033425d0ed
PR go/91781
reflect: promote integer closure return to full word
The libffi library expects an integer return type to be promoted to a
full word. Implement that when returning from a closure written in Go.
This only matters on big-endian systems when returning an integer smaller
than the pointer size, which is why we didn't notice it until now.
Fixes https://gcc.gnu.org/PR91781.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/195858
From-SVN: r275813
102 lines
2.6 KiB
C
102 lines
2.6 KiB
C
// Copyright 2014 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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#include "runtime.h"
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#ifdef USE_LIBFFI
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#include "ffi.h"
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#if FFI_GO_CLOSURES
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#define USE_LIBFFI_CLOSURES
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#endif
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#endif /* defined(USE_LIBFFI) */
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/* Declare C functions with the names used to call from Go. */
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void makeFuncFFI(void *cif, void *impl)
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__asm__ (GOSYM_PREFIX "reflect.makeFuncFFI");
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#ifdef USE_LIBFFI_CLOSURES
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/* The function that we pass to ffi_prep_closure_loc. This calls the Go
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function ffiCall with the pointer to the arguments, the results area,
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and the closure structure. */
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extern void ffiCallbackGo(void *result, void **args, ffi_go_closure *closure,
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int32 wordsize, _Bool big_endian)
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__asm__ (GOSYM_PREFIX "reflect.ffiCallbackGo");
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extern void makefuncfficanrecover(Slice)
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__asm__ (GOSYM_PREFIX "runtime.makefuncfficanrecover");
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extern void makefuncreturning(void)
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__asm__ (GOSYM_PREFIX "runtime.makefuncreturning");
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static void ffi_callback (ffi_cif *, void *, void **, void *)
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__asm__ ("reflect.ffi_callback");
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static void
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ffi_callback (ffi_cif* cif __attribute__ ((unused)), void *results,
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void **args, void *closure)
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{
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Location locs[8];
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int n;
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int i;
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/* This function is called from some series of FFI closure functions
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called by a Go function. We want to see whether the caller of
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the closure functions can recover. Look up the stack and skip
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the FFI functions. */
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n = runtime_callers (1, &locs[0], sizeof locs / sizeof locs[0], true);
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for (i = 0; i < n; i++)
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{
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const byte *name;
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if (locs[i].function.len == 0)
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continue;
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if (locs[i].function.len < 4)
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break;
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name = locs[i].function.str;
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if (name[0] != 'f' || name[1] != 'f' || name[2] != 'i' || name[3] != '_')
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break;
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}
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if (i < n)
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{
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Slice s;
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s.__values = (void *) &locs[i];
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s.__count = n - i;
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s.__capacity = n - i;
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makefuncfficanrecover (s);
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}
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ffiCallbackGo(results, args, closure, sizeof(ffi_arg),
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__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__);
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if (i < n)
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makefuncreturning ();
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}
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/* Allocate an FFI closure and arrange to call ffi_callback. */
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void
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makeFuncFFI(void *cif, void *impl)
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{
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ffi_prep_go_closure(impl, (ffi_cif*)cif, ffi_callback);
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}
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#else /* !defined(USE_LIBFFI_CLOSURES) */
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void
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makeFuncFFI(void *cif __attribute__ ((unused)),
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void *impl __attribute__ ((unused)))
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{
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runtime_panicstring ("libgo built without FFI does not support "
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"reflect.MakeFunc");
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}
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#endif
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