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Make sure that section and visibility are properly propagated. 

llvm-svn: 33870
This commit is contained in:
Reid Spencer 2007-02-04 04:28:18 +00:00
parent edfc7e5fa2
commit 2ea1bb2b8a
1 changed files with 101 additions and 85 deletions
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186
llvm/lib/Linker/LinkModules.cpp
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@ -20,7 +20,7 @@
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/SymbolTable.h"
#include "llvm/ValueSymbolTable.h"
#include "llvm/TypeSymbolTable.h"
#include "llvm/Instructions.h"
#include "llvm/Assembly/Writer.h"
@ -270,14 +270,14 @@ static void PrintMap(const std::map<const Value*, Value*> &M) {
// RemapOperand - Use ValueMap to convert references from one module to another.
// This is somewhat sophisticated in that it can automatically handle constant
// references correctly as well.
// This is somewhat sophisticated in that it can automatically handle constants
// correctly as well.
static Value *RemapOperand(const Value *In,
std::map<const Value*, Value*> &ValueMap) {
std::map<const Value*,Value*>::const_iterator I = ValueMap.find(In);
if (I != ValueMap.end()) return I->second;
// Check to see if it's a constant that we are interesting in transforming.
// Check to see if it's a constant that we are interested in transforming.
Value *Result = 0;
if (const Constant *CPV = dyn_cast<Constant>(In)) {
if ((!isa<DerivedType>(CPV->getType()) && !isa<ConstantExpr>(CPV)) ||
@ -296,8 +296,6 @@ static Value *RemapOperand(const Value *In,
Result = ConstantStruct::get(cast<StructType>(CPS->getType()), Operands);
} else if (isa<ConstantPointerNull>(CPV) || isa<UndefValue>(CPV)) {
Result = const_cast<Constant*>(CPV);
} else if (isa<GlobalValue>(CPV)) {
Result = cast<Constant>(RemapOperand(CPV, ValueMap));
} else if (const ConstantPacked *CP = dyn_cast<ConstantPacked>(CPV)) {
std::vector<Constant*> Operands(CP->getNumOperands());
for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
@ -308,6 +306,10 @@ static Value *RemapOperand(const Value *In,
for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i)
Ops.push_back(cast<Constant>(RemapOperand(CE->getOperand(i),ValueMap)));
Result = CE->getWithOperands(Ops);
} else if (isa<Function>(CPV)) {
Result = const_cast<Constant*>(CPV);// Functions map to themselves.
} else if (isa<GlobalValue>(CPV)) {
assert(0 && "Unmapped global?");
} else {
assert(0 && "Unknown type of derived type constant value!");
}
@ -315,12 +317,11 @@ static Value *RemapOperand(const Value *In,
Result = const_cast<Value*>(In);
}
// Cache the mapping in our local map structure...
// Cache the mapping in our local map structure
if (Result) {
ValueMap.insert(std::make_pair(In, Result));
return Result;
}
cerr << "LinkModules ValueMap: \n";
PrintMap(ValueMap);
@ -330,25 +331,22 @@ static Value *RemapOperand(const Value *In,
return 0;
}
/// ForceRenaming - The LLVM SymbolTable class autorenames globals that conflict
/// in the symbol table. This is good for all clients except for us. Go
/// through the trouble to force this back.
/// ForceRenaming - The LLVM ValueSymbolTable class autorenames globals that
/// conflict in the symbol table. This is good for all clients except for us.
/// Go through the trouble to force this back.
static void ForceRenaming(GlobalValue *GV, const std::string &Name) {
assert(GV->getName() != Name && "Can't force rename to self");
SymbolTable &ST = GV->getParent()->getValueSymbolTable();
ValueSymbolTable &ST = GV->getParent()->getValueSymbolTable();
// If there is a conflict, rename the conflict.
Value *ConflictVal = ST.lookup(GV->getType(), Name);
assert(ConflictVal&&"Why do we have to force rename if there is no conflic?");
GlobalValue *ConflictGV = cast<GlobalValue>(ConflictVal);
assert(ConflictGV->hasInternalLinkage() &&
"Not conflicting with a static global, should link instead!");
ConflictGV->setName(""); // Eliminate the conflict
GV->setName(Name); // Force the name back
ConflictGV->setName(Name); // This will cause ConflictGV to get renamed
assert(GV->getName() == Name && ConflictGV->getName() != Name &&
"ForceRenaming didn't work");
GlobalValue *ConflictGV = cast<GlobalValue>(ST.lookup(Name));
if (ConflictGV) {
ConflictGV->setName(""); // Eliminate the conflict
GV->setName(Name); // Force the name back
ConflictGV->setName(Name); // This will cause ConflictGV to get renamed
assert(GV->getName() == Name && ConflictGV->getName() != Name &&
"ForceRenaming didn't work");
}
}
/// GetLinkageResult - This analyzes the two global values and determines what
@ -393,7 +391,8 @@ static bool GetLinkageResult(GlobalValue *Dest, GlobalValue *Src,
LinkFromSrc = true; // Special cased.
LT = Src->getLinkage();
} else if (Src->hasWeakLinkage() || Src->hasLinkOnceLinkage()) {
// At this point we know that Dest has LinkOnce, External*, Weak, DLL* linkage.
// At this point we know that Dest has LinkOnce, External*, Weak, DLL*
// linkage.
if ((Dest->hasLinkOnceLinkage() && Src->hasWeakLinkage()) ||
Dest->hasExternalWeakLinkage()) {
LinkFromSrc = true;
@ -432,11 +431,10 @@ static bool GetLinkageResult(GlobalValue *Dest, GlobalValue *Src,
static bool LinkGlobals(Module *Dest, Module *Src,
std::map<const Value*, Value*> &ValueMap,
std::multimap<std::string, GlobalVariable *> &AppendingVars,
std::map<std::string, GlobalValue*> &GlobalsByName,
std::string *Err) {
// We will need a module level symbol table if the src module has a module
// level symbol table...
TypeSymbolTable *TST = &Dest->getTypeSymbolTable();
TypeSymbolTable *TyST = &Dest->getTypeSymbolTable();
// Loop over all of the globals in the src module, mapping them over as we go
for (Module::global_iterator I = Src->global_begin(), E = Src->global_end();
@ -444,17 +442,12 @@ static bool LinkGlobals(Module *Dest, Module *Src,
GlobalVariable *SGV = I;
GlobalVariable *DGV = 0;
// Check to see if may have to link the global.
if (SGV->hasName() && !SGV->hasInternalLinkage())
if (!(DGV = Dest->getGlobalVariable(SGV->getName(),
SGV->getType()->getElementType()))) {
std::map<std::string, GlobalValue*>::iterator EGV =
GlobalsByName.find(SGV->getName());
if (EGV != GlobalsByName.end())
DGV = dyn_cast<GlobalVariable>(EGV->second);
if (DGV)
// If types don't agree due to opaque types, try to resolve them.
RecursiveResolveTypes(SGV->getType(), DGV->getType(), TST, "");
}
if (SGV->hasName() && !SGV->hasInternalLinkage()) {
// See if the gvar exists already in the destination module
if ((DGV = Dest->getGlobalVariable(SGV->getName())))
// If types don't agree due to opaque types, try to resolve them.
RecursiveResolveTypes(SGV->getType(), DGV->getType(), TyST, "");
}
if (DGV && DGV->hasInternalLinkage())
DGV = 0;
@ -476,11 +469,10 @@ static bool LinkGlobals(Module *Dest, Module *Src,
new GlobalVariable(SGV->getType()->getElementType(),
SGV->isConstant(), SGV->getLinkage(), /*init*/0,
SGV->getName(), Dest);
// Propagate alignment info.
// Propagate alignment, section and visibility
NewDGV->setAlignment(SGV->getAlignment());
// Propagate section info.
NewDGV->setSection(SGV->getSection());
NewDGV->setVisibility(SGV->getVisibility());
// If the LLVM runtime renamed the global, but it is an externally visible
// symbol, DGV must be an existing global with internal linkage. Rename
@ -503,11 +495,10 @@ static bool LinkGlobals(Module *Dest, Module *Src,
SGV->isConstant(), SGV->getLinkage(), /*init*/0,
"", Dest);
// Propagate alignment info.
// Propagate alignment, section and visibility
NewDGV->setAlignment(std::max(DGV->getAlignment(), SGV->getAlignment()));
// Propagate section info.
NewDGV->setSection(SGV->getSection());
NewDGV->setVisibility(SGV->getVisibility());
// Make sure to remember this mapping...
ValueMap.insert(std::make_pair(SGV, NewDGV));
@ -515,11 +506,10 @@ static bool LinkGlobals(Module *Dest, Module *Src,
// Keep track that this is an appending variable...
AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV));
} else {
// Propagate alignment info.
// Propagate alignment, section and visibility info.
DGV->setAlignment(std::max(DGV->getAlignment(), SGV->getAlignment()));
// Propagate section info.
DGV->setSection(SGV->getSection());
DGV->setVisibility(SGV->getVisibility());
// Otherwise, perform the mapping as instructed by GetLinkageResult. If
// the types don't match, and if we are to link from the source, nuke DGV
@ -529,6 +519,8 @@ static bool LinkGlobals(Module *Dest, Module *Src,
new GlobalVariable(SGV->getType()->getElementType(),
DGV->isConstant(), DGV->getLinkage());
NewDGV->setAlignment(DGV->getAlignment());
NewDGV->setVisibility(DGV->getVisibility());
NewDGV->setSection(DGV->getSection());
Dest->getGlobalList().insert(DGV, NewDGV);
DGV->replaceAllUsesWith(
ConstantExpr::getBitCast(NewDGV, DGV->getType()));
@ -543,6 +535,7 @@ static bool LinkGlobals(Module *Dest, Module *Src,
// Inherit const as appropriate
DGV->setConstant(SGV->isConstant());
DGV->setInitializer(0);
DGV->setVisibility(SGV->getVisibility());
} else {
if (SGV->isConstant() && !DGV->isConstant()) {
if (DGV->isDeclaration())
@ -609,34 +602,64 @@ static bool LinkGlobalInits(Module *Dest, const Module *Src,
//
static bool LinkFunctionProtos(Module *Dest, const Module *Src,
std::map<const Value*, Value*> &ValueMap,
std::map<std::string,
GlobalValue*> &GlobalsByName,
std::string *Err) {
TypeSymbolTable *TST = &Dest->getTypeSymbolTable();
TypeSymbolTable *TyST = &Dest->getTypeSymbolTable();
// Loop over all of the functions in the src module, mapping them over as we
// go
for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) {
const Function *SF = I; // SrcFunction
Function *DF = 0;
if (SF->hasName() && !SF->hasInternalLinkage()) {
// Check to see if may have to link the function.
if (!(DF = Dest->getFunction(SF->getName(), SF->getFunctionType()))) {
std::map<std::string, GlobalValue*>::iterator EF =
GlobalsByName.find(SF->getName());
if (EF != GlobalsByName.end())
DF = dyn_cast<Function>(EF->second);
if (DF && RecursiveResolveTypes(SF->getType(), DF->getType(), TST, ""))
DF = 0; // FIXME: gross.
if (SF->hasName() && !SF->hasInternalLinkage())
// See if there is a function with the same name in the destination
if ((DF = Dest->getFunction(SF->getName()))) {
// Resolve Opaque types, etc.
RecursiveResolveTypes(SF->getType(), DF->getType(), TyST, "");
}
}
if (!DF || SF->hasInternalLinkage() || DF->hasInternalLinkage()) {
// If we have two globals of the same name but different type
if (DF && DF->getType() != SF->getType()) {
if (DF->isDeclaration() && !SF->isDeclaration()) {
// We have a definition of the same name but different type in the
// source module. Copy the prototype to the destination and replace
// uses of the destination's prototype with the new prototype.
Function *NewDF = new Function(SF->getFunctionType(), SF->getLinkage(),
SF->getName(), Dest);
NewDF->setCallingConv(SF->getCallingConv());
NewDF->setVisibility(SF->getVisibility());
// If the symbol table renamed the function, but it is an externally
// visible symbol, DF must be an existing function with internal
// linkage. Rename it.
if (NewDF->getName() != SF->getName() && !NewDF->hasInternalLinkage())
ForceRenaming(NewDF, SF->getName());
// Any uses of DF need to change to NewDF, with cast
DF->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF, DF->getType()));
DF->eraseFromParent();
// Remember this mapping so uses in the source module get remapped
// later by RemapOperand.
ValueMap.insert(std::make_pair(SF, NewDF));
} else if (SF->isDeclaration()) {
// The source is just a prototype, simply set up a mapping from the
// source to the destination function. We can't do the replacement
// now so its deferred to LinkFunctionBodies.
ValueMap.insert(std::make_pair(SF, DF));
} else {
// We have two definitions of different function types of the same
// name. This is a multiple definition error.
return Error(Err, "Function '" + DF->getName() + "' defined as both '" +
ToStr(SF->getFunctionType(), Src) + "' and '" +
ToStr(DF->getFunctionType(), Dest) + "'");
}
} else if (!DF || SF->hasInternalLinkage() || DF->hasInternalLinkage()) {
// Function does not already exist, simply insert an function signature
// identical to SF into the dest module...
Function *NewDF = new Function(SF->getFunctionType(), SF->getLinkage(),
SF->getName(), Dest);
NewDF->setCallingConv(SF->getCallingConv());
NewDF->setVisibility(SF->getVisibility());
// If the LLVM runtime renamed the function, but it is an externally
// visible symbol, DF must be an existing function with internal linkage.
@ -656,7 +679,7 @@ static bool LinkFunctionProtos(Module *Dest, const Module *Src,
}
} else {
ValueMap.insert(std::make_pair(SF, DF));
}
}
} else if (DF->isDeclaration() && !DF->hasDLLImportLinkage()) {
// If DF is external but SF is not...
// Link the external functions, update linkage qualifiers
@ -671,8 +694,6 @@ static bool LinkFunctionProtos(Module *Dest, const Module *Src,
if ((DF->hasLinkOnceLinkage() && SF->hasWeakLinkage()) ||
DF->hasExternalWeakLinkage())
DF->setLinkage(SF->getLinkage());
} else if (DF->hasWeakLinkage() || DF->hasLinkOnceLinkage()) {
// At this point we know that SF has LinkOnce or External* linkage.
ValueMap.insert(std::make_pair(SF, DF));
@ -743,18 +764,24 @@ static bool LinkFunctionBodies(Module *Dest, Module *Src,
std::map<const Value*, Value*> &ValueMap,
std::string *Err) {
// Loop over all of the functions in the src module, mapping them over as we
// go
// Loop over all of the functions in the src module, mapping them over
for (Module::iterator SF = Src->begin(), E = Src->end(); SF != E; ++SF) {
if (!SF->isDeclaration()) { // No body if function is external
if (!SF->isDeclaration()) { // No body if function is external
Function *DF = cast<Function>(ValueMap[SF]); // Destination function
// DF not external SF external?
if (DF->isDeclaration()) {
if (DF->isDeclaration())
// Only provide the function body if there isn't one already.
if (LinkFunctionBody(DF, SF, ValueMap, Err))
return true;
}
} else {
// The source function is a prototype. If there's a mapping for this,
// then replace all its uses with the mapped function, after cast. This
// occurs when two functions of the same name but different type
// are encountered.
Function *DF = cast<Function>(ValueMap[SF]); // Destination function
if (DF)
SF->replaceAllUsesWith(ConstantExpr::getBitCast(DF, SF->getType()));
}
}
return false;
@ -878,6 +905,7 @@ Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) {
}
}
// Copy the target triple from the source to dest if the dest is empty
if (Dest->getTargetTriple().empty() && !Src->getTargetTriple().empty())
Dest->setTargetTriple(Src->getTargetTriple());
@ -888,6 +916,7 @@ Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) {
Dest->getTargetTriple() != Src->getTargetTriple())
cerr << "WARNING: Linking two modules of different target triples!\n";
// Append the module inline asm string
if (!Src->getModuleInlineAsm().empty()) {
if (Dest->getModuleInlineAsm().empty())
Dest->setModuleInlineAsm(Src->getModuleInlineAsm());
@ -909,7 +938,8 @@ Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) {
// LinkTypes - Go through the symbol table of the Src module and see if any
// types are named in the src module that are not named in the Dst module.
// Make sure there are no type name conflicts.
if (LinkTypes(Dest, Src, ErrorMsg)) return true;
if (LinkTypes(Dest, Src, ErrorMsg))
return true;
// ValueMap - Mapping of values from what they used to be in Src, to what they
// are now in Dest.
@ -920,31 +950,17 @@ Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) {
// appended and the module is rewritten.
std::multimap<std::string, GlobalVariable *> AppendingVars;
// GlobalsByName - The LLVM SymbolTable class fights our best efforts at
// linking by separating globals by type. Until PR411 is fixed, we replicate
// it's functionality here.
std::map<std::string, GlobalValue*> GlobalsByName;
for (Module::global_iterator I = Dest->global_begin(), E = Dest->global_end();
I != E; ++I) {
// Add all of the appending globals already in the Dest module to
// AppendingVars.
if (I->hasAppendingLinkage())
AppendingVars.insert(std::make_pair(I->getName(), I));
// Keep track of all globals by name.
if (!I->hasInternalLinkage() && I->hasName())
GlobalsByName[I->getName()] = I;
}
// Keep track of all globals by name.
for (Module::iterator I = Dest->begin(), E = Dest->end(); I != E; ++I)
if (!I->hasInternalLinkage() && I->hasName())
GlobalsByName[I->getName()] = I;
// Insert all of the globals in src into the Dest module... without linking
// initializers (which could refer to functions not yet mapped over).
if (LinkGlobals(Dest, Src, ValueMap, AppendingVars, GlobalsByName, ErrorMsg))
if (LinkGlobals(Dest, Src, ValueMap, AppendingVars, ErrorMsg))
return true;
// Link the functions together between the two modules, without doing function
@ -952,7 +968,7 @@ Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) {
// function... We do this so that when we begin processing function bodies,
// all of the global values that may be referenced are available in our
// ValueMap.
if (LinkFunctionProtos(Dest, Src, ValueMap, GlobalsByName, ErrorMsg))
if (LinkFunctionProtos(Dest, Src, ValueMap, ErrorMsg))
return true;
// Update the initializers in the Dest module now that all globals that may