Make check failure and solution patch (faulty gr_basic_block sort in gr_flow_graph)

Hi All,
This patch makes the sort of basic_blocks reliable in gr_flowgraph.cc
Without it make check can fail in qa_gr_flowgraph.cc:240

background:
While working with new buffer code I found that make check can fail in
qa_gr_flowgraph.cc
240: CPPUNIT_ASSERT(graphs[0].size() == 4);

The cause of this is that the subgraphs are not in the order as
expected.
The code expects
graphs.size()==3
graphs[0].size()==4
graphs[1].size()==3
graphs[2].size()==2

But it gets
graphs.size()==3
graphs[0].size()==3
graphs[1].size()==2
graphs[2].size()==4

This only happens if there are a lot of big malloc /frees in code before
it.
The probable cause is that a plain std::sort is used for sorting vectors
of gr_basic_block
But for gr_basic_block the operator < is not defined.

I changed the code to use basic_block->unique_id() for sorting.
This should be more robust.

(I got rid of the make check failure)
This problem might be in more parts of the code

Greetings,
Martin

Index: gr_flowgraph.cc

— gr_flowgraph.cc (revision 9229)
+++ gr_flowgraph.cc (working copy)
@@ -30,6 +30,11 @@
#include

#define GR_FLOWGRAPH_DEBUG 0
+bool
+basic_block_sort_predicate(const gr_basic_block_sptr lhs, const
gr_basic_block_sptr rhs)
+{

  • return lhs->unique_id() < rhs->unique_id();
    +}

gr_edge::~gr_edge()
{
@@ -173,7 +178,8 @@
}

// Return vector of unique blocks

  • sort(tmp.begin(), tmp.end());
  • //sort(tmp.begin(), tmp.end());

  • sort(tmp.begin(), tmp.end(),basic_block_sort_predicate);
    unique_copy(tmp.begin(), tmp.end(), inserter);
    return result;
    }
    @@ -272,7 +278,7 @@
    tmp.push_back(p->dst().block());

    // Remove duplicates

  • sort(tmp.begin(), tmp.end());
  • sort(tmp.begin(), tmp.end(),basic_block_sort_predicate);
    unique_copy(tmp.begin(), tmp.end(), inserter);
    return result;
    }
    @@ -288,7 +294,7 @@
    tmp.push_back(p->dst().block());

    // Remove duplicates

  • sort(tmp.begin(), tmp.end());
  • sort(tmp.begin(), tmp.end(),basic_block_sort_predicate);
    unique_copy(tmp.begin(), tmp.end(), inserter);
    return result;
    }
    @@ -399,7 +405,7 @@
    }

    // Remove duplicates

  • sort(tmp.begin(), tmp.end());
  • sort(tmp.begin(), tmp.end(),basic_block_sort_predicate);
    unique_copy(tmp.begin(), tmp.end(), inserter);
    return result;
    }

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