delve: add ppc64le support

Documentation/backend_test_health.md

@@ -13,11 +13,22 @@ Tests skipped by each supported backend:
  * 4 not implemented
 * linux/386/pie skipped = 1
  * 1 broken
+* linux/ppc64le skipped = 1
+ * 1 broken - cgo stacktraces
+* linux/ppc64le/native skipped = 1
+ * 1 broken in linux ppc64le
+* linux/ppc64le/native/pie skipped = 11
+ * 11 broken - pie mode
 * pie skipped = 2
  * 2 upstream issue - https://github.com/golang/go/issues/29322
+* ppc64le skipped = 11
+ * 6 broken
+ * 1 broken - global variable symbolication
+ * 4 not implemented
 * windows skipped = 4
  * 1 broken
  * 3 see https://github.com/go-delve/delve/issues/2768
-* windows/arm64 skipped = 4
+* windows/arm64 skipped = 5
  * 3 broken
+ * 1 broken - cgo stacktraces
  * 1 broken - step concurrent

_fixtures/asmnilptr/main_ppc64le.s

@@ -0,0 +1,7 @@
+#include "textflag.h"
+
+TEXT ·asmFunc(SB),0,$0-16
+ MOVD arg+0(FP), R5
+ MOVD (R5), R5
+ MOVD R5, ret+8(FP)
+ RET

_fixtures/cgostacktest/hello.c

@@ -6,6 +6,8 @@
 #define BREAKPOINT asm("int3;")
 #elif __i386__
 #define BREAKPOINT asm("int3;")
+#elif __PPC64__
+#define BREAKPOINT asm("tw 31,0,0;")
 #elif __aarch64__
 #ifdef WIN32
 #define BREAKPOINT asm("brk 0xF000;")

_scripts/make.go

@@ -291,6 +291,9 @@ func tagFlags() string {
  if runtime.GOOS == "windows" && runtime.GOARCH == "arm64" {
  tags = append(tags, "exp.winarm64")
  }
+ if runtime.GOOS == "linux" && runtime.GOARCH == "ppc64le" {
+ tags = append(tags, "exp.linuxppc64le")
+ }
  if Tags != nil && len(*Tags) > 0 {
  tags = append(tags, *Tags...)
  }

_scripts/test_linux.sh

@@ -76,3 +76,11 @@ else
  exit $x
 fi
 
+export GOARCH=ppc64le
+go run _scripts/make.go --tags exp.linuxppc64le
+x=$?
+if [ "$version" = "gotip" ]; then
+ exit 0
+else
+ exit $x
+fi

cmd/dlv/dlv_test.go

@@ -213,6 +213,9 @@ func getDlvBin(t *testing.T) string {
  if runtime.GOOS == "windows" && runtime.GOARCH == "arm64" {
  tags = "-tags=exp.winarm64"
  }
+ if runtime.GOOS == "linux" && runtime.GOARCH == "ppc64le" {
+ tags = "-tags=exp.linuxppc64le"
+ }
  return getDlvBinInternal(t, tags)
 }
 
@@ -371,6 +374,10 @@ func TestGeneratedDoc(t *testing.T) {
  //TODO(qmuntal): investigate further when the Windows ARM64 backend is more stable.
  t.Skip("skipping test on Windows in CI")
  }
+ if runtime.GOOS == "linux" && runtime.GOARCH == "ppc64le" {
+ //TODO(alexsaezm): finish CI integration
+ t.Skip("skipping test on Linux/PPC64LE in CI")
+ }
  // Checks gen-cli-docs.go
  var generatedBuf bytes.Buffer
  commands := terminal.DebugCommands(nil)

pkg/dwarf/regnum/ppc64le.go

@@ -0,0 +1,115 @@
+package regnum
+
+import "fmt"
+
+// The mapping between hardware registers and DWARF registers is specified
+// in the 64-Bit ELF V2 ABI Specification of the Power Architecture in section
+// 2.4 DWARF Definition
+// https://openpowerfoundation.org/specifications/64bitelfabi/
+
+const (
+ // General Purpose Registers: from R0 to R31
+ PPC64LE_FIRST_GPR = 0
+ PPC64LE_R0 = PPC64LE_FIRST_GPR
+ PPC64LE_LAST_GPR = 31
+ // Floating point registers: from F0 to F31
+ PPC64LE_FIRST_FPR = 32
+ PPC64LE_F0 = PPC64LE_FIRST_FPR
+ PPC64LE_LAST_FPR = 63
+ // Vector (Altivec/VMX) registers: from V0 to V31
+ PPC64LE_FIRST_VMX = 64
+ PPC64LE_V0 = PPC64LE_FIRST_VMX
+ PPC64LE_LAST_VMX = 95
+ // Vector Scalar (VSX) registers: from VS0 to VS63
+ PPC64LE_FIRST_VSX = 96
+ PPC64LE_VS0 = PPC64LE_FIRST_VSX
+ PPC64LE_LAST_VSX = 160
+ // Condition Registers: from CR0 to CR7
+ PPC64LE_CR0 = 0
+ // Special registers
+ PPC64LE_SP = 1 // Stack frame pointer: Gpr[1]
+ PPC64LE_PC = 12 // The documentation refers to this as the CIA (Current Instruction Address)
+ PPC64LE_LR = 65 // Link register
+)
+
+func PPC64LEToName(num uint64) string {
+ switch {
+ case num == PPC64LE_SP:
+ return "SP"
+ case num == PPC64LE_PC:
+ return "PC"
+ case num == PPC64LE_LR:
+ return "LR"
+ case isGPR(num):
+ return fmt.Sprintf("r%d", int(num-PPC64LE_FIRST_GPR))
+ case isFPR(num):
+ return fmt.Sprintf("f%d", int(num-PPC64LE_FIRST_FPR))
+ case isVMX(num):
+ return fmt.Sprintf("v%d", int(num-PPC64LE_FIRST_VMX))
+ case isVSX(num):
+ return fmt.Sprintf("vs%d", int(num-PPC64LE_FIRST_VSX))
+ default:
+ return fmt.Sprintf("unknown%d", num)
+ }
+}
+
+// PPC64LEMaxRegNum is 172 registers in total, across 4 categories:
+// General Purpose Registers or GPR (32 GPR + 9 special registers)
+// Floating Point Registers or FPR (32 FPR + 1 special register)
+// Altivec/VMX Registers or VMX (32 VMX + 2 special registers)
+// VSX Registers or VSX (64 VSX)
+// Documentation: https://lldb.llvm.org/cpp_reference/RegisterContextPOSIX__ppc64le_8cpp_source.html
+func PPC64LEMaxRegNum() uint64 {
+ return 172
+}
+
+func isGPR(num uint64) bool {
+ return num < PPC64LE_LAST_GPR
+}
+
+func isFPR(num uint64) bool {
+ return num >= PPC64LE_FIRST_FPR && num <= PPC64LE_LAST_FPR
+}
+
+func isVMX(num uint64) bool {
+ return num >= PPC64LE_FIRST_VMX && num <= PPC64LE_LAST_VMX
+}
+
+func isVSX(num uint64) bool {
+ return num >= PPC64LE_FIRST_VSX && num <= PPC64LE_LAST_VSX
+}
+
+var PPC64LENameToDwarf = func() map[string]int {
+ r := make(map[string]int)
+
+ r["nip"] = PPC64LE_PC
+ r["sp"] = PPC64LE_SP
+ r["bp"] = PPC64LE_SP
+ r["link"] = PPC64LE_LR
+
+ // General Purpose Registers: from R0 to R31
+ for i := 0; i <= 31; i++ {
+ r[fmt.Sprintf("r%d", i)] = PPC64LE_R0 + i
+ }
+
+ // Floating point registers: from F0 to F31
+ for i := 0; i <= 31; i++ {
+ r[fmt.Sprintf("f%d", i)] = PPC64LE_F0 + i
+ }
+
+ // Vector (Altivec/VMX) registers: from V0 to V31
+ for i := 0; i <= 31; i++ {
+ r[fmt.Sprintf("v%d", i)] = PPC64LE_V0 + i
+ }
+
+ // Vector Scalar (VSX) registers: from VS0 to VS63
+ for i := 0; i <= 63; i++ {
+ r[fmt.Sprintf("vs%d", i)] = PPC64LE_VS0 + i
+ }
+
+ // Condition Registers: from CR0 to CR7
+ for i := 0; i <= 7; i++ {
+ r[fmt.Sprintf("cr%d", i)] = PPC64LE_CR0 + i
+ }
+ return r
+}()

pkg/proc/arch.go

@@ -151,5 +151,6 @@ func nameToDwarfFunc(n2d map[string]int) func(string) (int, bool) {
 const (
  crosscall2SPOffsetBad = 0x8
  crosscall2SPOffsetWindowsAMD64 = 0x118
+ crosscall2SPOffsetLinuxPPC64LE = 0x158
  crosscall2SPOffset = 0x58
 )

pkg/proc/bininfo.go

@@ -129,6 +129,7 @@ var (
  elf.EM_X86_64: true,
  elf.EM_AARCH64: true,
  elf.EM_386: true,
+ elf.EM_PPC64: true,
  }
 
  supportedWindowsArch = map[_PEMachine]bool{
@@ -687,6 +688,8 @@ func NewBinaryInfo(goos, goarch string) *BinaryInfo {
  r.Arch = AMD64Arch(goos)
  case "arm64":
  r.Arch = ARM64Arch(goos)
+ case "ppc64le":
+ r.Arch = PPC64LEArch(goos)
  }
  return r
 }
@@ -1648,6 +1651,9 @@ func (bi *BinaryInfo) setGStructOffsetElf(image *Image, exe *elf.File, wg *sync.
 
  bi.gStructOffset = tlsg.Value + uint64(bi.Arch.PtrSize()*2) + ((tls.Vaddr - uint64(bi.Arch.PtrSize()*2)) & (tls.Align - 1))
 
+ case elf.EM_PPC64:
+ _ = getSymbol(image, bi.logger, exe, "runtime.tls_g")
+
  default:
  // we should never get here
  panic("architecture not supported")

pkg/proc/dump.go

@@ -136,6 +136,8 @@ func (t *Target) Dump(out elfwriter.WriteCloserSeeker, flags DumpFlags, state *D
  fhdr.Machine = elf.EM_386
  case "arm64":
  fhdr.Machine = elf.EM_AARCH64
+ case "ppc64le":
+ fhdr.Machine = elf.EM_PPC64
  default:
  panic("not implemented")
  }