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 "NVPTXUtilities.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
26using namespace llvm;
27
28namespace {
29/// NVPTXAssignValidGlobalNames
30class NVPTXAssignValidGlobalNames : public ModulePass {
31public:
32 static char ID;
33 NVPTXAssignValidGlobalNames() : ModulePass(ID) {}
34
35 bool runOnModule(Module &M) override;
36};
37} // namespace
38
39char NVPTXAssignValidGlobalNames::ID = 0;
40
41INITIALIZE_PASS(NVPTXAssignValidGlobalNames, "nvptx-assign-valid-global-names",
42 "Assign valid PTX names to globals", false, false)
43
44bool NVPTXAssignValidGlobalNames::runOnModule(Module &M) {
45 for (GlobalVariable &GV : M.globals()) {
46 // We are only allowed to rename symbols that are not externally linked by
47 // name
48 // - local symbols, as all references will be renamed
49 // - .extern .shared symbols, as they're the same regardless of name
50 if (GV.hasLocalLinkage() ||
51 (GV.hasExternalLinkage() &&
52 GV.getAddressSpace() == NVPTX::AddressSpace::Shared)) {
53 // setName doesn't do extra work if the name does not change.
54 // Note: this does not create collisions - if setName is asked to set the
55 // name to something that already exists, it adds a proper postfix to
56 // avoid collisions.
57 GV.setName(NVPTX::getValidPTXIdentifier(Name: GV.getName()));
58 }
59 }
60
61 // Do the same for local functions.
62 for (Function &F : M.functions())
63 if (F.hasLocalLinkage())
64 F.setName(NVPTX::getValidPTXIdentifier(Name: F.getName()));
65
66 return true;
67}
68
69ModulePass *llvm::createNVPTXAssignValidGlobalNamesPass() {
70 return new NVPTXAssignValidGlobalNames();
71}
72