[lld-macho] Fall back to raw path if we don't find anything under syslibroot

[int3]

Summary

This matches ld64's behavior

[smeenai]

Can you also add a test for the standard paths not being searched without a syslibroot prefix? As in, if you pass -syslibroot and there's e.g. no /usr/lib under it, we shouldn't add the standard /usr/lib to the search path.

[int3]

lld/test/MachO/syslibroot.test

3–6

As in, if you pass -syslibroot and there's e.g. no /usr/lib under it, we shouldn't add the standard /usr/lib to the search path.

This test covers that already :)

[smeenai]

lld/test/MachO/syslibroot.test

3–6

Indeed it does! Ignore me :)

lld/MachO/Driver.cpp

static TargetInfo *createTargetInfo(opt::InputArgList &args) {
   case llvm::MachO::AK_x86_64:
   case llvm::MachO::AK_x86_64h:
     return createX86_64TargetInfo();
   default:
     fatal("missing or unsupported -arch " + arch);
   }
 }
 
-static bool isDirectory(StringRef option, StringRef path) {
+static bool warnIfNotDirectory(StringRef option, StringRef path) {
   if (!fs::exists(path)) {
     warn("directory not found for option -" + option + path);
     return false;
   } else if (!fs::is_directory(path)) {
     warn("option -" + option + path + " references a non-directory path");
     return false;
   }
   return true;
 }
 
 static void getSearchPaths(std::vector<StringRef> &paths, unsigned optionCode,
                            opt::InputArgList &args,
                            const std::vector<StringRef> &roots,
                            const SmallVector<StringRef, 2> &systemPaths) {
-  StringRef optionLetter{(optionCode == OPT_F ? "F" : "L")};
-  for (auto const &path : args::getStrings(args, optionCode)) {
+  StringRef optionLetter{optionCode == OPT_F ? "F" : "L"};
+  for (StringRef path : args::getStrings(args, optionCode)) {
     // NOTE: only absolute paths are re-rooted to syslibroot(s)
-    if (llvm::sys::path::is_absolute(path, llvm::sys::path::Style::posix)) {
+    bool found = false;
+    if (path::is_absolute(path, path::Style::posix)) {
       for (StringRef root : roots) {
         SmallString<261> buffer(root);
-        llvm::sys::path::append(buffer, path);
+        path::append(buffer, path);
         // Do not warn about paths that are computed via the syslib roots
-        if (llvm::sys::fs::is_directory(buffer))
+        if (fs::is_directory(buffer)) {
           paths.push_back(saver.save(buffer.str()));
+          found = true;
+        }
       }
-    } else {
-      if (isDirectory(optionLetter, path))
-        paths.push_back(path);
     }
+    if (!found && warnIfNotDirectory(optionLetter, path))
+      paths.push_back(path);
   }
 
   // `-Z` suppresses the standard "system" search paths.
   if (args.hasArg(OPT_Z))
     return;
 
   for (auto const &path : systemPaths) {
     for (auto root : roots) {
       SmallString<261> buffer(root);
-      llvm::sys::path::append(buffer, path);
-      if (isDirectory(optionLetter, buffer))
+      path::append(buffer, path);
+      if (warnIfNotDirectory(optionLetter, buffer))
         paths.push_back(saver.save(buffer.str()));
     }
   }
 }
 
 static void getLibrarySearchPaths(opt::InputArgList &args,
                                   const std::vector<StringRef> &roots,
                                   std::vector<StringRef> &paths) {

lld/test/MachO/syslibroot.test

 # Ensure that a nonexistent path is ignored with a syslibroot
 
 RUN: lld -flavor darwinnew -v -syslibroot /var/empty | FileCheck %s -check-prefix CHECK-NONEXISTENT-SYSLIBROOT
 
 CHECK-NONEXISTENT-SYSLIBROOT: Library search paths:
 CHECK-NONEXISTENT-SYSLIBROOT-NEXT: Framework search paths:
 
 RUN: mkdir -p %t/usr/lib
 RUN: lld -flavor darwinnew -v -syslibroot %t | FileCheck %s -check-prefix CHECK-SYSLIBROOT -DROOT=%t
 
 CHECK-SYSLIBROOT: Library search paths:
 CHECK-SYSLIBROOT-NEXT: [[ROOT]]/usr/lib
 
 RUN: mkdir -p %t/Library/libxml2-development
 RUN: lld -flavor darwinnew -v -syslibroot %t -L /Library/libxml2-development | FileCheck %s -check-prefix CHECK-ABSOLUTE-PATH-REROOTED -DROOT=%t
 
 CHECK-ABSOLUTE-PATH-REROOTED: Library search paths:
 CHECK-ABSOLUTE-PATH-REROOTED: [[ROOT]]/Library/libxml2-development
 CHECK-ABSOLUTE-PATH-REROOTED: [[ROOT]]/usr/lib
 
+RUN: lld -flavor darwinnew -v -Z -syslibroot %t -L %t/Library/libxml2-development | FileCheck %s -check-prefix CHECK-PATH-WITHOUT-REROOT -DPATH=%t/Library/libxml2-development
+CHECK-PATH-WITHOUT-REROOT:      Library search paths:
+CHECK-PATH-WITHOUT-REROOT-NEXT: [[PATH]]
+
 # NOTE: the match here is fuzzy because the default search paths exist on Linux
 # and macOS, but not on Windows (that is we ignore `/var/empty`).  This allows
 # us to run the test uniformly on all the platforms.
 RUN: lld -flavor darwinnew -v -syslibroot /var/empty -syslibroot / 2>&1 | FileCheck %s -check-prefix CHECK-SYSLIBROOT-IGNORED
 
 CHECK-SYSLIBROOT-IGNORED: /usr/lib
 CHECK-SYSLIBROOT-IGNORED: /usr/local/lib