llvm-project/clang-tools-extra/clang-modernize/LoopConvert/VariableNaming.cpp

96 lines
3.3 KiB
C++

//===-- LoopConvert/VariableNaming.cpp - Gererate variable names ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief This file contains the definitino of the VariableNamer class, which
/// is responsible for generating new variable names and ensuring that they do
/// not conflict with existing ones.
///
//===----------------------------------------------------------------------===//
#include "VariableNaming.h"
using namespace llvm;
using namespace clang;
std::string VariableNamer::createIndexName() {
// FIXME: Add in naming conventions to handle:
// - Uppercase/lowercase indices
// - How to handle conflicts
// - An interactive process for naming
std::string IteratorName;
std::string ContainerName;
if (TheContainer)
ContainerName = TheContainer->getName().str();
size_t Len = ContainerName.length();
if (Len > 1 && ContainerName[Len - 1] == 's')
IteratorName = ContainerName.substr(0, Len - 1);
else
IteratorName = "elem";
if (!declarationExists(IteratorName))
return IteratorName;
IteratorName = ContainerName + "_" + OldIndex->getName().str();
if (!declarationExists(IteratorName))
return IteratorName;
IteratorName = ContainerName + "_elem";
if (!declarationExists(IteratorName))
return IteratorName;
IteratorName += "_elem";
if (!declarationExists(IteratorName))
return IteratorName;
IteratorName = "_elem_";
// Someone defeated my naming scheme...
while (declarationExists(IteratorName))
IteratorName += "i";
return IteratorName;
}
/// \brief Determines whether or not the the name \a Symbol conflicts with
/// language keywords or defined macros. Also checks if the name exists in
/// LoopContext, any of its parent contexts, or any of its child statements.
///
/// We also check to see if the same identifier was generated by this loop
/// converter in a loop nested within SourceStmt.
bool VariableNamer::declarationExists(StringRef Symbol) {
assert(Context != nullptr && "Expected an ASTContext");
IdentifierInfo &Ident = Context->Idents.get(Symbol);
// Check if the symbol is not an identifier (ie. is a keyword or alias).
if (!isAnyIdentifier(Ident.getTokenID()))
return true;
// Check for conflicting macro definitions.
if (Ident.hasMacroDefinition())
return true;
// Determine if the symbol was generated in a parent context.
for (const Stmt *S = SourceStmt; S != nullptr; S = ReverseAST->lookup(S)) {
StmtGeneratedVarNameMap::const_iterator I = GeneratedDecls->find(S);
if (I != GeneratedDecls->end() && I->second == Symbol)
return true;
}
// FIXME: Rather than detecting conflicts at their usages, we should check the
// parent context.
// For some reason, lookup() always returns the pair (NULL, NULL) because its
// StoredDeclsMap is not initialized (i.e. LookupPtr.getInt() is false inside
// of DeclContext::lookup()). Why is this?
// Finally, determine if the symbol was used in the loop or a child context.
DeclFinderASTVisitor DeclFinder(Symbol, GeneratedDecls);
return DeclFinder.findUsages(SourceStmt);
}