1 //===- SectionPriorities.h --------------------------------------*- C++ -*-===// 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 #ifndef LLD_MACHO_SECTION_PRIORITIES_H 10 #define LLD_MACHO_SECTION_PRIORITIES_H 11 12 #include "InputSection.h" 13 #include "llvm/ADT/DenseMap.h" 14 15 namespace lld { 16 namespace macho { 17 18 // Reads every input section's call graph profile, and combines them into 19 // config->callGraphProfile. If an order file is present, any edges where one 20 // or both of the vertices are specified in the order file are discarded. 21 void extractCallGraphProfile(); 22 23 // Reads the order file at `path` into config->priorities. 24 // 25 // An order file has one entry per line, in the following format: 26 // 27 // <cpu>:<object file>:<symbol name> 28 // 29 // <cpu> and <object file> are optional. If not specified, then that entry 30 // matches any symbol of that name. Parsing this format is not quite 31 // straightforward because the symbol name itself can contain colons, so when 32 // encountering a colon, we consider the preceding characters to decide if it 33 // can be a valid CPU type or file path. 34 // 35 // If a symbol is matched by multiple entries, then it takes the lowest-ordered 36 // entry (the one nearest to the front of the list.) 37 // 38 // The file can also have line comments that start with '#'. 39 void parseOrderFile(StringRef path); 40 41 // Returns layout priorities for some or all input sections. Sections are laid 42 // out in decreasing order; that is, a higher priority section will be closer 43 // to the beginning of its output section. 44 // 45 // If either an order file or a call graph profile are present, this is used 46 // as the source of priorities. If both are present, the order file takes 47 // precedence. If neither is present, an empty map is returned. 48 // 49 // Each section gets assigned the priority of the highest-priority symbol it 50 // contains. 51 llvm::DenseMap<const InputSection *, size_t> buildInputSectionPriorities(); 52 } // namespace macho 53 } // namespace lld 54 55 #endif 56