Statement Level Graph

Fixing a bug inside a 1,600-line function needs to know which statements read a variable and which wrote it — not just which files mention a symbol. Environment-Bootstrap (R11)

What shipped

graph_statements.py extracts a statement-level def-use graph, additively stored in the existing code-graph database alongside files/symbols/edges (.forge/codegraph.db):

• statements — one row per assignment / augmented assignment / annotated assignment / for target / with binding / def/class, with file, line, column, enclosing symbol, kind, and engine ∈ {exact, heuristic}.
• def_use — directed edges: the statement at (file, line) reads from and writes to which definitions.

Confidence is honest, not cosmetic:

• Python is ast-exact. Scoping is real (globals, nonlocals, nested functions, comprehension scopes), and shadowing follows true semantics — because resolution happens before a scope's own definitions register, x = x + 1 reads the previous x.
• Non-Python files get block rows with engine="heuristic" and no def_use edges — a visible shape for future work rather than silently wrong edges.

Accessing it

from atomic_forge.codegraph import CodeGraph

g = CodeGraph(project_dir).build()        # incremental; content-hashed
g.statements_near("app/handlers.py", 412, radius=15)
# -> statements defining / reading around line 412
g.uses_of("retry_budget", "app/config.py")
# -> every place that reads that name

And as an agent tool (auto-surfaced in the tool manifest, both backends):

statement_graph(file="app/handlers.py", line=412)

Enabled by default; disable with FORGE_STATEMENT_GRAPH=0 for huge repos where the extra pass isn't wanted.

Why: the long-function localization problem

The repair loop's localization used to stop at function granularity — useful, but in a long function it can't say "line 412 reads retry_budget, whose only writer is line 238". The REPAIR_SYSTEM prompt teaches the agent to use statement_graph for exactly that second-pass localization, and the evidence chain (traceback frame → symbol → statements) is recorded in the trajectory.

Measurement note (honest)

The design point is the ARISE-style improvement (statement-level localization over multi-hop dependency views, arXiv:2605.03117). The delta on forge's own benchmark cases with a live LLM is measured in Phase 3 — the graph itself, its semantics, and its tests (tests/test_graph_statements.py) are shipped and green. See Benchmarks for what's measured today.