[EABI] Add Clang support for -meabi flag

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.

A similar patch was introduced in LLVM.

Patch by Vinicius Tinti.

llvm-svn: 252463

clang/include/clang/Driver/Options.td

@@ -1281,6 +1281,8 @@ def mstack_probe_size : Joined<["-"], "mstack-probe-size=">, Group<m_Group>, Fla
   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>;

clang/include/clang/Frontend/CodeGenOptions.h

@@ -167,6 +167,9 @@ public:
   /// 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.

clang/lib/CodeGen/BackendUtil.cpp

@@ -515,6 +515,14 @@ TargetMachine *EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
   Options.UseInitArray = CodeGenOpts.UseInitArray;
   Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
   Options.CompressDebugSections = CodeGenOpts.CompressDebugSections;
+
+  // Set EABI version.
+  Options.EABIVersion = llvm::StringSwitch<llvm::EABI>(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;

clang/lib/Driver/Tools.cpp

@@ -3412,6 +3412,11 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     }
   }
 
+  if (Arg *A = Args.getLastArg(options::OPT_meabi)) {
+    CmdArgs.push_back("-meabi");
+    CmdArgs.push_back(A->getValue());
+  }
+
   CmdArgs.push_back("-mthread-model");
   if (Arg *A = Args.getLastArg(options::OPT_mthread_model))
     CmdArgs.push_back(A->getValue());

clang/lib/Frontend/CompilerInvocation.cpp

@@ -38,6 +38,7 @@
 #include "llvm/Support/Host.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Process.h"
+#include "llvm/Target/TargetOptions.h"
 #include <atomic>
 #include <memory>
 #include <sys/stat.h>
@@ -456,6 +457,20 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   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();
+    llvm::EABI EABIVersion = llvm::StringSwitch<llvm::EABI>(Value)
+                                 .Case("default", llvm::EABI::Default)
+                                 .Case("4", llvm::EABI::EABI4)
+                                 .Case("5", llvm::EABI::EABI5)
+                                 .Case("gnu", llvm::EABI::GNU)
+                                 .Default(llvm::EABI::Unknown);
+    if (EABIVersion == llvm::EABI::Unknown)
+      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) ||

clang/test/CodeGen/arm-eabi.c

@@ -0,0 +1,20 @@
+// 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));
+}

clang/test/Driver/eabi.c

@@ -0,0 +1,13 @@
+// RUN: %clang %s -meabi 4 -### 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-EABI4 %s
+// RUN: %clang %s -meabi 5 -### 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-EABI5 %s
+// RUN: %clang %s -meabi gnu -### 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-GNUEABI %s
+// RUN: not %clang %s -meabi unknown 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-UNKNOWN %s
+
+// CHECK-EABI4: "-meabi" "4"
+// CHECK-EABI5: "-meabi" "5"
+// CHECK-GNUEABI: "-meabi" "gnu"
+// CHECK-UNKNOWN: error: invalid value 'unknown' in '-meabi unknown'