[PATCH] D93802: [llvm-readelf/obj] - Improve the warning reported when unable to read the stack size.

[George Rimar via Phabricator via llvm-commits]

grimar created this revision.
grimar added reviewers: jhenderson, MaskRay.
Herald added subscribers: rupprecht, emaste.
Herald added a reviewer: espindola.
grimar requested review of this revision.
Herald added a project: LLVM.

It was discussed in D92545 <https://reviews.llvm.org/D92545> that we might want to improve messages
reported when something is wrong with the stack size section.
This patch does it.


https://reviews.llvm.org/D93802

Files:
  llvm/test/tools/llvm-readobj/ELF/stack-sizes.test
  llvm/tools/llvm-readobj/ELFDumper.cpp


Index: llvm/tools/llvm-readobj/ELFDumper.cpp
===================================================================
--- llvm/tools/llvm-readobj/ELFDumper.cpp
+++ llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -788,7 +788,7 @@
   virtual void printStackSizes() = 0;
   void printNonRelocatableStackSizes(std::function<void()> PrintHeader);
   void printRelocatableStackSizes(std::function<void()> PrintHeader);
-  void printFunctionStackSize(uint64_t SymValue,
+  bool printFunctionStackSize(uint64_t SymValue,
                               Optional<const Elf_Shdr *> FunctionSec,
                               const Elf_Shdr &StackSizeSec, DataExtractor Data,
                               uint64_t *Offset);
@@ -5862,7 +5862,7 @@
 }
 
 template <class ELFT>
-void DumpStyle<ELFT>::printFunctionStackSize(
+bool DumpStyle<ELFT>::printFunctionStackSize(
     uint64_t SymValue, Optional<const Elf_Shdr *> FunctionSec,
     const Elf_Shdr &StackSizeSec, DataExtractor Data, uint64_t *Offset) {
   uint32_t FuncSymIndex = 0;
@@ -5922,16 +5922,16 @@
 
   // Extract the size. The expectation is that Offset is pointing to the right
   // place, i.e. past the function address.
-  uint64_t PrevOffset = *Offset;
-  uint64_t StackSize = Data.getULEB128(Offset);
-  // getULEB128() does not advance Offset if it is not able to extract a valid
-  // integer.
-  if (*Offset == PrevOffset) {
+  Error Err = Error::success();
+  uint64_t StackSize = Data.getULEB128(Offset, &Err);
+  if (Err) {
     reportUniqueWarning("could not extract a valid stack size from " +
-                        describe(Obj, StackSizeSec));
-    return;
+                        describe(Obj, StackSizeSec) + ": " +
+                        toString(std::move(Err)));
+    return false;
   }
   printStackSizeEntry(StackSize, FuncName);
+  return true;
 }
 
 template <class ELFT>
@@ -6020,8 +6020,9 @@
         break;
       }
       uint64_t SymValue = Data.getAddress(&Offset);
-      printFunctionStackSize(SymValue, /*FunctionSec=*/None, Sec, Data,
-                             &Offset);
+      if (!printFunctionStackSize(SymValue, /*FunctionSec=*/None, Sec, Data,
+                                  &Offset))
+        break;
     }
   }
 }
Index: llvm/test/tools/llvm-readobj/ELF/stack-sizes.test
===================================================================
--- llvm/test/tools/llvm-readobj/ELF/stack-sizes.test
+++ llvm/test/tools/llvm-readobj/ELF/stack-sizes.test
@@ -442,11 +442,13 @@
 ## ends in a byte with the high bit set.
 
 # RUN: yaml2obj --docnum=6 %s -o %t06
-# RUN: llvm-readelf --stack-sizes %t06 2>&1 | FileCheck %s --check-prefix=BADSIZE -DFILE=%t06
-# RUN: llvm-readobj --stack-sizes %t06 2>&1 | FileCheck %s --check-prefix=BADSIZE -DFILE=%t06
+# RUN: llvm-readelf --stack-sizes %t06 2>&1 | \
+# RUN:   FileCheck %s --check-prefix=BADSIZE -DFILE=%t06 --implicit-check-not=warning:
+# RUN: llvm-readobj --stack-sizes %t06 2>&1 | \
+# RUN:   FileCheck %s --check-prefix=BADSIZE -DFILE=%t06 --implicit-check-not=warning:
 
-# BADSIZE: warning: '[[FILE]]': could not extract a valid stack size from SHT_PROGBITS section with index 2
-# BADSIZE: warning: '[[FILE]]': could not extract a valid stack size from SHT_PROGBITS section with index 3
+# BADSIZE: warning: '[[FILE]]': could not extract a valid stack size from SHT_PROGBITS section with index 2: unable to decode LEB128 at offset 0x00000008: malformed uleb128, extends past end
+# BADSIZE: warning: '[[FILE]]': could not extract a valid stack size from SHT_PROGBITS section with index 3: unable to decode LEB128 at offset 0x00000008: malformed uleb128, extends past end
 
 --- !ELF
 FileHeader:


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