Emit a symbol table entry for each function we output to the ELF file. This
allows objdump to know which function we are emitting to:
00000000 <foo>: <----
0: b8 01 00 00 00 mov $0x1,%eax
5: 03 44 24 04 add 0x4(%esp,1),%eax
9: c3 ret
... and allows .o files to be useful for linking :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22378 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/ELFWriter.cpp b/lib/CodeGen/ELFWriter.cpp
index 96668e2..2f2eec0 100644
--- a/lib/CodeGen/ELFWriter.cpp
+++ b/lib/CodeGen/ELFWriter.cpp
@@ -67,7 +67,37 @@
FnStart = OutputBuffer.size();
}
- void finishFunction(MachineFunction &F) {}
+ void finishFunction(MachineFunction &F) {
+ // We now know the size of the function, add a symbol to represent it.
+ ELFWriter::ELFSym FnSym(F.getFunction());
+
+ // Figure out the binding (linkage) of the symbol.
+ switch (F.getFunction()->getLinkage()) {
+ default:
+ // appending linkage is illegal for functions.
+ assert(0 && "Unknown linkage type!");
+ case GlobalValue::ExternalLinkage:
+ FnSym.SetBind(ELFWriter::ELFSym::STB_GLOBAL);
+ break;
+ case GlobalValue::LinkOnceLinkage:
+ case GlobalValue::WeakLinkage:
+ FnSym.SetBind(ELFWriter::ELFSym::STB_WEAK);
+ break;
+ case GlobalValue::InternalLinkage:
+ FnSym.SetBind(ELFWriter::ELFSym::STB_LOCAL);
+ break;
+ }
+
+ FnSym.SetType(ELFWriter::ELFSym::STT_FUNC);
+ FnSym.SectionIdx = EW.SectionList.size()-1; // .text section.
+ // Value = Offset from start of .text
+ FnSym.Value = FnStart - EW.SectionList.back().Offset;
+ FnSym.Size = OutputBuffer.size()-FnStart;
+
+ // Finally, add it to the symtab.
+ EW.SymbolTable.push_back(FnSym);
+ }
+
void emitConstantPool(MachineConstantPool *MCP) {
if (MCP->isEmpty()) return;
assert(0 && "unimp");