Bug 829514

Created attachment 590034 [details]
lcov-except-unreach.patch

Description of problem:
The format of gcov output files changed slightly in gcc 4.7, and lcov does not understand the new format. Unreachable code that can only be accessed via an exceptional path is now marked as ===== in the gcov output file (aside: the gcov manpage says ====, i.e. one '=' is missed) but lcov only understands ##### for unreachable code (which is now only used for non-exceptional paths). If given a gcov file containing the new syntax, lcov will generate an invalid .info file.

Version-Release number of selected component (if applicable):
lcov-1.9-2.fc17.noarch
gcc-4.7.0-5.fc17.x86_64

How reproducible:
Always.

Steps to Reproduce:
1. Compile the following simple C++ file:

#include <iostream>

int main()
{
  try {
    std::cout << "hello world" << std::endl;
  } catch (const std::exception &e) {
    std::cout << "caught exception" << std::endl;
  }
  return 0;
}

with
g++ -Wall -fprofile-arcs -ftest-coverage test.cpp 


2. Run with ./a.out
3. Process with lcov:
lcov -c -b . -d . -o test.info
  
Actual results:
Perl complains with:
geninfo: Argument "=====" isn't numeric in numeric gt (>) at /usr/bin/geninfo line 1126.

and the ===== lines get passed through to the .info file, which results in invalid lines:
DA:7,=====
DA:8,=====

Expected results:
No Perl errors; correctly formatted .info file.

Additional info:
It is straightforward to fix geninfo to work with the new format; see attached patch "lcov-except-unreach.patch".