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Fix a problem occuring with type unification of symbol table entries 

llvm-svn: 955
This commit is contained in:
Chris Lattner 2001-10-22 21:59:46 +00:00
parent 4dedee5dc4
commit 100884edad
1 changed files with 55 additions and 1 deletions
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56
llvm/lib/VMCore/SymbolTable.cpp
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@ -8,6 +8,7 @@
#include "llvm/InstrTypes.h"
#include "llvm/Support/StringExtras.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Method.h"
SymbolTable::~SymbolTable() {
// Drop all abstract type references in the type plane...
@ -158,6 +159,13 @@ void SymbolTable::refineAbstractType(const DerivedType *OldType,
const Type *NewType) {
if (OldType == NewType) return; // Noop, don't waste time dinking around
// Get a handle to the new type plane...
iterator NewTypeIt = find(NewType);
if (NewTypeIt == super::end()) // If no plane exists, add one
NewTypeIt = super::insert(make_pair(NewType, VarMap())).first;
VarMap &NewPlane = NewTypeIt->second;
// Search to see if we have any values of the type oldtype. If so, we need to
// move them into the newtype plane...
iterator TPI = find(OldType);
@ -165,8 +173,54 @@ void SymbolTable::refineAbstractType(const DerivedType *OldType,
VarMap &OldPlane = TPI->second;
while (!OldPlane.empty()) {
pair<const string, Value*> V = *OldPlane.begin();
// Check to see if there is already a value in the symbol table that this
// would collide with.
type_iterator TI = NewPlane.find(V.first);
if (TI != NewPlane.end() && TI->second == V.second) {
// No action
} else if (TI != NewPlane.end()) {
// The only thing we are allowing for now is two method prototypes being
// folded into one.
//
if (Method *ExistM = dyn_cast<Method>(TI->second))
if (Method *NewM = dyn_cast<Method>(V.second))
if (ExistM->isExternal() && NewM->isExternal()) {
// Ok we have two external methods. Make all uses of the new one
// use the old one...
//
NewM->replaceAllUsesWith(ExistM);
// Now we just convert it to an unnamed method... which won't get
// added to our symbol table. The problem is that if we call
// setName on the method that it will try to remove itself from
// the symbol table and die... because it's not in the symtab
// right now. To fix this, we temporarily insert it (by setting
// TI's entry to the old value. Then after it is removed, we
// restore ExistM into the symbol table.
//
if (NewM->getType() == NewType) {
TI->second = NewM; // Add newM to the symtab
// Remove newM from the symtab
NewM->setName("");
// Readd ExistM to the symbol table....
NewPlane.insert(make_pair(V.first, ExistM));
} else {
NewM->setName("");
}
continue;
}
assert(0 && "Two ploanes folded together with overlapping "
"value names!");
} else {
insertEntry(V.first, NewType, V.second);
}
// Remove the item from the old type plane
OldPlane.erase(OldPlane.begin());
insertEntry(V.first, NewType, V.second);
}
// Ok, now we are not referencing the type anymore... take me off your user