flang/lib/Optimizer/Transforms/ExternalNameConversion.cpp

   1 //===- ExternalNameConversion.cpp -- convert name with external convention ===//
   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 #include "flang/Common/Fortran.h"
  10 #include "flang/Optimizer/Dialect/FIRDialect.h"
  11 #include "flang/Optimizer/Dialect/FIROps.h"
  12 #include "flang/Optimizer/Dialect/FIROpsSupport.h"
  13 #include "flang/Optimizer/Support/InternalNames.h"
  14 #include "flang/Optimizer/Transforms/Passes.h"
  15 #include "mlir/IR/Attributes.h"
  16 #include "mlir/IR/SymbolTable.h"
  17 #include "mlir/Pass/Pass.h"
  18
  19 namespace fir {
  20 #define GEN_PASS_DEF_EXTERNALNAMECONVERSION
  21 #include "flang/Optimizer/Transforms/Passes.h.inc"
  22 } // namespace fir
  23
  24 using namespace mlir;
  25
  26 //===----------------------------------------------------------------------===//
  27 // Helper functions
  28 //===----------------------------------------------------------------------===//
  29
  30 /// Mangle the name with gfortran convention.
  31 std::string
  32 mangleExternalName(const std::pair<fir::NameUniquer::NameKind,
  33                                    fir::NameUniquer::DeconstructedName>
  34                        result,
  35                    bool appendUnderscore) {
  36   if (result.first == fir::NameUniquer::NameKind::COMMON &&
  37       result.second.name.empty())
  38     return Fortran::common::blankCommonObjectName;
  39   return Fortran::common::GetExternalAssemblyName(result.second.name,
  40                                                   appendUnderscore);
  41 }
  42
  43 namespace {
  44
  45 class ExternalNameConversionPass
  46     : public fir::impl::ExternalNameConversionBase<ExternalNameConversionPass> {
  47 public:
  48   using ExternalNameConversionBase<
  49       ExternalNameConversionPass>::ExternalNameConversionBase;
  50
  51   mlir::ModuleOp getModule() { return getOperation(); }
  52   void runOnOperation() override;
  53 };
  54 } // namespace
  55
  56 void ExternalNameConversionPass::runOnOperation() {
  57   auto op = getOperation();
  58   auto *context = &getContext();
  59
  60   llvm::DenseMap<mlir::StringAttr, mlir::FlatSymbolRefAttr> remappings;
  61   // Update names of external Fortran functions and names of Common Block
  62   // globals.
  63   for (auto &funcOrGlobal : op->getRegion(0).front()) {
  64     if (llvm::isa<mlir::func::FuncOp>(funcOrGlobal) ||
  65         llvm::isa<fir::GlobalOp>(funcOrGlobal)) {
  66       auto symName = funcOrGlobal.getAttrOfType<mlir::StringAttr>(
  67           mlir::SymbolTable::getSymbolAttrName());
  68       auto deconstructedName = fir::NameUniquer::deconstruct(symName);
  69       if (fir::NameUniquer::isExternalFacingUniquedName(deconstructedName)) {
  70         auto newName =
  71             mangleExternalName(deconstructedName, appendUnderscoreOpt);
  72         auto newAttr = mlir::StringAttr::get(context, newName);
  73         mlir::SymbolTable::setSymbolName(&funcOrGlobal, newAttr);
  74         auto newSymRef = mlir::FlatSymbolRefAttr::get(newAttr);
  75         remappings.try_emplace(symName, newSymRef);
  76         if (llvm::isa<mlir::func::FuncOp>(funcOrGlobal))
  77           funcOrGlobal.setAttr(fir::getInternalFuncNameAttrName(), symName);
  78       }
  79     }
  80   }
  81
  82   if (remappings.empty())
  83     return;
  84
  85   // Update all uses of the functions and globals that have been renamed.
  86   op.walk([&remappings](mlir::Operation *nestedOp) {
  87     llvm::SmallVector<std::pair<mlir::StringAttr, mlir::SymbolRefAttr>> updates;
  88     for (const mlir::NamedAttribute &attr : nestedOp->getAttrDictionary())
  89       if (auto symRef = llvm::dyn_cast<mlir::SymbolRefAttr>(attr.getValue()))
  90         if (auto remap = remappings.find(symRef.getRootReference());
  91             remap != remappings.end())
  92           updates.emplace_back(std::pair<mlir::StringAttr, mlir::SymbolRefAttr>{
  93               attr.getName(), mlir::SymbolRefAttr(remap->second)});
  94     for (auto update : updates)
  95       nestedOp->setAttr(update.first, update.second);
  96   });
  97 }