Skip to content

Add CopyTo() to ReadOnlySpan<T> #3251

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
josesimoes merged 2 commits into from
Dec 12, 2025
Merged

Add CopyTo() to ReadOnlySpan<T> #3251

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
a7403ba
Add `CopyTo()` to `ReadOnlySpan<T>`
josesimoes Dec 12, 2025
5d1181e
Code style fixes
nfbot Dec 12, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 3 additions & 2 deletions src/CLR/CorLib/corlib_native.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -702,6 +702,7 @@ static const CLR_RT_MethodHandler method_lookup[] =
nullptr,
nullptr,
nullptr,
Library_corlib_native_System_ReadOnlySpan_1::CopyTo___VOID__SystemSpan_1,
nullptr,
nullptr,
nullptr,
Expand Down Expand Up @@ -1613,7 +1614,7 @@ const CLR_RT_NativeAssemblyData g_CLR_AssemblyNative_mscorlib =

#if (NANOCLR_REFLECTION == TRUE)

0xF1828DE7,
0x4619DD1E,

#elif (NANOCLR_REFLECTION == FALSE)

Expand All @@ -1624,7 +1625,7 @@ const CLR_RT_NativeAssemblyData g_CLR_AssemblyNative_mscorlib =
#endif

method_lookup,
{ 100, 22, 0, 0 }
{ 100, 22, 0, 1 }
};

// clang-format on
1 change: 1 addition & 0 deletions src/CLR/CorLib/corlib_native.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -786,6 +786,7 @@ struct Library_corlib_native_System_ReadOnlySpan_1
static const int FIELD___length = 2;

NANOCLR_NATIVE_DECLARE(_ctor___VOID__VOIDptr__I4);
NANOCLR_NATIVE_DECLARE(CopyTo___VOID__SystemSpan_1);
NANOCLR_NATIVE_DECLARE(NativeReadOnlySpanConstructor___VOID__SZARRAY_GENERICTYPE__I4__I4);

//--//
Expand Down
42 changes: 42 additions & 0 deletions src/CLR/CorLib/corlib_native_System_ReadOnlySpan_1.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@
#include "CorLib.h"

typedef Library_corlib_native_System_Runtime_CompilerServices_RuntimeHelpers RuntimeHelpers;
typedef Library_corlib_native_System_Span_1 Span_1;

HRESULT Library_corlib_native_System_ReadOnlySpan_1::_ctor___VOID__VOIDptr__I4(CLR_RT_StackFrame &stack)
{
Expand Down Expand Up @@ -105,6 +106,47 @@ HRESULT Library_corlib_native_System_ReadOnlySpan_1::_ctor___VOID__VOIDptr__I4(C
NANOCLR_NOCLEANUP();
}

HRESULT Library_corlib_native_System_ReadOnlySpan_1::CopyTo___VOID__SystemSpan_1(CLR_RT_StackFrame &stack)
{
NANOCLR_HEADER();

CLR_RT_HeapBlock_Array *sourceArray;
CLR_RT_HeapBlock_Array *destinationArray;
CLR_RT_HeapBlock *thisSpan = stack.This();
CLR_RT_HeapBlock *destinationSpan = stack.Arg1().Dereference();

// check lengths - destination must be at least as large as source
if (thisSpan[FIELD___length].NumericByRefConst().u4 >
destinationSpan[Span_1::FIELD___length].NumericByRefConst().u4)
{
NANOCLR_SET_AND_LEAVE(CLR_E_INVALID_PARAMETER);
}

// get pointers to the arrays
sourceArray = thisSpan[FIELD___array].DereferenceArray();
destinationArray = destinationSpan[Span_1::FIELD___array].DereferenceArray();

{
// sanity check for empty source array
if (thisSpan[FIELD___length].NumericByRefConst().s4 == 0)
{
NANOCLR_SET_AND_LEAVE(S_OK);
}

// prevent GC from moving the arrays while we copy the data
CLR_RT_ProtectFromGC gc1(*sourceArray);
CLR_RT_ProtectFromGC gc2(*destinationArray);

// use memmove to safely handle potential overlapping memory regions
memmove(
destinationArray->GetElement(0),
sourceArray->GetElement(0),
thisSpan[FIELD___length].NumericByRefConst().s4 * sourceArray->m_sizeOfElement);
}

NANOCLR_NOCLEANUP();
}

HRESULT Library_corlib_native_System_ReadOnlySpan_1::NativeReadOnlySpanConstructor___VOID__SZARRAY_GENERICTYPE__I4__I4(
CLR_RT_StackFrame &stack)
{
Expand Down