Add and handle various dwarf5 addrx forms.

Given the almost nonexistent direct dwarfreader tests, I think
the best way to test these dwarf5 additions will be to add a full
dwarf5 compilation unit similar to the ones used incidentally in
the other tests. But I can't do that until enough dwarf5 is
correctly implemented.

Change-Id: I3418bda7212ae85c4b67232a2ab8fea9b9ca5d42
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/2258838
Reviewed-by: Mark Mentovai <mark@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>

1 files changed, 26 insertions, 9 deletions

diff --git a/src/common/dwarf/dwarf2reader.cc b/src/common/dwarf/dwarf2reader.cc
index 4f0c31dd..fbfff275 100644
--- a/src/common/dwarf/dwarf2reader.cc
+++ b/src/common/dwarf/dwarf2reader.cc
@@ -182,17 +182,21 @@ const uint8_t *CompilationUnit::SkipAttribute(const uint8_t *start,
 
     case DW_FORM_flag_present:
       return start;
+    case DW_FORM_addrx1:
     case DW_FORM_data1:
     case DW_FORM_flag:
     case DW_FORM_ref1:
     case DW_FORM_strx1:
       return start + 1;
+    case DW_FORM_addrx2:
     case DW_FORM_ref2:
     case DW_FORM_data2:
     case DW_FORM_strx2:
       return start + 2;
+    case DW_FORM_addrx3:
     case DW_FORM_strx3:
       return start + 3;
+    case DW_FORM_addrx4:
     case DW_FORM_ref4:
     case DW_FORM_data4:
     case DW_FORM_strx4:
@@ -208,6 +212,7 @@ const uint8_t *CompilationUnit::SkipAttribute(const uint8_t *start,
     case DW_FORM_strx:
     case DW_FORM_GNU_str_index:
     case DW_FORM_GNU_addr_index:
+    case DW_FORM_addrx:
       reader_->ReadUnsignedLEB128(start, &len);
       return start + len;
 
@@ -549,8 +554,7 @@ const uint8_t *CompilationUnit::ProcessAttribute(
       return start + 2;
     }
     case DW_FORM_strx3: {
-      uint64_t str_index = reader_->ReadTwoBytes(start);
-      str_index *= reader_->ReadOneByte(start + 2);
+      uint64_t str_index = reader_->ReadThreeBytes(start);
       ProcessFormStringIndex(dieoffset, attr, form, str_index);
       return start + 3;
     }
@@ -560,14 +564,27 @@ const uint8_t *CompilationUnit::ProcessAttribute(
       return start + 4;
     }
 
-    case DW_FORM_GNU_addr_index: {
-      uint64_t addr_index = reader_->ReadUnsignedLEB128(start, &len);
-      const uint8_t* addr_ptr =
-          addr_buffer_ + addr_base_ + addr_index * reader_->AddressSize();
-      ProcessAttributeUnsigned(dieoffset, attr, form,
-                               reader_->ReadAddress(addr_ptr));
+    case DW_FORM_addrx:
+    case DW_FORM_GNU_addr_index:
+      ProcessAttributeAddrIndex(
+          dieoffset, attr, form, reader_->ReadUnsignedLEB128(start, &len));
       return start + len;
-    }
+    case DW_FORM_addrx1:
+      ProcessAttributeAddrIndex(
+          dieoffset, attr, form, reader_->ReadOneByte(start));
+      return start + 1;
+    case DW_FORM_addrx2:
+      ProcessAttributeAddrIndex(
+          dieoffset, attr, form, reader_->ReadTwoBytes(start));
+      return start + 2;
+    case DW_FORM_addrx3:
+      ProcessAttributeAddrIndex(
+          dieoffset, attr, form, reader_->ReadThreeBytes(start));
+      return start + 3;
+    case DW_FORM_addrx4:
+      ProcessAttributeAddrIndex(
+          dieoffset, attr, form, reader_->ReadFourBytes(start));
+      return start + 4;
   }
   fprintf(stderr, "Unhandled form type\n");
   return NULL;