.. _debugger-expressions-list: Debugger Expressions Guide ========================== Expressions can be used anywhere a numeric parameter is expected. The syntax for expressions is very close to standard C-style syntax with full operator ordering and parentheses. There are a few operators missing (notably the trinary ? : operator), and a few new ones (memory accessors). The table below lists all the operators in their order, highest precedence operators first. | | ( ) : standard parentheses | ++ -- : postfix increment/decrement | ++ -- ~ ! - + b@ w@ d@ q@ : prefix inc/dec, binary NOT, logical NOT, unary +/-, memory access | * / % : multiply, divide, modulus | + - : add, subtract | << >> : shift left/right | < <= > >= : less than, less than or equal, greater than, greater than or equal | == != : equal, not equal | & : binary AND | ^ : binary XOR | | : binary OR | && : logical AND | || : logical OR | = \*= /= %= += -= <<= >>= &= \|= ^= : assignment | , : separate terms, function parameters | | Differences from C Behaviors ---------------------------- - First, all math is performed on full 64-bit unsigned values, so things like a < 0 won't work as expected. - Second, the logical operators && and || do not have short-circuit properties -- both halves are always evaluated. - Finally, the new memory operators work like this: - b@ refers to the byte read from . - Similarly, w@ refers to a word in memory, d@ refers to a dword in memory, and q@ refers to a qword in memory. The memory operators can be used as both lvalues and rvalues, so you can write b\@100 = ff to store a byte in memory. By default these operators read from the program memory space, but you can override that by prefixing them with a 'd' or an 'i'. So dw\@300 refers to data memory word at address 300 and id\@400 refers to an I/O memory dword at address 400.