NVPTXAssignValidGlobalNames.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
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/GlobalVariable.h"
22#include "llvm/IR/Module.h"
23#include "llvm/PassManager.h"
24#include "llvm/Support/raw_ostream.h"
25#include <string>
26
27using namespace llvm;
28
29namespace {
30/// \brief NVPTXAssignValidGlobalNames
31class NVPTXAssignValidGlobalNames : public ModulePass {
32public:
33  static char ID;
34  NVPTXAssignValidGlobalNames() : ModulePass(ID) {}
35
36  bool runOnModule(Module &M) override;
37
38  /// \brief 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  return true;
65}
66
67std::string NVPTXAssignValidGlobalNames::cleanUpName(StringRef Name) {
68  std::string ValidName;
69  raw_string_ostream ValidNameStream(ValidName);
70  for (unsigned I = 0, E = Name.size(); I != E; ++I) {
71    char C = Name[I];
72    if (C == '.' || C == '@') {
73      ValidNameStream << "_$_";
74    } else {
75      ValidNameStream << C;
76    }
77  }
78
79  return ValidNameStream.str();
80}
81
82ModulePass *llvm::createNVPTXAssignValidGlobalNamesPass() {
83  return new NVPTXAssignValidGlobalNames();
84}
85