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extern CGameEngine *g_psEngine; // assume g_psEngine is always valid.

#if !defined(BUILD_RELEASE) 
#define Debug(A) g_psEngine->DebugPrint(A);
#else 
#define Debug(A)
#endif 

if(!a)Debug(“Player Not Found”) 

ControlPlayer();
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  • Latest Post Latest Post by Ancient Dragon

Dani AI

Generated

As spotted, the dangerous bug is a control‑flow mismatch caused by the debug macro. Macros are plain text substitution: in one build the macro expands to a statement (so the if only controls that statement), and in the other it expands to nothing (so the if instead grabs the next real statement). That makes release behaviour different from debug and can easily break program logic.

Two practical fixes:

  • Make the intended grouping explicit at the call site — always use braces for single‑line ifs so the debug call cannot accidentally steal the following statement.
  • Replace the fragile macro with a form that always produces a single statement, or use an inline function. Example safe patterns:
#if !defined(BUILD_RELEASE)
#define DBG(msg) do { if (g_psEngine) g_psEngine->DebugPrint(msg); } while (0)
#else
#define DBG(msg) do { } while (0)
#endif

or

inline void DebugMessage(const char *msg) {
#ifndef BUILD_RELEASE
    if (g_psEngine) g_psEngine->DebugPrint(msg);
#endif
}

Either approach preserves statement semantics so the surrounding if behaves the same in all builds.

Quick troubleshooting notes: search the codebase for debug/log macros and single‑line if usages; run static analysis and enable warnings that flag suspicious conditional constructs; prefer braces and small inline functions for logging to avoid this whole class of errors. This addresses what asked and builds on ’s diagnosis; ’s suggestion to reason about the code first was the right starting point.

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Member Avatar for Ancient Dragon

when BUILD_RELEASE is defined the Debug macro is not evaluated and the function on line 11 of the code you posted will only be executed if a == 0, in otherwords line 11 becomes part of the if condition on line 9, just as if it were written like this:

if(!a)
    ControlPlayer();
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