void PTXAsmPrinter::EmitStartOfAsmFile(Module &M) { const PTXSubtarget& ST = TM.getSubtarget<PTXSubtarget>(); // Emit the PTX .version and .target attributes OutStreamer.EmitRawText(Twine("\t.version ") + ST.getPTXVersionString()); OutStreamer.EmitRawText(Twine("\t.target ") + ST.getTargetString() + (ST.supportsDouble() ? "" : ", map_f64_to_f32")); // .address_size directive is optional, but it must immediately follow // the .target directive if present within a module if (ST.supportsPTX23()) { const char *addrSize = ST.is64Bit() ? "64" : "32"; OutStreamer.EmitRawText(Twine("\t.address_size ") + addrSize); } OutStreamer.AddBlankLine(); // Define any .file directives DebugInfoFinder DbgFinder; DbgFinder.processModule(M); for (DebugInfoFinder::iterator I = DbgFinder.compile_unit_begin(), E = DbgFinder.compile_unit_end(); I != E; ++I) { DICompileUnit DIUnit(*I); StringRef FN = DIUnit.getFilename(); StringRef Dir = DIUnit.getDirectory(); GetOrCreateSourceID(FN, Dir); } OutStreamer.AddBlankLine(); // declare external functions for (Module::const_iterator i = M.begin(), e = M.end(); i != e; ++i) EmitFunctionDeclaration(i); // declare global variables for (Module::const_global_iterator i = M.global_begin(), e = M.global_end(); i != e; ++i) EmitVariableDeclaration(i); }
/// Remove any debug info for global variables/functions in the given module for /// which said global variable/function no longer exists (i.e. is null). /// /// Debugging information is encoded in llvm IR using metadata. This is designed /// such a way that debug info for symbols preserved even if symbols are /// optimized away by the optimizer. This special pass removes debug info for /// such symbols. bool StripDeadDebugInfo::runOnModule(Module &M) { bool Changed = false; LLVMContext &C = M.getContext(); // Find all debug info in F. This is actually overkill in terms of what we // want to do, but we want to try and be as resilient as possible in the face // of potential debug info changes by using the formal interfaces given to us // as much as possible. DebugInfoFinder F; F.processModule(M); // For each compile unit, find the live set of global variables/functions and // replace the current list of potentially dead global variables/functions // with the live list. SmallVector<Value *, 64> LiveGlobalVariables; SmallVector<Value *, 64> LiveSubprograms; DenseSet<const MDNode *> VisitedSet; for (DebugInfoFinder::iterator CI = F.compile_unit_begin(), CE = F.compile_unit_end(); CI != CE; ++CI) { // Create our compile unit. DICompileUnit DIC(*CI); assert(DIC.Verify() && "DIC must verify as a DICompileUnit."); // Create our live subprogram list. DIArray SPs = DIC.getSubprograms(); bool SubprogramChange = false; for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i) { DISubprogram DISP(SPs.getElement(i)); assert(DISP.Verify() && "DISP must verify as a DISubprogram."); // Make sure we visit each subprogram only once. if (!VisitedSet.insert(DISP).second) continue; // If the function referenced by DISP is not null, the function is live. if (DISP.getFunction()) LiveSubprograms.push_back(DISP); else SubprogramChange = true; } // Create our live global variable list. DIArray GVs = DIC.getGlobalVariables(); bool GlobalVariableChange = false; for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i) { DIGlobalVariable DIG(GVs.getElement(i)); assert(DIG.Verify() && "DIG must verify as DIGlobalVariable."); // Make sure we only visit each global variable only once. if (!VisitedSet.insert(DIG).second) continue; // If the global variable referenced by DIG is not null, the global // variable is live. if (DIG.getGlobal()) LiveGlobalVariables.push_back(DIG); else GlobalVariableChange = true; } // If we found dead subprograms or global variables, replace the current // subprogram list/global variable list with our new live subprogram/global // variable list. if (SubprogramChange) { // Make sure that 9 is still the index of the subprograms. This is to make // sure that an assert is hit if the location of the subprogram array // changes. This is just to make sure that this is updated if such an // event occurs. assert(DIC->getNumOperands() >= 10 && SPs == DIC->getOperand(9) && "DICompileUnits is expected to store Subprograms in operand " "9."); DIC->replaceOperandWith(9, MDNode::get(C, LiveSubprograms)); Changed = true; } if (GlobalVariableChange) { // Make sure that 10 is still the index of global variables. This is to // make sure that an assert is hit if the location of the subprogram array // changes. This is just to make sure that this index is updated if such // an event occurs. assert(DIC->getNumOperands() >= 11 && GVs == DIC->getOperand(10) && "DICompileUnits is expected to store Global Variables in operand " "10."); DIC->replaceOperandWith(10, MDNode::get(C, LiveGlobalVariables)); Changed = true; } // Reset lists for the next iteration. LiveSubprograms.clear(); LiveGlobalVariables.clear(); } return Changed; }