feat(extraction): C/C++ statement extraction

[shivasurya]

Summary

Adds ExtractCStatements and ExtractCppStatements — they walk a parsed function body and emit one *core.Statement per recognised construct (declaration, assignment, call, return, if/for/while/do/switch, plus throw / try / range-for in C++). The result feeds the CFG builder (PR-10) and the future variable-dependency graph.

Statement shapes captured

Construct	Statement
int x = a + b;	{Type: assignment, Def: x, Uses: [a, b]}
x = func(y);	{Type: assignment, Def: x, Uses: [y], CallTarget: func}
func(a, b);	{Type: call, CallTarget: func, Uses: [a, b]}
return x;	{Type: return, Uses: [x]}
if (x>0) { ... } else { ... }	{Type: if, Uses: [x], NestedStatements, ElseBranch}
for (int i=0; i<n; i++)	{Type: for, Def: i, Uses: [n]}
while (cond) { ... }	{Type: while, Uses: [cond]}
p->name = val;	{Type: assignment, Def: p, Uses: [val]}
buf[i] = input[j];	{Type: assignment, Def: buf, Uses: [input, i, j]}
obj.method(x);	{Type: call, CallTarget: method, CallChain: obj.method, Uses: [obj, x]}
ns::sort(begin, end);	{Type: call, CallTarget: ns::sort, Uses: [begin, end]}
auto x = obj.get();	{Type: assignment, Def: x, Uses: [obj], CallTarget: get}
throw std::runtime_error(msg);	{Type: raise, CallTarget: std::runtime_error}
for (auto x : items)	{Type: for, Def: x, Uses: [items]}

Design notes

• One shared dispatcher: clikeExtractor in statements_clike.go owns every node-type handler. C and C++ are thin wrappers that bind a keyword predicate (clike.IsCKeyword / clike.IsCppKeyword) and an extraNodeHandler hook for C++-only nodes. Adding the next clike construct touches one file.
• LHS collapsing: buf[i] = ..., p->name = ..., (*p) = ... all collapse to the base variable for Def; index/field expressions surface as additional Uses. Matches the def-use convention used by the Go and Python extractors.
• Loop-variable hygiene: the C-style and range-based for handlers add the defined loop variable to Def and remove it from Uses last, so the variable appears once even though it shows up in init / cond / update.
• Identifier walker filters field_identifier (the method name in obj.method), type_identifier, qualified_identifier (treated atomically as a call target rather than as variable uses), and every literal type — keeping Uses to true variable references.
• Catch clauses are flattened: the caught variable becomes the Def of an empty assignment statement so def-use sees the binding site, then the body's statements follow in ElseBranch.

Test plan

• go build ./...
• go test ./... — full suite green
• go vet ./...
• golangci-lint run ./graph/callgraph/extraction/ — 0 issues
• Coverage on new lines: 88.2%
• Spec C scenarios covered: assignment with binary op, assignment from call, bare call, if/else, for loop (with loop-var dropped from Uses), while, do-while, switch, pointer-arrow assignment, subscript assignment, keyword filter (sizeof, (int), NULL), bare declaration, forward declaration (nil function).
• Spec C++ scenarios covered: method call on object, qualified call, auto-from-method-call, throw constructor, try/catch (with bound exception name as Def), range-based for, C++ keyword filter (nullptr, static_cast, delete, this, auto), C-style fallthrough, namespace assignment.

Stacked on

shiva/cpp-cpp-call-graph (#675)

[safedep]

SafeDep Report Summary

No dependency changes detected. Nothing to scan.

View complete scan results →

_{This report is generated by SafeDep Github App}

[github-actions]

Code Pathfinder Security Scan

No security issues detected.

Metric	Value
Files Scanned	5
Rules	205

---

_{Powered by Code Pathfinder}

[codecov]

Codecov Report

❌ Patch coverage is 87.89346% with 50 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.39%. Comparing base (7814406) to head (c71dd83).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...ine/graph/callgraph/extraction/statements_clike.go	86.76%	33 Missing and 10 partials ⚠️
...ngine/graph/callgraph/extraction/statements_cpp.go	91.25%	5 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #676      +/-   ##
==========================================
+ Coverage   85.35%   85.39%   +0.03%     
==========================================
  Files         184      187       +3     
  Lines       26751    27164     +413     
==========================================
+ Hits        22834    23197     +363     
- Misses       3040     3078      +38     
- Partials      877      889      +12     

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[shivasurya]

• feat(python-sdk): @c_rule / @cpp_rule decorators with language scoping #678
• feat(cfg+scan+output): wire C/C++ pipeline end-to-end #677
• feat(extraction): C/C++ statement extraction #676 👈 (View in Graphite)
• feat(callgraph): C++ call graph builder #675
• feat(callgraph): C call graph builder #674
• feat(callgraph): C/C++ explicit type inference engines #673
• feat(callgraph): C/C++ module registry and include resolution #672
• feat(graph): C++ parser — classes, namespaces, templates, exception flow #671
• feat(graph): C parser — function defs, types, decls, calls, includes #670
• feat(graph/clike): shared C/C++ AST extraction helpers #669
• feat(graph): C/C++ file detection and tree-sitter parsing foundation #668
• main

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[shivasurya]

Merge activity

• May 3, 1:15 PM UTC: A user started a stack merge that includes this pull request via Graphite.
• May 3, 1:31 PM UTC: Graphite rebased this pull request as part of a merge.
• May 3, 1:32 PM UTC: @shivasurya merged this pull request with Graphite.