How to disable some msp430 gcc code injections

Question

I'm working on a project for MSP430 microcontrollers. This project is a code instrumenter tool which requires all of the code that is deployed on the device to be instrumented. The tool is basically ready but for one problem: in order to work it needs all of the source code of a certain application, in either assembly or C, to be available prior to its compilation.

However, when compiling certain applications with mspgcc, which is an open source version of gcc made for MSP430 microcontrollers, the compiler creates some code stubs to optimise the whole app. These stubs, for instance, can be used to perform multiple shift operations, allowing the app to jump to the entry point whenever it needs to perform a certain number of shifts (rather than inlining them). Here's an example:

00005df4 <__mspabi_srll_4>:
5df4:       12 c3           clrc
5df6:       0d 10           rrc     r13             ;
5df8:       0c 10           rrc     r12             ;

00005dfa <__mspabi_srll_3>:
    5dfa:       12 c3           clrc
    5dfc:       0d 10           rrc     r13             ;
    5dfe:       0c 10           rrc     r12             ;

00005e00 <__mspabi_srll_2>:
    5e00:       12 c3           clrc
    5e02:       0d 10           rrc     r13             ;
    5e04:       0c 10           rrc     r12             ;

00005e06 <__mspabi_srll_1>:
    5e06:       12 c3           clrc
    5e08:       0d 10           rrc     r13             ;
    5e0a:       0c 10           rrc     r12             ;
    5e0c:       10 01           reta                    ;

00005e0e <.L1^B3>:
    5e0e:       3e 53           add     #-1,    r14     ;r3 As==11
    5e10:       12 c3           clrc
    5e12:       0d 10           rrc     r13             ;
    5e14:       0c 10           rrc     r12             ;

00005e16 <__mspabi_srll>:
    5e16:       0e 93           cmp     #0,     r14     ;r3 As==00
    5e18:       fa 23           jnz     $-10            ;abs 0x5e0e
    5e1a:       10 01           reta                    ;

This assembly code allows the application to perform a jump to these entry points, with a simple CALL:

    CALLA   #__mspabi_srll

There a several of these additional code stubs added by the compiler, and all of them are called "_mspabi....". Since, however, I have no way to instrument the code of these function (since it's added at linking time I believe) I must do one of the following:

1. Prevent the compiler/linker from using these instructions (they are used both on -O0 and -O3)
2. Modify the source code for these instructions to instrument them (I suppose they are statically linked libraries or something like it, with no available source code. I tried removing all include directives but the extra code is still injected)
3. Implement my own instrumented code stubs so that they are used instead of these ones (which, at that point, must not be included in the binary)

Could anybody help me achieve one of the three options? Or maybe some other advice! Thank you in advance, I'd really appreciate any help.