Add llvm::sys::path::canonical(), which provides the canonicalized

name of a path, after resolving symbolic links and eliminating excess
path elements such as "foo/../" and "./".

This routine still needs a Windows implementation, but I don't have a
Windows machine available. Help? Please?

llvm-svn: 125228

1 files changed, 30 insertions, 0 deletions

diff --git a/llvm/lib/Support/Unix/PathV2.inc b/llvm/lib/Support/Unix/PathV2.inc
index 03ff28367e4..7fa838b16b7 100644
--- a/llvm/lib/Support/Unix/PathV2.inc
+++ b/llvm/lib/Support/Unix/PathV2.inc
@@ -503,5 +503,35 @@ error_code get_magic(const Twine &path, uint32_t len,
 }
 
 } // end namespace fs
+
+namespace path {
+
+void canonical(const char *path, SmallVectorImpl<char> &buffer) {
+  buffer.resize(PATH_MAX);
+  char *result = realpath(path, buffer.data());
+  if (result) {
+    buffer.resize(strlen(result));
+    return;
+  }
+
+  // A common extension is to support memory allocation of the result when
+  // passing NULL as the second argument.
+  result = realpath(path, 0);
+  if (result) {
+    size_t length = strlen(result);
+    buffer.resize(length);
+    memcpy(buffer.data(), result, length);
+    free(result);
+    return buffer.data();
+  }
+
+  size_t length = strlen(path);
+  buffer.resize(length);
+  memcpy(buffer.data(), path, length);
+  return path;
+}
+
+} // end namespace path
+
 } // end namespace sys
 } // end namespace llvm