lib/Target/NVPTX/NVPTXAssignValidGlobalNames.cpp

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