[clang] Add initial support for -meabi flag

[tinti]

Summary

The -meabi flag to control LLVM EABI version.

Without '-meabi' or with '-meabi default' imply LLVM triple default.
With '-meabi gnu' sets EABI GNU.
With '-meabi 4' or '-meabi 5' set EABI version 4 and 5 respectively.

[rengolin]

You forgot to add the context. It makes a big difference in the driver code. :)

But overall, looks good to me.

@jroelofs @compnerd @t.p.northover, can you see anything that might impact your workloads?

cheers,
--renato

[tinti]

Add context

[compnerd]

This looks like what I had in mind wrt use of -meabi.

lib/CodeGen/BackendUtil.cpp

524

I'd really rather see this written in the LLVM Style:

EABI4, EABI5, GNU

since all of them are initialisms.

BTW, please clang-format this change.

lib/Frontend/CompilerInvocation.cpp

458

If llvm::EABI::EABIVersionType had an Invalid value in the enumeration, you could convert directly to the value here, and report the error if the value was Invalid.

[tinti]

lib/CodeGen/BackendUtil.cpp

524

Agreed.

lib/Frontend/CompilerInvocation.cpp

458

I chose this way because none of the other target options have it [1].

Do you prefer with it?

[1] https://github.com/llvm-mirror/llvm/blob/master/include/llvm/Target/TargetOptions.h#L27

[tinti]

lib/Frontend/CompilerInvocation.cpp

458

Looks like that in LLVM the Invalid is not defined but in Clang there are target specific enums that define them [1].

[1] https://github.com/llvm-mirror/clang/blob/master/lib/Driver/Tools.h#L263

[rengolin]

lib/Frontend/CompilerInvocation.cpp

458

@compnerd, it seems that this code is already checking for invalid values, I'm not sure what you're asking about.

Also, EABI::EABIVersionType has no field Invalid, and I don't think it should, either.

[tinti]

• Clang format code.
• Update eabi names to match new LLVM patch.

[tinti]

Clang format.

[tinti]

lib/Frontend/CompilerInvocation.cpp

459

This part of the code does not include TargetOptions.h (so EABI is an undefined type). Can I add it here?

[rengolin]

lib/Driver/Tools.cpp

3415

Shouldn't we only add the option if it was used in the command line?

lib/Frontend/CompilerInvocation.cpp

459

If you mean up there, at the beginning of the file, then I suspect you should. Though, I though some other header would get it by now. If they don't, then please add it.

[tinti]

• Add test for error check
• Change StringSwitch to use lllvm::EABI type

[tinti]

lib/Driver/Tools.cpp

3415

Good point! Fixed.

lib/Frontend/CompilerInvocation.cpp

460

I have added. It requires to add an invalid or more apropriate name Unknown version.

If the backend ever sees an Unknown it will consider it as a Default.
The frontend considers Unknown as an invalid state and raises an error.

[rengolin]

LGTM, thanks!

[rengolin]

r252463

include/clang/Driver/Options.td

   HelpText<"Set the stack probe size">;
 def mthread_model : Separate<["-"], "mthread-model">, Group<m_Group>, Flags<[CC1Option]>,
   HelpText<"The thread model to use, e.g. posix, single (posix by default)">;
+def meabi : Separate<["-"], "meabi">, Group<m_Group>, Flags<[CC1Option]>,
+  HelpText<"Set EABI type, e.g. 4, 5 or gnu (default depends on triple)">;
 
 def mmmx : Flag<["-"], "mmmx">, Group<m_x86_Features_Group>;
 def mno_3dnowa : Flag<["-"], "mno-3dnowa">, Group<m_x86_Features_Group>;

include/clang/Frontend/CodeGenOptions.h

   /// Name of the profile file to use as input for -fprofile-instr-use
   std::string InstrProfileInput;
 
+  /// The EABI version to use
+  std::string EABIVersion;
+
   /// A list of file names passed with -fcuda-include-gpubinary options to
   /// forward to CUDA runtime back-end for incorporating them into host-side
   /// object file.

lib/CodeGen/BackendUtil.cpp

   Options.UseInitArray = CodeGenOpts.UseInitArray;
   Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
   Options.CompressDebugSections = CodeGenOpts.CompressDebugSections;
+
+  // Set EABI version.
+  Options.EABIVersion =
+    llvm::StringSwitch<llvm::EABI::EABIVersionType>(CodeGenOpts.EABIVersion)
+      .Case("4",   llvm::EABI::Eabi4)
+      .Case("5",   llvm::EABI::Eabi5)
+      .Case("gnu", llvm::EABI::Gnu)
+      .Default(llvm::EABI::Default);
+
   Options.LessPreciseFPMADOption = CodeGenOpts.LessPreciseFPMAD;
   Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
   Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;

lib/Driver/Tools.cpp

     }
   }
 
+  CmdArgs.push_back("-meabi");
+  if (Arg *A = Args.getLastArg(options::OPT_meabi))
+    CmdArgs.push_back(A->getValue());
+  else
+    CmdArgs.push_back("default");
+
   CmdArgs.push_back("-mthread-model");
   if (Arg *A = Args.getLastArg(options::OPT_mthread_model))
     CmdArgs.push_back(A->getValue());

lib/Frontend/CompilerInvocation.cpp

   Opts.DisableFree = Args.hasArg(OPT_disable_free);
   Opts.DisableTailCalls = Args.hasArg(OPT_mdisable_tail_calls);
   Opts.FloatABI = Args.getLastArgValue(OPT_mfloat_abi);
+  if (Arg *A = Args.getLastArg(OPT_meabi)) {
+    StringRef Value = A->getValue();
+    bool Valid = llvm::StringSwitch<bool>(Value)
+      .Case("default", true)
+      .Case("gnu",     true)
+      .Case("4",       true)
+      .Case("5",       true)
+      .Default(false);
+    if (!Valid)
+      Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args)
+          << Value;
+    else
+      Opts.EABIVersion = Value;
+  }
   Opts.LessPreciseFPMAD = Args.hasArg(OPT_cl_mad_enable);
   Opts.LimitFloatPrecision = Args.getLastArgValue(OPT_mlimit_float_precision);
   Opts.NoInfsFPMath = (Args.hasArg(OPT_menable_no_infinities) ||

test/CodeGen/arm-eabi.c

+// REQUIRES: arm-registered-target
+// RUN: %clang -target arm-none-eabi -S -o - %s | FileCheck -check-prefix=CHECK-EABI %s
+// RUN: %clang -target arm-none-eabi -S -meabi gnu -o - %s | FileCheck -check-prefix=CHECK-GNUEABI %s
+// RUN: %clang -target arm-none-eabihf -S -o - %s | FileCheck -check-prefix=CHECK-EABI %s
+// RUN: %clang -target arm-none-eabihf -S -meabi gnu -o - %s | FileCheck -check-prefix=CHECK-GNUEABI %s
+// RUN: %clang -target arm-none-gnueabi -S -o - %s | FileCheck -check-prefix=CHECK-GNUEABI %s
+// RUN: %clang -target arm-none-gnueabi -S -meabi 5 -o - %s | FileCheck -check-prefix=CHECK-EABI %s
+// RUN: %clang -target arm-none-gnueabihf -S -o - %s | FileCheck -check-prefix=CHECK-GNUEABI %s
+// RUN: %clang -target arm-none-gnueabihf -S -meabi 5 -o - %s | FileCheck -check-prefix=CHECK-EABI %s
+
+struct my_s {
+  unsigned long a[18];
+};
+
+// CHECK-LABEL: foo
+// CHECK-EABI: bl __aeabi_memcpy4
+// CHECK-GNUEABI: bl memcpy
+void foo(unsigned long *t) {
+  *(struct my_s *)t = *((struct my_s *)(1UL));
+}

test/Driver/eabi.c

+// RUN: %clang %s -### -o %t.o 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-DEFAULT %s
+// RUN: %clang %s -meabi default -### -o %t.o 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-DEFAULT %s
+// RUN: %clang %s -meabi 4 -### -o %t.o 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-EABI4 %s
+// RUN: %clang %s -meabi 5 -### -o %t.o 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-EABI5 %s
+// RUN: %clang %s -meabi gnu -### -o %t.o 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-GNUEABI %s
+
+// CHECK-DEFAULT: "-meabi" "default"
+// CHECK-EABI4: "-meabi" "4"
+// CHECK-EABI5: "-meabi" "5"
+// CHECK-GNUEABI: "-meabi" "gnu"