cfe77f23d6
I intend to slowly upgrade all alignments to the Align type in lld as well. Some places talk about alignment in Bytes while other specify them as Log2(Bytes). Let's make sure all of this is coherent. Differential Revision: https://reviews.llvm.org/D139181
88 lines
2.9 KiB
C++
88 lines
2.9 KiB
C++
//===- OutputSegment.h -----------------------------------------*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "OutputSegment.h"
|
|
#include "InputChunks.h"
|
|
#include "lld/Common/Memory.h"
|
|
|
|
#define DEBUG_TYPE "lld"
|
|
|
|
using namespace llvm;
|
|
using namespace llvm::wasm;
|
|
|
|
namespace lld {
|
|
|
|
namespace wasm {
|
|
|
|
void OutputSegment::addInputSegment(InputChunk *inSeg) {
|
|
alignment = std::max(alignment, inSeg->alignment);
|
|
inputSegments.push_back(inSeg);
|
|
size = llvm::alignTo(size, inSeg->alignment);
|
|
LLVM_DEBUG(dbgs() << "addInputSegment: " << inSeg->name << " oname=" << name
|
|
<< " size=" << inSeg->getSize() << " align="
|
|
<< Log2(inSeg->alignment) << " at:" << size << "\n");
|
|
inSeg->outputSeg = this;
|
|
inSeg->outputSegmentOffset = size;
|
|
size += inSeg->getSize();
|
|
}
|
|
|
|
// This function scans over the input segments.
|
|
//
|
|
// It removes MergeInputChunks from the input section array and adds
|
|
// new synthetic sections at the location of the first input section
|
|
// that it replaces. It then finalizes each synthetic section in order
|
|
// to compute an output offset for each piece of each input section.
|
|
void OutputSegment::finalizeInputSegments() {
|
|
LLVM_DEBUG(llvm::dbgs() << "finalizeInputSegments: " << name << "\n");
|
|
std::vector<SyntheticMergedChunk *> mergedSegments;
|
|
std::vector<InputChunk *> newSegments;
|
|
for (InputChunk *s : inputSegments) {
|
|
MergeInputChunk *ms = dyn_cast<MergeInputChunk>(s);
|
|
if (!ms) {
|
|
newSegments.push_back(s);
|
|
continue;
|
|
}
|
|
|
|
// A segment should not make it here unless its alive
|
|
assert(ms->live);
|
|
|
|
auto i = llvm::find_if(mergedSegments, [=](SyntheticMergedChunk *seg) {
|
|
return seg->flags == ms->flags && seg->alignment == ms->alignment;
|
|
});
|
|
if (i == mergedSegments.end()) {
|
|
LLVM_DEBUG(llvm::dbgs() << "new merge segment: " << name
|
|
<< " alignment=" << Log2(ms->alignment) << "\n");
|
|
auto *syn =
|
|
make<SyntheticMergedChunk>(name, Log2(ms->alignment), ms->flags);
|
|
syn->outputSeg = this;
|
|
mergedSegments.push_back(syn);
|
|
i = std::prev(mergedSegments.end());
|
|
newSegments.push_back(syn);
|
|
} else {
|
|
LLVM_DEBUG(llvm::dbgs() << "adding to merge segment: " << name << "\n");
|
|
}
|
|
(*i)->addMergeChunk(ms);
|
|
}
|
|
|
|
for (auto *ms : mergedSegments)
|
|
ms->finalizeContents();
|
|
|
|
inputSegments = newSegments;
|
|
size = 0;
|
|
for (InputChunk *seg : inputSegments) {
|
|
size = llvm::alignTo(size, seg->alignment);
|
|
LLVM_DEBUG(llvm::dbgs() << "outputSegmentOffset set: " << seg->name
|
|
<< " -> " << size << "\n");
|
|
seg->outputSegmentOffset = size;
|
|
size += seg->getSize();
|
|
}
|
|
}
|
|
|
|
} // namespace wasm
|
|
} // namespace lld
|