[Bug c++/30633] New: Weird uninit in Boost `add_edge'

[Scott at coral8 dot com]

Ran across this while using the Boost graph package.  Test program:

--
#include 
#include 


namespace boost {
enum vertex_subgraph_t { vertex_subgraph };
BOOST_INSTALL_PROPERTY(vertex, subgraph);
enum vertex_order_t { vertex_order };
BOOST_INSTALL_PROPERTY(vertex, order);
enum edge_back_t { edge_back };
BOOST_INSTALL_PROPERTY(edge, back);

};

typedef boost::property > > > VertexProperty;
typedef boost::property EdgeProperties;

typedef boost::adjacency_list< boost::vecS, boost::vecS, boost::bidirectionalS,
VertexProperty, EdgeProperties > FlowLayoutGraph;

typedef boost::graph_traits< FlowLayoutGraph >::vertex_descriptor 
vertex_descriptor;

void break_gcc(FlowLayoutGraph& m_graph, vertex_descriptor v1,
vertex_descriptor v2)
{
add_edge(v1, v2, m_graph);
}



Obtain and unpack Boost 1.33.1.  Compile the above with a command like:

g++ -c -I/path/to/boost_1_33_1 -O -Wuninitialized filename.cpp

You should see a message complaining that `p$m_value' is used uninitialized. 
(This is, as you probably already realize, a name generated internally by g++;
there is no such variable in the source.)


-- 
   Summary: Weird uninit in Boost `add_edge'
   Product: gcc
   Version: 4.1.1
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: Scott at coral8 dot com
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30633

[Bug c++/30633] Weird uninit in Boost `add_edge'

[Scott at coral8 dot com]

--- Comment #1 from Scott at coral8 dot com  2007-02-05 23:40 ---
I tried 4.1.2 RC1 -- the bug is still present.


-- 

Scott at coral8 dot com changed:

   What|Removed |Added

  Known to fail||4.1.1 4.1.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30633

[Bug c++/30633] Weird uninit in Boost `add_edge'

[Scott at coral8 dot com]

--- Comment #3 from Scott at coral8 dot com  2007-02-06 00:17 ---
Actually, I didn't look closely enough; the error generated by 4.1.2 RC1 is
different:

/usr/local/gcc-4.1.2/lib/gcc/i386-pc-solaris2.11/4.1.2/../../../../include/c++/4.1.2/ext/new_allocator.h:
In function void break_gcc(FlowLayoutGraph&, vertex_descriptor,
vertex_descriptor):
/usr/local/gcc-4.1.2/lib/gcc/i386-pc-solaris2.11/4.1.2/../../../../include/c++/4.1.2/ext/new_allocator.h:104:
warning: p.boost::property::m_value is used uninitialized in this function


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30633

[Bug c++/30633] Weird uninit in Boost `add_edge'

[Scott at coral8 dot com]

--- Comment #4 from Scott at coral8 dot com  2007-02-06 00:21 ---
Created an attachment (id=13010)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13010&action=view)
Preprocessed source, as requested (gzipped)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30633

[Bug c++/30633] Weird uninit in Boost `add_edge'

[Scott at coral8 dot com]

--- Comment #6 from Scott at coral8 dot com  2007-02-06 01:01 ---
Ah, very good.  Thanks for taking a look at this.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30633