Is there a way to know which compiler generated a static library ?

Answer 1

You can try the unix utility file:

file foo.a

Answer 2

Is the library supposed to be a C or C++ library?

If it is a C library then name mangling can not be the problem, as there is none in C. It could be however in a wrong format. Unices used to have libraries in the a.out format but almost all newer versions switched to more powerful formats like ELF.

If it is a C++ library then name mangling can be an issue. Most compilers embed some symbols that are compiler specific into the code, so if you have a tool like nm to list the symbols you can hopefully deduce from what compiler it came.

For example g++ creates a symbol

__gxx_personality_v0

in it's libraries

Answer 3

Extract the object files from the archive then run the strings command on some of them (first on the smaller ones since there'd be less noise to sift through). Many compilers insert ASCII signatures in the object files.

For example, the following meaningless source file, foo.c:

extern void blah();

when compiled on my Fedora 10 machine into foo.o via gcc -c -o foo.o foo.c results in a 647 byte foo.o object file. Running strings on foo.o results in

GCC: (GNU) 4.3.2 20081105 (Red Hat 4.3.2-7)
.symtab
.strtab
.shstrtab
.text
.data
.bss
.comment
.note.GNU-stack
foo.c

which makes it clear the compiler was GCC. Even if I'd compiled it with -fno-ident, the .GNU-stack note ELF section would have still been present.

You can extract the object files using the ar utility, or using Midnight Commander (which integrates ar), or you can simply run strings on the archive (which might give you more noise and be less relevant, but would still help.)

Answer 4

I tend to use the strings program (with the '-a' option, or my own variant where the '-a' behaviour is standard) and look for the tell-tale signs. For example, in one of my own libraries, I find:

/work1/gcc/v4.2.3/bin/../lib/gcc/sparc-sun-solaris2.10/4.2.3/include
/work1/gcc/v4.3.0/bin/../lib/gcc/sparc-sun-solaris2.10/4.3.0/include
/work1/gcc/v4.3.1/bin/../lib/gcc/sparc-sun-solaris2.10/4.3.1/include
/work1/gcc/v4.3.3/bin/../lib/gcc/sparc-sun-solaris2.10/4.3.3/include

That suggests that the code in the library has been compiled with a variety of versions of GCC over a period of years (actually, I'm quite startled to find so many versions in a single library).

Another library contains:

cg: Sun Compiler Common 11 Patch 120760-06 2006/05/26
acomp: Sun C 5.8 Patch 121015-02 2006/03/29
iropt: Sun Compiler Common 11 Patch 120760-06 2006/05/26
/compilers/v11/SUNWspro/prod/bin/cc -O -v -Xa -xarch=v9 ...

So, there are usually fingerprints in the object files indicating which compiler was used. But you have to know how to look for them.