[Support][Program] Add findProgramByName(Name, OptionalPaths)

[oota-llvm.git] / lib / Support / Unix / Program.inc

diff --git a/lib/Support/Unix/Program.inc b/lib/Support/Unix/Program.inc
index 7bf6eceda73389b35f75037abc72aa787e9e3527..4124340dfedcddabce0fa93bff5d2b4aac1e2586 100644 (file)
--- a/lib/Support/Unix/Program.inc
+++ b/lib/Support/Unix/Program.inc
@@ -17,6 +17,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "Unix.h"
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/raw_ostream.h"
@@ -100,6 +101,33 @@ sys::FindProgramByName(const std::string& progName) {
   return "";
 }
 
+ErrorOr<std::string> sys::findProgramByName(StringRef Name,
+                                            ArrayRef<StringRef> Paths) {
+  assert(!Name.empty() && "Must have a name!");
+  // Use the given path verbatim if it contains any slashes; this matches
+  // the behavior of sh(1) and friends.
+  if (Name.find('/') != StringRef::npos)
+    return std::string(Name);
+
+  if (Paths.empty()) {
+    SmallVector<StringRef, 16> SearchPaths;
+    SplitString(std::getenv("PATH"), SearchPaths, ":");
+    return findProgramByName(Name, SearchPaths);
+  }
+
+  for (auto Path : Paths) {
+    if (Path.empty())
+      continue;
+
+    // Check to see if this first directory contains the executable...
+    SmallString<128> FilePath(Path);
+    sys::path::append(FilePath, Name);
+    if (sys::fs::can_execute(FilePath.c_str()))
+      return std::string(FilePath.str()); // Found the executable!
+  }
+  return std::errc::no_such_file_or_directory;
+}
+
 static bool RedirectIO(const StringRef *Path, int FD, std::string* ErrMsg) {
   if (!Path) // Noop
     return false;