Replace the nested if-else branch-analysis architecture with a flat DFA
model using CodeGen.emitFlat — a single DFS walk emitting each block as
a C label followed by its code and gotos to all successors.
Removed:
- _branchDescendants / emitBranch / generateCallWithError
- _generateCallWithError, _noWalkNext, _genVisited
- generateNextCode, findBackEdges
- WCDecision._branchDescendants / _emitBranch / overridden generateCode
Added:
- CodeGen.emitFlat(entry) — flat DFS emit with labels + gotos
- WCBlock.generateFlowCode() — base emits gotos from wcNextFlow
- WCDecision.generateFlowCode() — if-goto / goto for decisions
- WCProcCall.generateFlowCode() — if (call != 0) goto err / goto ok
Output is flat — zero nested if-else for branch/error handling.
Tests use local out/ directory.
Success-exclusive code was emitted outside the if-else, so it ran even
when the call failed. Now it's wrapped in else { ... } — shared code
(blocks reachable from both error and success paths) stays outside.
- _emitBranch now sets _genVisited on blocks before calling generateOwnCode
so that proc calls inside loop bodies can seed their error-handling
visited set from the main traversal, preventing loop-decision re-walk
- Add _noWalkNext flag on proc calls when error handling is active, so
_emitBranch skips redundant nextFlow walking (the success path was
already covered by the error-handling branch emission)
- Known issue: shared blocks that are direct roots of emitBranch (from
the shared set) may still be re-walked when they were already emitted
by a downstream proc call's error-handling success path
- _emitBranch walk no longer adds decisions to visited before calling
generateCode — let the decision's own generateCode manage its visited
tracking. Otherwise the decision's generateCode sees itself as already
visited and returns empty, dropping its entire subtree.
- Same fix in both codegen/index.js and blocks-algo.js
- Add CodeGen.findBackEdges(root) pre-pass — DFS-based back-edge
detection that finds all blocks targeted by at least one back-edge
- Only those blocks get C labels; only those back-edges emit goto
- emitBranch reverts to generateOwnCode + manual successor walking
(respects stop set properly for shared blocks)
- generateCode/generateNextCode accept loopTargets parameter;
visited-but-not-back-edge blocks are silently skipped
- No more -Wunused-label warnings in compiled output
- Every block now emits a C label (its id) before its code
- generateNextCode emits goto label; for back-edges (visited targets)
- _emitBranch delegates to generateCode (not generateOwnCode), so labels
are emitted consistently in both main and branch traversals
- generateCallWithError threads a shared visited set across all three
emitBranch calls, preventing duplicate label emission for shared blocks
- emitBranch skips roots already visited by previous roots in the same
branch (prevents spurious gotos from shared-block traversal)
- Create codegen/index.js with pure branchDescendants, emitBranch,
generateCallWithError, and generateCFile — zero DOM dependencies
- blocks-proc.js adapters delegate to CodeGen with browser instanceof check
- run.js uses the same CodeGen module instead of duplicating block classes
with their own branchDescendants/emitBranch logic
- Load codegen/index.js in browser before blocks-proc.js
adrien