swift.org/LICENSE.txt for license information
+# See http://swift.org/CONTRIBUTORS.txt for Swift project authors
+
+add_library(CToolchainCASPlugin STATIC
+  ToolchainCASPluginImpl.c)

Sources/CToolchainCASPlugin/ToolchainCASPluginImpl.c

@@ -0,0 +1,3 @@
+// This file is here to prevent the package manager from warning about a
+// target with no sources.
+#include "include/ToolchainCASPlugin_CAPI.h"