https://github.com/DavidSpickett created https://github.com/llvm/llvm-project/pull/217837
Fixes #217359 The first issue is obvious, when checking the previous breakpoint we should push back prev_pos->second, instead of pos->second. The second problem is what happens when lower_bound returns end(). Before, `if (pos != end)` would stop us checking the previous breakpoint. If lower_bound returned end() but there were breakpoints, the last breakpoint may start before addr and extend past it. This was being missed. To fix that: * Remove the `if (pos != end)` check. * Return early if there are no breakpoints. * If lower_bound does not find the first one, look at the previous one. * Look at the rest from pos onwards. The earlly return means we know that m_breakpoints.begin() != m_breakpoints.end() and so even if lower_bound returns end(), we are safe to decrement that iterator. I think this will fix the API tests in #217348, when those are enabled from debugserver. >From 396578efcebae6d768c5ba8f5a9e3a701e075b9b Mon Sep 17 00:00:00 2001 From: David Spickett <[email protected]> Date: Fri, 21 Aug 2026 07:40:46 +0000 Subject: [PATCH] [lldb][debugserver] Fix bugs in FindBreakpointsThatOverlapRange Fixes #217359 The first issue is obvious, when checking the previous breakpoint we should push back prev_pos->second, instead of pos->second. The second problem is what happens when lower_bound returns end(). Before, `if (pos != end)` would stop us checking the previous breakpoint. If lower_bound returned end() but there were breakpoints, the last breakpoint may start before addr and extend past it. This was being missed. To fix that: * Remove the `if (pos != end)` check. * Return early if there are no breakpoints. * If lower_bound does not find the first one, look at the previous one. * Look at the rest from pos onwards. The earlly return means we know that m_breakpoints.begin() != m_breakpoints.end() and so even if lower_bound returns end(), we are safe to decrement that iterator. I think this will fix the API tests in #217348, when those are enabled from debugserver. --- .../debugserver/source/DNBBreakpoint.cpp | 46 ++++++++++--------- 1 file changed, 25 insertions(+), 21 deletions(-) diff --git a/lldb/tools/debugserver/source/DNBBreakpoint.cpp b/lldb/tools/debugserver/source/DNBBreakpoint.cpp index 74f0fb17129f3..eecce96d2d2bd 100644 --- a/lldb/tools/debugserver/source/DNBBreakpoint.cpp +++ b/lldb/tools/debugserver/source/DNBBreakpoint.cpp @@ -125,34 +125,38 @@ DNBBreakpointList::FindNearestWatchpoint(nub_addr_t addr) const { size_t DNBBreakpointList::FindBreakpointsThatOverlapRange( nub_addr_t addr, nub_addr_t size, std::vector<DNBBreakpoint *> &bps) { bps.clear(); + + if (m_breakpoints.empty()) + return bps.size(); + iterator end = m_breakpoints.end(); // Find the first breakpoint with an address >= to "addr" iterator pos = m_breakpoints.lower_bound(addr); - if (pos != end) { - if (pos != m_breakpoints.begin()) { - // Watch out for a breakpoint at an address less than "addr" that might - // still overlap - iterator prev_pos = pos; - --prev_pos; - if (prev_pos->second.IntersectsRange(addr, size, NULL, NULL, NULL)) - bps.push_back(&pos->second); - } - while (pos != end) { - // When we hit a breakpoint whose start address is greater than "addr + - // size" we are done. - // Do the math in a way that doesn't risk unsigned overflow with bad - // input. - if ((pos->second.Address() - addr) >= size) - break; + if (pos != m_breakpoints.begin()) { + // Watch out for a breakpoint at an address less than "addr" that might + // still overlap + iterator prev_pos = pos; + --prev_pos; + if (prev_pos->second.IntersectsRange(addr, size, NULL, NULL, NULL)) + bps.push_back(&prev_pos->second); + } - // Check if this breakpoint overlaps, and if it does, add it to the list - if (pos->second.IntersectsRange(addr, size, NULL, NULL, NULL)) - bps.push_back(&pos->second); + while (pos != end) { + // When we hit a breakpoint whose start address is greater than "addr + + // size" we are done. + // Do the math in a way that doesn't risk unsigned overflow with bad + // input. + if ((pos->second.Address() - addr) >= size) + break; - ++pos; - } + // Check if this breakpoint overlaps, and if it does, add it to the list + if (pos->second.IntersectsRange(addr, size, NULL, NULL, NULL)) + bps.push_back(&pos->second); + + ++pos; } + return bps.size(); } _______________________________________________ lldb-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
