Possible memory leak in te_compile

[aeonSolutions]

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I'm getting the following crash report on a ESP32 S3 MCU when executing the expression " (p-(-10))*dt " with p=85.0 and dt=-1.0 with te_compile 39 times.

Guru Meditation Error: Core  1 panic'ed (Unhandled debug exception). 
Debug exception reason: Stack canary watchpoint triggered (loopTask) 
Core  1 register dump:
PC      : 0x420fd7ab  PS      : 0x00060536  A0      : 0x820fe4d9  A1      : 0x3fce0ef0  
A2      : 0x00000000  A3      : 0x3fcf272d  A4      : 0x3fce133c  A5      : 0x3c155edc  
A6      : 0x00060d23  A7      : 0x00000001  A8      : 0x803803ae  A9      : 0x3fce0f70  
A10     : 0x3fce2f10  A11     : 0x00000018  A12     : 0x00000009  A13     : 0x00000020  
A14     : 0x3fcf272c  A15     : 0x00000000  SAR     : 0x00000018  EXCCAUSE: 0x00000001  
EXCVADDR: 0x00000000  LBEG    : 0x400570e8  LEND    : 0x400570f3  LCOUNT  : 0x00000000  


Backtrace:0x420fd7a8:0x3fce0ef00x420fe4d6:0x3fce0fb0 0x4200d50d:0x3fce0fd0 0x4200d953:0x3fce1000 0x4200d98a:0x3fce1030 0x4200d9e6:0x3fce1060 0x4200d6be:0x3fce1090 0x4200d732:0x3fce10c0 0x4200d91a:0x3fce10f0 0x4200d939:0x3fce1120 0x4200d98a:0x3fce1150 0x4200d9e6:0x3fce1180 0x4200d6f4:0x3fce11b0 0x4200d732:0x3fce11e0 0x4200d91a:0x3fce1210 0x4200d939:0x3fce1240 0x4200d98a:0x3fce1270 0x4200d9e6:0x3fce12a0 0x4200d6be:0x3fce12d0 0x4200d732:0x3fce1300 0x4200df55:0x3fce1330 0x42008ebf:0x3fce1380 0x42008f2b:0x3fce1420 0x42008f2b:0x3fce14c0 0x42008f2b:0x3fce1560 0x42008f2b:0x3fce1600 0x42008f2b:0x3fce16a0 0x42008f2b:0x3fce1740 0x42008f2b:0x3fce17e0 0x42008f2b:0x3fce1880 0x42008f2b:0x3fce1920 0x42008f2b:0x3fce19c0 0x42008f2b:0x3fce1a60 0x42008f2b:0x3fce1b00 0x42008f2b:0x3fce1ba0 0x42008f2b:0x3fce1c40 0x42008f2b:0x3fce1ce0 0x42008f2b:0x3fce1d80 0x42008f2b:0x3fce1e20 0x42008f2b:0x3fce1ec0 0x42008f2b:0x3fce1f60 0x42008f2b:0x3fce2000 0x42008f2b:0x3fce20a0 0x42008f2b:0x3fce2140 0x42008f2b:0x3fce21e0 0x42008f2b:0x3fce2280 0x42008f2b:0x3fce2320 0x42008f2b:0x3fce23c0 0x42008f2b:0x3fce2460 0x42008f2b:0x3fce2500 0x42008f2b:0x3fce25a0 0x42008f2b:0x3fce2640 0x42008f2b:0x3fce26e0 0x42008f2b:0x3fce2780 0x42008f2b:0x3fce2820 0x42008f2b:0x3fce28c0 0x42008f2b:0x3fce2960 0x42008f2b:0x3fce2a00 0x42008f2b:0x3fce2aa0 0x42008f2b:0x3fce2b40 0x42008f2b:0x3fce2be0 0x4200ac55:0x3fce2c80 0x420040cd:0x3fce2ce0 0x42021801:0x3fce2da0 

    double a=this->measureValues[0];
    double h=this->measureValues[1];
    double pt=this->measureValues[2];
    double dt=this->measureValues[3];
    double p=this->measureValues[4];
    double m=this->measureValues[5];
    double t=this->measureValues[6];
    double u=this->measureValues[7];

    const char* a_n="a";
    const char* h_n="h";
    const char* pt_n="pt";
    const char* dt_n="dt";
    const char* p_n="p";
    const char* m_n="m";
    const char* t_n="t";
    const char* u_n="u";

    te_variable vars[]= { 
                            {.name=dt_n, .address = &dt},  
                            {.name=p_n, .address = &p}
                        };



    int err;
    te_expr *n = te_compile(this->config.custom_maturity_equation.c_str(), vars, numVars, &err);

[codeplea]

You're almost certainly doing something wrong with the te_compile or evaluate call. Your example is weird, because you define a bunch of doubles and char pointers, but you only use dt and p. Also, you don't show numVars, but if it's anything more than 2, that could definitely cause a memory error.

Furthermore, you don't need to copy the array to doubles.

This code is equivalent to what you have above:

    te_variable vars[]= { 
                            {.name="dt", .address = this->measureValues+3},  
                            {.name="p", .address = this->measureValues+4}
                        };
    int numVars = 2;
    int err;
    te_expr *n = te_compile(this->config.custom_maturity_equation.c_str(), vars, numVars, &err);

I've done a lot of embed programming myself. I highly suggest you actually get all this stuff working on a PC first. It's much easier to develop, test, and learn in that environment. After all that's good, you can port it to the embedded environment and save yourself a lot of work.

Edit: see my post in the other thread. Your definitely setting numVars incorrectly, which is causing the memory error.