Function buildConditional

src/strands/strands_conditionals.js:38–127

(strandsContext, conditional)

  }
}
function buildConditional(strandsContext, conditional) {
  const cfg = strandsContext.cfg;
  const branches = conditional.branches;
  const mergeBlock = CFG.createBasicBlock(cfg, BlockType.MERGE);
  const results = [];
  const branchBlocks = [];
  const branchEndBlocks = [];
  const mergedAssignments = {};
  const phiBlockDependencies = {};
  // Create a BRANCH block to handle phi node declarations
  const branchBlock = CFG.createBasicBlock(cfg, BlockType.BRANCH);
  CFG.addEdge(cfg, cfg.currentBlock, branchBlock);
  CFG.addEdge(cfg, branchBlock, mergeBlock);
  let previousBlock = branchBlock;
  for (let i = 0; i < branches.length; i++) {
    const { condition, branchCallback, blockType } = branches[i];
    if (condition !== null) {
      const conditionBlock = CFG.createBasicBlock(cfg, BlockType.IF_COND);
      CFG.addEdge(cfg, previousBlock, conditionBlock);
      CFG.pushBlock(cfg, conditionBlock);
      cfg.blockConditions[conditionBlock] = condition.id;
      previousBlock = conditionBlock;
      CFG.popBlock(cfg);
    } else {
      const elseCondBlock = CFG.createBasicBlock(cfg, BlockType.ELSE_COND);
      CFG.addEdge(cfg, previousBlock, elseCondBlock);
      previousBlock = elseCondBlock;
    }
    const scopeStartBlock = CFG.createBasicBlock(cfg, BlockType.SCOPE_START);
    CFG.addEdge(cfg, previousBlock, scopeStartBlock);
    const branchContentBlock = CFG.createBasicBlock(cfg, blockType);
    CFG.addEdge(cfg, scopeStartBlock, branchContentBlock);
    branchBlocks.push(branchContentBlock);
    CFG.pushBlock(cfg, branchContentBlock);
    const branchResults = branchCallback();
    for (const key in branchResults) {
      branchResults[key] = strandsContext.p5.strandsNode(branchResults[key]);
    }
    for (const key in branchResults) {
      if (!phiBlockDependencies[key]) {
        phiBlockDependencies[key] = [{ value: branchResults[key], blockId: branchContentBlock }];
      } else {
        phiBlockDependencies[key].push({ value: branchResults[key], blockId: branchContentBlock });
      }
    }
    results.push(branchResults);

    // Create BRANCH_END block for phi assignments
    const branchEndBlock = CFG.createBasicBlock(cfg, BlockType.DEFAULT);
    CFG.addEdge(cfg, cfg.currentBlock, branchEndBlock);
    branchEndBlocks.push(branchEndBlock);
    CFG.popBlock(cfg);

    const scopeEndBlock = CFG.createBasicBlock(cfg, BlockType.SCOPE_END);
    CFG.addEdge(cfg, branchEndBlock, scopeEndBlock);
    CFG.addEdge(cfg, scopeEndBlock, mergeBlock);
    previousBlock = scopeStartBlock;
  }