[XCOFF][AIX] Read-only data section object file generation

[jasonliu]

Summary

This patch is a follow up on read-only assembly patch D70182.
It intends to enable object file generation for the read-only data section on AIX.

[jasonliu]

Fix test.

[daltenty]

Other than minor nit, LGTM

llvm/test/CodeGen/PowerPC/aix-xcoff-rodata.ll

4

nit: should these have "-verify-machineinstrs -mcpu=pwr7" for consistency?

[jasonliu]

llvm/test/CodeGen/PowerPC/aix-xcoff-rodata.ll

4

Yes, I will add them in.

[DiggerLin]

llvm/test/CodeGen/PowerPC/aix-xcoff-rodata.ll

285

since we have a tool which can print out the raw section content. you want to test the readonly raw data in .text section in the this patch ? or you want to create a new patch for it ?

[jasonliu]

Added -verify-machine-instr and -mcpu for consistency.
Added raw data testing.

[jasonliu]

llvm/test/CodeGen/PowerPC/aix-xcoff-rodata.ll

285

Thanks for the reminder. I added it this patch.

[DiggerLin]

LGTM

llvm/lib/MC/XCOFFObjectWriter.cpp

class XCOFFObjectWriter : public MCObjectWriter {
   support::endian::Writer W;
   std::unique_ptr<MCXCOFFObjectTargetWriter> TargetObjectWriter;
   StringTableBuilder Strings;
 
   // CsectGroups. These store the csects which make up different parts of
   // the sections. Should have one for each set of csects that get mapped into
   // the same section and get handled in a 'similar' way.
   CsectGroup ProgramCodeCsects;
+  CsectGroup ReadOnlyCsects;
   CsectGroup DataCsects;
   CsectGroup FuncDSCsects;
   CsectGroup TOCCsects;
   CsectGroup BSSCsects;
 
   // The Predefined sections.
   Section Text;
   Section Data;
XCOFFObjectWriter(std::unique_ptr<MCXCOFFObjectTargetWriter> MOTW,
                     raw_pwrite_stream &OS);
 };
 
 XCOFFObjectWriter::XCOFFObjectWriter(
     std::unique_ptr<MCXCOFFObjectTargetWriter> MOTW, raw_pwrite_stream &OS)
     : W(OS, support::big), TargetObjectWriter(std::move(MOTW)),
       Strings(StringTableBuilder::XCOFF),
       Text(".text", XCOFF::STYP_TEXT, /* IsVirtual */ false,
-           CsectGroups{&ProgramCodeCsects}),
+           CsectGroups{&ProgramCodeCsects, &ReadOnlyCsects}),
       Data(".data", XCOFF::STYP_DATA, /* IsVirtual */ false,
            CsectGroups{&DataCsects, &FuncDSCsects, &TOCCsects}),
       BSS(".bss", XCOFF::STYP_BSS, /* IsVirtual */ true,
           CsectGroups{&BSSCsects}) {}
 
 void XCOFFObjectWriter::reset() {
   // Reset any sections we have written to, and empty the section header table.
   for (auto *Sec : Sections)

 }
 
 CsectGroup &XCOFFObjectWriter::getCsectGroup(const MCSectionXCOFF *MCSec) {
   switch (MCSec->getMappingClass()) {
   case XCOFF::XMC_PR:
     assert(XCOFF::XTY_SD == MCSec->getCSectType() &&
            "Only an initialized csect can contain program code.");
     return ProgramCodeCsects;
+  case XCOFF::XMC_RO:
+    assert(XCOFF::XTY_SD == MCSec->getCSectType() &&
+           "Only an initialized csect can contain read only data.");
+    return ReadOnlyCsects;
   case XCOFF::XMC_RW:
     if (XCOFF::XTY_CM == MCSec->getCSectType())
       return BSSCsects;
 
     if (XCOFF::XTY_SD == MCSec->getCSectType())
       return DataCsects;
 
     report_fatal_error("Unhandled mapping of read-write csect to section.");

llvm/test/CodeGen/PowerPC/aix-xcoff-rodata.ll

 ; RUN: llc -verify-machineinstrs -mcpu=pwr7 -mtriple powerpc-ibm-aix-xcoff  < %s | FileCheck %s
 ; RUN: llc -verify-machineinstrs -mcpu=pwr7 -mtriple powerpc64-ibm-aix-xcoff < %s | FileCheck %s
 
+; RUN: llc -verify-machineinstrs -mcpu=pwr7 -mtriple powerpc-ibm-aix-xcoff -filetype=obj -o %t.o < %s
+; RUN: llvm-readobj --section-headers --file-header %t.o | \
+; RUN: FileCheck --check-prefix=OBJ %s
+; RUN: llvm-readobj --syms %t.o | FileCheck --check-prefix=SYMS %s
+; RUN: llvm-objdump -D %t.o | FileCheck --check-prefix=DIS %s
+
+; RUN: not llc -verify-machineinstrs -mcpu=pwr7 -mtriple powerpc64-ibm-aix-xcoff -filetype=obj < %s 2>&1 | \
+; RUN: FileCheck --check-prefix=XCOFF64 %s
+; XCOFF64: LLVM ERROR: 64-bit XCOFF object files are not supported yet.
+
 @const_ivar = constant i32 35, align 4
 @const_llvar = constant i64 36, align 8
 @const_svar = constant i16 37, align 2
 @const_fvar = constant float 8.000000e+02, align 4
 @const_dvar = constant double 9.000000e+02, align 8
 @const_over_aligned = constant double 9.000000e+02, align 32
 @const_chrarray = constant [4 x i8] c"abcd", align 1
 @const_dblarr = constant [4 x double] [double 1.000000e+00, double 2.000000e+00, double 3.000000e+00, double 4.000000e+00], align 8

 ; CHECK-NEXT:          .byte   100
 ; CHECK-NEXT:          .globl  const_dblarr
 ; CHECK-NEXT:          .align  3
 ; CHECK-NEXT:  const_dblarr:
 ; CHECK-NEXT:          .llong  4607182418800017408
 ; CHECK-NEXT:          .llong  4611686018427387904
 ; CHECK-NEXT:          .llong  4613937818241073152
 ; CHECK-NEXT:          .llong  4616189618054758400
+
+
+; OBJ:      File: {{.*}}aix-xcoff-rodata.ll.tmp.o
+; OBJ-NEXT: Format: aixcoff-rs6000
+; OBJ-NEXT: Arch: powerpc
+; OBJ-NEXT: AddressSize: 32bit
+; OBJ-NEXT: FileHeader {
+; OBJ-NEXT:   Magic: 0x1DF
+; OBJ-NEXT:   NumberOfSections: 1
+; OBJ-NEXT:   TimeStamp: None (0x0)
+; OBJ-NEXT:   SymbolTableOffset: 0x8C
+; OBJ-NEXT:   SymbolTableEntries: 20
+; OBJ-NEXT:   OptionalHeaderSize: 0x0
+; OBJ-NEXT:   Flags: 0x0
+; OBJ-NEXT: }
+
+; OBJ:      Sections [
+; OBJ:        Section {
+; OBJ-NEXT:     Index: 1
+; OBJ-NEXT:     Name: .text
+; OBJ-NEXT:     PhysicalAddress: 0x0
+; OBJ-NEXT:     VirtualAddress: 0x0
+; OBJ-NEXT:     Size: 0x50
+; OBJ-NEXT:     RawDataOffset: 0x3C
+; OBJ-NEXT:     RelocationPointer: 0x0
+; OBJ-NEXT:     LineNumberPointer: 0x0
+; OBJ-NEXT:     NumberOfRelocations: 0
+; OBJ-NEXT:     NumberOfLineNumbers: 0
+; OBJ-NEXT:     Type: STYP_TEXT (0x20)
+; OBJ-NEXT:   }
+; OBJ-NEXT: ]
+
+
+; SYMS:       File: {{.*}}aix-xcoff-rodata.ll.tmp.o
+; SYMS-NEXT:  Format: aixcoff-rs6000
+; SYMS-NEXT:  Arch: powerpc
+; SYMS-NEXT:  AddressSize: 32bit
+; SYMS:       Symbols [
+; SYMS:        Symbol {{[{][[:space:]] *}}Index: [[#INDX:]]{{[[:space:]] *}}Name: .rodata
+; SYMS-NEXT:     Value (RelocatableAddress): 0x0
+; SYMS-NEXT:     Section: .text
+; SYMS-NEXT:     Type: 0x0
+; SYMS-NEXT:     StorageClass: C_HIDEXT (0x6B)
+; SYMS-NEXT:     NumberOfAuxEntries: 1
+; SYMS-NEXT:     CSECT Auxiliary Entry {
+; SYMS-NEXT:       Index: [[#INDX+1]]
+; SYMS-NEXT:       SectionLen: 80
+; SYMS-NEXT:       ParameterHashIndex: 0x0
+; SYMS-NEXT:       TypeChkSectNum: 0x0
+; SYMS-NEXT:       SymbolAlignmentLog2: 5
+; SYMS-NEXT:       SymbolType: XTY_SD (0x1)
+; SYMS-NEXT:       StorageMappingClass: XMC_RO (0x1)
+; SYMS-NEXT:       StabInfoIndex: 0x0
+; SYMS-NEXT:       StabSectNum: 0x0
+; SYMS-NEXT:     }
+; SYMS-NEXT:   }
+
+; SYMS:        Symbol {
+; SYMS-NEXT:     Index: [[#INDX+2]]
+; SYMS-NEXT:     Name: const_ivar
+; SYMS-NEXT:     Value (RelocatableAddress): 0x0
+; SYMS-NEXT:     Section: .text
+; SYMS-NEXT:     Type: 0x0
+; SYMS-NEXT:     StorageClass: C_EXT (0x2)
+; SYMS-NEXT:     NumberOfAuxEntries: 1
+; SYMS-NEXT:     CSECT Auxiliary Entry {
+; SYMS-NEXT:       Index: [[#INDX+3]]
+; SYMS-NEXT:       ContainingCsectSymbolIndex: 2
+; SYMS-NEXT:       ParameterHashIndex: 0x0
+; SYMS-NEXT:       TypeChkSectNum: 0x0
+; SYMS-NEXT:       SymbolAlignmentLog2: 0
+; SYMS-NEXT:       SymbolType: XTY_LD (0x2)
+; SYMS-NEXT:       StorageMappingClass: XMC_RO (0x1)
+; SYMS-NEXT:       StabInfoIndex: 0x0
+; SYMS-NEXT:       StabSectNum: 0x0
+; SYMS-NEXT:     }
+; SYMS-NEXT:   }
+
+; SYMS:        Symbol {
+; SYMS-NEXT:     Index: [[#INDX+4]]
+; SYMS-NEXT:     Name: const_llvar
+; SYMS-NEXT:     Value (RelocatableAddress): 0x8
+; SYMS-NEXT:     Section: .text
+; SYMS-NEXT:     Type: 0x0
+; SYMS-NEXT:     StorageClass: C_EXT (0x2)
+; SYMS-NEXT:     NumberOfAuxEntries: 1
+; SYMS-NEXT:     CSECT Auxiliary Entry {
+; SYMS-NEXT:       Index: [[#INDX+5]]
+; SYMS-NEXT:       ContainingCsectSymbolIndex: 2
+; SYMS-NEXT:       ParameterHashIndex: 0x0
+; SYMS-NEXT:       TypeChkSectNum: 0x0
+; SYMS-NEXT:       SymbolAlignmentLog2: 0
+; SYMS-NEXT:       SymbolType: XTY_LD (0x2)
+; SYMS-NEXT:       StorageMappingClass: XMC_RO (0x1)
+; SYMS-NEXT:       StabInfoIndex: 0x0
+; SYMS-NEXT:       StabSectNum: 0x0
+; SYMS-NEXT:     }
+; SYMS-NEXT:   }
+
+; SYMS:        Symbol {
+; SYMS-NEXT:     Index: [[#INDX+6]]
+; SYMS-NEXT:     Name: const_svar
+; SYMS-NEXT:     Value (RelocatableAddress): 0x10
+; SYMS-NEXT:     Section: .text
+; SYMS-NEXT:     Type: 0x0
+; SYMS-NEXT:     StorageClass: C_EXT (0x2)
+; SYMS-NEXT:     NumberOfAuxEntries: 1
+; SYMS-NEXT:     CSECT Auxiliary Entry {
+; SYMS-NEXT:       Index: [[#INDX+7]]
+; SYMS-NEXT:       ContainingCsectSymbolIndex: 2
+; SYMS-NEXT:       ParameterHashIndex: 0x0
+; SYMS-NEXT:       TypeChkSectNum: 0x0
+; SYMS-NEXT:       SymbolAlignmentLog2: 0
+; SYMS-NEXT:       SymbolType: XTY_LD (0x2)
+; SYMS-NEXT:       StorageMappingClass: XMC_RO (0x1)
+; SYMS-NEXT:       StabInfoIndex: 0x0
+; SYMS-NEXT:       StabSectNum: 0x0
+; SYMS-NEXT:     }
+; SYMS-NEXT:   }
+
+; SYMS:        Symbol {
+; SYMS-NEXT:     Index: [[#INDX+8]]
+; SYMS-NEXT:     Name: const_fvar
+; SYMS-NEXT:     Value (RelocatableAddress): 0x14
+; SYMS-NEXT:     Section: .text
+; SYMS-NEXT:     Type: 0x0
+; SYMS-NEXT:     StorageClass: C_EXT (0x2)
+; SYMS-NEXT:     NumberOfAuxEntries: 1
+; SYMS-NEXT:     CSECT Auxiliary Entry {
+; SYMS-NEXT:       Index: [[#INDX+9]]
+; SYMS-NEXT:       ContainingCsectSymbolIndex: 2
+; SYMS-NEXT:       ParameterHashIndex: 0x0
+; SYMS-NEXT:       TypeChkSectNum: 0x0
+; SYMS-NEXT:       SymbolAlignmentLog2: 0
+; SYMS-NEXT:       SymbolType: XTY_LD (0x2)
+; SYMS-NEXT:       StorageMappingClass: XMC_RO (0x1)
+; SYMS-NEXT:       StabInfoIndex: 0x0
+; SYMS-NEXT:       StabSectNum: 0x0
+; SYMS-NEXT:     }
+; SYMS-NEXT:   }
+
+; SYMS:        Symbol {
+; SYMS-NEXT:     Index: [[#INDX+10]]
+; SYMS-NEXT:     Name: const_dvar
+; SYMS-NEXT:     Value (RelocatableAddress): 0x18
+; SYMS-NEXT:     Section: .text
+; SYMS-NEXT:     Type: 0x0
+; SYMS-NEXT:     StorageClass: C_EXT (0x2)
+; SYMS-NEXT:     NumberOfAuxEntries: 1
+; SYMS-NEXT:     CSECT Auxiliary Entry {
+; SYMS-NEXT:       Index: [[#INDX+11]]
+; SYMS-NEXT:       ContainingCsectSymbolIndex: 2
+; SYMS-NEXT:       ParameterHashIndex: 0x0
+; SYMS-NEXT:       TypeChkSectNum: 0x0
+; SYMS-NEXT:       SymbolAlignmentLog2: 0
+; SYMS-NEXT:       SymbolType: XTY_LD (0x2)
+; SYMS-NEXT:       StorageMappingClass: XMC_RO (0x1)
+; SYMS-NEXT:       StabInfoIndex: 0x0
+; SYMS-NEXT:       StabSectNum: 0x0
+; SYMS-NEXT:     }
+; SYMS-NEXT:   }
+
+; SYMS:        Symbol {
+; SYMS-NEXT:     Index: [[#INDX+12]]
+; SYMS-NEXT:     Name: const_over_aligned
+; SYMS-NEXT:     Value (RelocatableAddress): 0x20
+; SYMS-NEXT:     Section: .text
+; SYMS-NEXT:     Type: 0x0
+; SYMS-NEXT:     StorageClass: C_EXT (0x2)
+; SYMS-NEXT:     NumberOfAuxEntries: 1
+; SYMS-NEXT:     CSECT Auxiliary Entry {
+; SYMS-NEXT:       Index: [[#INDX+13]]
+; SYMS-NEXT:       ContainingCsectSymbolIndex: 2
+; SYMS-NEXT:       ParameterHashIndex: 0x0
+; SYMS-NEXT:       TypeChkSectNum: 0x0
+; SYMS-NEXT:       SymbolAlignmentLog2: 0
+; SYMS-NEXT:       SymbolType: XTY_LD (0x2)
+; SYMS-NEXT:       StorageMappingClass: XMC_RO (0x1)
+; SYMS-NEXT:       StabInfoIndex: 0x0
+; SYMS-NEXT:       StabSectNum: 0x0
+; SYMS-NEXT:     }
+; SYMS-NEXT:   }
+
+; SYMS:        Symbol {
+; SYMS-NEXT:     Index: [[#INDX+14]]
+; SYMS-NEXT:     Name: const_chrarray
+; SYMS-NEXT:     Value (RelocatableAddress): 0x28
+; SYMS-NEXT:     Section: .text
+; SYMS-NEXT:     Type: 0x0
+; SYMS-NEXT:     StorageClass: C_EXT (0x2)
+; SYMS-NEXT:     NumberOfAuxEntries: 1
+; SYMS-NEXT:     CSECT Auxiliary Entry {
+; SYMS-NEXT:       Index: [[#INDX+15]]
+; SYMS-NEXT:       ContainingCsectSymbolIndex: 2
+; SYMS-NEXT:       ParameterHashIndex: 0x0
+; SYMS-NEXT:       TypeChkSectNum: 0x0
+; SYMS-NEXT:       SymbolAlignmentLog2: 0
+; SYMS-NEXT:       SymbolType: XTY_LD (0x2)
+; SYMS-NEXT:       StorageMappingClass: XMC_RO (0x1)
+; SYMS-NEXT:       StabInfoIndex: 0x0
+; SYMS-NEXT:       StabSectNum: 0x0
+; SYMS-NEXT:     }
+; SYMS-NEXT:   }
+
+; SYMS:        Symbol {
+; SYMS-NEXT:     Index: [[#INDX+16]]
+; SYMS-NEXT:     Name: const_dblarr
+; SYMS-NEXT:     Value (RelocatableAddress): 0x30
+; SYMS-NEXT:     Section: .text
+; SYMS-NEXT:     Type: 0x0
+; SYMS-NEXT:     StorageClass: C_EXT (0x2)
+; SYMS-NEXT:     NumberOfAuxEntries: 1
+; SYMS-NEXT:     CSECT Auxiliary Entry {
+; SYMS-NEXT:       Index: [[#INDX+17]]
+; SYMS-NEXT:       ContainingCsectSymbolIndex: 2
+; SYMS-NEXT:       ParameterHashIndex: 0x0
+; SYMS-NEXT:       TypeChkSectNum: 0x0
+; SYMS-NEXT:       SymbolAlignmentLog2: 0
+; SYMS-NEXT:       SymbolType: XTY_LD (0x2)
+; SYMS-NEXT:       StorageMappingClass: XMC_RO (0x1)
+; SYMS-NEXT:       StabInfoIndex: 0x0
+; SYMS-NEXT:       StabSectNum: 0x0
+; SYMS-NEXT:     }
+; SYMS-NEXT:   }
+; SYMS:      ]
+
+; DIS: Disassembly of section .text:
+; DIS: 00000000 const_ivar:
+; DIS-NEXT:        0: 00 00 00 23
+; DIS-NEXT:        4: 00 00 00 00
+
+; DIS: 00000008 const_llvar:
+; DIS-NEXT:        8: 00 00 00 00
+; DIS-NEXT:        c: 00 00 00 24
+
+; DIS: 00000010 const_svar:
+; DIS-NEXT:       10: 00 25 00 00
+
+; DIS: 00000014 const_fvar:
+; DIS-NEXT:       14: 44 48 00 00
+
+; DIS: 00000018 const_dvar:
+; DIS-NEXT:       18: 40 8c 20 00
+; DIS-NEXT:       1c: 00 00 00 00
+
+; DIS: 00000020 const_over_aligned:
+; DIS-NEXT:       20: 40 8c 20 00
+; DIS-NEXT:       24: 00 00 00 00
+
+; DIS: 00000028 const_chrarray:
+; DIS-NEXT:       28: 61 62 63 64
+; DIS-NEXT:       2c: 00 00 00 00
+
+; DIS: 00000030 const_dblarr:
+; DIS-NEXT:       30: 3f f0 00 00
+; DIS-NEXT:       34: 00 00 00 00
+; DIS-NEXT:       38: 40 00 00 00
+; DIS-NEXT:       3c: 00 00 00 00
+; DIS-NEXT:       40: 40 08 00 00
+; DIS-NEXT:       44: 00 00 00 00
+; DIS-NEXT:       48: 40 10 00 00
+; DIS-NEXT:       4c: 00 00 00 00