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"
22 namespace lldb_private {
26 /// @class DYLDRendezvous
27 /// @brief Interface to the runtime linker.
29 /// A structure is present in a processes memory space which is updated by the
30 /// runtime liker each time a module is loaded or unloaded. This class provides
31 /// an interface to this structure and maintains a consistent snapshot of the
32 /// currently loaded modules.
33 class DYLDRendezvous {
35 // This structure is used to hold the contents of the debug rendezvous
36 // information (struct r_debug) as found in the inferiors memory. Note that
37 // the layout of this struct is not binary compatible, it is simply large
38 // enough to hold the information on both 32 and 64 bit platforms.
41 lldb::addr_t map_addr;
47 : version(0), map_addr(0), brk(0), state(0), ldbase(0) { }
51 // Various metadata supplied by the inferior's threading library to describe
52 // the per-thread state.
54 bool valid; // whether we read valid metadata
55 uint32_t dtv_offset; // offset of DTV pointer within pthread
56 uint32_t dtv_slot_size; // size of one DTV slot
57 uint32_t modid_offset; // offset of module ID within link_map
58 uint32_t tls_offset; // offset of TLS pointer within DTV slot
61 DYLDRendezvous(lldb_private::Process *process);
63 /// Update the internal snapshot of runtime linker rendezvous and recompute
64 /// the currently loaded modules.
66 /// This method should be called once one start up, then once each time the
67 /// runtime linker enters the function given by GetBreakAddress().
69 /// @returns true on success and false on failure.
71 /// @see GetBreakAddress().
75 /// @returns true if this rendezvous has been located in the inferiors
76 /// address space and false otherwise.
80 /// @returns the address of the rendezvous structure in the inferiors
83 GetRendezvousAddress() const { return m_rendezvous_addr; }
85 /// @returns the version of the rendezvous protocol being used.
87 GetVersion() const { return m_current.version; }
89 /// @returns address in the inferiors address space containing the linked
90 /// list of shared object descriptors.
92 GetLinkMapAddress() const { return m_current.map_addr; }
94 /// A breakpoint should be set at this address and Resolve called on each
97 /// @returns the address of a function called by the runtime linker each
98 /// time a module is loaded/unloaded, or about to be loaded/unloaded.
102 GetBreakAddress() const { return m_current.brk; }
104 /// Returns the current state of the rendezvous structure.
106 GetState() const { return m_current.state; }
108 /// @returns the base address of the runtime linker in the inferiors address
111 GetLDBase() const { return m_current.ldbase; }
113 /// @returns the thread layout metadata from the inferiors thread library.
117 /// @returns true if modules have been loaded into the inferior since the
118 /// last call to Resolve().
120 ModulesDidLoad() const { return !m_added_soentries.empty(); }
122 /// @returns true if modules have been unloaded from the inferior since the
123 /// last call to Resolve().
125 ModulesDidUnload() const { return !m_removed_soentries.empty(); }
128 DumpToLog(lldb_private::Log *log) const;
130 /// @brief Constants describing the state of the rendezvous.
133 enum RendezvousState {
139 /// @brief Structure representing the shared objects currently loaded into
140 /// the inferior process.
142 /// This object is a rough analogue to the struct link_map object which
143 /// actually lives in the inferiors memory.
145 lldb::addr_t link_addr; ///< Address of this link_map.
146 lldb::addr_t base_addr; ///< Base address of the loaded object.
147 lldb::addr_t path_addr; ///< String naming the shared object.
148 lldb::addr_t dyn_addr; ///< Dynamic section of shared object.
149 lldb::addr_t next; ///< Address of next so_entry.
150 lldb::addr_t prev; ///< Address of previous so_entry.
151 std::string path; ///< File name of shared object.
153 SOEntry() { clear(); }
155 bool operator ==(const SOEntry &entry) {
156 return this->path == entry.path;
171 typedef std::list<SOEntry> SOEntryList;
174 typedef SOEntryList::const_iterator iterator;
176 /// Iterators over all currently loaded modules.
177 iterator begin() const { return m_soentries.begin(); }
178 iterator end() const { return m_soentries.end(); }
180 /// Iterators over all modules loaded into the inferior since the last call
182 iterator loaded_begin() const { return m_added_soentries.begin(); }
183 iterator loaded_end() const { return m_added_soentries.end(); }
185 /// Iterators over all modules unloaded from the inferior since the last
186 /// call to Resolve().
187 iterator unloaded_begin() const { return m_removed_soentries.begin(); }
188 iterator unloaded_end() const { return m_removed_soentries.end(); }
191 lldb_private::Process *m_process;
193 // Cached copy of executable pathname
194 char m_exe_path[PATH_MAX];
196 /// Location of the r_debug structure in the inferiors address space.
197 lldb::addr_t m_rendezvous_addr;
199 /// Current and previous snapshots of the rendezvous structure.
200 Rendezvous m_current;
201 Rendezvous m_previous;
203 /// List of SOEntry objects corresponding to the current link map state.
204 SOEntryList m_soentries;
206 /// List of SOEntry's added to the link map since the last call to Resolve().
207 SOEntryList m_added_soentries;
209 /// List of SOEntry's removed from the link map since the last call to
211 SOEntryList m_removed_soentries;
213 /// Threading metadata read from the inferior.
214 ThreadInfo m_thread_info;
216 /// Reads an unsigned integer of @p size bytes from the inferior's address
217 /// space starting at @p addr.
219 /// @returns addr + size if the read was successful and false otherwise.
221 ReadWord(lldb::addr_t addr, uint64_t *dst, size_t size);
223 /// Reads an address from the inferior's address space starting at @p addr.
225 /// @returns addr + target address size if the read was successful and
228 ReadPointer(lldb::addr_t addr, lldb::addr_t *dst);
230 /// Reads a null-terminated C string from the memory location starting at @p
233 ReadStringFromMemory(lldb::addr_t addr);
235 /// Reads an SOEntry starting at @p addr.
237 ReadSOEntryFromMemory(lldb::addr_t addr, SOEntry &entry);
239 /// Updates the current set of SOEntries, the set of added entries, and the
240 /// set of removed entries.
245 UpdateSOEntriesForAddition();
248 UpdateSOEntriesForDeletion();
250 /// Reads the current list of shared objects according to the link map
251 /// supplied by the runtime linker.
253 TakeSnapshot(SOEntryList &entry_list);
255 enum PThreadField { eSize, eNElem, eOffset };
257 bool FindMetadata(const char *name, PThreadField field, uint32_t& value);