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authormseaborn@chromium.org <mseaborn@chromium.org>2014-12-03 20:39:55 +0000
committermseaborn@chromium.org <mseaborn@chromium.org>2014-12-03 20:39:55 +0000
commit10baadae400ca0a06acd309f42b20972521cf923 (patch)
tree53382034b7bc5afcd47045529ccdff18aa98bf4f
parentMicrodumps: support aarch64 and lib mapping from APK (diff)
downloadbreakpad-10baadae400ca0a06acd309f42b20972521cf923.tar.xz
dump_syms: Fix handling of DW_FORM_ref_addr to work with DWARF 4
Previously, dump_syms did not handle DW_FORM_ref_addr if it appeared in DWARF 4 debugging info. Also fix a DW_FORM_ref_addr case so that it doesn't fall through to the next switch case when assertions are disabled and the DWARF version isn't recognised. The following steps will reproduce the problem when using LLVM 3.4: cat <<END >example1.c int main() { return 0; } END cat <<END >example2.c void foo(int x) {} END clang -emit-llvm -g -c example1.c -o example1.bc clang -emit-llvm -g -c example2.c -o example2.bc llvm-link-3.4 example1.bc example2.bc -o combined.bc clang combined.bc -o executable ./google-breakpad/build/src/tools/linux/dump_syms/dump_syms executable When using LLVM bitcode linking in this way, LLVM's backend generates partially-merged DWARF debugging info in which some of the references to the "int" type go via "DW_FORM_ref_addr". Since PNaCl uses LLVM bitcode linking, this dump_syms failure occurs with nexes produced by the PNaCl toolchain. BUG= https://code.google.com/p/chromium/issues/detail?id=416368 TEST= see above R=mark@chromium.org, mcgrathr@chromium.org Review URL: https://breakpad.appspot.com/5744002 git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1408 4c0a9323-5329-0410-9bdc-e9ce6186880e
-rw-r--r--src/common/dwarf/dwarf2reader.cc13
1 files changed, 7 insertions, 6 deletions
diff --git a/src/common/dwarf/dwarf2reader.cc b/src/common/dwarf/dwarf2reader.cc
index a26143c7..f2f3d581 100644
--- a/src/common/dwarf/dwarf2reader.cc
+++ b/src/common/dwarf/dwarf2reader.cc
@@ -183,14 +183,15 @@ const char* CompilationUnit::SkipAttribute(const char* start,
case DW_FORM_addr:
return start + reader_->AddressSize();
case DW_FORM_ref_addr:
- // DWARF2 and 3 differ on whether ref_addr is address size or
+ // DWARF2 and 3/4 differ on whether ref_addr is address size or
// offset size.
- assert(header_.version == 2 || header_.version == 3);
+ assert(header_.version >= 2);
if (header_.version == 2) {
return start + reader_->AddressSize();
- } else if (header_.version == 3) {
+ } else if (header_.version >= 3) {
return start + reader_->OffsetSize();
}
+ break;
case DW_FORM_block1:
return start + 1 + reader_->ReadOneByte(start);
@@ -390,14 +391,14 @@ const char* CompilationUnit::ProcessAttribute(
+ offset_from_section_start_);
return start + len;
case DW_FORM_ref_addr:
- // DWARF2 and 3 differ on whether ref_addr is address size or
+ // DWARF2 and 3/4 differ on whether ref_addr is address size or
// offset size.
- assert(header_.version == 2 || header_.version == 3);
+ assert(header_.version >= 2);
if (header_.version == 2) {
handler_->ProcessAttributeReference(dieoffset, attr, form,
reader_->ReadAddress(start));
return start + reader_->AddressSize();
- } else if (header_.version == 3) {
+ } else if (header_.version >= 3) {
handler_->ProcessAttributeReference(dieoffset, attr, form,
reader_->ReadOffset(start));
return start + reader_->OffsetSize();