问题
I have a statically linked application binary that links against multiple user libraries and the pthread library. The application only uses a limited set of functions from each of these libraries. From a previous post Size of a library and the executable and from my experiments I realize that the linker only includes functions(in the executable) that are used/needed and not the entire contents of library.
I want to find out which functions from each of the respective libraries are linked to the executable and their addresses (VMA). Ultimately I want to compile a list that contains the start and the end Virtual Memory Addresses (VMAs) for the each of the libraries based on the functions (in the library) that are mapped to the text segment.
One approach to do this is to make a list of functions in the library and then look for each of these functions in the executable and the corresponding Virtual Memory address it is mapped to. But this seems rather tedious to me. Is there a simpler way to accomplish this? Thanks.
回答1:
I want to find out which functions from each of the respective libraries are linked to the executable and their addresses (VMA).
Add -Wl,-Map=foo.map argument to your link line. The resulting foo.map file will tell you all of the above.
Ultimately I want to compile a list that contains the start and the end Virtual Memory Addresses (VMAs) for the each of the libraries
That assumes that the linker does not re-order functions (and thus all functions from a single library occupy continuous range of text addresses). This assumption is probably true in simple cases, but in no way is guaranteed. See e.g. this patch.
来源：https://stackoverflow.com/questions/15146879/examining-text-segment-in-a-statically-linked-executable