Java: Improve join order.

[aschackmull]

Before:

[2026-07-10 15:15:58] Evaluated non-recursive predicate ControlFlowGraph::NonReturningCalls::EffectivelyNonVirtualMethod.getAnAccess/0#dispred#efac59ed@090459qt in 4303ms (size: 186002).
Evaluated relational algebra for predicate ControlFlowGraph::NonReturningCalls::EffectivelyNonVirtualMethod.getAnAccess/0#dispred#efac59ed@090459qt with tuple counts:
           790592  ~0%    {2} r1 = JOIN `Expr::MethodCall.getMethod/0#dispred#41989dc9_10#join_rhs` WITH `Member::Method.getSourceDeclaration/0#dispred#93e6cdf8` ON FIRST 1 OUTPUT Rhs.1, Lhs.1
        539755681  ~2%    {2}    | JOIN WITH `Member::SrcMethod.getAPossibleImplementationOfSrcMethod/0#dispred#4f4317e6#bf` ON FIRST 1 OUTPUT Rhs.1, Lhs.1
           186002  ~2%    {2}    | JOIN WITH ControlFlowGraph::NonReturningCalls::EffectivelyNonVirtualMethod#86c19e07 ON FIRST 1 OUTPUT Lhs.0, Lhs.1
                          return r1

After:

[2026-07-10 15:29:39] Evaluated non-recursive predicate ControlFlowGraph::NonReturningCalls::EffectivelyNonVirtualMethod.getAnAccess/0#dispred#efac59ed@32fb2e61 in 10ms (size: 186002).
Evaluated relational algebra for predicate ControlFlowGraph::NonReturningCalls::EffectivelyNonVirtualMethod.getAnAccess/0#dispred#efac59ed@32fb2e61 with tuple counts:
        122765  ~0%    {2} r1 = SCAN ControlFlowGraph::NonReturningCalls::EffectivelyNonVirtualMethod#86c19e07 OUTPUT In.0, In.0
        122766  ~0%    {2}    | JOIN WITH `Member::SrcMethod.getAPossibleImplementationOfSrcMethod/0#dispred#4f4317e6_10#join_rhs` ON FIRST 1 OUTPUT Rhs.1, Lhs.1
        126911  ~0%    {2}    | JOIN WITH `Member::Method.getSourceDeclaration/0#dispred#93e6cdf8_10#join_rhs` ON FIRST 1 OUTPUT Rhs.1, Lhs.1
        186002  ~2%    {2}    | JOIN WITH `Expr::MethodCall.getMethod/0#dispred#41989dc9_10#join_rhs` ON FIRST 1 OUTPUT Lhs.1, Rhs.1
                       return r1

[Copilot]

Pull request overview

This PR optimizes evaluation of a Java CFG helper predicate by changing the join order via a binding hint, significantly reducing evaluation time for ControlFlowGraph::NonReturningCalls::EffectivelyNonVirtualMethod.getAnAccess/0.

Changes:

• Rewrites EffectivelyNonVirtualMethod.getAnAccess() into a block body and applies pragma[only_bind_out] to this to improve join order/performance.

Show a summary per file

File	Description
java/ql/lib/semmle/code/java/ControlFlowGraph.qll	Adds an only_bind_out pragma in getAnAccess() to steer evaluation and reduce join blowup.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 0
• Review effort level: Low

[owen-mc]

Consider running DCA?