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🚨 The C Rule That Breaks Your Code Without Warning 🚨 (Most developers never hear about it… until they hit a mysterious bug.) # AvNet board giveaway: https://lnkd.in/dtcYQ9VP Have you ever written C code that: ✅ Compiles fine ✅ Works in debug mode ❌ But gives completely different output with -O2 optimizations? You may have just broken the strict aliasing rule. What is strict aliasing? It’s a compiler rule that says: Two pointers of different, incompatible types are assumed not to point to the same memory. Why? Because this assumption lets the compiler make aggressive optimizations. If you break it → you invite undefined behavior. Example: int x = 10; float *p = (float*)&x; // 🚨 strict aliasing violation *p = 20.0f; printf("%d\n", x); Without optimizations: prints some big integer (bit pattern of 20.0f). With -O2: might print 10 or something else entirely. Allowed exceptions: Access via char* or unsigned char* Compatible types (e.g., int* and const int*) Certain struct member accesses How to avoid breaking it: Use memcpy() for type-punning Use unions carefully (C only) Stick to allowed exceptions As a last resort, compile with -fno-strict-aliasing (you lose optimizations) 💡 Takeaway: Your code might “work” today… until the compiler gets smarter. Understand strict aliasing → avoid invisible bugs → write portable, reliable C. 🚀 Practice real-world C Firmware tasks & problems to build pro-level skills https://lnkd.in/g_HgzJHW #EWskills #EmbeddedC #EmbeddedSystems #LearnByDoing #EarlyCareerEngineer #𝗤𝘂𝗲𝘀𝘁𝗶𝗼𝗻𝗙𝗼𝗿𝗚𝗿𝗼𝘂𝗽 #𝗙𝗶𝗿𝗺𝘄𝗮𝗿𝗲𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗺𝗲𝗻𝘁 #𝗠𝗶𝗰𝗿𝗼𝗰𝗼𝗻𝘁𝗿𝗼𝗹𝗹𝗲𝗿𝘀 #𝗣𝗜𝗖 #𝗥𝗧𝗢𝗦 #𝗜𝗻𝘁𝗲𝗿𝗿𝘂𝗽𝘁𝘀 #𝗜𝗼𝗧 #𝗖𝗼𝗱𝗶𝗻𝗴𝗧𝗶𝗽𝘀 #𝗦𝘁𝘂𝗱𝗲𝗻𝘁𝗣𝗿𝗼𝗷𝗲𝗰𝘁𝘀 #𝗘𝗹𝗲𝗰𝘁𝗿𝗼𝗻𝗶𝗰𝘀𝗘𝗻𝗴𝗶𝗻𝗲𝗲𝗿𝗶𝗻𝗴 #𝗙𝗶𝗿𝗺𝘄𝗮𝗿𝗲𝗧𝗶𝗽𝘀 #𝗔𝘂𝘁𝗼𝗺𝗮𝘁𝗶𝗼𝗻 #𝗣𝗲𝘁𝗧𝗲𝗰𝗵 #𝗗𝗜𝗬𝗣𝗿𝗼𝗷𝗲𝗰𝘁𝘀 #𝗧𝗲𝗰𝗵𝗙𝗼𝗿𝗚𝗼𝗼𝗱 #𝗘𝗺𝗯𝗲𝗱𝗱𝗲𝗱𝗦𝘆𝘀𝘁𝗲𝗺𝘀 #𝗔𝗿𝗱𝘂𝗶𝗻𝗼 #𝗥𝗮𝘀𝗽𝗯𝗲𝗿𝗿𝘆𝗣𝗶 #𝗣𝗲𝘁𝗖𝗮𝗿𝗲 #𝗠𝗮𝗸𝗲𝗿𝘀𝗚𝗼𝗻𝗻𝗮𝗠𝗮𝗸𝗲 #𝗔𝗿𝗱𝘂𝗶𝗻𝗼 #𝗘𝗺𝗯𝗲𝗱𝗱𝗲𝗱𝗦𝘆𝘀𝘁𝗲𝗺𝘀 #𝗥𝗼𝗯𝗼𝘁𝗶𝗰𝘀 #𝗢𝗯𝗷𝗲𝗰𝘁𝗔𝘃𝗼𝗶𝗱𝗮𝗻𝗰𝗲 #𝗦𝗧𝗘𝗠 #𝗘𝗹𝗲𝗰𝘁𝗿𝗼𝗻𝗶𝗰𝘀 #𝗣𝗮𝘀𝘀𝗶𝗼𝗻𝗣𝗿𝗼𝗷𝗲𝗰𝘁 #𝗟𝗲𝗮𝗿𝗻𝗶𝗻𝗴𝗕𝘆𝗗𝗼𝗶𝗻𝗴 #𝗜𝗻𝗻𝗼𝘃𝗮𝘁𝗶𝗼𝗻 #𝗟𝗶𝗻𝗸𝗲𝗱𝗜𝗻𝗣𝗿𝗼𝗷𝗲𝗰𝘁 #PCBDesign #RFDesign #SignalIntegrity #ViaStitching #ThermalManagement #EmbeddedSystems #HardwareEngineering #WirelessTech