[FileSystem] Add expand_tilde function

In D54435 there was some discussion about the expand_tilde flag for
real_path that I wanted to expose through the VFS. The consensus is that
these two things should be separate functions. Since we already have the
code for this I went ahead and added a function expand_tilde that does
just that.

Differential revision: https://reviews.llvm.org/D54448

llvm-svn: 346776

1 files changed, 21 insertions, 0 deletions

diff --git a/llvm/unittests/Support/Path.cpp b/llvm/unittests/Support/Path.cpp
index c18eb929e91..854b69b6825 100644
--- a/llvm/unittests/Support/Path.cpp
+++ b/llvm/unittests/Support/Path.cpp
@@ -516,6 +516,8 @@ TEST_F(FileSystemTest, RealPath) {
   EXPECT_EQ(Expected, Actual);
 
   SmallString<64> HomeDir;
+
+  // This can fail if $HOME is not set and getpwuid fails.
   bool Result = llvm::sys::path::home_directory(HomeDir);
   if (Result) {
     ASSERT_NO_ERROR(fs::real_path(HomeDir, Expected));
@@ -528,6 +530,25 @@ TEST_F(FileSystemTest, RealPath) {
   ASSERT_NO_ERROR(fs::remove_directories(Twine(TestDirectory) + "/test1"));
 }
 
+TEST_F(FileSystemTest, ExpandTilde) {
+  SmallString<64> Expected;
+  SmallString<64> Actual;
+  SmallString<64> HomeDir;
+
+  // This can fail if $HOME is not set and getpwuid fails.
+  bool Result = llvm::sys::path::home_directory(HomeDir);
+  if (Result) {
+    fs::expand_tilde(HomeDir, Expected);
+
+    fs::expand_tilde("~", Actual);
+    EXPECT_EQ(Expected, Actual);
+
+    path::append(Expected, "foo");
+    fs::expand_tilde("~/foo", Actual);
+    EXPECT_EQ(Expected, Actual);
+  }
+}
+
 #ifdef LLVM_ON_UNIX
 TEST_F(FileSystemTest, RealPathNoReadPerm) {
   SmallString<64> Expanded;