declare function support and linker flags

.github/workflows/ci.yml

@@ -68,10 +68,10 @@ jobs:
             exit 1
           fi
 
-      - name: Build tree-sitter TypeScript objects
+      - name: Build tree-sitter TSX objects
         run: |
           mkdir -p build
-          TS_SRC=node_modules/tree-sitter-typescript/typescript/src
+          TS_SRC=node_modules/tree-sitter-typescript/tsx/src
           TS_INCLUDE=node_modules/tree-sitter-typescript
           clang -c -O2 -fPIC -I $TS_SRC -I $TS_INCLUDE $TS_SRC/parser.c -o build/tree-sitter-typescript-parser.o
           clang -c -O2 -fPIC -I $TS_SRC -I $TS_INCLUDE $TS_SRC/scanner.c -o build/tree-sitter-typescript-scanner.o
@@ -158,10 +158,10 @@ jobs:
             exit 1
           fi
 
-      - name: Build tree-sitter TypeScript objects
+      - name: Build tree-sitter TSX objects
         run: |
           mkdir -p build
-          TS_SRC=node_modules/tree-sitter-typescript/typescript/src
+          TS_SRC=node_modules/tree-sitter-typescript/tsx/src
           TS_INCLUDE=node_modules/tree-sitter-typescript
           clang -c -O2 -fPIC -I $TS_SRC -I $TS_INCLUDE $TS_SRC/parser.c -o build/tree-sitter-typescript-parser.o
           clang -c -O2 -fPIC -I $TS_SRC -I $TS_INCLUDE $TS_SRC/scanner.c -o build/tree-sitter-typescript-scanner.o

.github/workflows/cross-compile.yml

@@ -37,7 +37,7 @@ jobs:
       - name: Build tree-sitter objects
         run: |
           mkdir -p build
-          TS_SRC=node_modules/tree-sitter-typescript/typescript/src
+          TS_SRC=node_modules/tree-sitter-typescript/tsx/src
           TS_INCLUDE=node_modules/tree-sitter-typescript
           clang -c -O2 -fPIC -I $TS_SRC -I $TS_INCLUDE $TS_SRC/parser.c -o build/tree-sitter-typescript-parser.o
           clang -c -O2 -fPIC -I $TS_SRC -I $TS_INCLUDE $TS_SRC/scanner.c -o build/tree-sitter-typescript-scanner.o

src/analysis/semantic-analyzer.ts

@@ -305,6 +305,9 @@ export class SemanticAnalyzer {
   }
 
   private analyzeFunction(func: FunctionNode): void {
+    // External declarations have no body to analyze
+    if (func.declare) return;
+
     this.currentFunction = func.name;
 
     this.checkFunctionUnionTypes(func.name, func.paramTypes, func.returnType);

src/ast/types.ts

@@ -409,6 +409,9 @@ export interface FunctionNode {
   async?: boolean;
   parameters?: FunctionParameter[];
   loc?: SourceLocation;
+  // External C function declaration (declare function foo(): void)
+  // When true, codegen emits LLVM `declare` instead of `define`, no _cs_ prefix
+  declare?: boolean;
 }
 
 export interface ClassMethod {

src/chad-native.ts

@@ -5,6 +5,9 @@ import {
   setTargetCpu,
   setTargetTriple,
   setVerbose,
+  addLinkObj,
+  addLinkLib,
+  addLinkPath,
 } from "./native-compiler-lib.js";
 import { getDtsContent } from "./codegen/stdlib/embedded-dts.js";
 import { ArgumentParser } from "./argparse.js";
@@ -62,6 +65,21 @@ parser.addScopedOption(
   "build,run,ir",
 );
 parser.addScopedOption("target-cpu", "", "Set LLVM target CPU", "native", "build,run,ir");
+parser.addScopedOption("link-obj", "", "Extra .o files to link (comma-separated)", "", "build,run");
+parser.addScopedOption(
+  "link-lib",
+  "",
+  "Extra libraries to link, -l flags (comma-separated)",
+  "",
+  "build,run",
+);
+parser.addScopedOption(
+  "link-path",
+  "",
+  "Extra library paths, -L flags (comma-separated)",
+  "",
+  "build,run",
+);
 parser.addPositional("input", "Input .ts or .js file");
 
 parser.parse(process.argv);
@@ -180,6 +198,35 @@ if (cpuOpt.length > 0) {
   setTargetCpu(cpuOpt);
 }
 
+// Parse extra linker flags (comma-separated lists)
+const linkObjOpt = parser.getOption("link-obj");
+if (linkObjOpt.length > 0) {
+  const parts = linkObjOpt.split(",");
+  let _loi = 0;
+  while (_loi < parts.length) {
+    addLinkObj(parts[_loi]);
+    _loi = _loi + 1;
+  }
+}
+const linkLibOpt = parser.getOption("link-lib");
+if (linkLibOpt.length > 0) {
+  const parts = linkLibOpt.split(",");
+  let _lli = 0;
+  while (_lli < parts.length) {
+    addLinkLib(parts[_lli]);
+    _lli = _lli + 1;
+  }
+}
+const linkPathOpt = parser.getOption("link-path");
+if (linkPathOpt.length > 0) {
+  const parts = linkPathOpt.split(",");
+  let _lpi = 0;
+  while (_lpi < parts.length) {
+    addLinkPath(parts[_lpi]);
+    _lpi = _lpi + 1;
+  }
+}
+
 const inputFile = parser.getPositional(0);
 if (inputFile.length === 0) {
   console.log("chad: error: no input files");

src/chad-node.ts

@@ -12,6 +12,9 @@ import {
   setTarget,
   setTargetCpu,
   setStaticLink,
+  addLinkObj,
+  addLinkLib,
+  addLinkPath,
 } from "./compiler.js";
 import { LogLevel, logger } from "./utils/logger.js";
 import { runInit } from "./codegen/stdlib/init-templates.js";
@@ -52,6 +55,21 @@ parser.addScopedOption(
   "build,run,ir",
 );
 parser.addScopedFlag("static", "", "Link statically", "build,run");
+parser.addScopedOption("link-obj", "", "Extra .o files to link (comma-separated)", "", "build,run");
+parser.addScopedOption(
+  "link-lib",
+  "",
+  "Extra libraries to link, -l flags (comma-separated)",
+  "",
+  "build,run",
+);
+parser.addScopedOption(
+  "link-path",
+  "",
+  "Extra library paths, -L flags (comma-separated)",
+  "",
+  "build,run",
+);
 parser.addPositional("input", "Input .ts or .js file");
 
 // Node's process.argv includes [node, script, ...] — skip both.
@@ -218,6 +236,14 @@ if (targetOpt) {
 const cpuOpt = parser.getOption("target-cpu");
 if (cpuOpt) setTargetCpu(cpuOpt);
 
+// Parse extra linker flags (comma-separated lists)
+const linkObjOpt = parser.getOption("link-obj");
+if (linkObjOpt) linkObjOpt.split(",").forEach((o) => addLinkObj(o));
+const linkLibOpt = parser.getOption("link-lib");
+if (linkLibOpt) linkLibOpt.split(",").forEach((l) => addLinkLib(l));
+const linkPathOpt = parser.getOption("link-path");
+if (linkPathOpt) linkPathOpt.split(",").forEach((p) => addLinkPath(p));
+
 if (command === "ir") {
   setEmitLLVMOnly(true);
   setKeepTemps(true);

src/codegen/expressions/calls.ts

@@ -627,16 +627,17 @@ export class CallExpressionGenerator {
       }
     }
 
+    // Declared functions (TS `declare function`) are external C symbols —
+    // use their real name without the _cs_ prefix
+    const mangledName =
+      func && func.declare ? resolvedFuncName : this.ctx.mangleUserName(resolvedFuncName);
+
     if (returnType === "void") {
-      this.ctx.emitCallVoid(`@${this.ctx.mangleUserName(resolvedFuncName)}`, argsList.join(", "));
+      this.ctx.emitCallVoid(`@${mangledName}`, argsList.join(", "));
       return "0";
     }
 
-    const temp = this.ctx.emitCall(
-      returnType,
-      `@${this.ctx.mangleUserName(resolvedFuncName)}`,
-      argsList.join(", "),
-    );
+    const temp = this.ctx.emitCall(returnType, `@${mangledName}`, argsList.join(", "));
 
     return temp;
   }

src/codegen/llvm-generator.ts

@@ -33,6 +33,7 @@ import {
   AwaitExpressionNode,
   BinaryNode,
   SourceLocation,
+  FunctionParameter,
 } from "../ast/types.js";
 import { BaseGenerator, SymbolKind, SymbolTable } from "./infrastructure/base-generator.js";
 import {
@@ -76,6 +77,8 @@ import {
   stripNullable,
   tsTypeToLlvm,
   tsTypeToLlvmJson,
+  mapReturnTypeToLLVM,
+  mapParamTypeToLLVM,
 } from "./infrastructure/type-system.js";
 import type { ResolvedType } from "./infrastructure/type-system.js";
 import { DiagnosticEngine } from "../diagnostics/engine.js";
@@ -1413,6 +1416,9 @@ export class LLVMGenerator extends BaseGenerator implements IGeneratorContext {
   private typeAliasesCount: number = 0;
 
   private usesTreeSitter: boolean = false;
+  // Tracks function names from user `declare function` to avoid duplicate
+  // LLVM declarations when a name overlaps with hardcoded runtime declarations
+  public declaredExternFunctions: Set<string>;
   public sourceCode: string = "";
   public filename: string = "";
 
@@ -1421,6 +1427,7 @@ export class LLVMGenerator extends BaseGenerator implements IGeneratorContext {
 
     // Initialize complex fields in constructor (field initializers don't work in native code)
     this.externalFunctions = new Set();
+    this.declaredExternFunctions = new Set();
     this.topLevelObjectVariables = new Map();
     this.globalVariables = new Map();
     this.importAliasNames = [];
@@ -2517,7 +2524,7 @@ export class LLVMGenerator extends BaseGenerator implements IGeneratorContext {
     if (this.usesTreeSitter) {
       const tsDecls = this.treesitterGen.generateDeclarations();
       if (tsDecls) {
-        irParts.push(tsDecls);
+        irParts.push(this.filterDuplicateDeclarations(tsDecls));
       }
       irParts.push("\n");
     }
@@ -2576,13 +2583,15 @@ export class LLVMGenerator extends BaseGenerator implements IGeneratorContext {
     }
 
     finalParts.push(
-      getLLVMDeclarations({
-        curl: this.usesCurl !== 0,
-        crypto: this.usesCrypto !== 0,
-        sqlite: this.usesSqlite !== 0,
-        testRunner: this.usesTestRunner !== 0,
-        targetOS: this.getTargetOS(),
-      }),
+      this.filterDuplicateDeclarations(
+        getLLVMDeclarations({
+          curl: this.usesCurl !== 0,
+          crypto: this.usesCrypto !== 0,
+          sqlite: this.usesSqlite !== 0,
+          testRunner: this.usesTestRunner !== 0,
+          targetOS: this.getTargetOS(),
+        }),
+      ),
     );
 
     if (this.usesCurl) {
@@ -2608,7 +2617,7 @@ export class LLVMGenerator extends BaseGenerator implements IGeneratorContext {
     if (this.usesMongoose) {
       const httpServerDecls = this.httpServerGen.generateDeclarations();
       if (httpServerDecls) {
-        finalParts.push(httpServerDecls);
+        finalParts.push(this.filterDuplicateDeclarations(httpServerDecls));
       }
       finalParts.push("\n");
     }
@@ -2621,15 +2630,15 @@ export class LLVMGenerator extends BaseGenerator implements IGeneratorContext {
     if (needsLibuv) {
       const libuvDecls = this.libuvGen.generateDeclarations(this.usesCurl !== 0);
       if (libuvDecls) {
-        finalParts.push(libuvDecls);
+        finalParts.push(this.filterDuplicateDeclarations(libuvDecls));
       }
       finalParts.push("\n");
     }
 
     if (needsPromise) {
       const promiseDecls = this.promiseGen.generateDeclarations();
       if (promiseDecls) {
-        finalParts.push(promiseDecls);
+        finalParts.push(this.filterDuplicateDeclarations(promiseDecls));
       }
       finalParts.push("\n");
     }
@@ -2689,6 +2698,36 @@ export class LLVMGenerator extends BaseGenerator implements IGeneratorContext {
     return finalParts;
   }
 
+  /**
+   * Remove `declare` lines whose function name is already in the
+   * user-declared extern set (from `declare function` in TS source).
+   * Prevents LLVM "invalid redefinition" errors when hardcoded runtime
+   * declarations overlap with user declarations.
+   */
+  private filterDuplicateDeclarations(ir: string): string {
+    if (this.declaredExternFunctions.size === 0) return ir;
+    const lines = ir.split("\n");
+    const filtered: string[] = [];
+    for (let dli = 0; dli < lines.length; dli++) {
+      const line = lines[dli];
+      if (line.startsWith("declare ")) {
+        const atIdx = line.indexOf("@");
+        if (atIdx !== -1) {
+          const rest = line.substring(atIdx + 1);
+          const parenIdx = rest.indexOf("(");
+          if (parenIdx !== -1) {
+            const fnName = rest.substring(0, parenIdx);
+            if (this.declaredExternFunctions.has(fnName)) {
+              continue;
+            }
+          }
+        }
+      }
+      filtered.push(line);
+    }
+    return filtered.join("\n");
+  }
+
   /**
    * Generates LLVM IR for a function declaration and implementation.
    * Handles parameter types, allocas, body code generation, and return.
@@ -2723,6 +2762,11 @@ export class LLVMGenerator extends BaseGenerator implements IGeneratorContext {
   }
 
   private generateFunction(func: FunctionNode): string {
+    // External C function declaration: emit LLVM `declare` with correct types,
+    // no _cs_ prefix (external symbols use their real C names)
+    if (func.declare) {
+      return this.generateDeclareFunction(func);
+    }
     if (this.debugInfoEnabled && func.name) {
       const line = this.getLocLine(func);
       this.currentSubprogramId = this.dbgCreateSubprogram(func.name, line);
@@ -2733,6 +2777,34 @@ export class LLVMGenerator extends BaseGenerator implements IGeneratorContext {
     return ir;
   }
 
+  /** Emit an LLVM `declare` for an external C function (from TS `declare function`). */
+  private generateDeclareFunction(func: FunctionNode): string {
+    const retType = func.returnType
+      ? mapReturnTypeToLLVM(func.returnType, this.isEnumType(func.returnType))
+      : "double";
+
+    const paramLlvmTypes: string[] = [];
+    if (func.paramTypes) {
+      for (let i = 0; i < func.paramTypes.length; i++) {
+        const pt = func.paramTypes[i];
+        paramLlvmTypes.push(
+          mapParamTypeToLLVM(pt, func.params[i] || "", this.isEnumType(stripNullable(pt)), false),
+        );
+      }
+    } else if (func.parameters) {
+      for (let i = 0; i < func.parameters.length; i++) {
+        const p = func.parameters[i] as FunctionParameter;
+        const pType = p.type || "number";
+        paramLlvmTypes.push(
+          mapParamTypeToLLVM(pType, p.name || "", this.isEnumType(stripNullable(pType)), false),
+        );
+      }
+    }
+
+    this.declaredExternFunctions.add(func.name);
+    return `declare ${retType} @${func.name}(${paramLlvmTypes.join(", ")})\n`;
+  }
+
   /**
    * Allocate stack space for a variable declaration.
    * Handles all variable types: strings, arrays, objects, maps, sets, regex, classes, Response, etc.