Introduce line editor library.

This library will be used by clang-query. I can imagine LLDB becoming another
client of this library, so I think LLVM is a sensible place for it to live.
It wraps libedit, and adds tab completion support.

The code is loosely based on the line editor bits in LLDB, with a few
improvements:

 - Polymorphism for retrieving the list of tab completions, based on
   the concept pattern from the new pass manager.

 - Tab completion doesn't corrupt terminal output if the input covers
   multiple lines. Unfortunately this can only be done in a truly horrible
   way, as far as I can tell. But since the alternative is to implement our
   own line editor (which I don't think LLVM should be in the business of
   doing, at least for now) I think it may be acceptable.

 - Includes a fallback for the case where the user doesn't have libedit
   installed.

Note that this uses C stdio, mainly because libedit also uses C stdio.

Differential Revision: http://llvm-reviews.chandlerc.com/D2200

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200595 91177308-0d34-0410-b5e6-96231b3b80d8

unittests/CMakeLists.txt

@@ -12,6 +12,7 @@ add_subdirectory(CodeGen)
 add_subdirectory(DebugInfo)
 add_subdirectory(ExecutionEngine)
 add_subdirectory(IR)
+add_subdirectory(LineEditor)
 add_subdirectory(MC)
 add_subdirectory(Object)
 add_subdirectory(Option)

unittests/LineEditor/CMakeLists.txt

@@ -0,0 +1,7 @@
+set(LLVM_LINK_COMPONENTS
+  LineEditor
+  )
+
+add_llvm_unittest(LineEditorTests
+  LineEditor.cpp
+  )

unittests/LineEditor/LineEditor.cpp

@@ -0,0 +1,82 @@
+//===-- LineEditor.cpp ----------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/LineEditor/LineEditor.h"
+#include "llvm/Support/Path.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+class LineEditorTest : public testing::Test {
+public:
+  SmallString<64> HistPath;
+  LineEditor *LE;
+
+  LineEditorTest() {
+    init();
+  }
+
+  void init() {
+    sys::fs::createTemporaryFile("temp", "history", HistPath);
+    ASSERT_FALSE(HistPath.empty());
+    LE = new LineEditor("test", HistPath);
+  }
+
+  ~LineEditorTest() {
+    delete LE;
+    sys::fs::remove(HistPath.str());
+  }
+};
+
+TEST_F(LineEditorTest, HistorySaveLoad) {
+  LE->saveHistory();
+  LE->loadHistory();
+}
+
+struct TestListCompleter {
+  std::vector<LineEditor::Completion> Completions;
+
+  TestListCompleter(const std::vector<LineEditor::Completion> &Completions)
+      : Completions(Completions) {}
+
+  std::vector<LineEditor::Completion> operator()(StringRef Buffer,
+                                                 size_t Pos) const {
+    EXPECT_TRUE(Buffer.empty());
+    EXPECT_EQ(0u, Pos);
+    return Completions;
+  }
+};
+
+TEST_F(LineEditorTest, ListCompleters) {
+  std::vector<LineEditor::Completion> Comps;
+
+  Comps.push_back(LineEditor::Completion("foo", "int foo()"));
+  LE->setListCompleter(TestListCompleter(Comps));
+  LineEditor::CompletionAction CA = LE->getCompletionAction("", 0);
+  EXPECT_EQ(LineEditor::CompletionAction::AK_Insert, CA.Kind);
+  EXPECT_EQ("foo", CA.Text);
+
+  Comps.push_back(LineEditor::Completion("bar", "int bar()"));
+  LE->setListCompleter(TestListCompleter(Comps));
+  CA = LE->getCompletionAction("", 0);
+  EXPECT_EQ(LineEditor::CompletionAction::AK_ShowCompletions, CA.Kind);
+  ASSERT_EQ(2u, CA.Completions.size());
+  ASSERT_EQ("int foo()", CA.Completions[0]);
+  ASSERT_EQ("int bar()", CA.Completions[1]);
+
+  Comps.clear();
+  Comps.push_back(LineEditor::Completion("fee", "int fee()"));
+  Comps.push_back(LineEditor::Completion("fi", "int fi()"));
+  Comps.push_back(LineEditor::Completion("foe", "int foe()"));
+  Comps.push_back(LineEditor::Completion("fum", "int fum()"));
+  LE->setListCompleter(TestListCompleter(Comps));
+  CA = LE->getCompletionAction("", 0);
+  EXPECT_EQ(LineEditor::CompletionAction::AK_Insert, CA.Kind);
+  EXPECT_EQ("f", CA.Text);
+}

unittests/LineEditor/Makefile

@@ -0,0 +1,15 @@
+##===- unittests/LineEditor/Makefile -----------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../..
+TESTNAME = LineEditor
+LINK_COMPONENTS := lineeditor
+
+include $(LEVEL)/Makefile.config
+include $(LLVM_SRC_ROOT)/unittests/Makefile.unittest

unittests/Makefile

@@ -9,8 +9,8 @@
 
 LEVEL = ..
 
-PARALLEL_DIRS = ADT Analysis Bitcode CodeGen DebugInfo \
-		ExecutionEngine IR Linker MC Object Option Support Transforms
+PARALLEL_DIRS = ADT Analysis Bitcode CodeGen DebugInfo ExecutionEngine IR \
+		LineEditor Linker MC Object Option Support Transforms
 
 include $(LEVEL)/Makefile.config
 include $(LLVM_SRC_ROOT)/unittests/Makefile.unittest