cmd/link: enable c-shared and c-archive mode on s390x

Adding s390x to the list of architectures that support c-shared and c-archive.
Required adding load-time initialization (via _rt0_s390x_linux_lib) and adding s390x
to the c-shared and c-archive tests.

Change-Id: I75883b2891c310fe8ce7f08c27b06895c074e123
Reviewed-on: https://go-review.googlesource.com/74910
Reviewed-by: Michael Munday <mike.munday@ibm.com>

diff --git a/src/cmd/dist/test.go b/src/cmd/dist/test.go
index 69c85f046e56be90c1443de522233296965ca7aa..9053d6df7728c843918c44ecb75f633693ba118a 100644 (file)
--- a/src/cmd/dist/test.go
+++ b/src/cmd/dist/test.go
@@ -842,14 +842,14 @@ func (t *tester) supportedBuildmode(mode string) bool {
                }
                switch pair {
                case "darwin-386", "darwin-amd64", "darwin-arm", "darwin-arm64",
-                       "linux-amd64", "linux-386", "linux-ppc64le",
+                       "linux-amd64", "linux-386", "linux-ppc64le", "linux-s390x",
                        "windows-amd64", "windows-386":
                        return true
                }
                return false
        case "c-shared":
                switch pair {
-               case "linux-386", "linux-amd64", "linux-arm", "linux-arm64", "linux-ppc64le",
+               case "linux-386", "linux-amd64", "linux-arm", "linux-arm64", "linux-ppc64le", "linux-s390x",
                        "darwin-amd64", "darwin-386",
                        "android-arm", "android-arm64", "android-386",
                        "windows-amd64", "windows-386":

diff --git a/src/cmd/go/internal/work/init.go b/src/cmd/go/internal/work/init.go
index 425fa94c2ce80ecbe0a8caf0ab613ceac3bd2848..0e17286cf68921debb9a7011874c441d2ff20f2e 100644 (file)
--- a/src/cmd/go/internal/work/init.go
+++ b/src/cmd/go/internal/work/init.go
@@ -97,7 +97,7 @@ func buildModeInit() {
                        codegenArg = "-fPIC"
                } else {
                        switch platform {
-                       case "linux/amd64", "linux/arm", "linux/arm64", "linux/386", "linux/ppc64le",
+                       case "linux/amd64", "linux/arm", "linux/arm64", "linux/386", "linux/ppc64le", "linux/s390x",
                                "android/amd64", "android/arm", "android/arm64", "android/386":
                                codegenArg = "-shared"
                        case "darwin/amd64", "darwin/386":

diff --git a/src/cmd/link/internal/ld/config.go b/src/cmd/link/internal/ld/config.go
index 2f2f2b07b57fb3c4fbc5f3039ffd935d34854896..cc95392d772e767670dfe5a1e349d3c37131ea41 100644 (file)
--- a/src/cmd/link/internal/ld/config.go
+++ b/src/cmd/link/internal/ld/config.go
@@ -64,7 +64,7 @@ func (mode *BuildMode) Set(s string) error {
                *mode = BuildModeCArchive
        case "c-shared":
                switch objabi.GOARCH {
-               case "386", "amd64", "arm", "arm64", "ppc64le":
+               case "386", "amd64", "arm", "arm64", "ppc64le", "s390x":
                default:
                        return badmode()
                }

diff --git a/src/runtime/asm_s390x.s b/src/runtime/asm_s390x.s
index 487ed62306cce6e09b3046bc82bbd7eba6ab07ed..6b71830557707b64ae950f71d8b925e2d614710b 100644 (file)
--- a/src/runtime/asm_s390x.s
+++ b/src/runtime/asm_s390x.s
@@ -7,6 +7,83 @@
 #include "funcdata.h"
 #include "textflag.h"
 
+// _rt0_s390x_lib is common startup code for s390x systems when
+// using -buildmode=c-archive or -buildmode=c-shared. The linker will
+// arrange to invoke this function as a global constructor (for
+// c-archive) or when the shared library is loaded (for c-shared).
+// We expect argc and argv to be passed in the usual C ABI registers
+// R2 and R3.
+TEXT _rt0_s390x_lib(SB), NOSPLIT|NOFRAME, $0
+       STMG    R6, R15, 48(R15)
+       MOVD    R2, _rt0_s390x_lib_argc<>(SB)
+       MOVD    R3, _rt0_s390x_lib_argv<>(SB)
+
+       // Save R6-R15 in the register save area of the calling function.
+       STMG    R6, R15, 48(R15)
+
+       // Allocate 80 bytes on the stack.
+       MOVD    $-80(R15), R15
+
+       // Save F8-F15 in our stack frame.
+       FMOVD   F8, 16(R15)
+       FMOVD   F9, 24(R15)
+       FMOVD   F10, 32(R15)
+       FMOVD   F11, 40(R15)
+       FMOVD   F12, 48(R15)
+       FMOVD   F13, 56(R15)
+       FMOVD   F14, 64(R15)
+       FMOVD   F15, 72(R15)
+
+       // Synchronous initialization.
+       MOVD    $runtime·libpreinit(SB), R1
+       BL      R1
+
+       // Create a new thread to finish Go runtime initialization.
+       MOVD    _cgo_sys_thread_create(SB), R1
+       CMP     R1, $0
+       BEQ     nocgo
+       MOVD    $_rt0_s390x_lib_go(SB), R2
+       MOVD    $0, R3
+       BL      R1
+       BR      restore
+
+nocgo:
+       MOVD    $0x800000, R1              // stacksize
+       MOVD    R1, 0(R15)
+       MOVD    $_rt0_s390x_lib_go(SB), R1
+       MOVD    R1, 8(R15)                 // fn
+       MOVD    $runtime·newosproc(SB), R1
+       BL      R1
+
+restore:
+       // Restore F8-F15 from our stack frame.
+       FMOVD   16(R15), F8
+       FMOVD   24(R15), F9
+       FMOVD   32(R15), F10
+       FMOVD   40(R15), F11
+       FMOVD   48(R15), F12
+       FMOVD   56(R15), F13
+       FMOVD   64(R15), F14
+       FMOVD   72(R15), F15
+       MOVD    $80(R15), R15
+
+       // Restore R6-R15.
+       LMG     48(R15), R6, R15
+       RET
+
+// _rt0_s390x_lib_go initializes the Go runtime.
+// This is started in a separate thread by _rt0_s390x_lib.
+TEXT _rt0_s390x_lib_go(SB), NOSPLIT|NOFRAME, $0
+       MOVD    _rt0_s390x_lib_argc<>(SB), R2
+       MOVD    _rt0_s390x_lib_argv<>(SB), R3
+       MOVD    $runtime·rt0_go(SB), R1
+       BR      R1
+
+DATA _rt0_s390x_lib_argc<>(SB)/8, $0
+GLOBL _rt0_s390x_lib_argc<>(SB), NOPTR, $8
+DATA _rt0_s90x_lib_argv<>(SB)/8, $0
+GLOBL _rt0_s390x_lib_argv<>(SB), NOPTR, $8
+
 TEXT runtime·rt0_go(SB),NOSPLIT,$0
        // R2 = argc; R3 = argv; R11 = temp; R13 = g; R15 = stack pointer
        // C TLS base pointer in AR0:AR1

diff --git a/src/runtime/rt0_linux_s390x.s b/src/runtime/rt0_linux_s390x.s
index aedd6c7ef2dc9e9c101764551293ef0dec6bfd11..4b62c5a65ac7d564e38ef45ae280a078b2e2cc85 100644 (file)
--- a/src/runtime/rt0_linux_s390x.s
+++ b/src/runtime/rt0_linux_s390x.s
@@ -4,17 +4,20 @@
 
 #include "textflag.h"
 
-TEXT _rt0_s390x_linux(SB),NOSPLIT|NOFRAME,$0
+TEXT _rt0_s390x_linux(SB), NOSPLIT|NOFRAME, $0
        // In a statically linked binary, the stack contains argc,
        // argv as argc string pointers followed by a NULL, envv as a
        // sequence of string pointers followed by a NULL, and auxv.
        // There is no TLS base pointer.
-       //
-       // TODO: Support dynamic linking entry point
-       MOVD 0(R15), R2 // argc
-       ADD $8, R15, R3 // argv
-       BR main(SB)
 
-TEXT main(SB),NOSPLIT|NOFRAME,$0
-       MOVD    $runtime·rt0_go(SB), R11
-       BR      R11
+       MOVD 0(R15), R2  // argc
+       ADD  $8, R15, R3 // argv
+       BR   main(SB)
+
+TEXT _rt0_s390x_linux_lib(SB), NOSPLIT, $0
+       MOVD $_rt0_s390x_lib(SB), R1
+       BR   R1
+
+TEXT main(SB), NOSPLIT|NOFRAME, $0
+       MOVD $runtime·rt0_go(SB), R1
+       BR   R1