jingham created this revision.
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The pointer to the dyld trie data structure which lldb needs to parse to get
"trampoline kinds" on Darwin used to be a field in the LC_DYLD_INFO load
command. A new load command was added recently dedicated to this purpose:
LC_DYLD_EXPORTS_TRIE. The format of the trie did not change, however. So all
we have to do is use the new command if present. The commands are supposed to
be mutually exclusive, so I added an lldb_assert to warn if they are not.
Without this patch TestIndirectSymbols.py fails on systems that use the new
command, so there wasn't a need to write a test for this change.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D107673
Files:
lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
Index: lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
===================================================================
--- lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -2221,6 +2221,7 @@
llvm::MachO::symtab_command symtab_load_command = {0, 0, 0, 0, 0, 0};
llvm::MachO::linkedit_data_command function_starts_load_command = {0, 0, 0,
0};
+ llvm::MachO::linkedit_data_command exports_trie_load_command = {0, 0, 0, 0};
llvm::MachO::dyld_info_command dyld_info = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0};
// The data element of type bool indicates that this entry is thumb
// code.
@@ -2298,11 +2299,19 @@
}
} break;
+ case LC_DYLD_EXPORTS_TRIE:
+ exports_trie_load_command.cmd = lc.cmd;
+ exports_trie_load_command.cmdsize = lc.cmdsize;
+ if (m_data.GetU32(&offset, &exports_trie_load_command.dataoff, 2) ==
+ nullptr) // fill in offset and size fields
+ memset(&exports_trie_load_command, 0,
+ sizeof(exports_trie_load_command));
+ break;
case LC_FUNCTION_STARTS:
function_starts_load_command.cmd = lc.cmd;
function_starts_load_command.cmdsize = lc.cmdsize;
if (m_data.GetU32(&offset, &function_starts_load_command.dataoff, 2) ==
- nullptr) // fill in symoff, nsyms, stroff, strsize fields
+ nullptr) // fill in data offset and size fields
memset(&function_starts_load_command, 0,
sizeof(function_starts_load_command));
break;
@@ -2446,6 +2455,7 @@
dyld_info.export_off += linkedit_slide;
m_dysymtab.indirectsymoff += linkedit_slide;
function_starts_load_command.dataoff += linkedit_slide;
+ exports_trie_load_command.dataoff += linkedit_slide;
}
nlist_data.SetData(m_data, symtab_load_command.symoff,
@@ -2453,9 +2463,16 @@
strtab_data.SetData(m_data, symtab_load_command.stroff,
strtab_data_byte_size);
+ // We shouldn't have exports data from both the LC_DYLD_INFO command
+ // AND the LC_DYLD_EXPORTS_TRIE command in the same binary:
+ lldbassert(!((dyld_info.export_size > 0)
+ && (exports_trie_load_command.datasize > 0)));
if (dyld_info.export_size > 0) {
dyld_trie_data.SetData(m_data, dyld_info.export_off,
dyld_info.export_size);
+ } else if (exports_trie_load_command.datasize > 0) {
+ dyld_trie_data.SetData(m_data, exports_trie_load_command.dataoff,
+ exports_trie_load_command.datasize);
}
if (m_dysymtab.nindirectsyms != 0) {
Index: lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
===================================================================
--- lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -2221,6 +2221,7 @@
llvm::MachO::symtab_command symtab_load_command = {0, 0, 0, 0, 0, 0};
llvm::MachO::linkedit_data_command function_starts_load_command = {0, 0, 0, 0};
+ llvm::MachO::linkedit_data_command exports_trie_load_command = {0, 0, 0, 0};
llvm::MachO::dyld_info_command dyld_info = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
// The data element of type bool indicates that this entry is thumb
// code.
@@ -2298,11 +2299,19 @@
}
} break;
+ case LC_DYLD_EXPORTS_TRIE:
+ exports_trie_load_command.cmd = lc.cmd;
+ exports_trie_load_command.cmdsize = lc.cmdsize;
+ if (m_data.GetU32(&offset, &exports_trie_load_command.dataoff, 2) ==
+ nullptr) // fill in offset and size fields
+ memset(&exports_trie_load_command, 0,
+ sizeof(exports_trie_load_command));
+ break;
case LC_FUNCTION_STARTS:
function_starts_load_command.cmd = lc.cmd;
function_starts_load_command.cmdsize = lc.cmdsize;
if (m_data.GetU32(&offset, &function_starts_load_command.dataoff, 2) ==
- nullptr) // fill in symoff, nsyms, stroff, strsize fields
+ nullptr) // fill in data offset and size fields
memset(&function_starts_load_command, 0,
sizeof(function_starts_load_command));
break;
@@ -2446,6 +2455,7 @@
dyld_info.export_off += linkedit_slide;
m_dysymtab.indirectsymoff += linkedit_slide;
function_starts_load_command.dataoff += linkedit_slide;
+ exports_trie_load_command.dataoff += linkedit_slide;
}
nlist_data.SetData(m_data, symtab_load_command.symoff,
@@ -2453,9 +2463,16 @@
strtab_data.SetData(m_data, symtab_load_command.stroff,
strtab_data_byte_size);
+ // We shouldn't have exports data from both the LC_DYLD_INFO command
+ // AND the LC_DYLD_EXPORTS_TRIE command in the same binary:
+ lldbassert(!((dyld_info.export_size > 0)
+ && (exports_trie_load_command.datasize > 0)));
if (dyld_info.export_size > 0) {
dyld_trie_data.SetData(m_data, dyld_info.export_off,
dyld_info.export_size);
+ } else if (exports_trie_load_command.datasize > 0) {
+ dyld_trie_data.SetData(m_data, exports_trie_load_command.dataoff,
+ exports_trie_load_command.datasize);
}
if (m_dysymtab.nindirectsyms != 0) {
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