[llvm-readobj/elf] - Refine the warning about the broken PT_DYNAMIC segment.

[grimar]

Summary

Splitted out from D85519.

Currently we report "PT_DYNAMIC segment offset + size exceeds the size of the file",
this changes it to
"PT_DYNAMIC segment offset (0x1234) + file size (0x5678) exceeds the size of the file (0x68ab)"

[MaskRay]

"PT_DYNAMIC segment offset (0x1234) + file size (0x5678) exceeds the size of the file (0x9abc)"

The example needs a change. 0x1234+0x5678 < 0x9abc

[jhenderson]

LGTM.

llvm/test/Object/invalid.test

- Name:    .dynamic
     Content: "00"
 
 ## PT_DYNAMIC's p_offset field is so large that p_offset + p_filesz is larger
 ## than the object size. Check llvm-readobj reports it.
 
 # RUN: yaml2obj %s --docnum=22 -o %t22
 # RUN: llvm-readobj --dyn-relocations %t22 2>&1 | FileCheck -DFILE=%t22 --check-prefix=DYN-TABLE-PHDR %s
 
-# DYN-TABLE-PHDR: warning: '[[FILE]]': PT_DYNAMIC segment offset + size exceeds the size of the file
+# DYN-TABLE-PHDR: warning: '[[FILE]]': PT_DYNAMIC segment offset (0xffff0000) + file size (0x0) exceeds the size of the file (0x150)
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_EXEC
   Machine: EM_X86_64
 ProgramHeaders:
   - Type:   PT_DYNAMIC
     Offset: 0xffff0000
 
 ## PT_DYNAMIC's p_filesz field is so large that p_offset + p_filesz is larger
 ## than the object size. Check llvm-readobj reports it.
 
 # RUN: yaml2obj %s --docnum=23 -o %t23
 # RUN: llvm-readobj --dyn-relocations %t23 2>&1 \
-# RUN:  | FileCheck -DFILE=%t23 --check-prefix=DYN-TABLE-PHDR %s
+# RUN:  | FileCheck -DFILE=%t23 --check-prefix=DYN-TABLE-PHDR2 %s
+
+# DYN-TABLE-PHDR2: warning: '[[FILE]]': PT_DYNAMIC segment offset (0x78) + file size (0xffff0000) exceeds the size of the file (0x1a8)
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_EXEC
   Machine: EM_X86_64
 Sections:

llvm/test/tools/llvm-readobj/ELF/malformed-pt-dynamic.test

 # If the offset and/or size fields of the PT_DYNAMIC field become corrupted,
 # we should report a sensible message.
 
 # Creating such a malformed file is hard. The easiest way to simulate it is to
 # truncate the file. Note that the section headers must first be stripped or
 # llvm-readobj will fail to parse the file due to the section header table
 # offset pointing outside the file.
 
 # RUN: yaml2obj %s -o %t.base
 # RUN: llvm-objcopy --strip-sections %t.base %t.stripped
 
 # Test case where the size is too large to fit in the file, but the start is
 # within the file.
 # RUN: cp %t.stripped %t.truncated1
 # RUN: %python -c "with open(r'%t.truncated1', 'r+') as f: f.truncate(0x1001)"
-# RUN: llvm-readobj %t.truncated1 --dynamic-table 2>&1 | FileCheck -DFILE=%t.truncated1 %s
+# RUN: llvm-readobj %t.truncated1 --dynamic-table 2>&1 | \
+# RUN:   FileCheck -DFILE=%t.truncated1 %s --check-prefix=WARN1
+
+# WARN1: warning: '[[FILE]]': PT_DYNAMIC segment offset (0x1000) + file size (0x10) exceeds the size of the file (0x1001)
 
 # Test case where the offset is too large to be in the file.
 # RUN: cp %t.stripped %t.truncated2
 # RUN: %python -c "with open(r'%t.truncated2', 'r+') as f: f.truncate(0xFFF)"
-# RUN: llvm-readobj %t.truncated2 --dynamic-table 2>&1 | FileCheck -DFILE=%t.truncated2 %s
+# RUN: llvm-readobj %t.truncated2 --dynamic-table 2>&1 | \
+# RUN:   FileCheck -DFILE=%t.truncated2 %s  --check-prefix=WARN2
 
-# CHECK: warning: '[[FILE]]': PT_DYNAMIC segment offset + size exceeds the size of the file
+# WARN2: warning: '[[FILE]]': PT_DYNAMIC segment offset (0x1000) + file size (0x10) exceeds the size of the file (0xfff)
 
 --- !ELF
 FileHeader:
   Class:   ELFCLASS64
   Data:    ELFDATA2LSB
   Type:    ET_EXEC
   Machine: EM_X86_64
 Sections:

llvm/tools/llvm-readobj/ELFDumper.cpp

for (const Elf_Shdr &Sec : cantFail(Obj->sections())) {
     if (Sec.sh_type != ELF::SHT_DYNAMIC)
       continue;
     DynamicSec = &Sec;
     break;
   }
 
   if (DynamicPhdr && DynamicPhdr->p_offset + DynamicPhdr->p_filesz >
                          ObjF->getMemoryBufferRef().getBufferSize()) {
-    reportWarning(
-        createError(
-            "PT_DYNAMIC segment offset + size exceeds the size of the file"),
-        ObjF->getFileName());
+    reportUniqueWarning(createError(
+        "PT_DYNAMIC segment offset (0x" +
+        Twine::utohexstr(DynamicPhdr->p_offset) + ") + file size (0x" +
+        Twine::utohexstr(DynamicPhdr->p_filesz) +
+        ") exceeds the size of the file (0x" +
+        Twine::utohexstr(ObjF->getMemoryBufferRef().getBufferSize()) + ")"));
     // Don't use the broken dynamic header.
     DynamicPhdr = nullptr;
   }
 
   if (DynamicPhdr && DynamicSec) {
     StringRef Name =
         unwrapOrError(ObjF->getFileName(), Obj->getSectionName(DynamicSec));
     if (DynamicSec->sh_addr + DynamicSec->sh_size >