[mips] Pass the ABI to the integrated assembler and add tests the existing arguments.

[dsanders]

Summary

With this patch (and a corresponding LLVM patch), assembling an empty file with
GCC and Clang -fintegrated-as produce near identical objects. The remaining
differences are:

• GCC/GAS produce objects have a .pdr section
• GCC/GAS produce objects have a .gnu.attributes section

Other differences are insignificant such as precise file offsets and the order
of strings in the string table.

[atanasyan]

See my comment below.

lib/Driver/Tools.cpp

1042

Why do we need to turn off o32 and n64 features here? Why do we switch off only these features and and do not handle n32 and eabi the same way?

[dsanders]

lib/Driver/Tools.cpp

1042

It's to clear the possible backend default ABI's and replace them with the user-specied ABI or Clang's default. The backend can only use o32 or n64 by default

[atanasyan]

lib/Driver/Tools.cpp

1042

So we add a new dependency between the driver and the backend here. When or if somebody changes default ABI in the backend he or she must remember about driver. It does not sound good.

Can we fix the backend to be sure that if it gets a single ABI feature say +n32 it definitely override any default ABI settings?

[dsanders]

lib/Driver/Tools.cpp

1042

That's right and I agree that we need to find a better way. It will at least assert if they forget.

Can we fix the backend to be sure that if it gets a single ABI feature say +n32 it definitely override any default ABI settings?

Unfortunately no. There's currently no way to group them into a single mutually exclusive group and no way to distinguish a default ABI from a specified ABI. The long term solution to this is most likely to add support for the -target-abi option from 'clang -cc1' to 'clang -cc1as'.

[atanasyan]

lib/Driver/Tools.cpp

1042

Thanks. Now I see the problem.

The patch is looking good.

lib/Driver/Tools.cpp

 static void getMIPSTargetFeatures(const Driver &D, const llvm::Triple &Triple,
                                   const ArgList &Args,
                                   std::vector<const char *> &Features) {
   StringRef CPUName;
   StringRef ABIName;
   getMipsCPUAndABI(Args, Triple, CPUName, ABIName);
   ABIName = getGnuCompatibleMipsABIName(ABIName);
 
+  // Always override the backend's default ABI.
+  StringRef ABIFeature = llvm::StringSwitch<StringRef>(ABIName)
+                              .Case("32", "+o32")
+                              .Case("n32", "+n32")
+                              .Case("64", "+n64")
+                              .Case("eabi", "+eabi")
+                              .Default(("+" + ABIName).str());
+  Features.push_back("-o32");
+  Features.push_back("-n64");
+  Features.push_back(Args.MakeArgString(ABIFeature));
+
   StringRef FloatABI = getMipsFloatABI(D, Args);
   if (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");
   }
 

test/Driver/mips-integrated-as.s

+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
+// RUN:   FileCheck -check-prefix=ABI-O32 %s
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mabi=32 2>&1 | \
+// RUN:   FileCheck -check-prefix=ABI-O32 %s
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mabi=o32 2>&1 | \
+// RUN:   FileCheck -check-prefix=ABI-O32 %s
+// ABI-O32: -cc1as
+// ABI-O32: "-target-feature" "-n64"
+// ABI-O32: "-target-feature" "+o32"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mabi=eabi 2>&1 | \
+// RUN:   FileCheck -check-prefix=ABI-EABI32 %s
+// ABI-EABI32: -cc1as
+// ABI-EABI32: "-target-feature" "-o32"
+// ABI-EABI32: "-target-feature" "-n64"
+// ABI-EABI32: "-target-feature" "+eabi"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mips64 -mabi=n32 2>&1 | \
+// RUN:   FileCheck -check-prefix=ABI-N32 %s
+// RUN: %clang -target mips64-linux-gnu -### -fintegrated-as -c %s -mabi=n32 2>&1 | \
+// RUN:   FileCheck -check-prefix=ABI-N32 %s
+// ABI-N32: -cc1as
+// ABI-N32: "-target-feature" "-o32"
+// ABI-N32: "-target-feature" "-n64"
+// ABI-N32: "-target-feature" "+n32"
+
+// FIXME: We should also test '-target mips-linux-gnu -mips64' defaults to the
+//        default 64-bit ABI (N64 but GCC uses N32). It currently selects O32
+//        because of the triple.
+// RUN: %clang -target mips64-linux-gnu -### -fintegrated-as -c %s -mips64 2>&1 | \
+// RUN:   FileCheck -check-prefix=ABI-N64 %s
+//
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mips64 -mabi=64 2>&1 | \
+// RUN:   FileCheck -check-prefix=ABI-N64 %s
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mips64 -mabi=n64 2>&1 | \
+// RUN:   FileCheck -check-prefix=ABI-N64 %s
+// RUN: %clang -target mips64-linux-gnu -### -fintegrated-as -c %s -mips64 -mabi=64 2>&1 | \
+// RUN:   FileCheck -check-prefix=ABI-N64 %s
+// RUN: %clang -target mips64-linux-gnu -### -fintegrated-as -c %s -mips64 -mabi=n64 2>&1 | \
+// RUN:   FileCheck -check-prefix=ABI-N64 %s
+// ABI-N64: -cc1as
+// ABI-N64: "-target-feature" "-o32"
+// ABI-N64: "-target-feature" "+n64"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -msoft-float 2>&1 | \
+// RUN:   FileCheck -check-prefix=SOFTFLOAT %s
+// SOFTFLOAT: -cc1as
+// SOFTFLOAT: "-target-feature" "+soft-float"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
+// RUN:   FileCheck -check-prefix=HARDFLOAT %s
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mhard-float 2>&1 | \
+// RUN:   FileCheck -check-prefix=HARDFLOAT %s
+// HARDFLOAT: -cc1as
+// HARDFLOAT-NOT: "-target-feature" "+soft-float"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
+// RUN:   FileCheck -check-prefix=NAN-DEFAULT %s
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mips32r6 2>&1 | \
+// RUN:   FileCheck -check-prefix=NAN-DEFAULT %s
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mips64r6 2>&1 | \
+// RUN:   FileCheck -check-prefix=NAN-DEFAULT %s
+// NAN-DEFAULT: -cc1as
+// NAN-DEFAULT-NOT: "-target-feature" "{{[-+]}}nan2008"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mnan=legacy 2>&1 | \
+// RUN:   FileCheck -check-prefix=NAN-LEGACY %s
+// NAN-LEGACY: -cc1as
+// NAN-LEGACY: "-target-feature" "-nan2008"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mnan=2008 2>&1 | \
+// RUN:   FileCheck -check-prefix=NAN-2008 %s
+// NAN-2008: -cc1as
+// NAN-2008: "-target-feature" "+nan2008"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
+// RUN:   FileCheck -check-prefix=DEFAULT-FLOAT %s
+// DEFAULT-FLOAT: -cc1as
+// DEFAULT-FLOAT-NOT: "-target-feature" "{{[+-]}}single-float"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -msingle-float 2>&1 | \
+// RUN:   FileCheck -check-prefix=SINGLE-FLOAT %s
+// SINGLE-FLOAT: -cc1as
+// SINGLE-FLOAT: "-target-feature" "+single-float"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mdouble-float 2>&1 | \
+// RUN:   FileCheck -check-prefix=DOUBLE-FLOAT %s
+// DOUBLE-FLOAT: -cc1as
+// DOUBLE-FLOAT: "-target-feature" "-single-float"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS16-DEFAULT %s
+// MIPS16-DEFAULT: -cc1as
+// MIPS16-DEFAULT-NOT: "-target-feature" "{{[+-]}}mips16"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mips16 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS16-ON %s
+// MIPS16-ON: -cc1as
+// MIPS16-ON: "-target-feature" "+mips16"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mno-mips16 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS16-OFF %s
+// MIPS16-OFF: -cc1as
+// MIPS16-OFF: "-target-feature" "-mips16"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
+// RUN:   FileCheck -check-prefix=MICROMIPS-DEFAULT %s
+// MICROMIPS-DEFAULT: -cc1as
+// MICROMIPS-DEFAULT-NOT: "-target-feature" "{{[+-]}}micromips"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mmicromips 2>&1 | \
+// RUN:   FileCheck -check-prefix=MICROMIPS-ON %s
+// MICROMIPS-ON: -cc1as
+// MICROMIPS-ON: "-target-feature" "+micromips"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mno-micromips 2>&1 | \
+// RUN:   FileCheck -check-prefix=MICROMIPS-OFF %s
+// MICROMIPS-OFF: -cc1as
+// MICROMIPS-OFF: "-target-feature" "-micromips"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
+// RUN:   FileCheck -check-prefix=DSP-DEFAULT %s
+// DSP-DEFAULT: -cc1as
+// DSP-DEFAULT-NOT: "-target-feature" "{{[+-]}}dsp"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mdsp 2>&1 | \
+// RUN:   FileCheck -check-prefix=DSP-ON %s
+// DSP-ON: -cc1as
+// DSP-ON: "-target-feature" "+dsp"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mno-dsp 2>&1 | \
+// RUN:   FileCheck -check-prefix=DSP-OFF %s
+// DSP-OFF: -cc1as
+// DSP-OFF: "-target-feature" "-dsp"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
+// RUN:   FileCheck -check-prefix=DSPR2-DEFAULT %s
+// DSPR2-DEFAULT: -cc1as
+// DSPR2-DEFAULT-NOT: "-target-feature" "{{[+-]}}dspr2"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mdspr2 2>&1 | \
+// RUN:   FileCheck -check-prefix=DSPR2-ON %s
+// DSPR2-ON: -cc1as
+// DSPR2-ON: "-target-feature" "+dspr2"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mno-dspr2 2>&1 | \
+// RUN:   FileCheck -check-prefix=DSPR2-OFF %s
+// DSPR2-OFF: -cc1as
+// DSPR2-OFF: "-target-feature" "-dspr2"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
+// RUN:   FileCheck -check-prefix=MSA-DEFAULT %s
+// MSA-DEFAULT: -cc1as
+// MSA-DEFAULT-NOT: "-target-feature" "{{[+-]}}msa"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mmsa 2>&1 | \
+// RUN:   FileCheck -check-prefix=MSA-ON %s
+// MSA-ON: -cc1as
+// MSA-ON: "-target-feature" "+msa"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mno-msa 2>&1 | \
+// RUN:   FileCheck -check-prefix=MSA-OFF %s
+// MSA-OFF: -cc1as
+// MSA-OFF: "-target-feature" "-msa"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
+// RUN:   FileCheck -check-prefix=FPXX-DEFAULT %s
+// FPXX-DEFAULT: -cc1as
+// FPXX-DEFAULT-NOT: "-target-feature" "+fpxx"
+// FPXX-DEFAULT-NOT: "-target-feature" "+nooddspreg"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mfp32 2>&1 | \
+// RUN:   FileCheck -check-prefix=FP32 %s
+// FP32: -cc1as
+// FP32: "-target-feature" "-fp64"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mfpxx 2>&1 | \
+// RUN:   FileCheck -check-prefix=FPXX %s
+// FPXX: -cc1as
+// FPXX: "-target-feature" "+fpxx"
+// FPXX: "-target-feature" "+nooddspreg"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mfp64 2>&1 | \
+// RUN:   FileCheck -check-prefix=FP64 %s
+// FP64: -cc1as
+// FP64: "-target-feature" "+fp64"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s 2>&1 | \
+// RUN:   FileCheck -check-prefix=ODDSPREG-DEFAULT %s
+// ODDSPREG-DEFAULT: -cc1as
+// ODDSPREG-DEFAULT-NOT: "-target-feature" "{{[+-]}}nooddspreg"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -modd-spreg 2>&1 | \
+// RUN:   FileCheck -check-prefix=ODDSPREG-ON %s
+// ODDSPREG-ON: -cc1as
+// ODDSPREG-ON: "-target-feature" "-nooddspreg"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mno-odd-spreg 2>&1 | \
+// RUN:   FileCheck -check-prefix=ODDSPREG-OFF %s
+// ODDSPREG-OFF: -cc1as
+// ODDSPREG-OFF: "-target-feature" "+nooddspreg"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mfpxx -modd-spreg 2>&1 | \
+// RUN:   FileCheck -check-prefix=FPXX-ODDSPREG %s
+// FPXX-ODDSPREG: -cc1as
+// FPXX-ODDSPREG: "-target-feature" "+fpxx"
+// FPXX-ODDSPREG: "-target-feature" "-nooddspreg"