feat: restrict //export different symbol names to baremetal targets only

- Modified cl/import.go to check LLGO_TARGET_BAREMETAL env var
- For baremetal targets: //export SymbolName allows different export name (TinyGo-style)
- For normal targets: //export SymbolName uses SymbolName as function name (standard Go)
- Set LLGO_TARGET_BAREMETAL=1 in internal/build/build.go when baremetal tag present
- Added test for normal targets in _demo/normal/export/
- Added CI test to verify both embedded and normal target behavior

Generated with [codeagent](https://github.com/qbox/codeagent)
Co-authored-by: luoliwoshang <51194195+luoliwoshang@users.noreply.github.com>

.github/workflows/export_test.sh

@@ -0,0 +1,117 @@
+#!/bin/bash
+
+# Test script for //export with different symbol names
+# This is essential for embedded development where hardware specifications require
+# specific symbol names (e.g., ARM Cortex-M interrupt handlers).
+
+set -e  # Exit on any error
+
+# Use current working directory (workflow already cd's to the test directory)
+WORK_DIR="$(pwd)"
+
+# Colors for output
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m' # No Color
+
+# Function to print colored output
+print_status() {
+    echo -e "${GREEN}[INFO]${NC} $1"
+}
+
+print_error() {
+    echo -e "${RED}[ERROR]${NC} $1"
+}
+
+# Check if llgo command is available
+if ! command -v llgo &> /dev/null; then
+    print_error "llgo command not found, please install llgo first"
+    exit 1
+fi
+
+# Check if LLGO_ROOT is set
+if [[ -z "$LLGO_ROOT" ]]; then
+    print_error "LLGO_ROOT environment variable is not set"
+    exit 1
+fi
+
+print_status "Starting export symbol name test..."
+print_status "Working directory: $WORK_DIR"
+print_status "LLGO_ROOT: $LLGO_ROOT"
+
+echo ""
+
+# Build the test program
+print_status "=== Building test program ==="
+if llgo build -o test_export main.go; then
+    print_status "Build succeeded"
+else
+    print_error "Build failed"
+    exit 1
+fi
+
+# Check for expected symbols using nm
+print_status "=== Checking exported symbols with nm ==="
+if ! command -v nm &> /dev/null; then
+    print_error "nm command not found, skipping symbol verification"
+    exit 1
+fi
+
+NM_OUTPUT=$(nm test_export)
+
+# Verify LPSPI2_IRQHandler symbol exists (not interruptLPSPI2)
+if echo "$NM_OUTPUT" | grep -q "LPSPI2_IRQHandler"; then
+    print_status "✓ Symbol LPSPI2_IRQHandler found"
+else
+    print_error "✗ Symbol LPSPI2_IRQHandler not found"
+    echo "Available symbols:"
+    echo "$NM_OUTPUT"
+    exit 1
+fi
+
+# Verify SysTick_Handler symbol exists (not systemTickHandler)
+if echo "$NM_OUTPUT" | grep -q "SysTick_Handler"; then
+    print_status "✓ Symbol SysTick_Handler found"
+else
+    print_error "✗ Symbol SysTick_Handler not found"
+    echo "Available symbols:"
+    echo "$NM_OUTPUT"
+    exit 1
+fi
+
+# Verify Add symbol exists (same name)
+if echo "$NM_OUTPUT" | grep -q "Add"; then
+    print_status "✓ Symbol Add found"
+else
+    print_error "✗ Symbol Add not found"
+    echo "Available symbols:"
+    echo "$NM_OUTPUT"
+    exit 1
+fi
+
+# Verify that the original function names are NOT exported as main symbols
+# (they should only appear as internal symbols, not as exported text symbols 'T')
+EXPORTED_SYMBOLS=$(echo "$NM_OUTPUT" | grep " T " || true)
+
+if echo "$EXPORTED_SYMBOLS" | grep -q "interruptLPSPI2"; then
+    print_error "✗ Unexpected exported symbol: interruptLPSPI2 (should be LPSPI2_IRQHandler)"
+    exit 1
+else
+    print_status "✓ interruptLPSPI2 not exported as main symbol"
+fi
+
+if echo "$EXPORTED_SYMBOLS" | grep -q "systemTickHandler"; then
+    print_error "✗ Unexpected exported symbol: systemTickHandler (should be SysTick_Handler)"
+    exit 1
+else
+    print_status "✓ systemTickHandler not exported as main symbol"
+fi
+
+echo ""
+print_status "=== All symbol name tests passed! ==="
+
+# Cleanup
+rm -f test_export
+
+print_status "Export symbol name test completed successfully!"

.github/workflows/export_test_normal.sh

@@ -0,0 +1,101 @@
+#!/bin/bash
+
+# Test script for //export on normal (non-baremetal) targets
+# This ensures that //export with different symbol names does NOT work on normal targets
+
+set -e  # Exit on any error
+
+# Use current working directory (workflow already cd's to the test directory)
+WORK_DIR="$(pwd)"
+
+# Colors for output
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m' # No Color
+
+# Function to print colored output
+print_status() {
+    echo -e "${GREEN}[INFO]${NC} $1"
+}
+
+print_error() {
+    echo -e "${RED}[ERROR]${NC} $1"
+}
+
+# Check if llgo command is available
+if ! command -v llgo &> /dev/null; then
+    print_error "llgo command not found, please install llgo first"
+    exit 1
+fi
+
+# Check if LLGO_ROOT is set
+if [[ -z "$LLGO_ROOT" ]]; then
+    print_error "LLGO_ROOT environment variable is not set"
+    exit 1
+fi
+
+print_status "Starting export symbol name test for normal targets..."
+print_status "Working directory: $WORK_DIR"
+print_status "LLGO_ROOT: $LLGO_ROOT"
+
+echo ""
+
+# Build the test program
+print_status "=== Building test program ==="
+if llgo build -o test_export main.go; then
+    print_status "Build succeeded"
+else
+    print_error "Build failed"
+    exit 1
+fi
+
+# Check for expected symbols using nm
+print_status "=== Checking exported symbols with nm ==="
+if ! command -v nm &> /dev/null; then
+    print_error "nm command not found, skipping symbol verification"
+    exit 1
+fi
+
+NM_OUTPUT=$(nm test_export)
+
+# For normal targets, //export SymbolName should export the FUNCTION NAME, not the symbol name
+# So we expect LPSPI2_IRQHandler, SysTick_Handler, Add (the function names)
+
+# Verify LPSPI2_IRQHandler symbol exists (function name)
+if echo "$NM_OUTPUT" | grep -q "LPSPI2_IRQHandler"; then
+    print_status "✓ Symbol LPSPI2_IRQHandler found (function name)"
+else
+    print_error "✗ Symbol LPSPI2_IRQHandler not found"
+    echo "Available symbols:"
+    echo "$NM_OUTPUT"
+    exit 1
+fi
+
+# Verify SysTick_Handler symbol exists (function name)
+if echo "$NM_OUTPUT" | grep -q "SysTick_Handler"; then
+    print_status "✓ Symbol SysTick_Handler found (function name)"
+else
+    print_error "✗ Symbol SysTick_Handler not found"
+    echo "Available symbols:"
+    echo "$NM_OUTPUT"
+    exit 1
+fi
+
+# Verify Add symbol exists (same name)
+if echo "$NM_OUTPUT" | grep -q "Add"; then
+    print_status "✓ Symbol Add found"
+else
+    print_error "✗ Symbol Add not found"
+    echo "Available symbols:"
+    echo "$NM_OUTPUT"
+    exit 1
+fi
+
+echo ""
+print_status "=== All symbol name tests passed for normal targets! ==="
+
+# Cleanup
+rm -f test_export
+
+print_status "Export symbol name test for normal targets completed successfully!"

.github/workflows/llgo.yml

@@ -133,6 +133,20 @@ jobs:
           chmod +x test.sh
           ./test.sh
 
+      - name: Test export symbol names for embedded targets
+        run: |
+          echo "Testing //export with different symbol names for embedded development..."
+          chmod +x .github/workflows/export_test.sh
+          cd _demo/embed/export
+          bash ../../../.github/workflows/export_test.sh
+
+      - name: Test export symbol names for normal targets
+        run: |
+          echo "Testing //export behavior for normal (non-embedded) targets..."
+          chmod +x .github/workflows/export_test_normal.sh
+          cd _demo/normal/export
+          bash ../../../.github/workflows/export_test_normal.sh
+
       - name: _xtool build tests
         run: |
           cd _xtool

_demo/embed/export/main.go

@@ -0,0 +1,22 @@
+package main
+
+//export LPSPI2_IRQHandler
+func interruptLPSPI2() {
+	println("LPSPI2 interrupt handled")
+}
+
+//export SysTick_Handler
+func systemTickHandler() {
+	println("System tick")
+}
+
+//export Add
+func Add(a, b int) int {
+	return a + b
+}
+
+func main() {
+	interruptLPSPI2()
+	systemTickHandler()
+	println("Add(2, 3) =", Add(2, 3))
+}

_demo/normal/export/main.go

@@ -0,0 +1,22 @@
+package main
+
+//export LPSPI2_IRQHandler
+func LPSPI2_IRQHandler() {
+	println("LPSPI2 interrupt handled")
+}
+
+//export SysTick_Handler
+func SysTick_Handler() {
+	println("System tick")
+}
+
+//export Add
+func Add(a, b int) int {
+	return a + b
+}
+
+func main() {
+	LPSPI2_IRQHandler()
+	SysTick_Handler()
+	println("Add(2, 3) =", Add(2, 3))
+}

cl/import.go

@@ -278,7 +278,8 @@ func (p *context) initLinknameByDoc(doc *ast.CommentGroup, fullName, inPkgName s
 		for n := len(doc.List) - 1; n >= 0; n-- {
 			line := doc.List[n].Text
 			ret := p.initLinkname(line, func(name string) (_ string, _, ok bool) {
-				return fullName, isVar, name == inPkgName
+				// support empty name for //export directive
+				return fullName, isVar, name == inPkgName || name == ""
 			})
 			if ret != unknownDirective {
 				return ret == hasLinkname
@@ -312,10 +313,32 @@ func (p *context) initLinkname(line string, f func(inPkgName string) (fullName s
 		p.initLink(line, len(llgolink), false, f)
 		return hasLinkname
 	} else if strings.HasPrefix(line, export) {
-		// rewrite //export FuncName to //export FuncName FuncName
-		funcName := strings.TrimSpace(line[len(export):])
-		line = line + " " + funcName
-		p.initLink(line, len(export), true, f)
+		// support //export ExportName
+		// format: //export ExportName or //export FuncName ExportName
+		exportName := strings.TrimSpace(line[len(export):])
+		var inPkgName string
+		isBaremetal := os.Getenv("LLGO_TARGET_BAREMETAL") == "1"
+		if idx := strings.IndexByte(exportName, ' '); idx > 0 {
+			// format: //export FuncName ExportName (go-style)
+			inPkgName = exportName[:idx]
+			exportName = strings.TrimLeft(exportName[idx+1:], " ")
+		} else {
+			// format: //export ExportName (tinygo-style, only for baremetal targets)
+			if !isBaremetal {
+				// For non-baremetal targets, treat as function name (standard Go behavior)
+				inPkgName = exportName
+			} else {
+				// For baremetal targets, use empty string to match any function
+				inPkgName = ""
+			}
+		}
+		if fullName, _, ok := f(inPkgName); ok {
+			p.prog.SetLinkname(fullName, exportName)
+			p.pkg.SetExport(fullName, exportName)
+		} else {
+			fmt.Fprintln(os.Stderr, "==>", line)
+			fmt.Fprintf(os.Stderr, "llgo: export %s not found and ignored\n", inPkgName)
+		}
 		return hasLinkname
 	} else if strings.HasPrefix(line, directive) {
 		// skip unknown annotation but continue to parse the next annotation

internal/build/build.go

@@ -222,6 +222,13 @@ func Do(args []string, conf *Config) ([]Package, error) {
 	}
 	if len(export.BuildTags) > 0 {
 		tags += "," + strings.Join(export.BuildTags, ",")
+		// Set environment variable if building for baremetal target
+		for _, tag := range export.BuildTags {
+			if tag == "baremetal" {
+				os.Setenv("LLGO_TARGET_BAREMETAL", "1")
+				break
+			}
+		}
 	}
 	cfg := &packages.Config{
 		Mode:       loadSyntax | packages.NeedDeps | packages.NeedModule | packages.NeedExportFile,