[PATCH] D37567: [llvm-readobj] - Teach tool to report error if some section is in multiple COMDAT groups at once.

[Rafael Avila de Espindola via llvm-commits]

Can you check if readelf prints this to stderr or stdout and if its exit
status is 0 or 1?

Thanks,
Rafael

George Rimar via Phabricator <reviews at reviews.llvm.org> writes:

> grimar updated this revision to Diff 115184.
> grimar added a comment.
>
> - Rebased after r313236.
>
>
> https://reviews.llvm.org/D37567
>
> Files:
>   test/tools/llvm-readobj/broken-group.test
>   tools/llvm-readobj/ELFDumper.cpp
>
> Index: tools/llvm-readobj/ELFDumper.cpp
> ===================================================================
> --- tools/llvm-readobj/ELFDumper.cpp
> +++ tools/llvm-readobj/ELFDumper.cpp
> @@ -18,6 +18,7 @@
>  #include "StackMapPrinter.h"
>  #include "llvm-readobj.h"
>  #include "llvm/ADT/ArrayRef.h"
> +#include "llvm/ADT/DenseMap.h"
>  #include "llvm/ADT/Optional.h"
>  #include "llvm/ADT/PointerIntPair.h"
>  #include "llvm/ADT/SmallString.h"
> @@ -2489,18 +2490,38 @@
>    }
>    return Ret;
>  }
> +
> +DenseMap<uint64_t, const GroupSection *>
> +mapSectionsToGroups(ArrayRef<GroupSection> Groups) {
> +  DenseMap<uint64_t, const GroupSection *> Ret;
> +  for (const GroupSection &G : Groups)
> +    for (const GroupMember &GM : G.Members)
> +      Ret.insert({GM.Index, &G});
> +  return Ret;
> +}
> +
>  } // namespace
>  
>  template <class ELFT> void GNUStyle<ELFT>::printGroupSections(const ELFO *Obj) {
>    std::vector<GroupSection> V = getGroups<ELFT>(Obj);
> +  DenseMap<uint64_t, const GroupSection *> Map = mapSectionsToGroups(V);
>    for (const GroupSection &G : V) {
>      OS << "\n"
>         << getGroupType(G.Type) << " group section ["
>         << format_decimal(G.Index, 5) << "] `" << G.Name << "' [" << G.Signature
>         << "] contains " << G.Members.size() << " sections:\n"
>         << "   [Index]    Name\n";
> -    for (const GroupMember &GM : G.Members)
> +    for (const GroupMember &GM : G.Members) {
> +      const GroupSection *MainGroup = Map[GM.Index];
> +      if (MainGroup != &G) {
> +        OS << "Error: section [" << format_decimal(GM.Index, 5)
> +           << "] in group section [" << format_decimal(G.Index, 5)
> +           << "] already in group section ["
> +           << format_decimal(MainGroup->Index, 5) << "]";
> +        continue;
> +      }
>        OS << "   [" << format_decimal(GM.Index, 5) << "]   " << GM.Name << "\n";
> +    }
>    }
>  
>    if (V.empty())
> @@ -3525,16 +3546,25 @@
>  void LLVMStyle<ELFT>::printGroupSections(const ELFO *Obj) {
>    DictScope Lists(W, "Groups");
>    std::vector<GroupSection> V = getGroups<ELFT>(Obj);
> +  DenseMap<uint64_t, const GroupSection *> Map = mapSectionsToGroups(V);
>    for (const GroupSection &G : V) {
>      DictScope D(W, "Group");
>      W.printNumber("Name", G.Name, G.ShName);
>      W.printNumber("Index", G.Index);
>      W.printHex("Type", getGroupType(G.Type), G.Type);
>      W.startLine() << "Signature: " << G.Signature << "\n";
>  
>      ListScope L(W, "Section(s) in group");
> -    for (const GroupMember &GM : G.Members)
> +    for (const GroupMember &GM : G.Members) {
> +      const GroupSection *MainGroup = Map[GM.Index];
> +      if (MainGroup != &G) {
> +        W.startLine() << "Error: " << GM.Name << " (" << GM.Index
> +                      << ") already in a group " + MainGroup->Name + " ("
> +                      << MainGroup->Index << ")\n";
> +        continue;
> +      }
>        W.startLine() << GM.Name << " (" << GM.Index << ")\n";
> +    }
>    }
>  
>    if (V.empty())
> Index: test/tools/llvm-readobj/broken-group.test
> ===================================================================
> --- test/tools/llvm-readobj/broken-group.test
> +++ test/tools/llvm-readobj/broken-group.test
> @@ -0,0 +1,73 @@
> +# RUN: yaml2obj %s -o %t.o
> +
> +# RUN: llvm-readobj --elf-section-groups -elf-output-style=GNU %t.o \
> +# RUN:   | FileCheck %s -check-prefix=GNU
> +# GNU:      COMDAT group section [    2] `.group' [bar] contains 1 sections:
> +# GNU-NEXT:   [Index]    Name
> +# GNU-NEXT:   [    3]   .foo
> +# GNU:      COMDAT group section [    4] `.group1' [zed] contains 1 sections:
> +# GNU-NEXT:   [Index]    Name
> +# GNU-NEXT:   Error: section [    3] in group section [    4] already in group section [    2]
> +
> +# RUN: llvm-readobj --elf-section-groups %t.o \
> +# RUN:   | FileCheck %s -check-prefix=LLVM
> +# LLVM:      Groups {
> +# LLVM-NEXT:   Group {
> +# LLVM-NEXT:     Name: .group
> +# LLVM-NEXT:     Index: 2
> +# LLVM-NEXT:     Type: COMDAT
> +# LLVM-NEXT:     Signature: bar
> +# LLVM-NEXT:     Section(s) in group [
> +# LLVM-NEXT:       .foo (3)
> +# LLVM-NEXT:     ]
> +# LLVM-NEXT:   }
> +# LLVM-NEXT:   Group {
> +# LLVM-NEXT:     Name: .group1
> +# LLVM-NEXT:     Index: 4
> +# LLVM-NEXT:     Type: COMDAT
> +# LLVM-NEXT:     Signature: zed
> +# LLVM-NEXT:     Section(s) in group [
> +# LLVM-NEXT:       Error: .foo (3) already in a group .group (2)
> +# LLVM-NEXT:     ]
> +# LLVM-NEXT:   }
> +# LLVM-NEXT: }
> +
> +!ELF
> +FileHeader:      
> +  Class:           ELFCLASS64
> +  Data:            ELFDATA2LSB
> +  Type:            ET_REL
> +  Machine:         EM_X86_64
> +Sections:        
> +  - Name:            .text
> +    Type:            SHT_PROGBITS
> +    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
> +    AddressAlign:    0x0000000000000004
> +    Content:         ''
> +  - Name:            .group
> +    Type:            SHT_GROUP
> +    Link:            .symtab
> +    AddressAlign:    0x0000000000000004
> +    Info:            bar
> +    Members:         
> +      - SectionOrType:   GRP_COMDAT
> +      - SectionOrType:   .foo
> +  - Name:            .foo
> +    Type:            SHT_PROGBITS
> +    Flags:           [ SHF_ALLOC, SHF_EXECINSTR, SHF_GROUP ]
> +    AddressAlign:    0x0000000000000001
> +    Content:         ''
> +  - Name:            .group1
> +    Type:            SHT_GROUP
> +    Link:            .symtab
> +    AddressAlign:    0x0000000000000004
> +    Info:            zed
> +    Members:         
> +      - SectionOrType:   GRP_COMDAT
> +      - SectionOrType:   .foo
> +Symbols:         
> +  Local:           
> +    - Name:            bar
> +      Section:         .group
> +    - Name:            zed
> +      Section:         .group1