improve error message to include package names when circular dependen…

…cy is detected (fix #18)

src/rospack.cpp

@@ -58,6 +58,7 @@
  #include <sys/time.h>
 #endif
 
+#include <algorithm>
 #include <climits>
 
 #include <sys/stat.h>
@@ -1773,15 +1774,15 @@ Rosstackage::gatherDeps(Stackage* stackage, bool direct,
  deps_hash, deps, false, indented_deps, no_recursion_on_wet);
 }
 
-// Pre-condition: computeDeps(stackage) succeeded
 void
-Rosstackage::gatherDepsFull(Stackage* stackage, bool direct, 
- traversal_order_t order, int depth, 
+_gatherDepsFull(Stackage* stackage, bool direct,
+ traversal_order_t order, int depth,
  std::tr1::unordered_set<Stackage*>& deps_hash,
  std::vector<Stackage*>& deps,
  bool get_indented_deps,
  std::vector<std::string>& indented_deps,
- bool no_recursion_on_wet)
+ bool no_recursion_on_wet,
+ std::vector<std::string>& dep_chain)
 {
  if(stackage->is_wet_package_ && no_recursion_on_wet)
  {
@@ -1797,8 +1798,25 @@ Rosstackage::gatherDepsFull(Stackage* stackage, bool direct,
  return;
  }
 
- if(depth > MAX_DEPENDENCY_DEPTH)
- throw Exception("maximum dependency depth exceeded (likely circular dependency)");
+ if(depth > MAX_DEPENDENCY_DEPTH) {
+ std::string cycle;
+ for(std::vector<std::string>::const_iterator it = dep_chain.begin();
+ it != dep_chain.end();
+ ++it)
+ {
+ std::vector<std::string>::const_iterator begin = dep_chain.begin();
+ std::vector<std::string>::const_iterator cycle_begin = std::find(begin, it, *it);
+ if(cycle_begin != it) {
+ cycle = ": ";
+ for(std::vector<std::string>::const_iterator jt = cycle_begin; jt != it; ++jt) {
+ if(jt != cycle_begin) cycle += ", ";
+ cycle += *jt;
+ }
+ break;
+ }
+ }
+ throw Exception(std::string("maximum dependency depth exceeded (likely circular dependency") + cycle + ")");
+ }
 
  for(std::vector<Stackage*>::const_iterator it = stackage->deps_.begin();
  it != stackage->deps_.end();
@@ -1827,8 +1845,11 @@ Rosstackage::gatherDepsFull(Stackage* stackage, bool direct,
  // We always descend, even if we're encountering this stackage for the
  // nth time, so that we'll throw an error on recursive dependencies
  // (detected via max stack depth being exceeded).
- gatherDepsFull(*it, direct, order, depth+1, deps_hash, deps,
- get_indented_deps, indented_deps);
+ dep_chain.push_back((*it)->name_);
+ _gatherDepsFull(*it, direct, order, depth+1, deps_hash, deps,
+ get_indented_deps, indented_deps,
+ no_recursion_on_wet, dep_chain);
+ dep_chain.pop_back();
  }
  if(first)
  {
@@ -1838,6 +1859,28 @@ Rosstackage::gatherDepsFull(Stackage* stackage, bool direct,
  }
 }
 
+// Pre-condition: computeDeps(stackage) succeeded
+void
+Rosstackage::gatherDepsFull(Stackage* stackage, bool direct,
+ traversal_order_t order, int depth,
+ std::tr1::unordered_set<Stackage*>& deps_hash,
+ std::vector<Stackage*>& deps,
+ bool get_indented_deps,
+ std::vector<std::string>& indented_deps,
+ bool no_recursion_on_wet)
+{
+ std::vector<std::string> dep_chain;
+ dep_chain.push_back(stackage->name_);
+ _gatherDepsFull(stackage, direct,
+ order, depth,
+ deps_hash,
+ deps,
+ get_indented_deps,
+ indented_deps,
+ no_recursion_on_wet,
+ dep_chain);
+}
+
 std::string
 Rosstackage::getCachePath()
 {