Fix a few issues with comdat handling on COFF.
* Section association cannot use just the section name as many
sections can have the same name. With this patch, the comdat symbol in
an assoc section is interpreted to mean a symbol in the associated
section and the mapping is discovered from it.
* Comdat symbols were not being set correctly. Instead we were getting
whatever was output first for that section.
A consequence is that associative sections now must use .section to
set the association. Using .linkonce would not work since it is not
possible to change a sections comdat symbol (it is used to decide if
we should create a new section or reuse an existing one).
This includes r210298, which was reverted because it was asserting
on an associated section having the same comdat as the associated
section.
llvm-svn: 210367
diff --git a/llvm/lib/MC/MCSectionCOFF.cpp b/llvm/lib/MC/MCSectionCOFF.cpp
index 335b8cd..fc2bd36 100644
--- a/llvm/lib/MC/MCSectionCOFF.cpp
+++ b/llvm/lib/MC/MCSectionCOFF.cpp
@@ -30,14 +30,9 @@
return false;
}
-void MCSectionCOFF::setSelection(int Selection,
- const MCSectionCOFF *Assoc) const {
+void MCSectionCOFF::setSelection(int Selection) const {
assert(Selection != 0 && "invalid COMDAT selection type");
- assert((Selection == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) ==
- (Assoc != nullptr) &&
- "associative COMDAT section must have an associated section");
this->Selection = Selection;
- this->Assoc = Assoc;
Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
}
@@ -82,7 +77,7 @@
OS << "same_contents,";
break;
case COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE:
- OS << "associative " << Assoc->getSectionName() << ",";
+ OS << "associative,";
break;
case COFF::IMAGE_COMDAT_SELECT_LARGEST:
OS << "largest,";