RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-10-19 02:52:53 +02:00
Code Issues Projects Releases Wiki Activity

[dsymutil] Fix handling of common symbols.

Browse Source 
llvm-dsymutil was misinterpreting the value of common symbols as their
address when it actually contains their size. This didn't impact
llvm-dsymutil's ability to link the debug information for common symbols
because these are always found by name and not by address. Things could
however go wrong when the size of a common object matched the object
file address of another symbol. Depending on the link order of the symbols
the common object might incorrectly evict this other object from the
address to symbol mapping, and then link the evicted symbol with a wrong
binary address.

Use the new ability to have symbols without an object file address to fix
this.

llvm-svn: 259318
This commit is contained in:
Frederic Riss 2016-01-31 04:29:34 +00:00
parent b7d5b18cde
commit f067530e7a
9 changed files with 43 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

BIN
test/tools/dsymutil/Inputs/common.macho.x86_64 Executable file
View File

Binary file not shown.

BIN
test/tools/dsymutil/Inputs/common.macho.x86_64.o Normal file
View File

Binary file not shown.

24
test/tools/dsymutil/X86/common-sym.test Normal file
View File

@ -0,0 +1,24 @@
RUN: llvm-dsymutil -oso-prepend-path %p/.. %p/../Inputs/common.macho.x86_64 -f -o - | llvm-dwarfdump -debug-dump=info - | Filecheck %s
The test was compiled from a single source:
$ cat common.c
char common[16];
int main() { return 0;}
void bar() {}
$ clang -g -c common.c -o common.macho.x86_64.o
$ clang common.macho.x86_64.o -o common.macho.x86_64
CHECK: DW_TAG_variable
CHECK: DW_AT_name {{.*}} "common"
CHECK-NOT: {{NULL|DW_TAG}}
CHECK: DW_AT_location {{.*}} (<0x09> 03 00 10 00 00 01 00 00 00 )
CHECK: DW_TAG_subprogram
CHECK-NEXT: DW_AT_low_pc{{.*}}(0x0000000100000f80)
CHECK-NOT: {{NULL|DW_TAG}}
CHECK: DW_AT_name {{.*}} "main"
CHECK: DW_TAG_subprogram
CHECK-NEXT: DW_AT_low_pc{{.*}}(0x0000000100000f90)
CHECK-NOT: {{NULL|DW_TAG}}
CHECK: DW_AT_name {{.*}} "bar"

3
test/tools/dsymutil/absolute_symbol.test
View File

@ -13,4 +13,5 @@ compiled for i386. This create an absolute symbol .objc_class_name_Foo
We must not consider this symbol for debug info linking as its address
might conflict with other real symbols in the same file.
CHECK-NOT: objc_class_name_Foo
CHECK: objc_class_name_Foo
CHECK-SAME-NOT: objAddr

4
test/tools/dsymutil/basic-linking.test
View File

@ -44,7 +44,7 @@ CHECK-NEXT: TAG_compile_unit
CHECK-NOT: TAG
CHECK: AT_name {{.*}}basic3.c
CHECK-NOT: Found valid debug map entry
CHECK: Found valid debug map entry: _val 0000000000000004 => 0000000100001004
CHECK: Found valid debug map entry: _val ffffffffffffffff => 0000000100001004
CHECK-NEXT: DW_TAG_variable
CHECK-NEXT: DW_AT_name {{.*}}"val"
CHECK-NOT: Found valid debug map entry
@ -137,7 +137,7 @@ CHECK-ARCHIVE-NEXT: TAG_compile_unit
CHECK-ARCHIVE-NOT: TAG
CHECK-ARCHIVE: AT_name {{.*}}basic3.c
CHECK-ARCHIVE-NOT: Found valid debug map entry
CHECK-ARCHIVE: Found valid debug map entry: _val 0000000000000004 => 0000000100001008
CHECK-ARCHIVE: Found valid debug map entry: _val ffffffffffffffff => 0000000100001008
CHECK-ARCHIVE-NEXT: DW_TAG_variable
CHECK-ARCHIVE-NEXT: DW_AT_name {{.*}}"val"
CHECK-ARCHIVE-NOT: Found valid debug map entry

4
test/tools/dsymutil/debug-map-parsing.test
View File

@ -21,7 +21,7 @@ CHECK-DAG: sym: _private_int, objAddr: 0x0000000000000560, binAddr: 0x000000010
CHECK: filename{{.*}}/Inputs/basic3.macho.x86_64.o
CHECK-DAG: sym: _bar, objAddr: 0x0000000000000020, binAddr: 0x0000000100000F40, size: 0x00000050
CHECK-DAG: sym: _inc, objAddr: 0x0000000000000070, binAddr: 0x0000000100000F90, size: 0x00000019
CHECK-DAG: sym: _val, objAddr: 0x0000000000000004, binAddr: 0x0000000100001004, size: 0x00000000
CHECK-DAG: sym: _val, binAddr: 0x0000000100001004, size: 0x00000000
CHECK: ...
@ -65,7 +65,7 @@ CHECK-ARCHIVE-DAG: sym: _private_int, objAddr: 0x0000000000000560, binAddr: 0x0
CHECK-ARCHIVE: /Inputs/./libbasic.a(basic3.macho.x86_64.o)
CHECK-ARCHIVE-DAG: sym: _bar, objAddr: 0x0000000000000020, binAddr: 0x0000000100000F40, size: 0x00000050
CHECK-ARCHIVE-DAG: sym: _inc, objAddr: 0x0000000000000070, binAddr: 0x0000000100000F90, size: 0x00000019
CHECK-ARCHIVE-DAG: sym: _val, objAddr: 0x0000000000000004, binAddr: 0x0000000100001008, size: 0x00000000
CHECK-ARCHIVE-DAG: sym: _val, binAddr: 0x0000000100001008, size: 0x00000000
CHECK-ARCHIVE: ...
Check that we warn about missing object files (this presumes that the files aren't

4
test/tools/dsymutil/yaml-object-address-rewrite.test
View File

@ -23,7 +23,7 @@
# CHECK-NEXT: filename:{{.*}}/Inputs/./libbasic.a(basic3.macho.x86_64.o)'
# CHECK-NEXT: timestamp: 0
# CHECK-NEXT: symbols:
# CHECK-DAG: sym: _val, objAddr: 0x0000000000000004, binAddr: 0x0000000100001008, size: 0x00000000
# CHECK-DAG: sym: _val, binAddr: 0x0000000100001008, size: 0x00000000
# CHECK-DAG: sym: _bar, objAddr: 0x0000000000000020, binAddr: 0x0000000100000F40, size: 0x00000050
# CHECK-DAG: sym: _inc, objAddr: 0x0000000000000070, binAddr: 0x0000000100000F90, size: 0x00000019
# CHECK-NOT: { sym:
@ -42,7 +42,7 @@ objects:
- { sym: _baz, objAddr: 0x0, binAddr: 0x0000000100001000, size: 0x00000000 }
- filename: /Inputs/./libbasic.a(basic3.macho.x86_64.o)
symbols:
- { sym: _val, objAddr: 0x0, binAddr: 0x0000000100001008, size: 0x00000000 }
- { sym: _val, binAddr: 0x0000000100001008, size: 0x00000000 }
- { sym: _bar, objAddr: 0x0, binAddr: 0x0000000100000F40, size: 0x00000050 }
- { sym: _inc, objAddr: 0x0, binAddr: 0x0000000100000F90, size: 0x00000019 }
...

3
tools/dsymutil/DebugMap.cpp
View File

@ -229,7 +229,8 @@ MappingTraits<dsymutil::DebugMapObject>::YamlDMO::denormalize(IO &IO) {
for (const auto &Sym : ErrOrObjectFile->symbols()) {
uint64_t Address = Sym.getValue();
ErrorOr<StringRef> Name = Sym.getName();
if (!Name)
if (!Name ||
(Sym.getFlags() & (SymbolRef::SF_Absolute | SymbolRef::SF_Common)))
continue;
SymbolAddresses[*Name] = Address;
}

17
tools/dsymutil/MachODebugMapParser.cpp
View File

@ -389,8 +389,6 @@ void MachODebugMapParser::handleStabSymbolTableEntry(uint32_t StringIndex,
if (ObjectSymIt == CurrentObjectAddresses.end())
return Warning("could not find object file symbol for symbol " +
Twine(Name));
if (!ObjectSymIt->getValue())
return;
if (!CurrentDebugMapObject->addSymbol(Name, ObjectSymIt->getValue(), Value,
Size))
return Warning(Twine("failed to insert symbol '") + Name +
@ -407,12 +405,15 @@ void MachODebugMapParser::loadCurrentObjectFileSymbols(
ErrorOr<StringRef> Name = Sym.getName();
if (!Name)
continue;
// Objective-C on i386 uses artificial absolute symbols to
// perform some link time checks. Those symbols have a fixed 0
// address that might conflict with real symbols in the object
// file. As I cannot see a way for absolute symbols to find
// their way into the debug information, let's just ignore those.
if (Sym.getFlags() & SymbolRef::SF_Absolute)
// The value of some categories of symbols isn't meaningful. For
// example common symbols store their size in the value field, not
// their address. Absolute symbols have a fixed address that can
// conflict with standard symbols. These symbols (especially the
// common ones), might still be referenced by relocations. These
// relocations will use the symbol itself, and won't need an
// object file address. The object file address field is optional
// in the DebugMap, leave it unassigned for these symbols.
if (Sym.getFlags() & (SymbolRef::SF_Absolute | SymbolRef::SF_Common))
CurrentObjectAddresses[*Name] = None;
else
CurrentObjectAddresses[*Name] = Addr;