[yaml2obj][obj2yaml] - Change how symbol's binding is descibed when parsing/dumping.
Currently, YAML has the following syntax for describing the symbols:
Symbols:
Local:
LocalSymbol1:
...
LocalSymbol2:
...
...
Global:
GlobalSymbol1:
...
Weak:
...
GNUUnique:
I.e. symbols are grouped by their bindings. That is not very convenient,
because:
It does not allow to set a custom binding, what can be useful for producing
broken/special outputs for test cases. Adding a new binding would require to
change a syntax (what we observed when added GNUUnique recently).
It does not allow to change the order of the symbols in .symtab/.dynsym,
i.e. currently all Local symbols are placed first, then Global, Weak and GNUUnique
are following, but we are not able to change the order.
It is not consistent. Binding is just one of the properties of the symbol,
we do not group them by other properties.
It makes the code more complex that it can be. This patch shows it can be simplified
with the change performed.
The patch changes the syntax to just:
Symbols:
Symbol1:
...
Symbol2:
...
...
With that, we are able to work with the binding field just like with any other symbol property.
Differential revision: https://reviews.llvm.org/D60122
llvm-svn: 357595
diff --git a/llvm/tools/yaml2obj/yaml2elf.cpp b/llvm/tools/yaml2obj/yaml2elf.cpp
index 7a8b0cc..1507504 100644
--- a/llvm/tools/yaml2obj/yaml2elf.cpp
+++ b/llvm/tools/yaml2obj/yaml2elf.cpp
@@ -133,7 +133,7 @@
const ELFYAML::Object &Doc;
bool buildSectionIndex();
- bool buildSymbolIndex(const ELFYAML::SymbolsDef &);
+ bool buildSymbolIndex(ArrayRef<ELFYAML::Symbol> Symbols);
void initELFHeader(Elf_Ehdr &Header);
void initProgramHeaders(std::vector<Elf_Phdr> &PHeaders);
bool initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
@@ -145,8 +145,7 @@
ContiguousBlobAccumulator &CBA);
void setProgramHeaderLayout(std::vector<Elf_Phdr> &PHeaders,
std::vector<Elf_Shdr> &SHeaders);
- void addSymbols(const std::vector<ELFYAML::Symbol> &Symbols,
- std::vector<Elf_Sym> &Syms, unsigned SymbolBinding,
+ void addSymbols(ArrayRef<ELFYAML::Symbol> Symbols, std::vector<Elf_Sym> &Syms,
const StringTableBuilder &Strtab);
void writeSectionContent(Elf_Shdr &SHeader,
const ELFYAML::RawContentSection &Section,
@@ -171,7 +170,6 @@
bool writeSectionContent(Elf_Shdr &SHeader,
const ELFYAML::DynamicSection &Section,
ContiguousBlobAccumulator &CBA);
- bool hasDynamicSymbols() const;
SmallVector<const char *, 5> implicitSectionNames() const;
// - SHT_NULL entry (placed first, i.e. 0'th entry)
@@ -323,6 +321,13 @@
return true;
}
+static size_t findFirstNonGlobal(ArrayRef<ELFYAML::Symbol> Symbols) {
+ for (size_t I = 0; I < Symbols.size(); ++I)
+ if (Symbols[I].Binding.value != ELF::STB_LOCAL)
+ return I;
+ return Symbols.size();
+}
+
template <class ELFT>
void ELFState<ELFT>::initSymtabSectionHeader(Elf_Shdr &SHeader,
SymtabType STType,
@@ -335,7 +340,7 @@
const auto &Symbols = IsStatic ? Doc.Symbols : Doc.DynamicSymbols;
auto &Strtab = IsStatic ? DotStrtab : DotDynstr;
// One greater than symbol table index of the last local symbol.
- SHeader.sh_info = Symbols.Local.size() + 1;
+ SHeader.sh_info = findFirstNonGlobal(Symbols) + 1;
SHeader.sh_entsize = sizeof(Elf_Sym);
SHeader.sh_addralign = 8;
@@ -359,10 +364,7 @@
Syms.push_back(Sym);
}
- addSymbols(Symbols.Local, Syms, ELF::STB_LOCAL, Strtab);
- addSymbols(Symbols.Global, Syms, ELF::STB_GLOBAL, Strtab);
- addSymbols(Symbols.Weak, Syms, ELF::STB_WEAK, Strtab);
- addSymbols(Symbols.GNUUnique, Syms, ELF::STB_GNU_UNIQUE, Strtab);
+ addSymbols(Symbols, Syms, Strtab);
writeArrayData(
CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign),
@@ -471,16 +473,15 @@
}
template <class ELFT>
-void ELFState<ELFT>::addSymbols(const std::vector<ELFYAML::Symbol> &Symbols,
+void ELFState<ELFT>::addSymbols(ArrayRef<ELFYAML::Symbol> Symbols,
std::vector<Elf_Sym> &Syms,
- unsigned SymbolBinding,
const StringTableBuilder &Strtab) {
for (const auto &Sym : Symbols) {
Elf_Sym Symbol;
zero(Symbol);
if (!Sym.Name.empty())
Symbol.st_name = Strtab.getOffset(Sym.Name);
- Symbol.setBindingAndType(SymbolBinding, Sym.Type);
+ Symbol.setBindingAndType(Sym.Binding, Sym.Type);
if (!Sym.Section.empty()) {
unsigned Index;
if (SN2I.lookup(Sym.Section, Index)) {
@@ -796,45 +797,41 @@
}
template <class ELFT>
-bool ELFState<ELFT>::buildSymbolIndex(const ELFYAML::SymbolsDef &Symbols) {
+bool ELFState<ELFT>::buildSymbolIndex(ArrayRef<ELFYAML::Symbol> Symbols) {
+ bool GlobalSymbolSeen = false;
std::size_t I = 0;
- for (const std::vector<ELFYAML::Symbol> &V :
- {Symbols.Local, Symbols.Global, Symbols.Weak, Symbols.GNUUnique}) {
- for (const auto &Sym : V) {
- ++I;
- if (Sym.Name.empty())
- continue;
- if (SymN2I.addName(Sym.Name, I)) {
- WithColor::error() << "Repeated symbol name: '" << Sym.Name << "'.\n";
- return false;
- }
+ for (const auto &Sym : Symbols) {
+ ++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() && SymN2I.addName(Name, I)) {
+ WithColor::error() << "Repeated symbol name: '" << Name << "'.\n";
+ return false;
}
}
return true;
}
template <class ELFT> void ELFState<ELFT>::finalizeStrings() {
- auto AddSymbols = [](StringTableBuilder &StrTab,
- const ELFYAML::SymbolsDef &Symbols) {
- for (const auto &Sym : Symbols.Local)
- StrTab.add(Sym.Name);
- for (const auto &Sym : Symbols.Global)
- StrTab.add(Sym.Name);
- for (const auto &Sym : Symbols.Weak)
- StrTab.add(Sym.Name);
- for (const auto &Sym : Symbols.GNUUnique)
- StrTab.add(Sym.Name);
- };
-
// Add the regular symbol names to .strtab section.
- AddSymbols(DotStrtab, Doc.Symbols);
+ for (const ELFYAML::Symbol &Sym : Doc.Symbols)
+ DotStrtab.add(Sym.Name);
DotStrtab.finalize();
- if (!hasDynamicSymbols())
+ if (Doc.DynamicSymbols.empty())
return;
// Add the dynamic symbol names to .dynstr section.
- AddSymbols(DotDynstr, Doc.DynamicSymbols);
+ for (const ELFYAML::Symbol &Sym : Doc.DynamicSymbols)
+ DotDynstr.add(Sym.Name);
// SHT_GNU_verdef and SHT_GNU_verneed sections might also
// add strings to .dynstr section.
@@ -901,7 +898,7 @@
State.initStrtabSectionHeader(SHeaders[Index], ".strtab", State.DotStrtab, CBA);
Index = State.SN2I.get(".shstrtab");
State.initStrtabSectionHeader(SHeaders[Index], ".shstrtab", State.DotShStrtab, CBA);
- if (State.hasDynamicSymbols()) {
+ if (!Doc.DynamicSymbols.empty()) {
Index = State.SN2I.get(".dynsym");
State.initSymtabSectionHeader(SHeaders[Index], SymtabType::Dynamic, CBA);
SHeaders[Index].sh_flags |= ELF::SHF_ALLOC;
@@ -920,16 +917,9 @@
return 0;
}
-template <class ELFT> bool ELFState<ELFT>::hasDynamicSymbols() const {
- return !Doc.DynamicSymbols.Global.empty() ||
- !Doc.DynamicSymbols.Weak.empty() ||
- !Doc.DynamicSymbols.Local.empty() ||
- !Doc.DynamicSymbols.GNUUnique.empty();
-}
-
template <class ELFT>
SmallVector<const char *, 5> ELFState<ELFT>::implicitSectionNames() const {
- if (!hasDynamicSymbols())
+ if (Doc.DynamicSymbols.empty())
return {".symtab", ".strtab", ".shstrtab"};
return {".symtab", ".strtab", ".shstrtab", ".dynsym", ".dynstr"};
}