Bug 26261 - Fix logic for canonicalizing DW_TAG_subroutine_type DIEs
In the function compare_dies, the handling of DW_TAG_subroutine_type
was unfinished.
This DIE represents function types pointed-to by function pointer. It
doesn't represent the type of a "real" function type like the
abigail::ir::function_type would. The represent more an interface to
a function, which a pointer can point to or which can be used to issue
a call.
So intended idea is that compare_dies compares two DIEs of the
DW_TAG_subroutine_type and DW_TAG_subprogram kind (the later
represents real function definitions) among other kinds, structurally,
but by trying to optimize for speed, for the purpose of canonicalizing
DIEs even before type canonicalization happens at the libabigail IR
level. This is critical to save space (and time) by doing DIE
de-duplication on huge binaries.
This patch finishes to implement the comparison for
DW_TAG_subroutine_type and comes with a carefully crafted test case
that hits that code path.
* src/abg-dwarf-reader.cc (compare_dies): Get out early if we are
are in the middle of a potential recursive comparison of function
types. Likewise if we detect that the two function types have
different textual representations, linkage names, or have a the
same textual representation, linkage names and are defined in the
same translation unit.
* tests/data/test-read-dwarf/PR26261/PR26261-exe: New test binary
input file.
* tests/data/test-read-dwarf/PR26261/PR26261-exe.abi: New
reference test output file.
* tests/data/test-read-dwarf/PR26261/PR26261-main.c: Source code
of the binary above.
* tests/data/test-read-dwarf/PR26261/PR26261-obj{a,b}.{c,h}:
Likewise.
* tests/data/test-read-dwarf/PR26261/Makefile: Makefile to
build the exe out of the source files.
* tests/data/Makefile.am: Add the new test input files to source
distribution.
* tests/test-read-dwarf.cc (in_out_spec): Add the binary test
input above to the test harness.
Signed-off-by: Dodji Seketeli <dodji@redhat.com>
11 files changed
