lib/Target/NVPTX/NVPTXAssignValidGlobalNames.cpp

   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 }