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Get list of bb start/end eas for loops in extract.py #1253

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12 changes: 10 additions & 2 deletions floss/features/extract.py
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Original file line number Diff line number Diff line change
Expand Up @@ -291,6 +291,7 @@ def extract_function_loop(f):
parse if a function has a loop
"""
edges = []
bb_by_va = {bb.va: bb for bb in f.basic_blocks}
Comment on lines 293 to +294
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@gemini-code-assist gemini-code-assist Bot Apr 2, 2026

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medium

The dictionary bb_by_va is created for every function, even those without loops. Since most functions do not contain loops (SCCs of size >= 2), this is an unnecessary overhead. It is more efficient to initialize this dictionary lazily only when a loop is detected.

Suggested change
edges = []
bb_by_va = {bb.va: bb for bb in f.basic_blocks}
edges = []


for bb in f.basic_blocks:
if len(bb.instructions) > 0:
Expand All @@ -313,8 +314,15 @@ def extract_function_loop(f):
comps = strongly_connected_components(g)
for comp in comps:
if len(comp) >= 2:
# TODO get list of bb start/end eas
yield Loop(comp)
loop_bb_ranges = []
for bb_va in sorted(comp):
bb = bb_by_va.get(bb_va)
if bb is None:
continue

loop_bb_ranges.append((bb.va, bb.va + bb.size))

yield Loop(comp, bb_ranges=loop_bb_ranges)
Comment on lines 315 to +325
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@gemini-code-assist gemini-code-assist Bot Apr 2, 2026

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medium

Implementing lazy initialization for bb_by_va here ensures that the dictionary is only constructed when at least one loop is identified in the function, avoiding unnecessary computation for the majority of functions.

    bb_by_va = None
    for comp in comps:
        if len(comp) >= 2:
            if bb_by_va is None:
                bb_by_va = {bb.va: bb for bb in f.basic_blocks}
            loop_bb_ranges = []
            for bb_va in sorted(comp):
                bb = bb_by_va.get(bb_va)
                if bb is None:
                    continue

                loop_bb_ranges.append((bb.va, bb.va + bb.size))

            yield Loop(comp, bb_ranges=loop_bb_ranges)



FUNCTION_HANDLERS = (
Expand Down
3 changes: 2 additions & 1 deletion floss/features/features.py
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Original file line number Diff line number Diff line change
Expand Up @@ -172,10 +172,11 @@ def score(self):
class Loop(Feature):
weight = MEDIUM

def __init__(self, comp):
def __init__(self, comp, bb_ranges=None):
super(Loop, self).__init__(len(comp))

self.comp = comp
self.bb_ranges = bb_ranges or []

def score(self):
return 1.0
Expand Down
12 changes: 8 additions & 4 deletions floss/main.py
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@williballenthin williballenthin Apr 2, 2026

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revert this please

Original file line number Diff line number Diff line change
Expand Up @@ -126,7 +126,8 @@ def make_parser(argv):
" 1. Go: strings from binaries written in Go\n"
" 2. Rust: strings from binaries written in Rust\n"
)
epilog = textwrap.dedent("""
epilog = textwrap.dedent(
"""
only displaying core arguments, run `floss -H` to see all supported options

examples:
Expand All @@ -138,8 +139,10 @@ def make_parser(argv):

only extract stack and tight strings
floss --only stack tight -- suspicious.exe
""")
epilog_advanced = textwrap.dedent("""
"""
)
epilog_advanced = textwrap.dedent(
"""
examples:
extract all strings from 32-bit shellcode
floss -f sc32 shellcode.bin
Expand All @@ -149,7 +152,8 @@ def make_parser(argv):

extract strings from a binary written in Go (if automatic language identification fails)
floss --language go program.exe
""")
"""
)

show_all_options = "-H" in argv

Expand Down
6 changes: 4 additions & 2 deletions tests/test_load.py
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@williballenthin williballenthin Apr 2, 2026

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revert this

Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,8 @@
import floss.main

# floss --no static -j tests/data/src/decode-in-place/bin/test-decode-in-place.exe
RESULTS = textwrap.dedent("""
RESULTS = textwrap.dedent(
"""
{
"analysis": {
"enable_decoded_strings": true,
Expand Down Expand Up @@ -83,7 +84,8 @@
"tight_strings": []
}
}
""")
"""
)


def test_load(tmp_path):
Expand Down