1 //===-- DYLDRendezvous.h ----------------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef liblldb_Rendezvous_H_
11 #define liblldb_Rendezvous_H_
18 // Other libraries and framework includes
19 #include "lldb/lldb-defines.h"
20 #include "lldb/lldb-types.h"
21 #include "lldb/Host/FileSpec.h"
23 namespace lldb_private {
27 /// @class DYLDRendezvous
28 /// @brief Interface to the runtime linker.
30 /// A structure is present in a processes memory space which is updated by the
31 /// runtime liker each time a module is loaded or unloaded. This class provides
32 /// an interface to this structure and maintains a consistent snapshot of the
33 /// currently loaded modules.
34 class DYLDRendezvous {
36 // This structure is used to hold the contents of the debug rendezvous
37 // information (struct r_debug) as found in the inferiors memory. Note that
38 // the layout of this struct is not binary compatible, it is simply large
39 // enough to hold the information on both 32 and 64 bit platforms.
42 lldb::addr_t map_addr;
48 : version(0), map_addr(0), brk(0), state(0), ldbase(0) { }
52 // Various metadata supplied by the inferior's threading library to describe
53 // the per-thread state.
55 bool valid; // whether we read valid metadata
56 uint32_t dtv_offset; // offset of DTV pointer within pthread
57 uint32_t dtv_slot_size; // size of one DTV slot
58 uint32_t modid_offset; // offset of module ID within link_map
59 uint32_t tls_offset; // offset of TLS pointer within DTV slot
62 DYLDRendezvous(lldb_private::Process *process);
64 /// Update the internal snapshot of runtime linker rendezvous and recompute
65 /// the currently loaded modules.
67 /// This method should be called once one start up, then once each time the
68 /// runtime linker enters the function given by GetBreakAddress().
70 /// @returns true on success and false on failure.
72 /// @see GetBreakAddress().
76 /// @returns true if this rendezvous has been located in the inferiors
77 /// address space and false otherwise.
81 /// @returns the address of the rendezvous structure in the inferiors
84 GetRendezvousAddress() const { return m_rendezvous_addr; }
86 /// @returns the version of the rendezvous protocol being used.
88 GetVersion() const { return m_current.version; }
90 /// @returns address in the inferiors address space containing the linked
91 /// list of shared object descriptors.
93 GetLinkMapAddress() const { return m_current.map_addr; }
95 /// A breakpoint should be set at this address and Resolve called on each
98 /// @returns the address of a function called by the runtime linker each
99 /// time a module is loaded/unloaded, or about to be loaded/unloaded.
103 GetBreakAddress() const { return m_current.brk; }
105 /// Returns the current state of the rendezvous structure.
107 GetState() const { return m_current.state; }
109 /// @returns the base address of the runtime linker in the inferiors address
112 GetLDBase() const { return m_current.ldbase; }
114 /// @returns the thread layout metadata from the inferiors thread library.
118 /// @returns true if modules have been loaded into the inferior since the
119 /// last call to Resolve().
121 ModulesDidLoad() const { return !m_added_soentries.empty(); }
123 /// @returns true if modules have been unloaded from the inferior since the
124 /// last call to Resolve().
126 ModulesDidUnload() const { return !m_removed_soentries.empty(); }
129 DumpToLog(lldb_private::Log *log) const;
131 /// @brief Constants describing the state of the rendezvous.
134 enum RendezvousState {
140 /// @brief Structure representing the shared objects currently loaded into
141 /// the inferior process.
143 /// This object is a rough analogue to the struct link_map object which
144 /// actually lives in the inferiors memory.
146 lldb::addr_t link_addr; ///< Address of this link_map.
147 lldb::addr_t base_addr; ///< Base address of the loaded object.
148 lldb::addr_t path_addr; ///< String naming the shared object.
149 lldb::addr_t dyn_addr; ///< Dynamic section of shared object.
150 lldb::addr_t next; ///< Address of next so_entry.
151 lldb::addr_t prev; ///< Address of previous so_entry.
152 lldb_private::FileSpec file_spec; ///< File spec of shared object.
154 SOEntry() { clear(); }
156 bool operator ==(const SOEntry &entry) {
157 return file_spec == entry.file_spec;
172 typedef std::list<SOEntry> SOEntryList;
175 typedef SOEntryList::const_iterator iterator;
177 /// Iterators over all currently loaded modules.
178 iterator begin() const { return m_soentries.begin(); }
179 iterator end() const { return m_soentries.end(); }
181 /// Iterators over all modules loaded into the inferior since the last call
183 iterator loaded_begin() const { return m_added_soentries.begin(); }
184 iterator loaded_end() const { return m_added_soentries.end(); }
186 /// Iterators over all modules unloaded from the inferior since the last
187 /// call to Resolve().
188 iterator unloaded_begin() const { return m_removed_soentries.begin(); }
189 iterator unloaded_end() const { return m_removed_soentries.end(); }
192 lldb_private::Process *m_process;
194 // Cached copy of executable file spec
195 lldb_private::FileSpec m_exe_file_spec;
197 /// Location of the r_debug structure in the inferiors address space.
198 lldb::addr_t m_rendezvous_addr;
200 /// Current and previous snapshots of the rendezvous structure.
201 Rendezvous m_current;
202 Rendezvous m_previous;
204 /// List of SOEntry objects corresponding to the current link map state.
205 SOEntryList m_soentries;
207 /// List of SOEntry's added to the link map since the last call to Resolve().
208 SOEntryList m_added_soentries;
210 /// List of SOEntry's removed from the link map since the last call to
212 SOEntryList m_removed_soentries;
214 /// Threading metadata read from the inferior.
215 ThreadInfo m_thread_info;
217 /// Reads an unsigned integer of @p size bytes from the inferior's address
218 /// space starting at @p addr.
220 /// @returns addr + size if the read was successful and false otherwise.
222 ReadWord(lldb::addr_t addr, uint64_t *dst, size_t size);
224 /// Reads an address from the inferior's address space starting at @p addr.
226 /// @returns addr + target address size if the read was successful and
229 ReadPointer(lldb::addr_t addr, lldb::addr_t *dst);
231 /// Reads a null-terminated C string from the memory location starting at @p
234 ReadStringFromMemory(lldb::addr_t addr);
236 /// Reads an SOEntry starting at @p addr.
238 ReadSOEntryFromMemory(lldb::addr_t addr, SOEntry &entry);
240 /// Updates the current set of SOEntries, the set of added entries, and the
241 /// set of removed entries.
246 UpdateSOEntriesForAddition();
249 UpdateSOEntriesForDeletion();
252 SOEntryIsMainExecutable(const SOEntry &entry);
254 /// Reads the current list of shared objects according to the link map
255 /// supplied by the runtime linker.
257 TakeSnapshot(SOEntryList &entry_list);
259 enum PThreadField { eSize, eNElem, eOffset };
261 bool FindMetadata(const char *name, PThreadField field, uint32_t& value);