[libllbuild] Add support for getting command descriptions.

Author: ddunbar

examples/c-api/buildsystem/main.c

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
+// Copyright (c) 2015 - 2016 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
@@ -34,9 +34,12 @@ static const char* basename(const char* path) {
 
 static void command_started(void* context,
                             llb_buildsystem_command_t* command) {
+  char* description = llb_buildsystem_command_get_description(command);
   llb_data_t name;
   llb_buildsystem_command_get_name(command, &name);
-  printf("%s: %.*s\n", __FUNCTION__, (int)name.length, name.data);
+  printf("%s: %.*s -- %s\n", __FUNCTION__, (int)name.length, name.data,
+         description);
+  free(description);
 }
 
 static void command_finished(void* context,

products/libllbuild/BuildSystem-C-API.cpp

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
+// Copyright (c) 2015 - 2016 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
@@ -17,6 +17,7 @@
 #include "llbuild/BuildSystem/BuildSystemFrontend.h"
 #include "llbuild/Core/BuildEngine.h"
 
+#include "llvm/ADT/SmallString.h"
 #include "llvm/Support/SourceMgr.h"
 
 #include <cassert>
@@ -158,3 +159,21 @@ void llb_buildsystem_command_get_name(llb_buildsystem_command_t* command_p,
   key_out->length = name.size();
   key_out->data = (const uint8_t*) name.data();
 }
+
+char* llb_buildsystem_command_get_description(
+    llb_buildsystem_command_t* command_p) {
+  auto command = (Command*) command_p;
+
+  SmallString<256> result;
+  command->getShortDescription(result);
+  return strdup(result.c_str());
+}
+
+char* llb_buildsystem_command_get_verbose_description(
+    llb_buildsystem_command_t* command_p) {
+  auto command = (Command*) command_p;
+
+  SmallString<256> result;
+  command->getVerboseDescription(result);
+  return strdup(result.c_str());
+}

products/libllbuild/public-api/llbuild/buildsystem.h

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
+// Copyright (c) 2015 - 2016 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
@@ -99,6 +99,25 @@ LLBUILD_EXPORT void
 llb_buildsystem_command_get_name(llb_buildsystem_command_t* command,
                                  llb_data_t* key_out);
 
+/// Get the description for the given command.
+///
+/// \returns The command description, as a new C string. The client is
+/// resonpsible for calling \see free() on the result.
+//
+// FIXME: This API most likely doesn't belong.
+LLBUILD_EXPORT char*
+llb_buildsystem_command_get_description(llb_buildsystem_command_t* command);
+
+/// Get the verbose description for the given command.
+///
+/// \returns The verbose command description, as a new C string. The client is
+/// resonpsible for calling \see free() on the result.
+//
+// FIXME: This API most likely doesn't belong.
+LLBUILD_EXPORT char*
+llb_buildsystem_command_get_verbose_description(
+    llb_buildsystem_command_t* command);
+
 /// @}
 
 #endif

tests/Examples/buildsystem-capi.llbuild

@@ -1,10 +1,10 @@
 # Check that the BuildSystem C API example builds and runs correctly.
 #
-# RUN: cc -o %t.exe %{srcroot}/examples/c-api/buildsystem/main.c -I %{srcroot}/products/libllbuild/public-api -lllbuild -L %{llbuild-lib-dir}
+# RUN: cc -o %t.exe %{srcroot}/examples/c-api/buildsystem/main.c -I %{srcroot}/products/libllbuild/public-api -lllbuild -L %{llbuild-lib-dir} -Werror
 # RUN: env LD_LIBRARY_PATH=%{llbuild-lib-dir} %t.exe %s > %t.out
 # RUN: %{FileCheck} %s --input-file %t.out
 #
-# CHECK: command_started: <hello>
+# CHECK: command_started: <hello> -- HELLO
 # CHECK: command_finished: <hello>
 # CHECK: command_started: <all>
 # CHECK: command_finished: <all>
@@ -26,3 +26,4 @@ commands:
     tool: shell
     args: ["echo", "Hello, world!"]
     outputs: ["<hello>"]
+    description: HELLO