This patch adds an experimental out-of-bounds checker to the analyzer.
The checker was tested on coreutils, curl, httpd and openssh. It is mostly
accurate but does produce false-positives on yacc-generated files and
sometimes when the analyzer misses an invariant. These cases will be
documented in bugzilla.
Regression-tested on Linux x86-64, further ran the analyzer tests with
the -m32 option.
2022-08-11 Tim Lange <mail@tim-lange.me>
gcc/analyzer/ChangeLog:
PR analyzer/106000
* analyzer.opt: Add Wanalyzer-out-of-bounds.
* region-model.cc (class out_of_bounds): Diagnostics base class
for all out-of-bounds diagnostics.
(class past_the_end): Base class derived from out_of_bounds for
the buffer_overflow and buffer_overread diagnostics.
(class buffer_overflow): Buffer overflow diagnostics.
(class buffer_overread): Buffer overread diagnostics.
(class buffer_underflow): Buffer underflow diagnostics.
(class buffer_underread): Buffer overread diagnostics.
(region_model::check_region_bounds): New function to check region
bounds for out-of-bounds accesses.
(region_model::check_region_access):
Add call to check_region_bounds.
(region_model::get_representative_tree): New function that accepts
a region instead of an svalue.
* region-model.h (class region_model):
Add region_model::check_region_bounds.
* region.cc (region::symbolic_p): New predicate.
(offset_region::get_byte_size_sval): Only return the remaining
byte size on offset_regions.
* region.h: Add region::symbolic_p.
* store.cc (byte_range::intersects_p):
Add new function equivalent to bit_range::intersects_p.
(byte_range::exceeds_p): New function.
(byte_range::falls_short_of_p): New function.
* store.h (struct byte_range): Add byte_range::intersects_p,
byte_range::exceeds_p and byte_range::falls_short_of_p.