| Summary: | addr2line reports null symbol for inline frame | ||
|---|---|---|---|
| Product: | binutils | Reporter: | Milian Wolff <mail> |
| Component: | binutils | Assignee: | Not yet assigned to anyone <unassigned> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | mail, nickc |
| Priority: | P2 | ||
| Version: | 2.31 | ||
| Target Milestone: | --- | ||
| Host: | Target: | ||
| Build: | Last reconfirmed: | ||
| Attachments: | correctly pass through name from nested find_abstract_instance calls | ||
Created attachment 11274 [details]
correctly pass through name from nested find_abstract_instance calls
The attached patch fixes the issue for me. Apparently the compilers generate debug information with nested instance, i.e. find_abstract_instance calls itself in dwarf2.c. In such a scenario, the inner call will correctly set its pname to the name it found. But the outer call will then override it with name = NULL at the end of find_abstract_instance.
Fix this by passing the pointer to the name when calling find_abstract_instance from itself. I've tested this patch with addr2line and perf on the example source code provided in the bug report. Both work again with this fix applied!
are there really no unit tests for libbfd? The master branch has been updated by Nick Clifton <nickc@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=c8d3f93237d77f76d14e09e44bc770ce9428b0e4 commit c8d3f93237d77f76d14e09e44bc770ce9428b0e4 Author: Millan Wolff <mail@milianw.de> Date: Wed Oct 3 12:06:09 2018 +0100 Fix the handling of inlined frames in DWARF debug info. PR 23715 * dwarf2.c (find_abstract_instance): Allow recursive invocations of find_abstract_instance to override the name variable. Hi Milian, Thanks for the bug report and patch. I have now checked the patch in to the mainline sources. In answer to your question, "no - there are currently no unit tests for the binutils". This is not because there is a policy against them, but rather because no-one has had the time and energy to add the necessary framework and then start writing the tests. Of course volunteers are always welcome. Cheers Nick Thanks a lot for merging the patch and providing the background information. I was asking mostly because I was wondering whether my patch was missing a unit test. Cheers |
Since some time addr2line, and libbfd as used by perf, fail to associate the symbol name to inlined frames. Note the "??" in the output of addr2line in the reproducer below: $ cat test.cpp #include <cmath> #include <complex> #include <iostream> #include <random> using namespace std; int main() { uniform_real_distribution<double> uniform(-1E5, 1E5); default_random_engine engine; double s = 0; for (int i = 0; i < 10000000; ++i) { s += norm(complex<double>(uniform(engine), uniform(engine))); } return static_cast<int>(s); } $ g++ -g -O2 test.cpp $ addr2line -e a.out 766 -if main /usr/include/c++/8.2.1/bits/random.tcc:123 ?? /usr/include/c++/8.2.1/bits/random.h:257 main /tmp/test.cpp:11 I'm using libbfd 2.31.1 with gcc 8.2.1 or clang 6.0.1 currently. eu-addr2line seems to work correctly, which makes me believe it's an issue with libbfd / addr2line from binutils: $ eu-addr2line -e a.out 766 -if _ZNSt26linear_congruential_engineImLm16807ELm0ELm2147483647EE4seedEm inlined at /usr/include/c++/8.2.1/bits/random.h:257:9 in main /usr/include/c++/8.2.1/bits/random.tcc:123:2 _ZNSt26linear_congruential_engineImLm16807ELm0ELm2147483647EEC4Em /usr/include/c++/8.2.1/bits/random.h:257:9 main /tmp/test.cpp:11:27