2 files changed, 34 insertions, 6 deletions

diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index 68d5214fdfd..4b8182e54b2 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -1085,6 +1085,18 @@ DerivedArgList *Darwin::TranslateArgs(const DerivedArgList &Args,
     }
   }
 
+  auto Arch = tools::darwin::getArchTypeForMachOArchName(BoundArch);
+  if ((Arch == llvm::Triple::arm || Arch == llvm::Triple::thumb)) {
+    if (Args.hasFlag(options::OPT_fomit_frame_pointer,
+                     options::OPT_fno_omit_frame_pointer, false))
+      getDriver().Diag(clang::diag::warn_drv_unsupported_opt_for_target)
+          << "-fomit-frame-pointer" << BoundArch;
+    if (Args.hasFlag(options::OPT_momit_leaf_frame_pointer,
+                     options::OPT_mno_omit_leaf_frame_pointer, false))
+      getDriver().Diag(clang::diag::warn_drv_unsupported_opt_for_target)
+          << "-momit-leaf-frame-pointer" << BoundArch;
+  }
+
   return DAL;
 }
 
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 747f3ea57a1..895104e1c45 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -3232,8 +3232,20 @@ static bool areOptimizationsEnabled(const ArgList &Args) {
   return false;
 }
 
-static bool shouldUseFramePointerForTarget(const ArgList &Args,
-                                           const llvm::Triple &Triple) {
+static bool mustUseFramePointerForTarget(const llvm::Triple &Triple) {
+  switch (Triple.getArch()){
+  default:
+    return false;
+  case llvm::Triple::arm:
+  case llvm::Triple::thumb:
+    // ARM Darwin targets require a frame pointer to be always present to aid
+    // offline debugging via backtraces.
+    return Triple.isOSDarwin();
+  }
+}
+
+static bool useFramePointerForTargetByDefault(const ArgList &Args,
+                                              const llvm::Triple &Triple) {
   switch (Triple.getArch()) {
   case llvm::Triple::xcore:
   case llvm::Triple::wasm32:
@@ -3285,25 +3297,29 @@ static bool shouldUseFramePointer(const ArgList &Args,
                                   const llvm::Triple &Triple) {
   if (Arg *A = Args.getLastArg(options::OPT_fno_omit_frame_pointer,
                                options::OPT_fomit_frame_pointer))
-    return A->getOption().matches(options::OPT_fno_omit_frame_pointer);
+    return A->getOption().matches(options::OPT_fno_omit_frame_pointer) ||
+           mustUseFramePointerForTarget(Triple);
+
   if (Args.hasArg(options::OPT_pg))
     return true;
 
-  return shouldUseFramePointerForTarget(Args, Triple);
+  return useFramePointerForTargetByDefault(Args, Triple);
 }
 
 static bool shouldUseLeafFramePointer(const ArgList &Args,
                                       const llvm::Triple &Triple) {
   if (Arg *A = Args.getLastArg(options::OPT_mno_omit_leaf_frame_pointer,
                                options::OPT_momit_leaf_frame_pointer))
-    return A->getOption().matches(options::OPT_mno_omit_leaf_frame_pointer);
+    return A->getOption().matches(options::OPT_mno_omit_leaf_frame_pointer) ||
+           mustUseFramePointerForTarget(Triple);
+
   if (Args.hasArg(options::OPT_pg))
     return true;
 
   if (Triple.isPS4CPU())
     return false;
 
-  return shouldUseFramePointerForTarget(Args, Triple);
+  return useFramePointerForTargetByDefault(Args, Triple);
 }
 
 /// Add a CC1 option to specify the debug compilation directory.