From: George Rimar Date: Mon, 18 Mar 2019 14:27:41 +0000 (+0000) Subject: [llvm-objcopy] - Calculate the string table section sizes correctly. X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ab0a1d7699a58f9ebd13cdd944673bca6fd8985d;p=llvm [llvm-objcopy] - Calculate the string table section sizes correctly. This fixes the https://bugs.llvm.org/show_bug.cgi?id=40980. Previously if string optimization occurred as a result of StringTableBuilder's finalize() method, the size wasn't updated. This hopefully also makes the interaction between sections during finalization processes a bit more clear. Differential revision: https://reviews.llvm.org/D59488 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356371 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/test/tools/llvm-objcopy/ELF/basic-archive-copy.test b/test/tools/llvm-objcopy/ELF/basic-archive-copy.test index cf973d6cd3f..6d7e86c7e99 100644 --- a/test/tools/llvm-objcopy/ELF/basic-archive-copy.test +++ b/test/tools/llvm-objcopy/ELF/basic-archive-copy.test @@ -88,7 +88,7 @@ Symbols: # CHECK-NEXT: ] # CHECK-NEXT: Address: # CHECK-NEXT: Offset: -# CHECK-NEXT: Size: 6 +# CHECK-NEXT: Size: 5 # CHECK: Name: .shstrtab # CHECK-NEXT: Type: SHT_STRTAB diff --git a/test/tools/llvm-objcopy/ELF/cross-arch-sections-symbols.test b/test/tools/llvm-objcopy/ELF/cross-arch-sections-symbols.test index 1d959a97635..fa5832b9dfe 100644 --- a/test/tools/llvm-objcopy/ELF/cross-arch-sections-symbols.test +++ b/test/tools/llvm-objcopy/ELF/cross-arch-sections-symbols.test @@ -101,7 +101,7 @@ Symbols: # CHECK-NEXT: ] # CHECK-NEXT: Address: # CHECK-NEXT: Offset: -# CHECK-NEXT: Size: 10 +# CHECK-NEXT: Size: 9 # CHECK-NEXT: Link: 0 # CHECK-NEXT: Info: 0 # CHECK-NEXT: AddressAlignment: 1 diff --git a/test/tools/llvm-objcopy/ELF/shstrtab-optimize.test b/test/tools/llvm-objcopy/ELF/shstrtab-optimize.test new file mode 100644 index 00000000000..24b546cbaf5 --- /dev/null +++ b/test/tools/llvm-objcopy/ELF/shstrtab-optimize.test @@ -0,0 +1,28 @@ +# RUN: yaml2obj %s > %t +# RUN: llvm-objcopy %t %t2 +# RUN: llvm-readobj --sections %t2 | FileCheck %s + +## Check we have the correct size of the .shstrtab section +## after the strings tail merge optimization. + +# CHECK: Name: .shstrtab +# CHECK-NEXT: Type: SHT_STRTAB +# CHECK-NEXT: Flags [ +# CHECK-NEXT: ] +# CHECK-NEXT: Address: +# CHECK-NEXT: Offset: +# CHECK-NEXT: Size: 36 + +!ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_REL + Machine: EM_X86_64 +Sections: + - Name: .bar + Type: SHT_PROGBITS + Flags: [ ] + - Name: .foo.bar + Type: SHT_PROGBITS + Flags: [ ] diff --git a/test/tools/llvm-objcopy/ELF/strtab-optimize.test b/test/tools/llvm-objcopy/ELF/strtab-optimize.test new file mode 100644 index 00000000000..41f86814a80 --- /dev/null +++ b/test/tools/llvm-objcopy/ELF/strtab-optimize.test @@ -0,0 +1,21 @@ +# RUN: yaml2obj %s > %t +# RUN: llvm-objcopy %t %t2 --add-symbol='foo=1' --add-symbol='foofoo=2' +# RUN: llvm-readobj --sections %t2 | FileCheck %s + +## Check we have the correct size of the .strtab section +## after the strings tail merge optimization. + +# CHECK: Name: .strtab +# CHECK-NEXT: Type: SHT_STRTAB +# CHECK-NEXT: Flags [ +# CHECK-NEXT: ] +# CHECK-NEXT: Address: +# CHECK-NEXT: Offset: +# CHECK-NEXT: Size: 8 + +!ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_REL + Machine: EM_X86_64 diff --git a/tools/llvm-objcopy/ELF/Object.cpp b/tools/llvm-objcopy/ELF/Object.cpp index afa48e5c886..8b895826b3c 100644 --- a/tools/llvm-objcopy/ELF/Object.cpp +++ b/tools/llvm-objcopy/ELF/Object.cpp @@ -297,16 +297,16 @@ void CompressedSection::accept(MutableSectionVisitor &Visitor) { Visitor.visit(*this); } -void StringTableSection::addString(StringRef Name) { - StrTabBuilder.add(Name); - Size = StrTabBuilder.getSize(); -} +void StringTableSection::addString(StringRef Name) { StrTabBuilder.add(Name); } uint32_t StringTableSection::findIndex(StringRef Name) const { return StrTabBuilder.getOffset(Name); } -void StringTableSection::finalize() { StrTabBuilder.finalize(); } +void StringTableSection::prepareForLayout() { + StrTabBuilder.finalize(); + Size = StrTabBuilder.getSize(); +} void SectionWriter::visit(const StringTableSection &Sec) { Sec.StrTabBuilder.write(Out.getBufferStart() + Sec.Offset); @@ -468,9 +468,6 @@ void SymbolTableSection::initialize(SectionTableRef SecTable) { } void SymbolTableSection::finalize() { - // Make sure SymbolNames is finalized before getting name indexes. - SymbolNames->finalize(); - uint32_t MaxLocalIndex = 0; for (auto &Sym : Symbols) { Sym->NameIndex = SymbolNames->findIndex(Sym->Name); @@ -1612,11 +1609,14 @@ template Error ELFWriter::finalize() { if (Obj.SymbolTable != nullptr) Obj.SymbolTable->prepareForLayout(); + // Now that all strings are added we want to finalize string table builders, + // because that affects section sizes which in turn affects section offsets. + for (auto &Sec : Obj.sections()) + if (auto StrTab = dyn_cast(&Sec)) + StrTab->prepareForLayout(); + assignOffsets(); - // Finalize SectionNames first so that we can assign name indexes. - if (Obj.SectionNames != nullptr) - Obj.SectionNames->finalize(); // Finally now that all offsets and indexes have been set we can finalize any // remaining issues. uint64_t Offset = Obj.SHOffset + sizeof(Elf_Shdr); diff --git a/tools/llvm-objcopy/ELF/Object.h b/tools/llvm-objcopy/ELF/Object.h index 6bb80469c54..8e72cedcf27 100644 --- a/tools/llvm-objcopy/ELF/Object.h +++ b/tools/llvm-objcopy/ELF/Object.h @@ -421,7 +421,7 @@ public: void addString(StringRef Name); uint32_t findIndex(StringRef Name) const; - void finalize() override; + void prepareForLayout(); void accept(SectionVisitor &Visitor) const override; void accept(MutableSectionVisitor &Visitor) override;