[mips] llvm-readobj can parse .MIPS.abiflags. No need to check the bytes.

[dsanders]

Summary

A small tweak was required to llvm-readobj to avoid false passes.
In FileCheck, 'MIPS32' matches both 'MIPS32' and 'MIPS32r6' so llvm-readobj
now emits 'MIPS32 (MIPS32 revision 1)', 'MIPS2 (MIPS2 revision 0)', etc.

[atanasyan]

In general the patch is LGTM. But maybe it is better to achieve the same result without making the llvm-readobj more verbose. The following string does not produce false positive result on ISA: MIPS32r6 input:

ISA: {{MIPS32$}}

[dsanders]

Use regex to match EOL rather than make llvm-readobj more verbose.

test/MC/Mips/mips_abi_flags_xx.s

 # RUN: llvm-mc %s -arch=mips -mcpu=mips32 | \
 # RUN:   FileCheck %s -check-prefix=CHECK-ASM
 #
 # RUN: llvm-mc %s -arch=mips -mcpu=mips32 -filetype=obj -o - | \
-# RUN:   llvm-readobj -sections -section-data -section-relocations - | \
+# RUN:   llvm-readobj -sections -section-data -section-relocations -mips-abi-flags - | \
 # RUN:     FileCheck %s -check-prefix=CHECK-OBJ -check-prefix=CHECK-OBJ-R1
 
 # RUN: llvm-mc /dev/null -arch=mips -mcpu=mips32 -mattr=fpxx -filetype=obj -o - | \
-# RUN:   llvm-readobj -sections -section-data -section-relocations - | \
+# RUN:   llvm-readobj -sections -section-data -section-relocations -mips-abi-flags - | \
 # RUN:     FileCheck %s -check-prefix=CHECK-OBJ -check-prefix=CHECK-OBJ-R1
 
 # RUN: llvm-mc /dev/null -arch=mips -mcpu=mips32r6 -mattr=fpxx -filetype=obj -o - | \
-# RUN:   llvm-readobj -sections -section-data -section-relocations - | \
+# RUN:   llvm-readobj -sections -section-data -section-relocations -mips-abi-flags - | \
 # RUN:     FileCheck %s -check-prefix=CHECK-OBJ -check-prefix=CHECK-OBJ-R6
 
 # CHECK-ASM: .module fp=xx
 
 # Checking if the Mips.abiflags were correctly emitted.
 # CHECK-OBJ:       Section {
 # CHECK-OBJ:         Index: 5
 # CHECK-OBJ-LABEL:   Name: .MIPS.abiflags (12)
 # CHECK-OBJ:         Type: SHT_MIPS_ABIFLAGS (0x7000002A)
 # CHECK-OBJ:          Flags [ (0x2)
 # CHECK-OBJ:           SHF_ALLOC (0x2)
 # CHECK-OBJ:         ]
 # CHECK-OBJ:         Address: 0x0
 # CHECK-OBJ:         Size: 24
 # CHECK-OBJ:         Link: 0
 # CHECK-OBJ:         Info: 0
 # CHECK-OBJ:         AddressAlignment: 8
 # CHECK-OBJ:         EntrySize: 24
 # CHECK-OBJ:         Relocations [
 # CHECK-OBJ:         ]
-# CHECK-OBJ:         SectionData (
-# CHECK-OBJ-R1:        0000: 00002001 01010005 00000000 00000000  |.. .............|
-# CHECK-OBJ-R6:        0000: 00002006 01010005 00000000 00000000  |.. .............|
-# CHECK-OBJ:           0010: 00000001 00000000                    |........|
-# CHECK-OBJ:         )
 # CHECK-OBJ-LABEL: }
+# CHECK-OBJ:       MIPS ABI Flags {
+# CHECK-OBJ-NEXT:    Version: 0
+# CHECK-OBJ-R1-NEXT: ISA: MIPS32 (MIPS32 revision 1)
+# CHECK-OBJ-R6-NEXT: ISA: MIPS32r6 (MIPS32 revision 6)
+# CHECK-OBJ-NEXT:    ISA Extension: None (0x0)
+# CHECK-OBJ-NEXT:    ASEs [ (0x0)
+# CHECK-OBJ-NEXT:    ]
+# CHECK-OBJ-NEXT:    FP ABI: Hard float (32-bit CPU, Any FPU) (0x5)
+# CHECK-OBJ-NEXT:    GPR size: 32
+# CHECK-OBJ-NEXT:    CPR1 size: 32
+# CHECK-OBJ-NEXT:    CPR2 size: 0
+# CHECK-OBJ-NEXT:    Flags 1 [ (0x1)
+# CHECK-OBJ-NEXT:      ODDSPREG (0x1)
+# CHECK-OBJ-NEXT:    ]
+# CHECK-OBJ-NEXT:    Flags 2: 0x0
+# CHECK-OBJ-NEXT:  }
 
         .module fp=xx
 
 # FIXME: Test should include gnu_attributes directive when implemented.
 #        An explicit .gnu_attribute must be checked against the effective
 #        command line options and any inconsistencies reported via a warning.

test/MC/Mips/mips_abi_flags_xx_set.s

 # RUN: llvm-mc %s -arch=mips -mcpu=mips32 | \
 # RUN:   FileCheck %s -check-prefix=CHECK-ASM
 #
 # RUN: llvm-mc %s -arch=mips -mcpu=mips32 -filetype=obj -o - | \
-# RUN:   llvm-readobj -sections -section-data -section-relocations - | \
+# RUN:   llvm-readobj -sections -section-data -section-relocations -mips-abi-flags - | \
 # RUN:     FileCheck %s -check-prefix=CHECK-OBJ
 
 # CHECK-ASM: .module fp=xx
 # CHECK-ASM: .set    fp=64
 
 # Checking if the Mips.abiflags were correctly emitted.
 # CHECK-OBJ:       Section {
 # CHECK-OBJ:         Index: 5
 # CHECK-OBJ-LABEL:   Name: .MIPS.abiflags (12)
 # CHECK-OBJ:         Type: SHT_MIPS_ABIFLAGS (0x7000002A)
 # CHECK-OBJ:          Flags [ (0x2)
 # CHECK-OBJ:           SHF_ALLOC (0x2)
 # CHECK-OBJ:         ]
 # CHECK-OBJ:         Address: 0x0
 # CHECK-OBJ:         Size: 24
 # CHECK-OBJ:         Link: 0
 # CHECK-OBJ:         Info: 0
 # CHECK-OBJ:         AddressAlignment: 8
 # CHECK-OBJ:         EntrySize: 24
 # CHECK-OBJ:         Relocations [
 # CHECK-OBJ:         ]
-# CHECK-OBJ:         SectionData (
-# CHECK-OBJ:           0000: 00002001 01010005 00000000 00000000  |.. .............|
-# CHECK-OBJ:           0010: 00000001 00000000                    |........|
-# CHECK-OBJ:         )
 # CHECK-OBJ-LABEL: }
+# CHECK-OBJ:       MIPS ABI Flags {
+# CHECK-OBJ-NEXT:    Version: 0
+# CHECK-OBJ-NEXT:    ISA: MIPS32 (MIPS32 revision 1)
+# CHECK-OBJ-NEXT:    ISA Extension: None (0x0)
+# CHECK-OBJ-NEXT:    ASEs [ (0x0)
+# CHECK-OBJ-NEXT:    ]
+# CHECK-OBJ-NEXT:    FP ABI: Hard float (32-bit CPU, Any FPU) (0x5)
+# CHECK-OBJ-NEXT:    GPR size: 32
+# CHECK-OBJ-NEXT:    CPR1 size: 32
+# CHECK-OBJ-NEXT:    CPR2 size: 0
+# CHECK-OBJ-NEXT:    Flags 1 [ (0x1)
+# CHECK-OBJ-NEXT:      ODDSPREG (0x1)
+# CHECK-OBJ-NEXT:    ]
+# CHECK-OBJ-NEXT:    Flags 2: 0x0
+# CHECK-OBJ-NEXT:  }
 
         .module fp=xx
         .set    fp=64
 # FIXME: Test should include gnu_attributes directive when implemented.
 #        An explicit .gnu_attribute must be checked against the effective
 #        command line options and any inconsistencies reported via a warning.

tools/llvm-readobj/ELFDumper.cpp

template <class ELFT> void ELFDumper<ELFT>::printMipsABIFlags() {
   DictScope GS(W, "MIPS ABI Flags");
 
   W.printNumber("Version", Flags->version);
   W.startLine() << "ISA: ";
   if (Flags->isa_rev <= 1)
     OS << format("MIPS%u", Flags->isa_level);
   else
     OS << format("MIPS%ur%u", Flags->isa_level, Flags->isa_rev);
+  OS << format(" (MIPS%u revision %u)", Flags->isa_level, Flags->isa_rev);
   OS << "\n";
   W.printEnum("ISA Extension", Flags->isa_ext, makeArrayRef(ElfMipsISAExtType));
   W.printFlags("ASEs", Flags->ases, makeArrayRef(ElfMipsASEFlags));
   W.printEnum("FP ABI", Flags->fp_abi, makeArrayRef(ElfMipsFpABIType));
   W.printNumber("GPR size", getMipsRegisterSize(Flags->gpr_size));
   W.printNumber("CPR1 size", getMipsRegisterSize(Flags->cpr1_size));
   W.printNumber("CPR2 size", getMipsRegisterSize(Flags->cpr2_size));
   W.printFlags("Flags 1", Flags->flags1, makeArrayRef(ElfMipsFlags1));
   W.printHex("Flags 2", Flags->flags2);
 }