[llvm] r374139 - [dsymutil] Fix handling of common symbols in multiple object files.
Kristina Brooks via llvm-commits
llvm-commits at lists.llvm.org
Tue Oct 8 21:49:57 PDT 2019
+llvm-commits
On Wed, Oct 9, 2019 at 5:44 AM Kristina Brooks <notstina at gmail.com> wrote:
>
> Hi,
>
> Do you mind regenerating these test inputs so they have something like
> `comm`/`comm1.o` etc. since these names are reserved on Windows:
>
> test/tools/dsymutil/Inputs/private/tmp/common/com
> test/tools/dsymutil/Inputs/private/tmp/common/com1.o
> test/tools/dsymutil/Inputs/private/tmp/common/com2.o
>
> (According to MS docs - "Also avoid these names followed immediately
> by an extension; for example, NUL.txt is not recommended.")
>
> Thank you.
>
>
> On Wed, Oct 9, 2019 at 5:13 AM Jonas Devlieghere via llvm-commits
> <llvm-commits at lists.llvm.org> wrote:
> >
> > Author: jdevlieghere
> > Date: Tue Oct 8 21:16:18 2019
> > New Revision: 374139
> >
> > URL: http://llvm.org/viewvc/llvm-project?rev=374139&view=rev
> > Log:
> > [dsymutil] Fix handling of common symbols in multiple object files.
> >
> > For common symbols the linker emits only a single symbol entry in the
> > debug map. This caused dsymutil to not relocate common symbols when
> > linking DWARF coming form object files that did not have this entry.
> > This patch fixes that by keeping track of common symbols in the object
> > files and synthesizing a debug map entry for them using the address from
> > the main binary.
> >
> > Differential revision: https://reviews.llvm.org/D68680
> >
> > Added:
> > llvm/trunk/test/tools/dsymutil/Inputs/private/
> > llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/
> > llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/
> > llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com (with props)
> > llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com1.o (with props)
> > llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com2.o (with props)
> > llvm/trunk/test/tools/dsymutil/X86/common-sym-multi.test
> > Modified:
> > llvm/trunk/tools/dsymutil/MachODebugMapParser.cpp
> >
> > Added: llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com
> > URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com?rev=374139&view=auto
> > ==============================================================================
> > Binary file - no diff available.
> >
> > Propchange: llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com
> > ------------------------------------------------------------------------------
> > svn:executable = *
> >
> > Propchange: llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com
> > ------------------------------------------------------------------------------
> > svn:mime-type = application/octet-stream
> >
> > Added: llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com1.o
> > URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com1.o?rev=374139&view=auto
> > ==============================================================================
> > Binary file - no diff available.
> >
> > Propchange: llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com1.o
> > ------------------------------------------------------------------------------
> > svn:mime-type = application/octet-stream
> >
> > Added: llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com2.o
> > URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com2.o?rev=374139&view=auto
> > ==============================================================================
> > Binary file - no diff available.
> >
> > Propchange: llvm/trunk/test/tools/dsymutil/Inputs/private/tmp/common/com2.o
> > ------------------------------------------------------------------------------
> > svn:mime-type = application/octet-stream
> >
> > Added: llvm/trunk/test/tools/dsymutil/X86/common-sym-multi.test
> > URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/dsymutil/X86/common-sym-multi.test?rev=374139&view=auto
> > ==============================================================================
> > --- llvm/trunk/test/tools/dsymutil/X86/common-sym-multi.test (added)
> > +++ llvm/trunk/test/tools/dsymutil/X86/common-sym-multi.test Tue Oct 8 21:16:18 2019
> > @@ -0,0 +1,39 @@
> > +RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/common/com -f -o - | llvm-dwarfdump -debug-info - | FileCheck %s
> > +RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/common/com -dump-debug-map | FileCheck %s --check-prefix DEBUGMAP
> > +
> > +The test was compiled from two source files:
> > +$ cd /private/tmp/common
> > +$ cat com1.c
> > +int i[1000];
> > +int main() {
> > + return i[1];
> > +}
> > +$ cat com2.c
> > +extern int i[1000];
> > +int bar() {
> > + return i[0];
> > +}
> > +$ clang -fcommon -g -c com1.c -o com1.o
> > +$ clang -fcommon -g -c com2.c -o com2.o
> > +$ clang -fcommon -g com1.o com2.o -o com
> > +
> > +CHECK: DW_TAG_compile_unit
> > +CHECK: DW_TAG_variable
> > +CHECK-NOT: {{NULL|DW_TAG}}
> > +CHECK: DW_AT_name{{.*}}"i"
> > +CHECK-NOT: {{NULL|DW_TAG}}
> > +CHECK: DW_AT_location{{.*}}DW_OP_addr 0x100001000)
> > +
> > +CHECK: DW_TAG_compile_unit
> > +CHECK: DW_TAG_variable
> > +CHECK-NOT: {{NULL|DW_TAG}}
> > +CHECK: DW_AT_name{{.*}}"i"
> > +CHECK-NOT: {{NULL|DW_TAG}}
> > +CHECK: DW_AT_location{{.*}}DW_OP_addr 0x100001000)
> > +
> > +DEBUGMAP: filename:{{.*}}com1.o
> > +DEBUGMAP: symbols:
> > +DEBUGMAP: sym: _i, binAddr: 0x0000000100001000, size: 0x00000000
> > +DEBUGMAP: filename:{{.*}}com2.o
> > +DEBUGMAP: symbols:
> > +DEBUGMAP: sym: _i, binAddr: 0x0000000100001000, size: 0x00000000
> >
> > Modified: llvm/trunk/tools/dsymutil/MachODebugMapParser.cpp
> > URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/dsymutil/MachODebugMapParser.cpp?rev=374139&r1=374138&r2=374139&view=diff
> > ==============================================================================
> > --- llvm/trunk/tools/dsymutil/MachODebugMapParser.cpp (original)
> > +++ llvm/trunk/tools/dsymutil/MachODebugMapParser.cpp Tue Oct 8 21:16:18 2019
> > @@ -14,6 +14,7 @@
> > #include "llvm/Support/Path.h"
> > #include "llvm/Support/WithColor.h"
> > #include "llvm/Support/raw_ostream.h"
> > +#include <vector>
> >
> > namespace {
> > using namespace llvm;
> > @@ -51,6 +52,8 @@ private:
> > StringRef MainBinaryStrings;
> > /// The constructed DebugMap.
> > std::unique_ptr<DebugMap> Result;
> > + /// List of common symbols that need to be added to the debug map.
> > + std::vector<std::string> CommonSymbols;
> >
> > /// Map of the currently processed object file symbol addresses.
> > StringMap<Optional<uint64_t>> CurrentObjectAddresses;
> > @@ -81,6 +84,8 @@ private:
> > STE.n_value);
> > }
> >
> > + void addCommonSymbols();
> > +
> > /// Dump the symbol table output header.
> > void dumpSymTabHeader(raw_ostream &OS, StringRef Arch);
> >
> > @@ -122,11 +127,32 @@ void MachODebugMapParser::resetParserSta
> > CurrentDebugMapObject = nullptr;
> > }
> >
> > +/// Commons symbols won't show up in the symbol map but might need to be
> > +/// relocated. We can add them to the symbol table ourselves by combining the
> > +/// information in the object file (the symbol name) and the main binary (the
> > +/// address).
> > +void MachODebugMapParser::addCommonSymbols() {
> > + for (auto &CommonSymbol : CommonSymbols) {
> > + uint64_t CommonAddr = getMainBinarySymbolAddress(CommonSymbol);
> > + if (CommonAddr == 0) {
> > + // The main binary doesn't have an address for the given symbol.
> > + continue;
> > + }
> > + if (!CurrentDebugMapObject->addSymbol(CommonSymbol, None /*ObjectAddress*/,
> > + CommonAddr, 0 /*size*/)) {
> > + // The symbol is already present.
> > + continue;
> > + }
> > + }
> > + CommonSymbols.clear();
> > +}
> > +
> > /// Create a new DebugMapObject. This function resets the state of the
> > /// parser that was referring to the last object file and sets
> > /// everything up to add symbols to the new one.
> > void MachODebugMapParser::switchToNewDebugMapObject(
> > StringRef Filename, sys::TimePoint<std::chrono::seconds> Timestamp) {
> > + addCommonSymbols();
> > resetParserState();
> >
> > SmallString<80> Path(PathPrefix);
> > @@ -466,10 +492,15 @@ void MachODebugMapParser::loadCurrentObj
> > // 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))
> > + uint32_t Flags = Sym.getFlags();
> > + if (Flags & SymbolRef::SF_Absolute) {
> > CurrentObjectAddresses[*Name] = None;
> > - else
> > + } else if (Flags & SymbolRef::SF_Common) {
> > + CurrentObjectAddresses[*Name] = None;
> > + CommonSymbols.push_back(*Name);
> > + } else {
> > CurrentObjectAddresses[*Name] = Addr;
> > + }
> > }
> > }
> >
> >
> >
> > _______________________________________________
> > llvm-commits mailing list
> > llvm-commits at lists.llvm.org
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