// Copyright 2020 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package ld import ( "cmd/internal/obj" "cmd/link/internal/loader" "cmd/link/internal/sym" "sync" ) type unresolvedSymKey struct { from loader.Sym // Symbol that referenced unresolved "to" to loader.Sym // Unresolved symbol referenced by "from" } type symNameFn func(s loader.Sym) string // ErrorReporter is used to make error reporting thread safe. type ErrorReporter struct { loader.ErrorReporter unresSyms map[unresolvedSymKey]bool unresMutex sync.Mutex SymName symNameFn } // errorUnresolved prints unresolved symbol error for rs that is referenced from s. func (reporter *ErrorReporter) errorUnresolved(ldr *loader.Loader, s, rs loader.Sym) { reporter.unresMutex.Lock() defer reporter.unresMutex.Unlock() if reporter.unresSyms == nil { reporter.unresSyms = make(map[unresolvedSymKey]bool) } k := unresolvedSymKey{from: s, to: rs} if !reporter.unresSyms[k] { reporter.unresSyms[k] = true name := ldr.SymName(rs) // Try to find symbol under another ABI. var reqABI, haveABI obj.ABI haveABI = ^obj.ABI(0) reqABI, ok := sym.VersionToABI(ldr.SymVersion(rs)) if ok { for abi := obj.ABI(0); abi < obj.ABICount; abi++ { v := sym.ABIToVersion(abi) if v == -1 { continue } if rs1 := ldr.Lookup(name, v); rs1 != 0 && ldr.SymType(rs1) != sym.Sxxx && ldr.SymType(rs1) != sym.SXREF { haveABI = abi } } } // Give a special error message for main symbol (see #24809). if name == "main.main" { reporter.Errorf(s, "function main is undeclared in the main package") } else if haveABI != ^obj.ABI(0) { reporter.Errorf(s, "relocation target %s not defined for %s (but is defined for %s)", name, reqABI, haveABI) } else { reporter.Errorf(s, "relocation target %s not defined", name) } } }