go: cmd/link: external linking does not link dynamic libraries without cgo

https://golang.org/cl/232397 removes the cgo implementation from crypto/x509, which was preserved just for test purposes.

In doing so it seems to have broken external linking.

$ godev test crypto/x509 -ldflags=-linkmode=external
# crypto/x509.test
/Users/valsorda/go/pkg/tool/darwin_amd64/link: running clang failed: exit status 1
Undefined symbols for architecture x86_64:
  "_CFArrayGetCount", referenced from:
      _crypto/x509/internal/macos.x509_CFArrayGetCount_trampoline in go.o
  "_CFArrayGetValueAtIndex", referenced from:
      _crypto/x509/internal/macos.x509_CFArrayGetValueAtIndex_trampoline in go.o
  "_CFDataGetBytePtr", referenced from:
      _crypto/x509/internal/macos.x509_CFDataGetBytePtr_trampoline in go.o
  "_CFDataGetLength", referenced from:
      _crypto/x509/internal/macos.x509_CFDataGetLength_trampoline in go.o
  "_CFDictionaryGetValueIfPresent", referenced from:
      _crypto/x509/internal/macos.x509_CFDictionaryGetValueIfPresent_trampoline in go.o
  "_CFEqual", referenced from:
      _crypto/x509/internal/macos.x509_CFEqual_trampoline in go.o
  "_CFNumberGetValue", referenced from:
      _crypto/x509/internal/macos.x509_CFNumberGetValue_trampoline in go.o
  "_CFRelease", referenced from:
      _crypto/x509/internal/macos.x509_CFRelease_trampoline in go.o
  "_CFStringCreateWithBytes", referenced from:
      _crypto/x509/internal/macos.x509_CFStringCreateWithBytes_trampoline in go.o
  "_SecItemExport", referenced from:
      _crypto/x509/internal/macos.x509_SecItemExport_trampoline in go.o
  "_SecPolicyCopyProperties", referenced from:
      _crypto/x509/internal/macos.x509_SecPolicyCopyProperties_trampoline in go.o
  "_SecTrustSettingsCopyCertificates", referenced from:
      _crypto/x509/internal/macos.x509_SecTrustSettingsCopyCertificates_trampoline in go.o
  "_SecTrustSettingsCopyTrustSettings", referenced from:
      _crypto/x509/internal/macos.x509_SecTrustSettingsCopyTrustSettings_trampoline in go.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

https://storage.googleapis.com/go-build-log/14984eec/darwin-amd64-10_14_b0e9ceb1.log

I suppose the build was relying on the #cgo LDFLAGS: -framework CoreFoundation -framework Security line from the cgo file to bring in the dynamic libraries, even if it was not cgo to use them, as they were used via go:cgo_import_dynamic.

About this issue

Original URL
State: closed
Created 4 years ago
Comments: 15 (9 by maintainers)

Commits related to this issue

cmd/link: exit early when -d is used on libc platforms On platforms where we use libc for syscalls, we dynamically link with libc and therefore dynamic linking cannot be disabled. Exit early when -d ... — committed to golang/go by cherrymui 3 years ago

Most upvoted comments

Thanks. Yeah, we could make it a better and clearer error, or no-op.

cherrymui on Nov 18, 2021

@zchee the original issue is fixed. The fix was not elegant but unfortunately I couldn’t think of a better way. Closing. Thanks.

cherrymui on Aug 10, 2021

If you build a c-archive, when you link it into the final executable, try passing -framework CoreFoundation -framework Security flags to the C linker.

Since the final linking step is not controlled by the Go toolchain, unfortunately I don’t think there is anything we could do to help.

cherrymui on Aug 10, 2021

Hello @zchee

I don’t know if it can help you, but I have the same problem when I try to call a cgo lib with a call to “crypto/x509”. https://github.com/shenron/x509-go-ffi

tcastelly on Aug 10, 2021