[llvm] r312603 - Use the section name if a STT_SECTION symbol has empty name.
Rafael Espindola via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 5 17:57:53 PDT 2017
Author: rafael
Date: Tue Sep 5 17:57:53 2017
New Revision: 312603
URL: http://llvm.org/viewvc/llvm-project?rev=312603&view=rev
Log:
Use the section name if a STT_SECTION symbol has empty name.
Without this we would have multiple relocations pointing to symbols
with the same name: the empty string. There was no way for yaml2obj to
be able to handle that.
A more general solution would be to unique symbol names in a similar
way to how we unique section names. In practice I think this covers
all common cases and is a bit more user friendly than using names like
sym1, sym2, sym3, etc.
Added:
llvm/trunk/test/Object/X86/obj2yaml-dup-symbol-name.s
Modified:
llvm/trunk/test/Object/obj2yaml.test
llvm/trunk/tools/obj2yaml/elf2yaml.cpp
Added: llvm/trunk/test/Object/X86/obj2yaml-dup-symbol-name.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Object/X86/obj2yaml-dup-symbol-name.s?rev=312603&view=auto
==============================================================================
--- llvm/trunk/test/Object/X86/obj2yaml-dup-symbol-name.s (added)
+++ llvm/trunk/test/Object/X86/obj2yaml-dup-symbol-name.s Tue Sep 5 17:57:53 2017
@@ -0,0 +1,9 @@
+# RUN: llvm-mc %s -o %t.o -filetype=obj -triple=x86_64-pc-linux
+# RUN: obj2yaml %t.o | FileCheck %s
+
+# CHECK: Relocations:
+# CHECK: Symbol: .text
+# CHECK: Symbols:
+# CHECK: - Name: .text
+
+ .quad .text
Modified: llvm/trunk/test/Object/obj2yaml.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Object/obj2yaml.test?rev=312603&r1=312602&r2=312603&view=diff
==============================================================================
--- llvm/trunk/test/Object/obj2yaml.test (original)
+++ llvm/trunk/test/Object/obj2yaml.test Tue Sep 5 17:57:53 2017
@@ -268,19 +268,26 @@ ELF-MIPSEL-NEXT: - Name:
ELF-MIPSEL-NEXT: Type: STT_OBJECT
ELF-MIPSEL-NEXT: Section: .rodata.str1.1
ELF-MIPSEL-NEXT: Size: 0x000000000000000D
-ELF-MIPSEL-NEXT: - Type: STT_SECTION
+ELF-MIPSEL-NEXT: - Name: .text
+ELF-MIPSEL-NEXT: Type: STT_SECTION
ELF-MIPSEL-NEXT: Section: .text
-ELF-MIPSEL-NEXT: - Type: STT_SECTION
+ELF-MIPSEL-NEXT: - Name: .data
+ELF-MIPSEL-NEXT: Type: STT_SECTION
ELF-MIPSEL-NEXT: Section: .data
-ELF-MIPSEL-NEXT: - Type: STT_SECTION
+ELF-MIPSEL-NEXT: - Name: .bss
+ELF-MIPSEL-NEXT: Type: STT_SECTION
ELF-MIPSEL-NEXT: Section: .bss
-ELF-MIPSEL-NEXT: - Type: STT_SECTION
+ELF-MIPSEL-NEXT: - Name: .mdebug.abi32
+ELF-MIPSEL-NEXT: Type: STT_SECTION
ELF-MIPSEL-NEXT: Section: .mdebug.abi32
-ELF-MIPSEL-NEXT: - Type: STT_SECTION
+ELF-MIPSEL-NEXT: - Name: .rodata.str1.1
+ELF-MIPSEL-NEXT: Type: STT_SECTION
ELF-MIPSEL-NEXT: Section: .rodata.str1.1
-ELF-MIPSEL-NEXT: - Type: STT_SECTION
+ELF-MIPSEL-NEXT: - Name: .reginfo
+ELF-MIPSEL-NEXT: Type: STT_SECTION
ELF-MIPSEL-NEXT: Section: .reginfo
-ELF-MIPSEL-NEXT: - Type: STT_SECTION
+ELF-MIPSEL-NEXT: - Name: .MIPS.abiflags
+ELF-MIPSEL-NEXT: Type: STT_SECTION
ELF-MIPSEL-NEXT: Section: .MIPS.abiflags
ELF-MIPSEL-NEXT: Global:
ELF-MIPSEL-NEXT: - Name: main
@@ -336,17 +343,22 @@ ELF-MIPS64EL-NEXT: AddressAlign:
ELF-MIPS64EL-NEXT: Content: ''
ELF-MIPS64EL-NEXT: Symbols:
ELF-MIPS64EL-NEXT: Local:
-ELF-MIPS64EL-NEXT: - Type: STT_SECTION
+ELF-MIPS64EL-NEXT: - Name: .text
+ELF-MIPS64EL-NEXT: Type: STT_SECTION
ELF-MIPS64EL-NEXT: Section: .text
-ELF-MIPS64EL-NEXT: - Type: STT_SECTION
+ELF-MIPS64EL-NEXT: - Name: .data
+ELF-MIPS64EL-NEXT: Type: STT_SECTION
ELF-MIPS64EL-NEXT: Section: .data
-ELF-MIPS64EL-NEXT: - Type: STT_SECTION
+ELF-MIPS64EL-NEXT: - Name: .bss
+ELF-MIPS64EL-NEXT: Type: STT_SECTION
ELF-MIPS64EL-NEXT: Section: .bss
ELF-MIPS64EL-NEXT: - Name: bar
ELF-MIPS64EL-NEXT: Section: .data
-ELF-MIPS64EL-NEXT: - Type: STT_SECTION
+ELF-MIPS64EL-NEXT: - Name: .MIPS.options
+ELF-MIPS64EL-NEXT: Type: STT_SECTION
ELF-MIPS64EL-NEXT: Section: .MIPS.options
-ELF-MIPS64EL-NEXT: - Type: STT_SECTION
+ELF-MIPS64EL-NEXT: - Name: .pdr
+ELF-MIPS64EL-NEXT: Type: STT_SECTION
ELF-MIPS64EL-NEXT: Section: .pdr
ELF-MIPS64EL-NEXT: Global:
ELF-MIPS64EL-NEXT: - Name: zed
@@ -382,7 +394,7 @@ ELF-X86-64-NEXT: AddressAlign: 0x
ELF-X86-64-NEXT: Info: .text
ELF-X86-64-NEXT: Relocations:
ELF-X86-64-NEXT: - Offset: 0x000000000000000D
-ELF-X86-64-NEXT: Symbol: ''
+ELF-X86-64-NEXT: Symbol: .rodata.str1.1
ELF-X86-64-NEXT: Type: R_X86_64_32S
ELF-X86-64-NEXT: - Offset: 0x0000000000000012
ELF-X86-64-NEXT: Symbol: puts
@@ -396,11 +408,14 @@ ELF-X86-64-NEXT: Symbols:
ELF-X86-64-NEXT: Local:
ELF-X86-64-NEXT: - Name: trivial-object-test.s
ELF-X86-64-NEXT: Type: STT_FILE
-ELF-X86-64-NEXT: - Type: STT_SECTION
+ELF-X86-64-NEXT: - Name: .text
+ELF-X86-64-NEXT: Type: STT_SECTION
ELF-X86-64-NEXT: Section: .text
-ELF-X86-64-NEXT: - Type: STT_SECTION
+ELF-X86-64-NEXT: - Name: .rodata.str1.1
+ELF-X86-64-NEXT: Type: STT_SECTION
ELF-X86-64-NEXT: Section: .rodata.str1.1
-ELF-X86-64-NEXT: - Type: STT_SECTION
+ELF-X86-64-NEXT: - Name: .note.GNU-stack
+ELF-X86-64-NEXT: Type: STT_SECTION
ELF-X86-64-NEXT: Section: .note.GNU-stack
ELF-X86-64-NEXT: Global:
ELF-X86-64-NEXT: - Name: main
@@ -431,9 +446,11 @@ ELF-AVR-NEXT: AddressAlign: 0x000
ELF-AVR-NEXT: Content: ''
ELF-AVR-NEXT: Symbols:
ELF-AVR-NEXT: Local:
-ELF-AVR-NEXT: - Type: STT_SECTION
+ELF-AVR-NEXT: - Name: .text
+ELF-AVR-NEXT: Type: STT_SECTION
ELF-AVR-NEXT: Section: .text
-ELF-AVR-NEXT: - Type: STT_SECTION
+ELF-AVR-NEXT: - Name: .data
+ELF-AVR-NEXT: Type: STT_SECTION
ELF-AVR-NEXT: Section: .data
ELF-AVR-NEXT: Value: 0x0000000000800060
ELF-AVR-NEXT: - Name: a.o
Modified: llvm/trunk/tools/obj2yaml/elf2yaml.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/obj2yaml/elf2yaml.cpp?rev=312603&r1=312602&r2=312603&view=diff
==============================================================================
--- llvm/trunk/tools/obj2yaml/elf2yaml.cpp (original)
+++ llvm/trunk/tools/obj2yaml/elf2yaml.cpp Tue Sep 5 17:57:53 2017
@@ -36,6 +36,8 @@ class ELFDumper {
DenseSet<StringRef> UsedSectionNames;
std::vector<std::string> SectionNames;
Expected<StringRef> getUniquedSectionName(const Elf_Shdr *Sec);
+ Expected<StringRef> getSymbolName(const Elf_Sym *Sym, StringRef StrTable,
+ const Elf_Shdr *SymTab);
const object::ELFFile<ELFT> &Obj;
ArrayRef<Elf_Word> ShndxTable;
@@ -87,6 +89,23 @@ ELFDumper<ELFT>::getUniquedSectionName(c
return Ret;
}
+template <class ELFT>
+Expected<StringRef> ELFDumper<ELFT>::getSymbolName(const Elf_Sym *Sym,
+ StringRef StrTable,
+ const Elf_Shdr *SymTab) {
+ Expected<StringRef> SymbolNameOrErr = Sym->getName(StrTable);
+ if (!SymbolNameOrErr)
+ return SymbolNameOrErr;
+ StringRef Name = *SymbolNameOrErr;
+ if (Name.empty() && Sym->getType() == ELF::STT_SECTION) {
+ auto ShdrOrErr = Obj.getSection(Sym, SymTab, ShndxTable);
+ if (!ShdrOrErr)
+ return ShdrOrErr.takeError();
+ return getUniquedSectionName(*ShdrOrErr);
+ }
+ return Name;
+}
+
template <class ELFT> ErrorOr<ELFYAML::Object *> ELFDumper<ELFT>::dump() {
auto Y = make_unique<ELFYAML::Object>();
@@ -217,7 +236,7 @@ ELFDumper<ELFT>::dumpSymbol(const Elf_Sy
S.Size = Sym->st_size;
S.Other = Sym->st_other;
- Expected<StringRef> SymbolNameOrErr = Sym->getName(StrTable);
+ Expected<StringRef> SymbolNameOrErr = getSymbolName(Sym, StrTable, SymTab);
if (!SymbolNameOrErr)
return errorToErrorCode(SymbolNameOrErr.takeError());
S.Name = SymbolNameOrErr.get();
@@ -259,7 +278,7 @@ std::error_code ELFDumper<ELFT>::dumpRel
StringRef StrTab = *StrTabOrErr;
if (Sym) {
- Expected<StringRef> NameOrErr = Sym->getName(StrTab);
+ Expected<StringRef> NameOrErr = getSymbolName(Sym, StrTab, SymTab);
if (!NameOrErr)
return errorToErrorCode(NameOrErr.takeError());
R.Symbol = NameOrErr.get();
@@ -425,7 +444,7 @@ ErrorOr<ELFYAML::Group *> ELFDumper<ELFT
auto sectionContents = Obj.getSectionContents(Shdr);
if (!sectionContents)
return errorToErrorCode(sectionContents.takeError());
- Expected<StringRef> symbolName = symbol->getName(StrTab);
+ Expected<StringRef> symbolName = getSymbolName(symbol, StrTab, Symtab);
if (!symbolName)
return errorToErrorCode(symbolName.takeError());
S->Info = *symbolName;
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