[FileSpec] Re-implmenet removeLastPathComponent

When reading DBGSourcePathRemapping from a dSYM, we remove the last two
path components to make the source lookup more general. However, when
dealing with a relative path that has less than 2 components, we ended
up with an invalid (empty) FileSpec.

This patch changes the behavior of removeLastPathComponent to remove the
last path component, if possible. It does this by checking whether a
parent path exists, and if so using that as the new path. We rely
entirely on LLVM's path implementation to do the heavy lifting.

We now also return a boolean which indicates whether the operator was
successful or not.

Differential revision: https://reviews.llvm.org/D47495

rdar://37791687

llvm-svn: 333540

1 files changed, 41 insertions, 0 deletions

diff --git a/lldb/unittests/Utility/FileSpecTest.cpp b/lldb/unittests/Utility/FileSpecTest.cpp
index 03c9793fc15..2e02579797a 100644
--- a/lldb/unittests/Utility/FileSpecTest.cpp
+++ b/lldb/unittests/Utility/FileSpecTest.cpp
@@ -320,3 +320,44 @@ TEST(FileSpecTest, IsRelative) {
   }
 }
 
+TEST(FileSpecTest, RemoveLastPathComponent) {
+  FileSpec fs_posix("/foo/bar/baz", false, FileSpec::Style::posix);
+  EXPECT_STREQ("/foo/bar/baz", fs_posix.GetCString());
+  EXPECT_TRUE(fs_posix.RemoveLastPathComponent());
+  EXPECT_STREQ("/foo/bar", fs_posix.GetCString());
+  EXPECT_TRUE(fs_posix.RemoveLastPathComponent());
+  EXPECT_STREQ("/foo", fs_posix.GetCString());
+  EXPECT_TRUE(fs_posix.RemoveLastPathComponent());
+  EXPECT_STREQ("/", fs_posix.GetCString());
+  EXPECT_FALSE(fs_posix.RemoveLastPathComponent());
+  EXPECT_STREQ("/", fs_posix.GetCString());
+
+  FileSpec fs_posix_relative("./foo/bar/baz", false, FileSpec::Style::posix);
+  EXPECT_STREQ("foo/bar/baz", fs_posix_relative.GetCString());
+  EXPECT_TRUE(fs_posix_relative.RemoveLastPathComponent());
+  EXPECT_STREQ("foo/bar", fs_posix_relative.GetCString());
+  EXPECT_TRUE(fs_posix_relative.RemoveLastPathComponent());
+  EXPECT_STREQ("foo", fs_posix_relative.GetCString());
+  EXPECT_FALSE(fs_posix_relative.RemoveLastPathComponent());
+  EXPECT_STREQ("foo", fs_posix_relative.GetCString());
+
+  FileSpec fs_posix_relative2("./", false, FileSpec::Style::posix);
+  EXPECT_STREQ(".", fs_posix_relative2.GetCString());
+  EXPECT_FALSE(fs_posix_relative2.RemoveLastPathComponent());
+  EXPECT_STREQ(".", fs_posix_relative2.GetCString());
+  EXPECT_FALSE(fs_posix_relative.RemoveLastPathComponent());
+  EXPECT_STREQ(".", fs_posix_relative2.GetCString());
+
+  FileSpec fs_windows("C:\\foo\\bar\\baz", false, FileSpec::Style::windows);
+  EXPECT_STREQ("C:\\foo\\bar\\baz", fs_windows.GetCString());
+  EXPECT_TRUE(fs_windows.RemoveLastPathComponent());
+  EXPECT_STREQ("C:\\foo\\bar", fs_windows.GetCString());
+  EXPECT_TRUE(fs_windows.RemoveLastPathComponent());
+  EXPECT_STREQ("C:\\foo", fs_windows.GetCString());
+  EXPECT_TRUE(fs_windows.RemoveLastPathComponent());
+  EXPECT_STREQ("C:\\", fs_windows.GetCString());
+  EXPECT_TRUE(fs_windows.RemoveLastPathComponent());
+  EXPECT_STREQ("C:", fs_windows.GetCString());
+  EXPECT_FALSE(fs_windows.RemoveLastPathComponent());
+  EXPECT_STREQ("C:", fs_windows.GetCString());
+}