如何查找给定C函数及其内部声明的变量的分配内存（地址及其大小）？

Question

If I have simple C program with just one main function.

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1. How do I find out the address of the block the code is allocated
2. The size of the block of memory that the process is assigned ?
3. The status of the stack (ie the size of the stack and the base pointer to the stack)
4. The size and location of each of variable declared in a program. (I understand the use of (sizeof) and (&) operators. But, How do I track each of the blocks that were allocated to the process to the variables or the bookkeeping variables to which they are assigned.)

If these constructs are maintained by the operating system ? Which ones are accessible and why ?

Are there any tool available for visualizing such a program state when the program is executing ?

Thanks, de costo.

Answer 1

A debugger (such as gdb) can show you all of this information.

There's no simple way to find this information from within the program itself AFAIK.

To find the location of the code section, you can take an address of the main() function (simply take the function pointer and see where it points). Alternatively, look at the instruction pointer within inline assembly.

To find the location of the stack roughly, take an address of a local variable, or the stack pointer from within inline assembly.

Under linux, each process has a directory under /proc folder, where you can read out all sorts of information about the process. (I think some of that stuff is being moved to /sys)

Hope this helps.