[llvm] r253429 - [llvm-objdump] Use the COFF export table for additional symbols
David Majnemer via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 17 18:49:19 PST 2015
Author: majnemer
Date: Tue Nov 17 20:49:19 2015
New Revision: 253429
URL: http://llvm.org/viewvc/llvm-project?rev=253429&view=rev
Log:
[llvm-objdump] Use the COFF export table for additional symbols
Most linked executables do not have a symbol table in COFF.
However, it is pretty typical to have some export entries. Use those
entries to inform the disassembler about potential function definitions
and call targets.
Added:
llvm/trunk/test/tools/llvm-objdump/X86/Inputs/disassemble.dll.coff-i386 (with props)
llvm/trunk/test/tools/llvm-objdump/X86/coff-disassemble-export.test
Modified:
llvm/trunk/test/CodeGen/ARM/inlineasm-switch-mode.ll
llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp
Modified: llvm/trunk/test/CodeGen/ARM/inlineasm-switch-mode.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/inlineasm-switch-mode.ll?rev=253429&r1=253428&r2=253429&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/inlineasm-switch-mode.ll (original)
+++ llvm/trunk/test/CodeGen/ARM/inlineasm-switch-mode.ll Tue Nov 17 20:49:19 2015
@@ -15,8 +15,8 @@ define hidden i32 @bah(i8* %start) #0 al
; ARM: $t
; ARM-NEXT: 48 1c
-; THUMB: $a
+; THUMB: $a{{.*}}:
; THUMB-NEXT: 04 70
; THUMB-NEXT: 2d e5
-; THUMB: $t
+; THUMB: $t{{.*}}:
; THUMB-NEXT: 48 1c adds r0, r1, #1
Added: llvm/trunk/test/tools/llvm-objdump/X86/Inputs/disassemble.dll.coff-i386
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/X86/Inputs/disassemble.dll.coff-i386?rev=253429&view=auto
==============================================================================
Binary files llvm/trunk/test/tools/llvm-objdump/X86/Inputs/disassemble.dll.coff-i386 (added) and llvm/trunk/test/tools/llvm-objdump/X86/Inputs/disassemble.dll.coff-i386 Tue Nov 17 20:49:19 2015 differ
Propchange: llvm/trunk/test/tools/llvm-objdump/X86/Inputs/disassemble.dll.coff-i386
------------------------------------------------------------------------------
svn:executable = *
Added: llvm/trunk/test/tools/llvm-objdump/X86/coff-disassemble-export.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/X86/coff-disassemble-export.test?rev=253429&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objdump/X86/coff-disassemble-export.test (added)
+++ llvm/trunk/test/tools/llvm-objdump/X86/coff-disassemble-export.test Tue Nov 17 20:49:19 2015
@@ -0,0 +1,8 @@
+// RUN: llvm-objdump -d %p/Inputs/disassemble.dll.coff-i386 | \
+// RUN: FileCheck %s
+
+// CHECK-LABEL: g:
+// CHECK: calll 8 <f>
+
+// CHECK-LABEL: f:
+// CHECK: calll -24 <g>
Modified: llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp?rev=253429&r1=253428&r2=253429&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp (original)
+++ llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp Tue Nov 17 20:49:19 2015
@@ -886,27 +886,66 @@ static void DisassembleObject(const Obje
}
// Create a mapping from virtual address to symbol name. This is used to
- // pretty print the target of a call.
- std::vector<std::pair<uint64_t, StringRef>> AllSymbols;
- if (MIA) {
- for (const SymbolRef &Symbol : Obj->symbols()) {
- if (Symbol.getType() != SymbolRef::ST_Function)
- continue;
+ // pretty print the symbols while disassembling.
+ typedef std::vector<std::pair<uint64_t, StringRef>> SectionSymbolsTy;
+ std::map<SectionRef, SectionSymbolsTy> AllSymbols;
+ for (const SymbolRef &Symbol : Obj->symbols()) {
+ ErrorOr<uint64_t> AddressOrErr = Symbol.getAddress();
+ error(AddressOrErr.getError());
+ uint64_t Address = *AddressOrErr;
+
+ ErrorOr<StringRef> Name = Symbol.getName();
+ error(Name.getError());
+ if (Name->empty())
+ continue;
+
+ ErrorOr<section_iterator> SectionOrErr = Symbol.getSection();
+ error(SectionOrErr.getError());
+ section_iterator SecI = *SectionOrErr;
+ if (SecI == Obj->section_end())
+ continue;
- ErrorOr<uint64_t> AddressOrErr = Symbol.getAddress();
- error(AddressOrErr.getError());
- uint64_t Address = *AddressOrErr;
-
- ErrorOr<StringRef> Name = Symbol.getName();
- error(Name.getError());
- if (Name->empty())
+ AllSymbols[*SecI].emplace_back(Address, *Name);
+ }
+
+ // Create a mapping from virtual address to section.
+ std::vector<std::pair<uint64_t, SectionRef>> SectionAddresses;
+ for (SectionRef Sec : Obj->sections())
+ SectionAddresses.emplace_back(Sec.getAddress(), Sec);
+ array_pod_sort(SectionAddresses.begin(), SectionAddresses.end());
+
+ // Linked executables (.exe and .dll files) typically don't include a real
+ // symbol table but they might contain an export table.
+ if (const auto *COFFObj = dyn_cast<COFFObjectFile>(Obj)) {
+ for (const auto &ExportEntry : COFFObj->export_directories()) {
+ StringRef Name;
+ error(ExportEntry.getSymbolName(Name));
+ if (Name.empty())
continue;
- AllSymbols.push_back(std::make_pair(Address, *Name));
- }
+ uint32_t RVA;
+ error(ExportEntry.getExportRVA(RVA));
+
+ uint64_t VA = COFFObj->getImageBase() + RVA;
+ auto Sec = std::upper_bound(
+ SectionAddresses.begin(), SectionAddresses.end(), VA,
+ [](uint64_t LHS, const std::pair<uint64_t, SectionRef> &RHS) {
+ return LHS < RHS.first;
+ });
+ if (Sec != SectionAddresses.begin())
+ --Sec;
+ else
+ Sec = SectionAddresses.end();
- array_pod_sort(AllSymbols.begin(), AllSymbols.end());
+ if (Sec != SectionAddresses.end())
+ AllSymbols[Sec->second].emplace_back(VA, Name);
+ }
}
+ // Sort all the symbols, this allows us to use a simple binary search to find
+ // a symbol near an address.
+ for (std::pair<const SectionRef, SectionSymbolsTy> &SecSyms : AllSymbols)
+ array_pod_sort(SecSyms.second.begin(), SecSyms.second.end());
+
for (const SectionRef &Section : ToolSectionFilter(*Obj)) {
if (!DisassembleAll && (!Section.isText() || Section.isVirtual()))
continue;
@@ -916,33 +955,21 @@ static void DisassembleObject(const Obje
if (!SectSize)
continue;
- // Make a list of all the symbols in this section.
- std::vector<std::pair<uint64_t, StringRef>> Symbols;
+ // Get the list of all the symbols in this section.
+ SectionSymbolsTy &Symbols = AllSymbols[Section];
std::vector<uint64_t> DataMappingSymsAddr;
std::vector<uint64_t> TextMappingSymsAddr;
- for (const SymbolRef &Symbol : Obj->symbols()) {
- if (Section.containsSymbol(Symbol)) {
- ErrorOr<uint64_t> AddressOrErr = Symbol.getAddress();
- error(AddressOrErr.getError());
- uint64_t Address = *AddressOrErr;
- Address -= SectionAddr;
- if (Address >= SectSize)
- continue;
-
- ErrorOr<StringRef> Name = Symbol.getName();
- error(Name.getError());
- Symbols.push_back(std::make_pair(Address, *Name));
- if (Obj->isELF() && Obj->getArch() == Triple::aarch64) {
- if (Name->startswith("$d"))
- DataMappingSymsAddr.push_back(Address);
- if (Name->startswith("$x"))
- TextMappingSymsAddr.push_back(Address);
- }
+ if (Obj->isELF() && Obj->getArch() == Triple::aarch64) {
+ for (const auto &Symb : Symbols) {
+ uint64_t Address = Symb.first;
+ StringRef Name = Symb.second;
+ if (Name.startswith("$d"))
+ DataMappingSymsAddr.push_back(Address);
+ if (Name.startswith("$x"))
+ TextMappingSymsAddr.push_back(Address);
}
}
- // Sort the symbols by address, just in case they didn't come in that way.
- array_pod_sort(Symbols.begin(), Symbols.end());
std::sort(DataMappingSymsAddr.begin(), DataMappingSymsAddr.end());
std::sort(TextMappingSymsAddr.begin(), TextMappingSymsAddr.end());
@@ -991,11 +1018,16 @@ static void DisassembleObject(const Obje
// Disassemble symbol by symbol.
for (unsigned si = 0, se = Symbols.size(); si != se; ++si) {
- uint64_t Start = Symbols[si].first;
- // The end is either the section end or the beginning of the next symbol.
- uint64_t End = (si == se - 1) ? SectSize : Symbols[si + 1].first;
+ uint64_t Start = Symbols[si].first - SectionAddr;
+ // The end is either the section end or the beginning of the next
+ // symbol.
+ uint64_t End =
+ (si == se - 1) ? SectSize : Symbols[si + 1].first - SectionAddr;
+ // Don't try to disassemble beyond the end of section contents.
+ if (End > SectSize)
+ End = SectSize;
// If this symbol has the same address as the next symbol, then skip it.
- if (Start == End)
+ if (Start >= End)
continue;
outs() << '\n' << Symbols[si].second << ":\n";
@@ -1056,26 +1088,55 @@ static void DisassembleObject(const Obje
SectionAddr + Index, outs(), "", *STI);
outs() << CommentStream.str();
Comments.clear();
+
+ // Try to resolve the target of a call, tail call, etc. to a specific
+ // symbol.
if (MIA && (MIA->isCall(Inst) || MIA->isUnconditionalBranch(Inst) ||
MIA->isConditionalBranch(Inst))) {
uint64_t Target;
if (MIA->evaluateBranch(Inst, SectionAddr + Index, Size, Target)) {
- auto TargetSym = std::upper_bound(
- AllSymbols.begin(), AllSymbols.end(), Target,
- [](uint64_t LHS, const std::pair<uint64_t, StringRef> &RHS) {
- return LHS < RHS.first;
- });
- if (TargetSym != AllSymbols.begin())
- --TargetSym;
- else
- TargetSym = AllSymbols.end();
-
- if (TargetSym != AllSymbols.end()) {
- outs() << " <" << TargetSym->second;
- uint64_t Disp = Target - TargetSym->first;
- if (Disp)
- outs() << '+' << utohexstr(Disp);
- outs() << '>';
+ // In a relocatable object, the target's section must reside in
+ // the same section as the call instruction or it is accessed
+ // through a relocation.
+ //
+ // In a non-relocatable object, the target may be in any section.
+ //
+ // N.B. We don't walk the relocations in the relocatable case yet.
+ auto *TargetSectionSymbols = &Symbols;
+ if (!Obj->isRelocatableObject()) {
+ auto SectionAddress = std::upper_bound(
+ SectionAddresses.begin(), SectionAddresses.end(), Target,
+ [](uint64_t LHS,
+ const std::pair<uint64_t, SectionRef> &RHS) {
+ return LHS < RHS.first;
+ });
+ if (SectionAddress != SectionAddresses.begin()) {
+ --SectionAddress;
+ TargetSectionSymbols = &AllSymbols[SectionAddress->second];
+ } else {
+ TargetSectionSymbols = nullptr;
+ }
+ }
+
+ // Find the first symbol in the section whose offset is less than
+ // or equal to the target.
+ if (TargetSectionSymbols) {
+ auto TargetSym = std::upper_bound(
+ TargetSectionSymbols->begin(), TargetSectionSymbols->end(),
+ Target, [](uint64_t LHS,
+ const std::pair<uint64_t, StringRef> &RHS) {
+ return LHS < RHS.first;
+ });
+ if (TargetSym != Symbols.begin()) {
+ --TargetSym;
+ uint64_t TargetAddress = std::get<0>(*TargetSym);
+ StringRef TargetName = std::get<1>(*TargetSym);
+ outs() << " <" << TargetName;
+ uint64_t Disp = Target - TargetAddress;
+ if (Disp)
+ outs() << '+' << utohexstr(Disp);
+ outs() << '>';
+ }
}
}
}
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