[clang] c0f1eac - [SystemZ] Don't allow CL option -mpacked-stack with -mbackchain.

[Jonas Paulsson via cfe-commits]

Author: Jonas Paulsson
Date: 2020-01-03T12:26:54-08:00
New Revision: c0f1eac008e61e8345e3f41347cfd191e4ecb215

URL: https://github.com/llvm/llvm-project/commit/c0f1eac008e61e8345e3f41347cfd191e4ecb215
DIFF: https://github.com/llvm/llvm-project/commit/c0f1eac008e61e8345e3f41347cfd191e4ecb215.diff

LOG: [SystemZ]  Don't allow CL option -mpacked-stack with -mbackchain.

-mpacked-stack is currently not supported with -mbackchain, so this should
result in a compilation error message instead of being silently ignored.

Review: Ulrich Weigand

Added: 
    clang/test/Driver/mbackchain.c

Modified: 
    clang/include/clang/Driver/Options.td
    clang/lib/Driver/ToolChains/Clang.cpp
    llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 86aee334436a..808cca76c6be 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -2481,6 +2481,7 @@ def mrecord_mcount : Flag<["-"], "mrecord-mcount">, HelpText<"Generate a __mcoun
   Flags<[CC1Option]>, Group<m_Group>;
 def mpacked_stack : Flag<["-"], "mpacked-stack">, HelpText<"Use packed stack layout (SystemZ only).">,
   Flags<[CC1Option]>, Group<m_Group>;
+def mno_packed_stack : Flag<["-"], "mno-packed-stack">, Flags<[CC1Option]>, Group<m_Group>;
 def mips16 : Flag<["-"], "mips16">, Group<m_mips_Features_Group>;
 def mno_mips16 : Flag<["-"], "mno-mips16">, Group<m_mips_Features_Group>;
 def mmicromips : Flag<["-"], "mmicromips">, Group<m_mips_Features_Group>;

diff  --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 1b8eca0ea0d7..e75dd6badc14 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -1991,8 +1991,20 @@ void Clang::AddSparcTargetArgs(const ArgList &Args,
 
 void Clang::AddSystemZTargetArgs(const ArgList &Args,
                                  ArgStringList &CmdArgs) const {
-  if (Args.hasFlag(options::OPT_mbackchain, options::OPT_mno_backchain, false))
+  bool HasBackchain = Args.hasFlag(options::OPT_mbackchain,
+                                   options::OPT_mno_backchain, false);
+  bool HasPackedStack = Args.hasFlag(options::OPT_mpacked_stack,
+                                     options::OPT_mno_packed_stack, false);
+  if (HasBackchain && HasPackedStack) {
+    const Driver &D = getToolChain().getDriver();
+    D.Diag(diag::err_drv_unsupported_opt)
+      << Args.getLastArg(options::OPT_mpacked_stack)->getAsString(Args) +
+      " " + Args.getLastArg(options::OPT_mbackchain)->getAsString(Args);
+  }
+  if (HasBackchain)
     CmdArgs.push_back("-mbackchain");
+  if (HasPackedStack)
+    CmdArgs.push_back("-mpacked-stack");
 }
 
 void Clang::AddX86TargetArgs(const ArgList &Args,
@@ -5014,8 +5026,6 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     }
   }
 
-  Args.AddLastArg(CmdArgs, options::OPT_mpacked_stack);
-
   if (Args.getLastArg(options::OPT_fapple_kext) ||
       (Args.hasArg(options::OPT_mkernel) && types::isCXX(InputType)))
     CmdArgs.push_back("-fapple-kext");

diff  --git a/clang/test/Driver/mbackchain.c b/clang/test/Driver/mbackchain.c
new file mode 100644
index 000000000000..33076829ccd7
--- /dev/null
+++ b/clang/test/Driver/mbackchain.c
@@ -0,0 +1,3 @@
+// RUN: %clang -target s390x -c -### %s -mpacked-stack -mbackchain 2>&1 | FileCheck %s
+
+// CHECK: error: unsupported option '-mpacked-stack -mbackchain'

diff  --git a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
index 3e2b376d3be6..3cdf6bf98ee0 100644
--- a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
@@ -68,6 +68,8 @@ static bool usePackedStack(MachineFunction &MF) {
   bool CallConv = MF.getFunction().getCallingConv() != CallingConv::GHC;
   bool BackChain = MF.getFunction().hasFnAttribute("backchain");
   bool FramAddressTaken = MF.getFrameInfo().isFrameAddressTaken();
+  if (HasPackedStackAttr && BackChain)
+    report_fatal_error("packed-stack with backchain is currently unsupported.");
   return HasPackedStackAttr && !IsVarArg && CallConv && !BackChain &&
          !FramAddressTaken;
 }