// getBBName returns the name (or ID if unnamed) of a basic block.
func getBBName(v llvm.Value) (string, error) {
if !v.IsBasicBlock() {
return "", errutil.Newf("invalid value type; expected basic block, got %v", v.Type())
}
// Locate the name of a named basic block.
if name := v.Name(); len(name) > 0 {
return name, nil
}
// Locate the ID of an unnamed basic block by parsing the value dump in
// search for its basic block label.
//
// Example value dump:
// 0:
// br i1 true, label %1, label %2
//
// Each basic block is expected to have a label, which requires the
// "unnamed.patch" to be applied to the llvm.org/llvm/bindings/go/llvm code
// base.
s, err := hackDump(v)
if err != nil {
return "", errutil.Err(err)
}
tokens := lexer.ParseString(s)
if len(tokens) < 1 {
return "", errutil.Newf("unable to locate basic block label in %q", s)
}
tok := tokens[0]
if tok.Kind != token.Label {
return "", errutil.Newf("invalid token; expected %v, got %v", token.Label, tok.Kind)
}
return tok.Val, nil
}
// PushFunction creates debug metadata for the specified function,
// and pushes it onto the scope stack.
func (d *DIBuilder) PushFunction(fnptr llvm.Value, sig *types.Signature, pos token.Pos) {
var diFile llvm.Metadata
var line int
if file := d.fset.File(pos); file != nil {
d.fnFile = file.Name()
diFile = d.getFile(file)
line = file.Line(pos)
}
d.fn = d.builder.CreateFunction(d.scope(), llvm.DIFunction{
Name: fnptr.Name(), // TODO(axw) unmangled name?
LinkageName: fnptr.Name(),
File: diFile,
Line: line,
Type: d.DIType(sig),
IsDefinition: true,
})
fnptr.SetSubprogram(d.fn)
}
// Declare creates an llvm.dbg.declare call for the specified function
// parameter or local variable.
func (d *DIBuilder) Declare(b llvm.Builder, v ssa.Value, llv llvm.Value, paramIndex int) {
tag := tagAutoVariable
if paramIndex >= 0 {
tag = tagArgVariable
}
var diFile llvm.Value
var line int
if file := d.fset.File(v.Pos()); file != nil {
line = file.Line(v.Pos())
diFile = d.getFile(file)
}
localVar := d.builder.CreateLocalVariable(d.scope(), llvm.DILocalVariable{
Tag: tag,
Name: llv.Name(),
File: diFile,
Line: line,
ArgNo: paramIndex + 1,
Type: d.DIType(v.Type()),
})
expr := d.builder.CreateExpression(nil)
d.builder.InsertDeclareAtEnd(llv, localVar, expr, b.GetInsertBlock())
}
// bridgeRecoverFunc creates a function that may call recover(), and creates
// a call to it from the current frame. The created function will be called
// with a boolean parameter that indicates whether it may call recover().
//
// The created function will have the same name as the current frame's function
// with "$recover" appended, having the same return types and parameters with
// an additional boolean parameter appended.
//
// A new frame will be returned for the newly created function.
func (fr *frame) bridgeRecoverFunc(llfn llvm.Value, fti functionTypeInfo) *frame {
// The bridging function must not be inlined, or the return address
// may not correspond to the source function.
llfn.AddFunctionAttr(llvm.NoInlineAttribute)
// Call __go_can_recover, passing in the function's return address.
entry := llvm.AddBasicBlock(llfn, "entry")
fr.builder.SetInsertPointAtEnd(entry)
canRecover := fr.runtime.canRecover.call(fr, fr.returnAddress(0))[0]
returnType := fti.functionType.ReturnType()
argTypes := fti.functionType.ParamTypes()
argTypes = append(argTypes, canRecover.Type())
// Create and call the $recover function.
ftiRecover := fti
ftiRecover.functionType = llvm.FunctionType(returnType, argTypes, false)
llfnRecover := ftiRecover.declare(fr.module.Module, llfn.Name()+"$recover")
fr.addCommonFunctionAttrs(llfnRecover)
llfnRecover.SetLinkage(llvm.InternalLinkage)
args := make([]llvm.Value, len(argTypes)-1, len(argTypes))
for i := range args {
args[i] = llfn.Param(i)
}
args = append(args, canRecover)
result := fr.builder.CreateCall(llfnRecover, args, "")
if returnType.TypeKind() == llvm.VoidTypeKind {
fr.builder.CreateRetVoid()
} else {
fr.builder.CreateRet(result)
}
// The $recover function must condition calls to __go_recover on
// the result of __go_can_recover passed in as an argument.
fr = newFrame(fr.unit, llfnRecover)
fr.retInf = ftiRecover.retInf
fr.canRecover = fr.function.Param(len(argTypes) - 1)
return fr
}
