[libunwind] Add more information to eh_frame_hdr version error

[fmayer]

Summary

This makes it easier to find the offending ELF file.

[MaskRay]

Thanks for adding more information, but In ehdr at is incorrect. .eh_frame_hdr is a section. Its content is not in the ELF header.

[fmayer]

change string

[fmayer]

simplify string

[fmayer]

In D126841#3552040, @MaskRay wrote:

Thanks for adding more information, but In ehdr at is incorrect. .eh_frame_hdr is a section. Its content is not in the ELF header.

Removed the "in [...]" as the pointer is exactly the location of the version.

[MaskRay]

LGTM with some minor issues fixed.

The subject line does not end with a period. Please describe why you need extra information in the diagnostic.

libunwind/src/EHHeaderParser.hpp

60–61

The standard diagnostics do not use capitalization: https://llvm.org/docs/CodingStandards.html#error-and-warning-messages libunwind mostly doesn't use capitalization

61

Use static_cast<uint64_t>. pint_t is 32-bit on ELF32 platforms.

[fmayer]

fixes

libunwind/src/EHHeaderParser.hpp

 };
 
 template <typename A>
 bool EHHeaderParser<A>::decodeEHHdr(A &addressSpace, pint_t ehHdrStart,
                                     pint_t ehHdrEnd, EHHeaderInfo &ehHdrInfo) {
   pint_t p = ehHdrStart;
   uint8_t version = addressSpace.get8(p++);
   if (version != 1) {
-    _LIBUNWIND_LOG0("Unsupported .eh_frame_hdr version");
+    _LIBUNWIND_LOG("unsupported .eh_frame_hdr version: %" PRIu8 " at %" PRIx64,
+                   version, static_cast<uint64_t>(ehHdrStart));
     return false;
   }
 
   uint8_t eh_frame_ptr_enc = addressSpace.get8(p++);
   uint8_t fde_count_enc = addressSpace.get8(p++);
   ehHdrInfo.table_enc = addressSpace.get8(p++);
 
   ehHdrInfo.eh_frame_ptr =