compiler: improve debug info to cover initialization

compiler/compiler.go

@@ -362,9 +362,15 @@ func (c *Compiler) Compile(mainPath string) error {
 
 	// After all packages are imported, add a synthetic initializer function
 	// that calls the initializer of each package.
-	initFn := c.mod.NamedFunction("runtime.initAll")
-	initFn.SetLinkage(llvm.InternalLinkage)
-	block := c.ctx.AddBasicBlock(initFn, "entry")
+	initFn := c.ir.GetFunction(c.ir.Program.ImportedPackage("runtime").Members["initAll"].(*ssa.Function))
+	initFn.LLVMFn.SetLinkage(llvm.InternalLinkage)
+	difunc, err := c.attachDebugInfo(initFn)
+	if err != nil {
+		return err
+	}
+	pos := c.ir.Program.Fset.Position(initFn.Pos())
+	c.builder.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
+	block := c.ctx.AddBasicBlock(initFn.LLVMFn, "entry")
 	c.builder.SetInsertPointAtEnd(block)
 	for _, fn := range c.initFuncs {
 		c.builder.CreateCall(fn, nil, "")
@@ -811,6 +817,17 @@ func (c *Compiler) parseFuncDecl(f *ir.Function) (*Frame, error) {
 
 	if c.Debug && f.Syntax() != nil && len(f.Blocks) != 0 {
 		// Create debug info file if needed.
+		difunc, err := c.attachDebugInfo(f)
+		if err != nil {
+			return nil, err
+		}
+		frame.difunc = difunc
+	}
+
+	return frame, nil
+}
+
+func (c *Compiler) attachDebugInfo(f *ir.Function) (llvm.Metadata, error) {
 	pos := c.ir.Program.Fset.Position(f.Syntax().Pos())
 	if _, ok := c.difiles[pos.Filename]; !ok {
 		dir, file := filepath.Split(pos.Filename)
@@ -822,7 +839,7 @@ func (c *Compiler) parseFuncDecl(f *ir.Function) (*Frame, error) {
 	for _, param := range f.Params {
 		ditype, err := c.getDIType(param.Type())
 		if err != nil {
-				return nil, err
+			return llvm.Metadata{}, err
 		}
 		diparams = append(diparams, ditype)
 	}
@@ -831,7 +848,7 @@ func (c *Compiler) parseFuncDecl(f *ir.Function) (*Frame, error) {
 		Parameters: diparams,
 		Flags:      0, // ?
 	})
-		frame.difunc = c.dibuilder.CreateFunction(c.difiles[pos.Filename], llvm.DIFunction{
+	difunc := c.dibuilder.CreateFunction(c.difiles[pos.Filename], llvm.DIFunction{
 		Name:         f.RelString(nil),
 		LinkageName:  f.LinkName(),
 		File:         c.difiles[pos.Filename],
@@ -843,10 +860,8 @@ func (c *Compiler) parseFuncDecl(f *ir.Function) (*Frame, error) {
 		Flags:        llvm.FlagPrototyped,
 		Optimized:    true,
 	})
-		frame.fn.LLVMFn.SetSubprogram(frame.difunc)
-	}
-
-	return frame, nil
+	f.LLVMFn.SetSubprogram(difunc)
+	return difunc, nil
 }
 
 // Create a new global hashmap bucket, for map initialization.