[llvm-objdump] Allow --disassemble-functions to take demangled names

[ychen]

Summary

The --disassemble-functions switch takes demangled names when
--demangle is specified, otherwise the switch takes mangled names.

https://bugs.llvm.org/show_bug.cgi?id=41908

[jhenderson]

Can you persuade git/svn to do a rename of the test rather than a delete and add? That would make the diff easier to see.

I've reviewed this offline, so otherwise this LGTM, but I'd like another opinion.

[ychen]

In D63524#1549930, @jhenderson wrote:

Can you persuade git/svn to do a rename of the test rather than a delete and add? That would make the diff easier to see.

Didn't find a way to achieve that unless splitting the file rename part out. Seems it is how Git works (https://stackoverflow.com/questions/7938582/how-does-git-detect-similar-files-for-its-rename-detection),

[MaskRay]

llvm/test/tools/llvm-objdump/X86/disassemble-functions-mangling.test

22

You may make these *-MISS-NOT to check the warnings instead:

warning: failed to disassemble missing function _Z3foov

[ychen]

• update

[jhenderson]

Hi @ychen, would you mind posting a patch to update the docs for this behaviour change? I didn't mention it previously, because rL364019, which added --disassemble-functions to the listed options, was still under review, but it landed before this change did.

[ychen]

In D63524#1555266, @jhenderson wrote:

Hi @ychen, would you mind posting a patch to update the docs for this behaviour change? I didn't mention it previously, because rL364019, which added --disassemble-functions to the listed options, was still under review, but it landed before this change did.

Will do.

llvm/test/tools/llvm-objdump/X86/disassemble-functions-mangled-name.test

-## Show that the --disassemble-functions switch takes mangled names, not
-## demangled names.
-
-# RUN: yaml2obj %s -o %t.o
-# RUN: llvm-objdump -d --disassemble-functions=_Z3foov %t.o | FileCheck %s
-# RUN: llvm-objdump -d --disassemble-functions='foo()' %t.o | FileCheck %s --check-prefix=NOFOO
-# RUN: llvm-objdump -d -C --disassemble-functions='foo()' %t.o | FileCheck %s --check-prefix=NOFOO
-# RUN: llvm-objdump -d --disassemble-functions=foo %t.o | FileCheck %s --check-prefix=NOFOO
-
-# CHECK: _Z3foov:
-
-# NOFOO-NOT: foo
-
---- !ELF
-FileHeader:
-  Class:   ELFCLASS64
-  Data:    ELFDATA2LSB
-  Type:    ET_EXEC
-  Machine: EM_X86_64
-Sections:
-  - Name:  .text
-    Type:  SHT_PROGBITS
-    Flags: [SHF_ALLOC, SHF_EXECINSTR]
-    Content: '90'
-Symbols:
-  - Name:    _Z3foov
-    Section: .text

llvm/test/tools/llvm-objdump/X86/disassemble-functions-mangling.test

+## Show that the --disassemble-functions switch takes demangled names when
+## --demangle is specified, otherwise the switch takes mangled names.
+
+# RUN: yaml2obj %s -o %t.o
+
+## --disassemble-functions without --demangle.
+# RUN: llvm-objdump --disassemble-functions=_Z3foov %t.o | FileCheck %s --check-prefix=MANGLED
+# RUN: llvm-objdump --disassemble-functions='foo()' %t.o 2>&1 \
+# RUN:   | FileCheck %s --check-prefix=MANGLED-MISS
+# RUN: llvm-objdump --disassemble-functions=foo %t.o 2>&1 \
+# RUN:   | FileCheck %s --check-prefix=MANGLED-MISS
+# RUN: llvm-objdump --disassemble-functions='i,f' %t.o | FileCheck %s --check-prefix=NOMANGLE
+
+## --disassemble-functions with --demangle.
+# RUN: llvm-objdump -C --disassemble-functions='foo()' %t.o | FileCheck %s --check-prefix=DEMANGLED
+# RUN: llvm-objdump -C --disassemble-functions='_Z3foov' %t.o 2>&1 \
+# RUN:   | FileCheck %s --check-prefix=DEMANGLED-MISS
+# RUN: llvm-objdump -C --disassemble-functions='i,f' %t.o | FileCheck %s --check-prefix=NOMANGLE
+# RUN: llvm-objdump -C --disassemble-functions='std::allocator<wchar_t>::allocator()' %t.o 2>&1 \
+# RUN:   | FileCheck %s --check-prefix=DEMANGLED-MULTI
+
+# MANGLED: _Z3foov:
+# MANGLED-MISS: warning: failed to disassemble missing function foo
+
+# DEMANGLED: foo():
+# DEMANGLED-MISS: warning: failed to disassemble missing function _Z3foov
+
+# NOMANGLE: i:
+# NOMANGLE: f:
+
+# DEMANGLED-MULTI: std::allocator<wchar_t>::allocator():
+# DEMANGLED-MULTI: std::allocator<wchar_t>::allocator():
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name:  .text
+    Type:  SHT_PROGBITS
+    Flags: [SHF_ALLOC, SHF_EXECINSTR]
+    Address: 0x1000
+    Content: 9090909090
+Symbols:
+  - Name:    _Z3foov
+    Value:   0x1000
+    Section: .text
+  - Name:    i
+    Value:   0x1001
+    Section: .text
+  - Name:    f
+    Value:   0x1002
+    Section: .text
+  - Name:    _ZNSaIwEC1Ev
+    Value:   0x1003
+    Section: .text
+  - Name:    _ZNSaIwEC2Ev
+    Value:   0x1004
+    Section: .text

llvm/tools/llvm-objdump/llvm-objdump.cpp

cl::opt<bool> DisassembleAll(
     cl::cat(ObjdumpCat));
 static cl::alias DisassembleAllShort("D",
                                      cl::desc("Alias for --disassemble-all"),
                                      cl::NotHidden, cl::Grouping,
                                      cl::aliasopt(DisassembleAll));
 
 static cl::list<std::string>
     DisassembleFunctions("disassemble-functions", cl::CommaSeparated,
-                         cl::desc("List of functions to disassemble"),
+                         cl::desc("List of functions to disassemble. "
+                                  "Accept demangled names when --demangle is "
+                                  "specified, otherwise accept mangled names"),
                          cl::cat(ObjdumpCat));
 
 static cl::opt<bool> DisassembleZeroes(
     "disassemble-zeroes",
     cl::desc("Do not skip blocks of zeroes when disassembling"),
     cl::cat(ObjdumpCat));
 static cl::alias
     DisassembleZeroesShort("z", cl::desc("Alias for --disassemble-zeroes"),
for (const SectionRef &Section : ToolSectionFilter(*Obj)) {
     uint64_t Size;
     uint64_t Index;
     bool PrintedSection = false;
     std::vector<RelocationRef> Rels = RelocMap[Section];
     std::vector<RelocationRef>::const_iterator RelCur = Rels.begin();
     std::vector<RelocationRef>::const_iterator RelEnd = Rels.end();
     // Disassemble symbol by symbol.
     for (unsigned SI = 0, SE = Symbols.size(); SI != SE; ++SI) {
+      std::string SymbolName = std::get<1>(Symbols[SI]).str();
+      if (Demangle)
+        SymbolName = demangle(SymbolName);
+
       // Skip if --disassemble-functions is not empty and the symbol is not in
       // the list.
-      if (!DisasmFuncsSet.empty() &&
-          !DisasmFuncsSet.count(std::get<1>(Symbols[SI])))
+      if (!DisasmFuncsSet.empty() && !DisasmFuncsSet.count(SymbolName))
         continue;
 
       uint64_t Start = std::get<0>(Symbols[SI]);
       if (Start < SectionAddr || StopAddress <= Start)
         continue;
       else
-        FoundDisasmFuncsSet.insert(std::get<1>(Symbols[SI]));
+        FoundDisasmFuncsSet.insert(SymbolName);
 
       // The end is the section end, the beginning of the next symbol, or
       // --stop-address.
       uint64_t End = std::min<uint64_t>(SectionAddr + SectSize, StopAddress);
       if (SI + 1 < SE)
         End = std::min(End, std::get<0>(Symbols[SI + 1]));
       if (Start >= End || End <= StartAddress)
         continue;
for (unsigned SI = 0, SE = Symbols.size(); SI != SE; ++SI) {
         }
       }
 
       outs() << '\n';
       if (!NoLeadingAddr)
         outs() << format(Is64Bits ? "%016" PRIx64 " " : "%08" PRIx64 " ",
                          SectionAddr + Start + VMAAdjustment);
 
-      StringRef SymbolName = std::get<1>(Symbols[SI]);
-      if (Demangle)
-        outs() << demangle(SymbolName) << ":\n";
-      else
-        outs() << SymbolName << ":\n";
 
       // Don't print raw contents of a virtual section. A virtual section
       // doesn't have any contents in the file.
       if (Section.isVirtual()) {
         outs() << "...\n";
         continue;
       }