[llvm] r317654 - Revert "Reapply: Allow yaml2obj to order implicit sections for ELF"
Dave Lee via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 7 17:31:20 PST 2017
Author: kastiglione
Date: Tue Nov 7 17:31:20 2017
New Revision: 317654
URL: http://llvm.org/viewvc/llvm-project?rev=317654&view=rev
Log:
Revert "Reapply: Allow yaml2obj to order implicit sections for ELF"
This reverts commit r317646.
Removed:
llvm/trunk/test/tools/yaml2obj/section-ordering.yaml
llvm/trunk/test/tools/yaml2obj/unnamed-section.yaml
Modified:
llvm/trunk/lib/ObjectYAML/ELFYAML.cpp
llvm/trunk/tools/yaml2obj/yaml2elf.cpp
Modified: llvm/trunk/lib/ObjectYAML/ELFYAML.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ObjectYAML/ELFYAML.cpp?rev=317654&r1=317653&r2=317654&view=diff
==============================================================================
--- llvm/trunk/lib/ObjectYAML/ELFYAML.cpp (original)
+++ llvm/trunk/lib/ObjectYAML/ELFYAML.cpp Tue Nov 7 17:31:20 2017
@@ -388,7 +388,7 @@ void ScalarEnumerationTraits<ELFYAML::EL
#define ECase(X) IO.enumCase(Value, #X, ELF::X)
ECase(SHT_NULL);
ECase(SHT_PROGBITS);
- ECase(SHT_SYMTAB);
+ // No SHT_SYMTAB. Use the top-level `Symbols` key instead.
// FIXME: Issue a diagnostic with this information.
ECase(SHT_STRTAB);
ECase(SHT_RELA);
Removed: llvm/trunk/test/tools/yaml2obj/section-ordering.yaml
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/yaml2obj/section-ordering.yaml?rev=317653&view=auto
==============================================================================
--- llvm/trunk/test/tools/yaml2obj/section-ordering.yaml (original)
+++ llvm/trunk/test/tools/yaml2obj/section-ordering.yaml (removed)
@@ -1,29 +0,0 @@
-# Ensures that implicitly added sections can be ordered within Sections.
-# RUN: yaml2obj %s -o %t
-# RUN: llvm-readobj -sections %t | FileCheck %s
-
-!ELF
-FileHeader:
- Class: ELFCLASS64
- Data: ELFDATA2LSB
- Type: ET_EXEC
- Machine: EM_X86_64
-Sections:
- - Name: .text
- Type: SHT_PROGBITS
- Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
- - Name: .symtab
- Type: SHT_SYMTAB
- - Name: .data
- Type: SHT_PROGBITS
- Flags: [ SHF_ALLOC, SHF_WRITE ]
- - Name: .shstrtab
- Type: SHT_STRTAB
- - Name: .strtab
- Type: SHT_STRTAB
-
-# CHECK: Name: .text
-# CHECK: Name: .symtab
-# CHECK: Name: .data
-# CHECK: Name: .shstrtab
-# CHECK: Name: .strtab
Removed: llvm/trunk/test/tools/yaml2obj/unnamed-section.yaml
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/yaml2obj/unnamed-section.yaml?rev=317653&view=auto
==============================================================================
--- llvm/trunk/test/tools/yaml2obj/unnamed-section.yaml (original)
+++ llvm/trunk/test/tools/yaml2obj/unnamed-section.yaml (removed)
@@ -1,14 +0,0 @@
-# Ensure yaml2obj doesn't crash on unnamed sections
-# RUN: yaml2obj %s
-
-!ELF
-FileHeader:
- Class: ELFCLASS64
- Data: ELFDATA2LSB
- Type: ET_EXEC
- Machine: EM_X86_64
-Sections:
- - Type: SHT_PROGBITS
- - Name: .text
- Type: SHT_PROGBITS
- Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
Modified: llvm/trunk/tools/yaml2obj/yaml2elf.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/yaml2obj/yaml2elf.cpp?rev=317654&r1=317653&r2=317654&view=diff
==============================================================================
--- llvm/trunk/tools/yaml2obj/yaml2elf.cpp (original)
+++ llvm/trunk/tools/yaml2obj/yaml2elf.cpp Tue Nov 7 17:31:20 2017
@@ -74,14 +74,6 @@ public:
Idx = I->getValue();
return false;
}
- /// asserts if name is not present in the map
- unsigned get(StringRef Name) const {
- unsigned Idx = 0;
- auto missing = lookup(Name, Idx);
- assert(!missing && "Expected section not found in index");
- return Idx;
- }
- unsigned size() const { return Map.size(); }
};
} // end anonymous namespace
@@ -152,21 +144,19 @@ class ELFState {
ContiguousBlobAccumulator &CBA);
// - SHT_NULL entry (placed first, i.e. 0'th entry)
- // - symbol table (.symtab) (defaults to third to last)
- // - string table (.strtab) (defaults to second to last)
- // - section header string table (.shstrtab) (defaults to last)
- unsigned getDotSymTabSecNo() const { return SN2I.get(".symtab"); }
- unsigned getDotStrTabSecNo() const { return SN2I.get(".strtab"); }
- unsigned getDotShStrTabSecNo() const { return SN2I.get(".shstrtab"); }
- unsigned getSectionCount() const { return SN2I.size() + 1; }
+ // - symbol table (.symtab) (placed third to last)
+ // - string table (.strtab) (placed second to last)
+ // - section header string table (.shstrtab) (placed last)
+ unsigned getDotSymTabSecNo() const { return Doc.Sections.size() + 1; }
+ unsigned getDotStrTabSecNo() const { return Doc.Sections.size() + 2; }
+ unsigned getDotShStrTabSecNo() const { return Doc.Sections.size() + 3; }
+ unsigned getSectionCount() const { return Doc.Sections.size() + 4; }
ELFState(const ELFYAML::Object &D) : Doc(D) {}
public:
static int writeELF(raw_ostream &OS, const ELFYAML::Object &Doc);
};
-
-static const char * const ImplicitSecNames[] = {".symtab", ".strtab", ".shstrtab"};
} // end anonymous namespace
template <class ELFT>
@@ -221,6 +211,10 @@ bool ELFState<ELFT>::initSectionHeaders(
zero(SHeader);
SHeaders.push_back(SHeader);
+ for (const auto &Sec : Doc.Sections)
+ DotShStrtab.add(Sec->Name);
+ DotShStrtab.finalize();
+
for (const auto &Sec : Doc.Sections) {
zero(SHeader);
SHeader.sh_name = DotShStrtab.getOffset(Sec->Name);
@@ -553,9 +547,12 @@ bool ELFState<ELFT>::writeSectionContent
}
template <class ELFT> bool ELFState<ELFT>::buildSectionIndex() {
+ SN2I.addName(".symtab", getDotSymTabSecNo());
+ SN2I.addName(".strtab", getDotStrTabSecNo());
+ SN2I.addName(".shstrtab", getDotShStrTabSecNo());
+
for (unsigned i = 0, e = Doc.Sections.size(); i != e; ++i) {
StringRef Name = Doc.Sections[i]->Name;
- DotShStrtab.add(Name);
if (Name.empty())
continue;
// "+ 1" to take into account the SHT_NULL entry.
@@ -565,17 +562,6 @@ template <class ELFT> bool ELFState<ELFT
return false;
}
}
-
- auto SecNo = 1 + Doc.Sections.size();
- // Add special sections after input sections, if necessary.
- for (const auto &Name : ImplicitSecNames)
- if (!SN2I.addName(Name, SecNo)) {
- // Account for this section, since it wasn't in the Doc
- ++SecNo;
- DotShStrtab.add(Name);
- }
-
- DotShStrtab.finalize();
return true;
}
@@ -622,23 +608,32 @@ int ELFState<ELFT>::writeELF(raw_ostream
Header.e_shentsize * Header.e_shnum;
ContiguousBlobAccumulator CBA(SectionContentBeginOffset);
+ // Doc might not contain .symtab, .strtab and .shstrtab sections,
+ // but we will emit them, so make sure to add them to ShStrTabSHeader.
+ State.DotShStrtab.add(".symtab");
+ State.DotShStrtab.add(".strtab");
+ State.DotShStrtab.add(".shstrtab");
+
std::vector<Elf_Shdr> SHeaders;
- SHeaders.reserve(State.SN2I.size());
if(!State.initSectionHeaders(SHeaders, CBA))
return 1;
- // Populate SHeaders with implicit sections not present in the Doc
- for (const auto &Name : ImplicitSecNames)
- if (State.SN2I.get(Name) >= SHeaders.size())
- SHeaders.push_back({});
-
- // Initialize the implicit sections
- auto Index = State.SN2I.get(".symtab");
- State.initSymtabSectionHeader(SHeaders[Index], CBA);
- Index = State.SN2I.get(".strtab");
- State.initStrtabSectionHeader(SHeaders[Index], ".strtab", State.DotStrtab, CBA);
- Index = State.SN2I.get(".shstrtab");
- State.initStrtabSectionHeader(SHeaders[Index], ".shstrtab", State.DotShStrtab, CBA);
+ // .symtab section.
+ Elf_Shdr SymtabSHeader;
+ State.initSymtabSectionHeader(SymtabSHeader, CBA);
+ SHeaders.push_back(SymtabSHeader);
+
+ // .strtab string table header.
+ Elf_Shdr DotStrTabSHeader;
+ State.initStrtabSectionHeader(DotStrTabSHeader, ".strtab", State.DotStrtab,
+ CBA);
+ SHeaders.push_back(DotStrTabSHeader);
+
+ // .shstrtab string table header.
+ Elf_Shdr ShStrTabSHeader;
+ State.initStrtabSectionHeader(ShStrTabSHeader, ".shstrtab", State.DotShStrtab,
+ CBA);
+ SHeaders.push_back(ShStrTabSHeader);
// Now we can decide segment offsets
State.setProgramHeaderLayout(PHeaders, SHeaders);
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