Revert "[clang][Darwin] Remove legacy framework search path logic in the frontend (#75841)"

This reverts commit 61999b1.

See comments on #75841. This
was intended to be NFC but actually isn't.

Author: aeubanks

clang/lib/Driver/ToolChains/Darwin.cpp

@@ -758,14 +758,9 @@ void darwin::Linker::ConstructJob(Compilation &C, const JobAction &JA,
     }
   }
 
-  // Add framework include paths and library search paths.
-  // There are two flavors:
-  // 1. The "non-standard" paths, e.g. for DriverKit:
-  //      -L<sysroot>/System/DriverKit/usr/lib
-  //      -F<sysroot>/System/DriverKit/System/Library/Frameworks
-  // 2. The "standard" paths, e.g. for macOS and iOS:
-  //      -F<sysroot>/System/Library/Frameworks
-  //      -F<sysroot>/Library/Frameworks
+  // Add non-standard, platform-specific search paths, e.g., for DriverKit:
+  //  -L<sysroot>/System/DriverKit/usr/lib
+  //  -F<sysroot>/System/DriverKit/System/Library/Framework
   {
     bool NonStandardSearchPath = false;
     const auto &Triple = getToolChain().getTriple();
@@ -776,22 +771,18 @@ void darwin::Linker::ConstructJob(Compilation &C, const JobAction &JA,
           (Version.getMajor() == 605 && Version.getMinor().value_or(0) < 1);
     }
 
-    if (auto *Sysroot = Args.getLastArg(options::OPT_isysroot)) {
-      auto AddSearchPath = [&](StringRef Flag, StringRef SearchPath) {
-        SmallString<128> P(Sysroot->getValue());
-        AppendPlatformPrefix(P, Triple);
-        llvm::sys::path::append(P, SearchPath);
-        if (getToolChain().getVFS().exists(P)) {
-          CmdArgs.push_back(Args.MakeArgString(Flag + P));
-        }
-      };
-
-      if (NonStandardSearchPath) {
+    if (NonStandardSearchPath) {
+      if (auto *Sysroot = Args.getLastArg(options::OPT_isysroot)) {
+        auto AddSearchPath = [&](StringRef Flag, StringRef SearchPath) {
+          SmallString<128> P(Sysroot->getValue());
+          AppendPlatformPrefix(P, Triple);
+          llvm::sys::path::append(P, SearchPath);
+          if (getToolChain().getVFS().exists(P)) {
+            CmdArgs.push_back(Args.MakeArgString(Flag + P));
+          }
+        };
         AddSearchPath("-L", "/usr/lib");
         AddSearchPath("-F", "/System/Library/Frameworks");
-      } else if (!Triple.isDriverKit()) {
-        AddSearchPath("-F", "/System/Library/Frameworks");
-        AddSearchPath("-F", "/Library/Frameworks");
       }
     }
   }

clang/lib/Lex/InitHeaderSearch.cpp

@@ -324,9 +324,6 @@ bool InitHeaderSearch::ShouldAddDefaultIncludePaths(
     break;
   }
 
-  if (triple.isOSDarwin())
-    return false;
-
   return true; // Everything else uses AddDefaultIncludePaths().
 }
 
@@ -341,6 +338,21 @@ void InitHeaderSearch::AddDefaultIncludePaths(
   if (!ShouldAddDefaultIncludePaths(triple))
     return;
 
+  // NOTE: some additional header search logic is handled in the driver for
+  // Darwin.
+  if (triple.isOSDarwin()) {
+    if (HSOpts.UseStandardSystemIncludes) {
+      // Add the default framework include paths on Darwin.
+      if (triple.isDriverKit()) {
+        AddPath("/System/DriverKit/System/Library/Frameworks", System, true);
+      } else {
+        AddPath("/System/Library/Frameworks", System, true);
+        AddPath("/Library/Frameworks", System, true);
+      }
+    }
+    return;
+  }
+
   if (Lang.CPlusPlus && !Lang.AsmPreprocessor &&
       HSOpts.UseStandardCXXIncludes && HSOpts.UseStandardSystemIncludes) {
     if (HSOpts.UseLibcxx) {

clang/test/Driver/driverkit-path.c

@@ -31,3 +31,4 @@ int main() { return 0; }
 // INC:       [[PATH]]/System/DriverKit/usr/local/include
 // INC:       /lib{{(64)?}}/clang/{{[^/ ]+}}/include
 // INC:       [[PATH]]/System/DriverKit/usr/include
+// INC:       [[PATH]]/System/DriverKit/System/Library/Frameworks (framework directory)

clang/test/Preprocessor/cuda-macos-includes.cu

@@ -0,0 +1,13 @@
+// RUN: %clang -cc1 -fcuda-is-device -isysroot /var/empty \
+// RUN:   -triple nvptx-nvidia-cuda -aux-triple i386-apple-macosx \
+// RUN:   -E -fcuda-is-device -v -o /dev/null -x cuda %s 2>&1 | FileCheck %s
+
+// RUN: %clang -cc1 -isysroot /var/empty \
+// RUN:   -triple i386-apple-macosx -aux-triple nvptx-nvidia-cuda \
+// RUN:   -E -fcuda-is-device -v -o /dev/null -x cuda %s 2>&1 | FileCheck %s
+
+// Check that when we do CUDA host and device compiles on MacOS, we check for
+// includes in /System/Library/Frameworks and /Library/Frameworks.
+
+// CHECK-DAG: ignoring nonexistent directory "/var/empty/System/Library/Frameworks"
+// CHECK-DAG: ignoring nonexistent directory "/var/empty/Library/Frameworks"