[mips] Add support for static model on N64

[sdardis]

Summary

The patch teaches the Clang driver how to handle the N64 static
relocation model properly. It enforces the correct target feature
(+noabicalls) when -fno-pic is used. This is required as non-pic
N64 code as the abi extension to call PIC code (CPIC) is unsupported.

Make PIC the default for mips64 and mips64el, this affects both N32
& N64 ABIs, to better match GCC.

As part of this effort, clean up the assembler invocation command
builder, so the correct flags are used.

[seanbruno]

From a "does this work" perspective, FreeBSD compiles are better now with this in place.

[sdardis]

@slthakur can you take a look at this too?

Thanks,
Simon

[slthakur]

LGTM

cfe/trunk/lib/Driver/ToolChains.cpp

 
 bool Generic_GCC::isPICDefault() const {
   switch (getArch()) {
   case llvm::Triple::x86_64:
     return getTriple().isOSWindows();
   case llvm::Triple::ppc64:
   case llvm::Triple::ppc64le:
     return !getTriple().isOSBinFormatMachO() && !getTriple().isMacOSX();
+  case llvm::Triple::mips64:
+  case llvm::Triple::mips64el:
+    return true;
   default:
     return false;
   }
 }
 
 bool Generic_GCC::isPIEDefault() const { return false; }
 
 bool Generic_GCC::isPICDefaultForced() const {

cfe/trunk/lib/Driver/Tools.cpp

 static void getMIPSTargetFeatures(const Driver &D, const llvm::Triple &Triple,
                                   const ArgList &Args,
                                   std::vector<StringRef> &Features) {
   StringRef CPUName;
   StringRef ABIName;
   mips::getMipsCPUAndABI(Args, Triple, CPUName, ABIName);
   ABIName = getGnuCompatibleMipsABIName(ABIName);
 
+  // Historically, PIC code for MIPS was associated with -mabicalls, a.k.a
+  // SVR4 abicalls. Static code does not use SVR4 calling sequences. An ABI
+  // extension was developed by Richard Sandiford & Code Sourcery to support
+  // static code calling PIC code (CPIC). For O32 and N32 this means we have
+  // several combinations of PIC/static and abicalls. Pure static, static
+  // with the CPIC extension, and pure PIC code.
+
+  // At final link time, O32 and N32 with CPIC will have another section
+  // added to the binary which contains the stub functions to perform
+  // any fixups required for PIC code.
+
+  // For N64, the situation is more regular: code can either be static
+  // (non-abicalls) or PIC (abicalls). GCC has traditionally picked PIC code
+  // code for N64. Since Clang has already built the relocation model portion
+  // of the commandline, we pick add +noabicalls feature in the N64 static
+  // case.
+
+  // The is another case to be accounted for: -msym32, which enforces that all
+  // symbols have 32 bits in size. In this case, N64 can in theory use CPIC
+  // but it is unsupported.
+
+  // The combinations for N64 are:
+  // a) Static without abicalls and 64bit symbols.
+  // b) Static with abicalls and 32bit symbols.
+  // c) PIC with abicalls and 64bit symbols.
+
+  // For case (a) we need to add +noabicalls for N64.
+
+  bool IsN64 = ABIName == "64";
+  bool NonPIC = false;
+
+  Arg *LastPICArg = Args.getLastArg(options::OPT_fPIC, options::OPT_fno_PIC,
+                                    options::OPT_fpic, options::OPT_fno_pic,
+                                    options::OPT_fPIE, options::OPT_fno_PIE,
+                                    options::OPT_fpie, options::OPT_fno_pie);
+  if (LastPICArg) {
+    Option O = LastPICArg->getOption();
+    NonPIC =
+        (O.matches(options::OPT_fno_PIC) || O.matches(options::OPT_fno_pic) ||
+         O.matches(options::OPT_fno_PIE) || O.matches(options::OPT_fno_pie));
+  }
+
+  if (IsN64 && NonPIC) {
+    Features.push_back("+noabicalls");
+  } else {
     AddTargetFeature(Args, Features, options::OPT_mno_abicalls,
                      options::OPT_mabicalls, "noabicalls");
+  }
 
   mips::FloatABI FloatABI = getMipsFloatABI(D, Args);
   if (FloatABI == mips::FloatABI::Soft) {
     // FIXME: Note, this is a hack. We need to pass the selected float
     // mode to the MipsTargetInfoBase to define appropriate macros there.
     // Now it is the only method.
     Features.push_back("+soft-float");
   }
if (!EmbeddedPISupported)
           << LastRWPIArg->getSpelling() << Triple.str();
     RWPI = true;
   }
 
   // ROPI and RWPI are not comaptible with PIC or PIE.
   if ((ROPI || RWPI) && (PIC || PIE))
     ToolChain.getDriver().Diag(diag::err_drv_ropi_rwpi_incompatible_with_pic);
 
+  // When targettng MIPS64 with N64, the default is PIC, unless -mno-abicalls is
+  // used.
+  if ((Triple.getArch() == llvm::Triple::mips64 ||
+       Triple.getArch() == llvm::Triple::mips64el) &&
+      Args.hasArg(options::OPT_mno_abicalls))
+    return std::make_tuple(llvm::Reloc::Static, 0U, false);
+
   if (PIC)
     return std::make_tuple(llvm::Reloc::PIC_, IsPICLevelTwo ? 2U : 1U, PIE);
 
   llvm::Reloc::Model RelocM = llvm::Reloc::Static;
   if (ROPI && RWPI)
     RelocM = llvm::Reloc::ROPI_RWPI;
   else if (ROPI)
     RelocM = llvm::Reloc::ROPI;
case llvm::Triple::mips64el: {
 
     // -mno-shared should be emitted unless -fpic, -fpie, -fPIC, -fPIE,
     // or -mshared (not implemented) is in effect.
     if (RelocationModel == llvm::Reloc::Static)
       CmdArgs.push_back("-mno-shared");
 
     // LLVM doesn't support -mplt yet and acts as if it is always given.
     // However, -mplt has no effect with the N64 ABI.
-    CmdArgs.push_back(ABIName == "64" ? "-KPIC" : "-call_nonpic");
+    if (ABIName != "64" && !Args.hasArg(options::OPT_mno_abicalls))
+      CmdArgs.push_back("-call_nonpic");
 
     if (getToolChain().getArch() == llvm::Triple::mips ||
         getToolChain().getArch() == llvm::Triple::mips64)
       CmdArgs.push_back("-EB");
     else
       CmdArgs.push_back("-EL");
 
     if (Arg *A = Args.getLastArg(options::OPT_mnan_EQ)) {

cfe/trunk/test/Driver/mips-as.c

 // MIPS32R2-EB-PIC: "-KPIC"
 //
 // RUN: %clang -target mipsel-linux-gnu -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS32R2-DEF-EL-AS %s
 // MIPS32R2-DEF-EL-AS: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EL"
 //
 // RUN: %clang -target mips64-linux-gnu -### \
-// RUN:   -no-integrated-as -c %s 2>&1 \
+// RUN:   -no-integrated-as -fno-pic -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS64R2-EB-AS %s
-// MIPS64R2-EB-AS: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "64" "-mno-shared" "-KPIC" "-EB"
+// MIPS64R2-EB-AS: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "64" "-mno-shared" "-EB"
 //
-// RUN: %clang -target mips64el-linux-gnu -### \
+// RUN: %clang -target mips64-linux-gnu -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=MIPS64R2-EB-AS-PIC %s
+// MIPS64R2-EB-AS-PIC: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "64" "-EB" "-KPIC"
+//
+// RUN: %clang -target mips64el-linux-gnu -### \
+// RUN:   -no-integrated-as -c -fno-pic %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS64R2-DEF-EL-AS %s
-// MIPS64R2-DEF-EL-AS: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "64"  "-mno-shared" "-KPIC" "-EL"
+// MIPS64R2-DEF-EL-AS: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "64"  "-mno-shared" "-EL"
+//
+// RUN: %clang -target mips64el-linux-gnu -### \
+// RUN:   -no-integrated-as -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=MIPS64R2-DEF-EL-AS-PIC %s
+// MIPS64R2-DEF-EL-AS-PIC: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "64" "-EL" "-KPIC"
 //
 // RUN: %clang -target mips64-linux-gnu -mabi=n32 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=MIPS-N32-PIC %s
+// MIPS-N32-PIC: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "n32" "-call_nonpic" "-EB" "-KPIC"
+//
+// RUN: %clang -target mips64-linux-gnu -mabi=n32 -### \
+// RUN:   -no-integrated-as -c %s -fno-pic 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-N32 %s
 // MIPS-N32: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "n32" "-mno-shared" "-call_nonpic" "-EB"
 //
 // RUN: %clang -target mipsel-linux-gnu -mabi=32 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS32R2-EL-AS %s
 // RUN: %clang -target mips-linux-gnu -mabi=32 -### \
 // RUN:   -no-integrated-as -c %s -EL 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS32R2-EL-AS %s
 // MIPS32R2-EL-AS: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EL"
 //
 // RUN: %clang -target mips64el-linux-gnu -mabi=64 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=MIPS64R2-EL-AS-PIC %s
+// MIPS64R2-EL-AS-PIC: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "64" "-EL" "-KPIC"
+//
+// RUN: %clang -target mips64el-linux-gnu -mabi=64 -### \
+// RUN:   -no-integrated-as -c %s -fno-pic 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS64R2-EL-AS %s
-// MIPS64R2-EL-AS: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "64" "-mno-shared" "-KPIC" "-EL"
+// MIPS64R2-EL-AS: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "64" "-mno-shared" "-EL"
 //
 // RUN: %clang -target mips-linux-gnu -march=mips32r2 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-32R2 %s
 // MIPS-32R2: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB"
 //
 // RUN: %clang -target mips-linux-gnu -march=p5600 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-P5600 %s
 // MIPS-P5600: as{{(.exe)?}}" "-march" "p5600" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB"
 //
 // RUN: %clang -target mips64-linux-gnu -march=octeon -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=MIPS-OCTEON-PIC %s
+// MIPS-OCTEON-PIC: as{{(.exe)?}}" "-march" "octeon" "-mabi" "64" "-EB" "-KPIC"
+//
+// RUN: %clang -target mips64-linux-gnu -march=octeon -### \
+// RUN:   -no-integrated-as -c %s -fno-pic 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-OCTEON %s
-// MIPS-OCTEON: as{{(.exe)?}}" "-march" "octeon" "-mabi" "64" "-mno-shared" "-KPIC" "-EB"
+// MIPS-OCTEON: as{{(.exe)?}}" "-march" "octeon" "-mabi" "64" "-mno-shared" "-EB"
 //
 // RUN: %clang -target mips-linux-gnu -mips1 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-ALIAS-1 %s
 // MIPS-ALIAS-1: as{{(.exe)?}}" "-march" "mips1" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB"
 //
 // RUN: %clang -target mips-linux-gnu -mips2 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \

 //
 // RUN: %clang -target mips-linux-gnu -mips32r6 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-ALIAS-32R6 %s
 // MIPS-ALIAS-32R6: as{{(.exe)?}}" "-march" "mips32r6" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB"
 //
 // RUN: %clang -target mips64-linux-gnu -mips64 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=MIPS-ALIAS-64-PIC %s
+// MIPS-ALIAS-64-PIC: as{{(.exe)?}}" "-march" "mips64" "-mabi" "64" "-EB" "-KPIC"
+//
+// RUN: %clang -target mips64-linux-gnu -mips64 -### \
+// RUN:   -no-integrated-as -c -fno-pic %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-ALIAS-64 %s
-// MIPS-ALIAS-64: as{{(.exe)?}}" "-march" "mips64" "-mabi" "64" "-mno-shared" "-KPIC" "-EB"
+// MIPS-ALIAS-64: as{{(.exe)?}}" "-march" "mips64" "-mabi" "64" "-mno-shared" "-EB"
 //
 // RUN: %clang -target mips64-linux-gnu -mips64r2 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
-// RUN:   | FileCheck -check-prefix=MIPS-ALIAS-64R2 %s
-// MIPS-ALIAS-64R2: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "64" "-mno-shared" "-KPIC" "-EB"
+// RUN:   | FileCheck -check-prefix=MIPS-ALIAS-64R2-PIC %s
+// MIPS-ALIAS-64R2-PIC: as{{(.exe)?}}" "-march" "mips64r2" "-mabi" "64" "-EB" "-KPIC"
 //
 // RUN: %clang -target mips64-linux-gnu -mips64r3 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=MIPS-ALIAS-64R3-PIC %s
+// MIPS-ALIAS-64R3-PIC: as{{(.exe)?}}" "-march" "mips64r3" "-mabi" "64" "-EB" "-KPIC"
+//
+// RUN: %clang -target mips64-linux-gnu -mips64r3 -### \
+// RUN:   -no-integrated-as -c %s -fno-pic 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-ALIAS-64R3 %s
-// MIPS-ALIAS-64R3: as{{(.exe)?}}" "-march" "mips64r3" "-mabi" "64" "-mno-shared" "-KPIC" "-EB"
+// MIPS-ALIAS-64R3: as{{(.exe)?}}" "-march" "mips64r3" "-mabi" "64" "-mno-shared" "-EB"
 //
 // RUN: %clang -target mips64-linux-gnu -mips64r5 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=MIPS-ALIAS-64R5-PIC %s
+// MIPS-ALIAS-64R5-PIC: as{{(.exe)?}}" "-march" "mips64r5" "-mabi" "64" "-EB" "-KPIC"
+//
+// RUN: %clang -target mips64-linux-gnu -mips64r5 -### \
+// RUN:   -no-integrated-as -c %s -fno-pic 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-ALIAS-64R5 %s
-// MIPS-ALIAS-64R5: as{{(.exe)?}}" "-march" "mips64r5" "-mabi" "64" "-mno-shared" "-KPIC" "-EB"
+// MIPS-ALIAS-64R5: as{{(.exe)?}}" "-march" "mips64r5" "-mabi" "64" "-mno-shared" "-EB"
 //
 // RUN: %clang -target mips64-linux-gnu -mips64r6 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=MIPS-ALIAS-64R6-PIC %s
+// MIPS-ALIAS-64R6-PIC: as{{(.exe)?}}" "-march" "mips64r6" "-mabi" "64" "-EB" "-KPIC"
+//
+// RUN: %clang -target mips64-linux-gnu -mips64r6 -### \
+// RUN:   -no-integrated-as -c %s -fno-pic 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-ALIAS-64R6 %s
-// MIPS-ALIAS-64R6: as{{(.exe)?}}" "-march" "mips64r6" "-mabi" "64" "-mno-shared" "-KPIC" "-EB"
+// MIPS-ALIAS-64R6: as{{(.exe)?}}" "-march" "mips64r6" "-mabi" "64" "-mno-shared" "-EB"
 //
 // RUN: %clang -target mips-linux-gnu -mno-mips16 -mips16 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=MIPS-16 %s
 // MIPS-16: as{{(.exe)?}}" "-march" "mips32r2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB" "-mips16"
 //
 // RUN: %clang -target mips-linux-gnu -mips16 -mno-mips16 -### \
 // RUN:   -no-integrated-as -c %s 2>&1 \

 //
 // RUN: %clang -target mips-linux-gnu -### -no-integrated-as -c %s -mcpu=mips2 \
 // RUN:   2>&1 | FileCheck -check-prefix=MIPS2-EB-AS %s
 // MIPS2-EB-AS: as{{(.exe)?}}" "-march" "mips2" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB"
 // MIPS2-EB-AS-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-KPIC"
 //
 // RUN: %clang -target mips64-linux-gnu -### -no-integrated-as -c %s -mcpu=mips3 \
 // RUN:   2>&1 | FileCheck -check-prefix=MIPS3-EB-AS %s
-// MIPS3-EB-AS: as{{(.exe)?}}" "-march" "mips3" "-mabi" "64" "-mno-shared" "-KPIC" "-EB"
+// MIPS3-EB-AS: as{{(.exe)?}}" "-march" "mips3" "-mabi" "64" "-EB" "-KPIC"
 //
 // RUN: %clang -target mips64-linux-gnu -### -no-integrated-as -c %s -mcpu=mips4 \
 // RUN:   2>&1 | FileCheck -check-prefix=MIPS4-EB-AS %s
-// MIPS4-EB-AS: as{{(.exe)?}}" "-march" "mips4" "-mabi" "64" "-mno-shared" "-KPIC" "-EB"
+// MIPS4-EB-AS: as{{(.exe)?}}" "-march" "mips4" "-mabi" "64" "-EB" "-KPIC"
 //
 // RUN: %clang -target mips64-linux-gnu -### -no-integrated-as -c %s -mcpu=mips5 \
 // RUN:   2>&1 | FileCheck -check-prefix=MIPS5-EB-AS %s
-// MIPS5-EB-AS: as{{(.exe)?}}" "-march" "mips5" "-mabi" "64" "-mno-shared" "-KPIC" "-EB"
+// MIPS5-EB-AS: as{{(.exe)?}}" "-march" "mips5" "-mabi" "64" "-EB" "-KPIC"
 //
 // RUN: %clang -target mips-linux-gnu -### -no-integrated-as -c %s -mcpu=mips32 \
 // RUN:   2>&1 | FileCheck -check-prefix=MIPS32-EB-AS %s
 // MIPS32-EB-AS: as{{(.exe)?}}" "-march" "mips32" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB"
 // MIPS32-EB-AS-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-KPIC"
 //
 // RUN: %clang -target mips-linux-gnu -### -no-integrated-as -c %s -mcpu=mips32r6 \
 // RUN:   2>&1 | FileCheck -check-prefix=MIPS32R6-EB-AS %s
 // MIPS32R6-EB-AS: as{{(.exe)?}}" "-march" "mips32r6" "-mabi" "32" "-mno-shared" "-call_nonpic" "-EB"
 // MIPS32R6-EB-AS-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-KPIC"
 //
 // RUN: %clang -target mips64-linux-gnu -### -no-integrated-as -c %s -mcpu=mips64 \
 // RUN:   2>&1 | FileCheck -check-prefix=MIPS64-EB-AS %s
-// MIPS64-EB-AS: as{{(.exe)?}}" "-march" "mips64" "-mabi" "64" "-mno-shared" "-KPIC" "-EB"
+// MIPS64-EB-AS: as{{(.exe)?}}" "-march" "mips64" "-mabi" "64" "-EB" "-KPIC"
 //
 // RUN: %clang -target mips64-linux-gnu -### -no-integrated-as -c %s -mcpu=mips64r6 \
 // RUN:   2>&1 | FileCheck -check-prefix=MIPS64R6-EB-AS %s
-// MIPS64R6-EB-AS: as{{(.exe)?}}" "-march" "mips64r6" "-mabi" "64" "-mno-shared" "-KPIC" "-EB"
+// MIPS64R6-EB-AS: as{{(.exe)?}}" "-march" "mips64r6" "-mabi" "64" "-EB" "-KPIC"
 //
 // RUN: %clang -target mips-linux-gnu -### -no-integrated-as -msoft-float -mhard-float -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=HARDFLOAT --implicit-check-not=-msoft-float %s
 // HARDFLOAT: as{{(.exe)?}}"
 // HARDFLOAT: -mhard-float
 //
 // RUN: %clang -target mips-linux-gnu -### -no-integrated-as -mhard-float -msoft-float -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=SOFTFLOAT --implicit-check-not=-mhard-float %s