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

llvm-svn: 200595

1 files changed, 82 insertions, 0 deletions

diff --git a/llvm/unittests/LineEditor/LineEditor.cpp b/llvm/unittests/LineEditor/LineEditor.cpp
new file mode 100644
index 0000000..cb115bd
--- /dev/null
+++ b/llvm/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);
+}