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 27 using namespace llvm; 28 29 namespace { 30 /// NVPTXAssignValidGlobalNames 31 class NVPTXAssignValidGlobalNames : public ModulePass { 32 public: 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 43 char NVPTXAssignValidGlobalNames::ID = 0; 44 45 namespace llvm { 46 void initializeNVPTXAssignValidGlobalNamesPass(PassRegistry &); 47 } 48 49 INITIALIZE_PASS(NVPTXAssignValidGlobalNames, "nvptx-assign-valid-global-names", 50 "Assign valid PTX names to globals", false, false) 51 52 bool 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 72 std::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 87 ModulePass *llvm::createNVPTXAssignValidGlobalNamesPass() { 88 return new NVPTXAssignValidGlobalNames(); 89 } 90