[llvm-readobj/llvm-readelf] - .stack_sizes: demangle symbol names in warnings reported.

I started this patch as a refactoring, tried to make a helper for
getting symbol names, similar to how we get section names
used in warning messages.

So this patch cleanups the code and fixes an issue: symbol names
in warning messages were not demangled.

Differential revision: https://reviews.llvm.org/D68012

llvm-svn: 372867

llvm/test/tools/llvm-readobj/stack-sizes.test

@@ -192,17 +192,21 @@ Symbols:
 # RUN: llvm-readobj --stack-sizes %t04 2> %t04-llvm.err | FileCheck %s --check-prefix=WRONGSECTION-LLVM
 # RUN: FileCheck %s < %t04-llvm.err --check-prefix=WRONGSECTION-ERR -DFILE=%t04
 
+# RUN: llvm-readelf --stack-sizes --demangle %t04 2>&1 | FileCheck %s --check-prefix=WRONGSECTION-DEMANGLE-ERR -DFILE=%t04
+# RUN: llvm-readobj --stack-sizes --demangle %t04 2>&1 | FileCheck %s --check-prefix=WRONGSECTION-DEMANGLE-ERR -DFILE=%t04
+
 # WRONGSECTION-GNU:      Size Function
-# WRONGSECTION-GNU-NEXT: 8 foo
+# WRONGSECTION-GNU-NEXT: 8 _Z3foof
 
 # WRONGSECTION-LLVM:      StackSizes [
 # WRONGSECTION-LLVM-NEXT:   Entry {
-# WRONGSECTION-LLVM-NEXT:     Function: foo
+# WRONGSECTION-LLVM-NEXT:     Function: _Z3foof
 # WRONGSECTION-LLVM-NEXT:     Size: 0x8
 # WRONGSECTION-LLVM-NEXT:   }
 # WRONGSECTION-LLVM-NEXT: ]
 
-# WRONGSECTION-ERR:  warning: '[[FILE]]': relocation symbol foo is not in the expected section
+# WRONGSECTION-ERR:           warning: '[[FILE]]': relocation symbol '_Z3foof' is not in the expected section
+# WRONGSECTION-DEMANGLE-ERR:  warning: '[[FILE]]': relocation symbol 'foo(float)' is not in the expected section
 
 --- !ELF
 FileHeader:
@@ -228,10 +232,10 @@ Sections:
     Info:    .stack_sizes
     Relocations:
       - Offset: 0
-        Symbol: foo 
+        Symbol: _Z3foof
         Type:   R_X86_64_64
 Symbols:
-  - Name:    foo
+  - Name:    _Z3foof
     Section: .text
     Type:    STT_FUNC
     Binding: STB_GLOBAL
@@ -309,6 +313,9 @@ Symbols:
 # RUN: llvm-readobj --stack-sizes %t07 2> %t07-llvm.err | FileCheck %s --check-prefix=BADSECTION-OUT-LLVM
 # RUN: FileCheck %s < %t07-llvm.err --check-prefix=BADSECTION-ERR -DFILE=%t07
 
+# RUN: llvm-readelf --stack-sizes --demangle %t07 2>&1 | FileCheck %s --check-prefix=BADSECTION-DEMANGLE-ERR -DFILE=%t07
+# RUN: llvm-readobj --stack-sizes --demangle %t07 2>&1 | FileCheck %s --check-prefix=BADSECTION-DEMANGLE-ERR -DFILE=%t07
+
 # BADSECTION-OUT-GNU: Size Function
 # BADSECTION-OUT-GNU:    8 ?
 
@@ -319,7 +326,8 @@ Symbols:
 # BADSECTION-OUT-LLVM-NEXT:   }
 # BADSECTION-OUT-LLVM-NEXT: ]
 
-# BADSECTION-ERR: warning: '[[FILE]]': cannot identify the section for relocation symbol foo
+# BADSECTION-ERR: warning: '[[FILE]]': cannot identify the section for relocation symbol '_Z3foof'
+# BADSECTION-DEMANGLE-ERR: warning: '[[FILE]]': cannot identify the section for relocation symbol 'foo(float)'
 
 --- !ELF
 FileHeader:
@@ -341,10 +349,10 @@ Sections:
     Info:    .stack_sizes
     Relocations:
     - Offset: 0
-      Symbol: foo 
+      Symbol: _Z3foof
       Type:   R_X86_64_64
 Symbols:
-  - Name:    foo
+  - Name:    _Z3foof
 ## An invalid section index.
     Index:   10
     Type:    STT_FUNC
@@ -540,8 +548,8 @@ Symbols:
 #      ARCHIVEWARN-GNU:File: [[FILE]]({{.*04}})
 #      ARCHIVEWARN-GNU:Stack Sizes:
 # ARCHIVEWARN-GNU-NEXT:         Size     Function
-#      ARCHIVEWARN-GNU:{{.*}}: warning: '{{.*04}}': relocation symbol foo is not in the expected section
-#      ARCHIVEWARN-GNU:            8     foo
+#      ARCHIVEWARN-GNU:{{.*}}: warning: '{{.*04}}': relocation symbol '_Z3foof' is not in the expected section
+#      ARCHIVEWARN-GNU:            8     _Z3foof
 #      ARCHIVEWARN-GNU:File: [[FILE]]({{.*01}})
 #      ARCHIVEWARN-GNU:Stack Sizes:
 # ARCHIVEWARN-GNU-NEXT:         Size     Function
@@ -553,9 +561,9 @@ Symbols:
 
 # ARCHIVEWARN-LLVM:      File: [[FILE]]({{.*04}})
 # ARCHIVEWARN-LLVM:      StackSizes [
-# ARCHIVEWARN-LLVM:      warning: '{{.*04}}': relocation symbol foo is not in the expected section
+# ARCHIVEWARN-LLVM:      warning: '{{.*04}}': relocation symbol '_Z3foof' is not in the expected section
 # ARCHIVEWARN-LLVM-NEXT:   Entry {
-# ARCHIVEWARN-LLVM-NEXT:     Function: foo
+# ARCHIVEWARN-LLVM-NEXT:     Function: _Z3foof
 # ARCHIVEWARN-LLVM-NEXT:     Size: 0x8
 # ARCHIVEWARN-LLVM-NEXT:   }
 # ARCHIVEWARN-LLVM-NEXT: ]

llvm/tools/llvm-readobj/ELFDumper.cpp

@@ -4688,6 +4688,26 @@ void GNUStyle<ELFT>::printELFLinkerOptions(const ELFFile<ELFT> *Obj) {
   OS << "printELFLinkerOptions not implemented!\n";
 }
 
+// Used for printing section names in places where possible errors can be
+// ignored.
+static StringRef getSectionName(const SectionRef &Sec) {
+  Expected<StringRef> NameOrErr = Sec.getName();
+  if (NameOrErr)
+    return *NameOrErr;
+  consumeError(NameOrErr.takeError());
+  return "<?>";
+}
+
+// Used for printing symbol names in places where possible errors can be
+// ignored.
+static std::string getSymbolName(const ELFSymbolRef &Sym) {
+  Expected<StringRef> NameOrErr = Sym.getName();
+  if (NameOrErr)
+    return maybeDemangle(*NameOrErr);
+  consumeError(NameOrErr.takeError());
+  return "<?>";
+}
+
 template <class ELFT>
 void DumpStyle<ELFT>::printFunctionStackSize(
     const ELFObjectFile<ELFT> *Obj, uint64_t SymValue, SectionRef FunctionSec,
@@ -4712,18 +4732,12 @@ void DumpStyle<ELFT>::printFunctionStackSize(
 
   std::string FuncName = "?";
   // A valid SymbolRef has a non-null object file pointer.
-  if (FuncSym.BasicSymbolRef::getObject()) {
-    // Extract the symbol name.
-    Expected<StringRef> FuncNameOrErr = FuncSym.getName();
-    if (FuncNameOrErr)
-      FuncName = maybeDemangle(*FuncNameOrErr);
-    else
-      consumeError(FuncNameOrErr.takeError());
-  } else {
+  if (FuncSym.BasicSymbolRef::getObject())
+    FuncName = getSymbolName(FuncSym);
+  else
     reportWarning(
         createError("could not identify function symbol for stack size entry"),
         Obj->getFileName());
-  }
 
   // Extract the size. The expectation is that Offset is pointing to the right
   // place, i.e. past the function address.
@@ -4765,23 +4779,17 @@ void DumpStyle<ELFT>::printStackSize(const ELFObjectFile<ELFT> *Obj,
     // Ensure that the relocation symbol is in the function section, i.e. the
     // section where the functions whose stack sizes we are reporting are
     // located.
-    StringRef SymName = "?";
-    Expected<StringRef> NameOrErr = RelocSym->getName();
-    if (NameOrErr)
-      SymName = *NameOrErr;
-    else
-      consumeError(NameOrErr.takeError());
-
     auto SectionOrErr = RelocSym->getSection();
     if (!SectionOrErr) {
       reportWarning(
-          createError("cannot identify the section for relocation symbol " +
-                      SymName),
+          createError("cannot identify the section for relocation symbol '" +
+                      getSymbolName(*RelocSym) + "'"),
           FileStr);
       consumeError(SectionOrErr.takeError());
     } else if (*SectionOrErr != FunctionSec) {
-      reportWarning(createError("relocation symbol " + SymName +
-                                " is not in the expected section"),
+      reportWarning(createError("relocation symbol '" +
+                                getSymbolName(*RelocSym) +
+                                "' is not in the expected section"),
                     FileStr);
       // Pretend that the symbol is in the correct section and report its
       // stack size anyway.
@@ -4810,16 +4818,6 @@ void DumpStyle<ELFT>::printStackSize(const ELFObjectFile<ELFT> *Obj,
                                Data, &Offset);
 }
 
-// Used for printing section names in places where possible errors can be
-// ignored.
-static StringRef getSectionName(const SectionRef &Sec) {
-  Expected<StringRef> NameOrErr = Sec.getName();
-  if (NameOrErr)
-    return *NameOrErr;
-  consumeError(NameOrErr.takeError());
-  return "<?>";
-}
-
 template <class ELFT>
 void DumpStyle<ELFT>::printNonRelocatableStackSizes(
     const ELFObjectFile<ELFT> *Obj, std::function<void()> PrintHeader) {