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/ADT/StringExtras.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
28using namespace llvm;
29
30namespace {
31/// NVPTXAssignValidGlobalNames
32class NVPTXAssignValidGlobalNames : public ModulePass {
33public:
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
44char NVPTXAssignValidGlobalNames::ID = 0;
45
46namespace llvm {
47void initializeNVPTXAssignValidGlobalNamesPass(PassRegistry &);
48}
49
50INITIALIZE_PASS(NVPTXAssignValidGlobalNames, "nvptx-assign-valid-global-names",
51 "Assign valid PTX names to globals", false, false)
52
53bool 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(Name: 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(Name: F.getName()));
69
70 return true;
71}
72
73std::string NVPTXAssignValidGlobalNames::cleanUpName(StringRef Name) {
74 std::string ValidName;
75 raw_string_ostream ValidNameStream(ValidName);
76 for (char C : Name) {
77 // While PTX also allows '%' at the start of identifiers, LLVM will throw a
78 // fatal error for '%' in symbol names in MCSymbol::print. Exclude for now.
79 if (isAlnum(C) || C == '_' || C == '$') {
80 ValidNameStream << C;
81 } else {
82 ValidNameStream << "_$_";
83 }
84 }
85
86 return ValidNameStream.str();
87}
88
89ModulePass *llvm::createNVPTXAssignValidGlobalNamesPass() {
90 return new NVPTXAssignValidGlobalNames();
91}
92