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[yaml2obj] - Allow placing local symbols after globals. 

This allows us to produce broken binaries with local
symbols placed after global in '.dynsym'/'.symtab'

Also, simplifies the code.

Differential revision: https://reviews.llvm.org/D66799

llvm-svn: 370331
This commit is contained in:
George Rimar 2019-08-29 10:58:47 +00:00
parent 72e9584698
commit de0bc44883
2 changed files with 33 additions and 29 deletions
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24
llvm/lib/ObjectYAML/ELFEmitter.cpp
View File

@ -995,24 +995,12 @@ template <class ELFT> bool ELFState<ELFT>::buildSectionIndex() {
}
static bool buildSymbolsMap(ArrayRef<ELFYAML::Symbol> V, NameToIdxMap &Map) {
bool GlobalSymbolSeen = false;
std::size_t I = 0;
for (const ELFYAML::Symbol &Sym : V) {
++I;
StringRef Name = Sym.Name;
if (Sym.Binding.value == ELF::STB_LOCAL && GlobalSymbolSeen) {
WithColor::error() << "Local symbol '" + Name +
"' after global in Symbols list.\n";
return false;
}
if (Sym.Binding.value != ELF::STB_LOCAL)
GlobalSymbolSeen = true;
if (!Name.empty() && !Map.addName(Name, I)) {
WithColor::error() << "Repeated symbol name: '" << Name << "'.\n";
return false;
}
for (size_t I = 0, S = V.size(); I < S; ++I) {
const ELFYAML::Symbol &Sym = V[I];
if (Sym.Name.empty() || Map.addName(Sym.Name, I + 1))
continue;
WithColor::error() << "Repeated symbol name: '" << Sym.Name << "'.\n";
return false;
}
return true;
}

38
llvm/test/tools/yaml2obj/elf-symbols-binding-order.yaml
View File

@ -1,18 +1,34 @@
## Check we restrict placing local symbols after global in .symtab
## We might want to change it later to allow doing that
## for producing broken outputs.
## Check we allow placing local symbols after global to
## .symtab and .dynsym. This allows us to produce broken outputs.
# RUN: not yaml2obj %s -o %t 2>&1 | FileCheck %s
# CHECK: error: Local symbol 'bar' after global in Symbols list.
# RUN: yaml2obj %s -o %t
# RUN: llvm-readelf --symbols %t | FileCheck %s
# CHECK: Symbol table '.dynsym' contains 3 entries:
# CHECK-NEXT: Num: Value Size Type Bind Vis Ndx Name
# CHECK-NEXT: 0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND
# CHECK-NEXT: 1: 0000000000000000 0 NOTYPE GLOBAL DEFAULT UND dynamicGlobal
# CHECK-NEXT: 2: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND dynamicLocal
# CHECK: Symbol table '.symtab' contains 3 entries:
# CHECK-NEXT: Num: Value Size Type Bind Vis Ndx Name
# CHECK-NEXT: 0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND
# CHECK-NEXT: 1: 0000000000000000 0 NOTYPE GLOBAL DEFAULT UND staticGlobal
# CHECK-NEXT: 2: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND staticLocal
--- !ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_REL
Machine: EM_X86_64
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_REL
Machine: EM_X86_64
Symbols:
- Name: foo
- Name: staticGlobal
Binding: STB_GLOBAL
- Name: bar
- Name: staticLocal
Binding: STB_LOCAL
DynamicSymbols:
- Name: dynamicGlobal
Binding: STB_GLOBAL
- Name: dynamicLocal
Binding: STB_LOCAL