2aae2b4609
The main problem is in the predicate passed to the `std::stable_sort()`. This predicate always returns false if **both** section's names do not start with `.init_array` or `.fini_array` prefixes. In short, it does not define a strict weak orderng. Suppose we have the following sections: .A .init_array.1 .init_array.2 The predicate states that: not .init_array.1 < .A not .A < .init_array.2 but .init_array.1 < .init_array.2 !!! The second problem is that `.init_array` section without number should go last in the list. Not it has the lowest priority '0' and goes first. The patch fixes both of the problems. llvm-svn: 209875
59 lines
2.0 KiB
C++
59 lines
2.0 KiB
C++
//===- lib/ReaderWriter/ELF/ArrayOrderPass.cpp ----------------------------===//
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//
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// The LLVM Linker
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#include "ArrayOrderPass.h"
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#include <algorithm>
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#include <limits>
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namespace lld {
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namespace elf {
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void ArrayOrderPass::perform(std::unique_ptr<MutableFile> &f) {
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auto definedAtoms = f->definedAtoms();
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// Move sections need to be sorted into the separate continious group.
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// That reduces a number of sorting elements and simplifies conditions
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// in the sorting predicate.
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auto last = std::stable_partition(definedAtoms.begin(), definedAtoms.end(),
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[](const DefinedAtom *atom) {
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if (atom->sectionChoice() != DefinedAtom::sectionCustomRequired)
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return false;
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StringRef name = atom->customSectionName();
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return name.startswith(".init_array") || name.startswith(".fini_array");
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});
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std::stable_sort(definedAtoms.begin(), last,
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[](const DefinedAtom *left, const DefinedAtom *right) {
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StringRef leftSec = left->customSectionName();
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StringRef rightSec = right->customSectionName();
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// Drop the front dot from the section name and get
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// an optional section's number starting after the second dot.
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StringRef leftNum = leftSec.drop_front().rsplit('.').second;
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StringRef rightNum = rightSec.drop_front().rsplit('.').second;
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// Sort {.init_array, .fini_array}[.<num>] sections
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// according to their number. Sections without optional
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// numer suffix should go last.
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uint32_t leftPriority = std::numeric_limits<uint32_t>::max();
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if (!leftNum.empty())
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leftNum.getAsInteger(10, leftPriority);
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uint32_t rightPriority = std::numeric_limits<uint32_t>::max();
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if (!rightNum.empty())
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rightNum.getAsInteger(10, rightPriority);
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return leftPriority < rightPriority;
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});
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}
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} // end namespace elf
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} // end namespace lld
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