6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-22 10:24:26 +00:00
Code Issues Projects Releases Wiki Activity

Use LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN instead of the "dso list".

Browse Source 
There are two ways one could implement hiding of linkonce_odr symbols in LTO:
* LLVM tells the linker which symbols can be hidden if not used from native
  files.
* The linker tells LLVM which symbols are not used from other object files,
  but will be put in the dso symbol table if present.

GOLD's API is the second option. It was implemented almost 1:1 in llvm by
passing the list down to internalize.

LLVM already had partial support for the first option. It is also very similar
to how ld64 handles hiding these symbols when *not* doing LTO.

This patch then
* removes the APIs for the DSO list.
* marks LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN all linkonce_odr unnamed_addr
  global values and other linkonce_odr whose address is not used.
* makes the gold plugin responsible for handling the API mismatch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193800 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Rafael Espindola
2013-10-31 20:51:58 +00:00
parent f7ba489730
commit 7e667c56cf
14 changed files with 96 additions and 130 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
lib/LTO/LTOCodeGenerator.cpp
View File

@ -313,7 +313,6 @@ bool LTOCodeGenerator::determineTarget(std::string &errMsg) {
void LTOCodeGenerator::
applyRestriction(GlobalValue &GV,
std::vector<const char*> &MustPreserveList,
std::vector<const char*> &DSOList,
SmallPtrSet<GlobalValue*, 8> &AsmUsed,
Mangler &Mangler) {
SmallString<64> Buffer;
@ -323,8 +322,6 @@ applyRestriction(GlobalValue &GV,
return;
if (MustPreserveSymbols.count(Buffer))
MustPreserveList.push_back(GV.getName().data());
if (DSOSymbols.count(Buffer))
DSOList.push_back(GV.getName().data());
if (AsmUndefinedRefs.count(Buffer))
AsmUsed.insert(&GV);
}
@ -352,18 +349,17 @@ void LTOCodeGenerator::applyScopeRestrictions() {
// mark which symbols can not be internalized
Mangler Mangler(TargetMach);
std::vector<const char*> MustPreserveList;
std::vector<const char*> DSOList;
SmallPtrSet<GlobalValue*, 8> AsmUsed;
for (Module::iterator f = mergedModule->begin(),
e = mergedModule->end(); f != e; ++f)
applyRestriction(*f, MustPreserveList, DSOList, AsmUsed, Mangler);
applyRestriction(*f, MustPreserveList, AsmUsed, Mangler);
for (Module::global_iterator v = mergedModule->global_begin(),
e = mergedModule->global_end(); v != e; ++v)
applyRestriction(*v, MustPreserveList, DSOList, AsmUsed, Mangler);
applyRestriction(*v, MustPreserveList, AsmUsed, Mangler);
for (Module::alias_iterator a = mergedModule->alias_begin(),
e = mergedModule->alias_end(); a != e; ++a)
applyRestriction(*a, MustPreserveList, DSOList, AsmUsed, Mangler);
applyRestriction(*a, MustPreserveList, AsmUsed, Mangler);
GlobalVariable *LLVMCompilerUsed =
mergedModule->getGlobalVariable("llvm.compiler.used");
@ -391,7 +387,7 @@ void LTOCodeGenerator::applyScopeRestrictions() {
LLVMCompilerUsed->setSection("llvm.metadata");
}
passes.add(createInternalizePass(MustPreserveList, DSOList));
passes.add(createInternalizePass(MustPreserveList));
// apply scope restrictions
passes.run(*mergedModule);