CODEWITHSUNDEEP
c++cgccgdb
aphid
aphid

Reputation: 1163

Expose debugging symbols for a program compiled with multiple languages

As per official instructions, to compile a program with debugging support you can run 

g++ -std=c++11 -O0 -g -c -o program1.o program1.cpp

Now to do the same with a C program, it's just: 

gcc -O0 -g -c -o program2.o program2.c

In order to link both types together, I could use: 

g++ --std=c++11  -O0 -g -o program program.o program2.o

Then, to debug: 

gdb program
gdb > run <PARAMS>

It worked completely after several attempts at tinkering with the compiler options (the above options are for a working version). In some cases the C symbols would load, but the C++ symbols would not.

Can someone shed some light as to what the recommended options are to enable debugging for non-trivial examples that mix several compiled languages? All of the documentation only refers to trivial examples.

Upvotes: 1

Views: 527

Answers (2)

aphid
aphid

Reputation: 1163

In each compilation and linking step, add the -g option to the compiler flags. -O0 is recommended too for debug builds so you don't get the compiler optimizing functions away. Being inconsistent may result in no debug symbols or partial debug symbols.

Upvotes: 0

Smeeheey
Smeeheey

Reputation: 10336

Note that if you use just the -g option then the compiler will use operating system's native format, which can vary. You can explicitly specify the format instead, using other -g... varieties (for example -gdwarf-3 or -g-stabs). This allows you to guarantee that your object files will all have a consistent debug format, irrespective of where they were built.

You can also disable gdb-only extensions by using this approach, should you wish to use other debuggers. See this for details.

Upvotes: 1

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