1//===-- NVPTXAssignValidGlobalNames.cpp - Assign valid names to globals ---===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// 9// Clean up the names of global variables in the module to not contain symbols 10// that are invalid in PTX. 11// 12// Currently NVPTX, like other backends, relies on generic symbol name 13// sanitizing done by MC. However, the ptxas assembler is more stringent and 14// disallows some additional characters in symbol names. This pass makes sure 15// such names do not reach MC at all. 16// 17//===----------------------------------------------------------------------===// 18 19#include "NVPTX.h" 20#include "llvm/IR/Function.h" 21#include "llvm/IR/GlobalVariable.h" 22#include "llvm/IR/LegacyPassManager.h" 23#include "llvm/IR/Module.h" 24#include "llvm/Support/raw_ostream.h" 25#include <string> 26 27using namespace llvm; 28 29namespace { 30/// NVPTXAssignValidGlobalNames 31class NVPTXAssignValidGlobalNames : public ModulePass { 32public: 33 static char ID; 34 NVPTXAssignValidGlobalNames() : ModulePass(ID) {} 35 36 bool runOnModule(Module &M) override; 37 38 /// Clean up the name to remove symbols invalid in PTX. 39 std::string cleanUpName(StringRef Name); 40}; 41} 42 43char NVPTXAssignValidGlobalNames::ID = 0; 44 45namespace llvm { 46void initializeNVPTXAssignValidGlobalNamesPass(PassRegistry &); 47} 48 49INITIALIZE_PASS(NVPTXAssignValidGlobalNames, "nvptx-assign-valid-global-names", 50 "Assign valid PTX names to globals", false, false) 51 52bool NVPTXAssignValidGlobalNames::runOnModule(Module &M) { 53 for (GlobalVariable &GV : M.globals()) { 54 // We are only allowed to rename local symbols. 55 if (GV.hasLocalLinkage()) { 56 // setName doesn't do extra work if the name does not change. 57 // Note: this does not create collisions - if setName is asked to set the 58 // name to something that already exists, it adds a proper postfix to 59 // avoid collisions. 60 GV.setName(cleanUpName(GV.getName())); 61 } 62 } 63 64 // Do the same for local functions. 65 for (Function &F : M.functions()) 66 if (F.hasLocalLinkage()) 67 F.setName(cleanUpName(F.getName())); 68 69 return true; 70} 71 72std::string NVPTXAssignValidGlobalNames::cleanUpName(StringRef Name) { 73 std::string ValidName; 74 raw_string_ostream ValidNameStream(ValidName); 75 for (unsigned I = 0, E = Name.size(); I != E; ++I) { 76 char C = Name[I]; 77 if (C == '.' || C == '@') { 78 ValidNameStream << "_$_"; 79 } else { 80 ValidNameStream << C; 81 } 82 } 83 84 return ValidNameStream.str(); 85} 86 87ModulePass *llvm::createNVPTXAssignValidGlobalNamesPass() { 88 return new NVPTXAssignValidGlobalNames(); 89} 90