runtime: unify 386 entry point code

Unify the 386 entry point code as much as possible.

The main function could not be unified because on Windows 386 it is
called _main. Putting main in asm_386.s caused multiple definition
errors when using the external linker.

Add the _lib entry point to various operating systems.  A future CL
will enable c-archive/c-shared mode for those targets.

Fix _rt0_386_windows_lib_go--it was passing arguments as though it
were amd64.

Change-Id: Ic73f1c95cdbcbea87f633f4a29bbc218a5db4f58
Reviewed-on: https://go-review.googlesource.com/70530
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

diff --git a/src/cmd/vet/all/whitelist/386.txt b/src/cmd/vet/all/whitelist/386.txt
index 5a6bde90c2828af1349baf658fd5b9186378d4e4..505856f36862190daf469dab9736866275884748 100644 (file)
--- a/src/cmd/vet/all/whitelist/386.txt
+++ b/src/cmd/vet/all/whitelist/386.txt
@@ -2,6 +2,10 @@
 
 runtime/asm_ARCHSUFF.s: [GOARCH] cannot check cross-package assembly function: Compare is in package bytes
 
+// startup code uses non-standard calling convention and intentionally
+// omits args.
+runtime/asm_386.s: [386] rt0_go: use of 4(SP) points beyond argument frame
+
 // reflect trampolines intentionally omit arg size. Same for morestack.
 runtime/asm_386.s: [386] morestack: use of 4(SP) points beyond argument frame
 runtime/asm_386.s: [386] morestack: use of 8(SP) points beyond argument frame
@@ -21,7 +25,3 @@ runtime/asm_386.s: [386] uint32tofloat64: function uint32tofloat64 missing Go de
 runtime/asm_386.s: [386] float64touint32: function float64touint32 missing Go declaration
 
 runtime/asm_386.s: [386] stackcheck: function stackcheck missing Go declaration
-
-// Clearer using FP than SP, but that requires named offsets.
-runtime/asm_386.s: [386] rt0_go: unknown variable argc
-runtime/asm_386.s: [386] rt0_go: unknown variable argv

diff --git a/src/runtime/asm_386.s b/src/runtime/asm_386.s
index f3b927f0b7001f0d64df70522c1669285258bccb..319b61579a4978cfc6aef27c2b5c668567592ec4 100644 (file)
--- a/src/runtime/asm_386.s
+++ b/src/runtime/asm_386.s
@@ -7,10 +7,87 @@
 #include "funcdata.h"
 #include "textflag.h"
 
+// _rt0_386 is common startup code for most 386 systems when using
+// internal linking. This is the entry point for the program from the
+// kernel for an ordinary -buildmode=exe program. The stack holds the
+// number of arguments and the C-style argv.
+TEXT _rt0_386(SB),NOSPLIT,$8
+       MOVL    8(SP), AX       // argc
+       LEAL    12(SP), BX      // argv
+       MOVL    AX, 0(SP)
+       MOVL    BX, 4(SP)
+       JMP     runtime·rt0_go(SB)
+
+// _rt0_386_lib is common startup code for most 386 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 on the stack following the
+// usual C ABI.
+TEXT _rt0_386_lib(SB),NOSPLIT,$0
+       PUSHL   BP
+       MOVL    SP, BP
+       PUSHL   BX
+       PUSHL   SI
+       PUSHL   DI
+
+       MOVL    8(BP), AX
+       MOVL    AX, _rt0_386_lib_argc<>(SB)
+       MOVL    12(BP), AX
+       MOVL    AX, _rt0_386_lib_argv<>(SB)
+
+       // Synchronous initialization.
+       CALL    runtime·libpreinit(SB)
+
+       SUBL    $8, SP
+
+       // Create a new thread to do the runtime initialization.
+       MOVL    _cgo_sys_thread_create(SB), AX
+       TESTL   AX, AX
+       JZ      nocgo
+       MOVL    $_rt0_386_lib_go(SB), BX
+       MOVL    BX, 0(SP)
+       MOVL    $0, 4(SP)
+
+       // TODO: We are calling a C function here so we should be
+       // aligning the stack.
+
+       CALL    AX
+       JMP     restore
+
+nocgo:
+       MOVL    $0x800000, 0(SP)                    // stacksize = 8192KB
+       MOVL    $_rt0_386_lib_go(SB), AX
+       MOVL    AX, 4(SP)                           // fn
+       CALL    runtime·newosproc0(SB)
+
+restore:
+       ADDL    $8, SP
+       POPL    DI
+       POPL    SI
+       POPL    BX
+       POPL    BP
+       RET
+
+// _rt0_386_lib_go initializes the Go runtime.
+// This is started in a separate thread by _rt0_386_lib.
+TEXT _rt0_386_lib_go(SB),NOSPLIT,$8
+       MOVL    _rt0_386_lib_argc<>(SB), AX
+       MOVL    AX, 0(SP)
+       MOVL    _rt0_386_lib_argv<>(SB), AX
+       MOVL    AX, 4(SP)
+       JMP     runtime·rt0_go(SB)
+
+DATA _rt0_386_lib_argc<>(SB)/4, $0
+GLOBL _rt0_386_lib_argc<>(SB),NOPTR, $4
+DATA _rt0_386_lib_argv<>(SB)/4, $0
+GLOBL _rt0_386_lib_argv<>(SB),NOPTR, $4
+
 TEXT runtime·rt0_go(SB),NOSPLIT,$0
-       // copy arguments forward on an even stack
-       MOVL    argc+0(FP), AX
-       MOVL    argv+4(FP), BX
+       // Copy arguments forward on an even stack.
+       // Users of this function jump to it, they don't call it.
+       MOVL    0(SP), AX
+       MOVL    4(SP), BX
        SUBL    $128, SP                // plenty of scratch
        ANDL    $~15, SP
        MOVL    AX, 120(SP)             // save argc, argv away

diff --git a/src/runtime/rt0_android_386.s b/src/runtime/rt0_android_386.s
index 9d20fc8f890e6176461dd2a60a40fe8da2b2ca02..eabdf812357c15d62f1e7f3086c99e682303a352 100644 (file)
--- a/src/runtime/rt0_android_386.s
+++ b/src/runtime/rt0_android_386.s
@@ -4,21 +4,13 @@
 
 #include "textflag.h"
 
-TEXT _rt0_386_android(SB),NOSPLIT,$8
-       MOVL    8(SP), AX  // argc
-       LEAL    12(SP), BX  // argv
-       MOVL    AX, 0(SP)
-       MOVL    BX, 4(SP)
-       CALL    main(SB)
-       INT     $3
+TEXT _rt0_386_android(SB),NOSPLIT,$0
+       JMP     _rt0_386(SB)
 
 TEXT _rt0_386_android_lib(SB),NOSPLIT,$0
        PUSHL   $_rt0_386_android_argv(SB)  // argv
        PUSHL   $1  // argc
-       CALL    _rt0_386_linux_lib(SB)
-       POPL    AX
-       POPL    AX
-       RET
+       JMP     _rt0_386_lib(SB)
 
 DATA _rt0_386_android_argv+0x00(SB)/4,$_rt0_386_android_argv0(SB)
 DATA _rt0_386_android_argv+0x04(SB)/4,$0  // argv terminate

diff --git a/src/runtime/rt0_darwin_386.s b/src/runtime/rt0_darwin_386.s
index 6b404db3a443df1dd0bbd15732e1f986033ecae1..a8d3a796d4b3aed3abfada4883a634da89199752 100644 (file)
--- a/src/runtime/rt0_darwin_386.s
+++ b/src/runtime/rt0_darwin_386.s
@@ -4,72 +4,14 @@
 
 #include "textflag.h"
 
-TEXT _rt0_386_darwin(SB),NOSPLIT,$8
-       MOVL    8(SP), AX
-       LEAL    12(SP), BX
-       MOVL    AX, 0(SP)
-       MOVL    BX, 4(SP)
-       CALL    main(SB)
-       INT     $3
+TEXT _rt0_386_darwin(SB),NOSPLIT,$0
+       JMP     _rt0_386(SB)
 
-// With -buildmode=c-archive, this symbol is called from a global constructor.
 TEXT _rt0_386_darwin_lib(SB),NOSPLIT,$0
-       PUSHL   BP
-       MOVL    SP, BP
-       PUSHL   BX
-       PUSHL   SI
-       PUSHL   DI
-
-       MOVL    8(BP), AX
-       MOVL    AX, _rt0_386_darwin_lib_argc<>(SB)
-       MOVL    12(BP), AX
-       MOVL    AX, _rt0_386_darwin_lib_argv<>(SB)
-
-       // Synchronous initialization.
-       MOVL    $runtime·libpreinit(SB), AX
-       CALL    AX
-
-       SUBL    $12, SP
-
-       // Create a new thread to do the runtime initialization and return.
-       MOVL    _cgo_sys_thread_create(SB), AX
-       TESTL   AX, AX
-       JZ      nocgo
-       MOVL    $_rt0_386_darwin_lib_go(SB), BX
-       MOVL    BX, 0(SP)
-       MOVL    $0, 4(SP)
-       CALL    AX
-       JMP     restore
-
-nocgo:
-       MOVL    $0x800000, 0(SP)               // stacksize = 8192KB
-       MOVL    $_rt0_386_darwin_lib_go(SB), AX
-       MOVL    AX, 4(SP)                      // fn
-       MOVL    $0, 8(SP)                      // fnarg
-       MOVL    $runtime·newosproc0(SB), AX
-       CALL    AX
-
-restore:
-       ADDL    $12, SP
-       POPL    DI
-       POPL    SI
-       POPL    BX
-       POPL    BP
-       RET
-
-TEXT _rt0_386_darwin_lib_go(SB),NOSPLIT,$12
-       MOVL    _rt0_386_darwin_lib_argc<>(SB), AX
-       MOVL    AX, 0(SP)
-       MOVL    _rt0_386_darwin_lib_argv<>(SB), AX
-       MOVL    AX, 4(SP)
-       MOVL    $runtime·rt0_go(SB), AX
-       CALL    AX
-       RET
-
-DATA _rt0_386_darwin_lib_argc<>(SB)/4, $0
-GLOBL _rt0_386_darwin_lib_argc<>(SB),NOPTR, $4
-DATA _rt0_386_darwin_lib_argv<>(SB)/4, $0
-GLOBL _rt0_386_darwin_lib_argv<>(SB),NOPTR, $4
+       JMP     _rt0_386_lib(SB)
 
 TEXT main(SB),NOSPLIT,$0
+       // Remove the return address from the stack.
+       // rt0_go doesn't expect it to be there.
+       ADDL    $4, SP
        JMP     runtime·rt0_go(SB)

diff --git a/src/runtime/rt0_freebsd_386.s b/src/runtime/rt0_freebsd_386.s
index cd7a915f843e340ea58e2638e8e831e78006c8c3..1808059838a270c80c5dc5f5825a8727fff0c79e 100644 (file)
--- a/src/runtime/rt0_freebsd_386.s
+++ b/src/runtime/rt0_freebsd_386.s
@@ -4,13 +4,14 @@
 
 #include "textflag.h"
 
-TEXT _rt0_386_freebsd(SB),NOSPLIT,$8
-       MOVL    8(SP), AX
-       LEAL    12(SP), BX
-       MOVL    AX, 0(SP)
-       MOVL    BX, 4(SP)
-       CALL    main(SB)
-       INT     $3
+TEXT _rt0_386_freebsd(SB),NOSPLIT,$0
+       JMP     _rt0_386(SB)
+
+TEXT _rt0_386_freebsd_lib(SB),NOSPLIT,$0
+       JMP     _rt0_386_lib(SB)
 
 TEXT main(SB),NOSPLIT,$0
+       // Remove the return address from the stack.
+       // rt0_go doesn't expect it to be there.
+       ADDL    $4, SP
        JMP     runtime·rt0_go(SB)

diff --git a/src/runtime/rt0_linux_386.s b/src/runtime/rt0_linux_386.s
index 23bfc98b100cddb5e647b8e40f09bd884f70fbaa..325066fc1db0223a1502cab6f160486b9c0dddcf 100644 (file)
--- a/src/runtime/rt0_linux_386.s
+++ b/src/runtime/rt0_linux_386.s
@@ -4,72 +4,14 @@
 
 #include "textflag.h"
 
-TEXT _rt0_386_linux(SB),NOSPLIT,$8
-       MOVL    8(SP), AX
-       LEAL    12(SP), BX
-       MOVL    AX, 0(SP)
-       MOVL    BX, 4(SP)
-       CALL    main(SB)
-       INT     $3
+TEXT _rt0_386_linux(SB),NOSPLIT,$0
+       JMP     _rt0_386(SB)
 
-// When building with -buildmode=c-shared, this symbol is called when the shared
-// library is loaded.
 TEXT _rt0_386_linux_lib(SB),NOSPLIT,$0
-       PUSHL   BP
-       MOVL    SP, BP
-       PUSHL   BX
-       PUSHL   SI
-       PUSHL   DI
-
-       MOVL    8(BP), AX
-       MOVL    AX, _rt0_386_linux_lib_argc<>(SB)
-       MOVL    12(BP), AX
-       MOVL    AX, _rt0_386_linux_lib_argv<>(SB)
-
-       // Synchronous initialization.
-       MOVL    $runtime·libpreinit(SB), AX
-       CALL    AX
-
-       SUBL    $8, SP
-
-       // Create a new thread to do the runtime initialization.
-       MOVL    _cgo_sys_thread_create(SB), AX
-       TESTL   AX, AX
-       JZ      nocgo
-       MOVL    $_rt0_386_linux_lib_go(SB), BX
-       MOVL    BX, 0(SP)
-       MOVL    $0, 4(SP)
-       CALL    AX
-       JMP     restore
-
-nocgo:
-       MOVL    $0x800000, 0(SP)                    // stacksize = 8192KB
-       MOVL    $_rt0_386_linux_lib_go(SB), AX
-       MOVL    AX, 4(SP)                           // fn
-       MOVL    $runtime·newosproc0(SB), AX
-       CALL    AX
-
-restore:
-       ADDL    $8, SP
-       POPL    DI
-       POPL    SI
-       POPL    BX
-       POPL    BP
-       RET
-
-TEXT _rt0_386_linux_lib_go(SB),NOSPLIT,$12
-       MOVL    _rt0_386_linux_lib_argc<>(SB), AX
-       MOVL    AX, 0(SP)
-       MOVL    _rt0_386_linux_lib_argv<>(SB), AX
-       MOVL    AX, 4(SP)
-       MOVL    $runtime·rt0_go(SB), AX
-       CALL    AX
-       RET
-
-DATA _rt0_386_linux_lib_argc<>(SB)/4, $0
-GLOBL _rt0_386_linux_lib_argc<>(SB),NOPTR, $4
-DATA _rt0_386_linux_lib_argv<>(SB)/4, $0
-GLOBL _rt0_386_linux_lib_argv<>(SB),NOPTR, $4
+       JMP     _rt0_386_lib(SB)
 
 TEXT main(SB),NOSPLIT,$0
+       // Remove the return address from the stack.
+       // rt0_go doesn't expect it to be there.
+       ADDL    $4, SP
        JMP     runtime·rt0_go(SB)

diff --git a/src/runtime/rt0_nacl_386.s b/src/runtime/rt0_nacl_386.s
index d4ba06306a5eb5f3fa697dae208f24f17464f0da..4c990022f1189d99821ae28d619e9be73e5b5e13 100644 (file)
--- a/src/runtime/rt0_nacl_386.s
+++ b/src/runtime/rt0_nacl_386.s
@@ -15,8 +15,10 @@ TEXT _rt0_386_nacl(SB),NOSPLIT,$8
        LEAL    argv+16(FP), BX
        MOVL    AX, 0(SP)
        MOVL    BX, 4(SP)
-       CALL    main(SB)
-       INT     $3
+       JMP     runtime·rt0_go(SB)
 
 TEXT main(SB),NOSPLIT,$0
+       // Remove the return address from the stack.
+       // rt0_go doesn't expect it to be there.
+       ADDL    $4, SP
        JMP     runtime·rt0_go(SB)

diff --git a/src/runtime/rt0_netbsd_386.s b/src/runtime/rt0_netbsd_386.s
index 70b8532538b671a461520065a3b1c15d1945e45f..cefc04a815aba7dc33a10f6f5f6e0194aabe66f8 100644 (file)
--- a/src/runtime/rt0_netbsd_386.s
+++ b/src/runtime/rt0_netbsd_386.s
@@ -4,13 +4,14 @@
 
 #include "textflag.h"
 
-TEXT _rt0_386_netbsd(SB),NOSPLIT,$8
-       MOVL    8(SP), AX
-       LEAL    12(SP), BX
-       MOVL    AX, 0(SP)
-       MOVL    BX, 4(SP)
-       CALL    main(SB)
-       INT     $3
+TEXT _rt0_386_netbsd(SB),NOSPLIT,$0
+       JMP     _rt0_386(SB)
+
+TEXT _rt0_386_netbsd_lib(SB),NOSPLIT,$0
+       JMP     _rt0_386_lib(SB)
 
 TEXT main(SB),NOSPLIT,$0
+       // Remove the return address from the stack.
+       // rt0_go doesn't expect it to be there.
+       ADDL    $4, SP
        JMP     runtime·rt0_go(SB)

diff --git a/src/runtime/rt0_openbsd_386.s b/src/runtime/rt0_openbsd_386.s
index f25d2e1cf0143977db0bf930e20bc755ed1b5fb3..959f4d655a4079bec1c8f1f34ba02b3c4198c3b0 100644 (file)
--- a/src/runtime/rt0_openbsd_386.s
+++ b/src/runtime/rt0_openbsd_386.s
@@ -4,13 +4,14 @@
 
 #include "textflag.h"
 
-TEXT _rt0_386_openbsd(SB),NOSPLIT,$8
-       MOVL    8(SP), AX
-       LEAL    12(SP), BX
-       MOVL    AX, 0(SP)
-       MOVL    BX, 4(SP)
-       CALL    main(SB)
-       INT     $3
+TEXT _rt0_386_openbsd(SB),NOSPLIT,$0
+       JMP     _rt0_386(SB)
+
+TEXT _rt0_386_openbsd_lib(SB),NOSPLIT,$0
+       JMP     _rt0_386_lib(SB)
 
 TEXT main(SB),NOSPLIT,$0
+       // Remove the return address from the stack.
+       // rt0_go doesn't expect it to be there.
+       ADDL    $4, SP
        JMP     runtime·rt0_go(SB)

diff --git a/src/runtime/rt0_plan9_386.s b/src/runtime/rt0_plan9_386.s
index cbbf245632cc9e32f1be7bb8513d5775dab78171..64716158f19807a1b4f8de1e6566c1dc0ff6d0bf 100644 (file)
--- a/src/runtime/rt0_plan9_386.s
+++ b/src/runtime/rt0_plan9_386.s
@@ -14,7 +14,7 @@ TEXT _rt0_386_plan9(SB),NOSPLIT,$12
        MOVL    AX, 0(SP)
        LEAL    inargv+0(FP), AX
        MOVL    AX, 4(SP)
-       CALL    runtime·rt0_go(SB)
+       JMP     runtime·rt0_go(SB)
 
 GLOBL _tos(SB), NOPTR, $4
 GLOBL _privates(SB), NOPTR, $4

diff --git a/src/runtime/rt0_windows_386.s b/src/runtime/rt0_windows_386.s
index b9407a9879472231095f9e6a7899732eb95ad14b..fa39edd787c3d5d71b2443e0ef0a49061f53cd54 100644 (file)
--- a/src/runtime/rt0_windows_386.s
+++ b/src/runtime/rt0_windows_386.s
@@ -4,13 +4,8 @@
 
 #include "textflag.h"
 
-TEXT _rt0_386_windows(SB),NOSPLIT,$12
-       MOVL    12(SP), AX
-       LEAL    16(SP), BX
-       MOVL    AX, 4(SP)
-       MOVL    BX, 8(SP)
-       MOVL    $-1, 0(SP) // return PC for main
-       JMP     _main(SB)
+TEXT _rt0_386_windows(SB),NOSPLIT,$0
+       JMP     _rt0_386(SB)
 
 // When building with -buildmode=(c-shared or c-archive), this
 // symbol is called. For dynamic libraries it is called when the
@@ -41,10 +36,12 @@ TEXT _rt0_386_windows_lib(SB),NOSPLIT,$0x1C
        RET
 
 TEXT _rt0_386_windows_lib_go(SB),NOSPLIT,$0
-       MOVL  $0, DI
-       MOVL    $0, SI
-       MOVL    $runtime·rt0_go(SB), AX
-       JMP     AX
+       PUSHL   $0
+       PUSHL   $0
+       JMP     runtime·rt0_go(SB)
 
 TEXT _main(SB),NOSPLIT,$0
+       // Remove the return address from the stack.
+       // rt0_go doesn't expect it to be there.
+       ADDL    $4, SP
        JMP     runtime·rt0_go(SB)