IDebugControl3::ControlledOutputVaList method (dbgeng.h)

The ControlledOutputVaList method formats a string and sends the result to output callbacks that were registered with some of the engine's clients.

Syntax

HRESULT ControlledOutputVaList(
  [in] ULONG   OutputControl,
  [in] ULONG   Mask,
  [in] PCSTR   Format,
  [in] va_list Args
);

Parameters

[in] OutputControl

Specifies an output control that determines which client's output callbacks will receive the output. For possible values, see DEBUG_OUTCTL_XXX. For more information about output, see Input and Output.

[in] Mask

Specifies the output-type bit field. See DEBUG_OUTPUT_XXX for possible values.

[in] Format

Specifies the format string, as in printf. Typically, conversion characters work exactly as they do in C. For the floating-point conversion characters, the 64-bit argument is interpreted as a 32-bit floating-point number unless the l modifier is used.

The %p conversion character is supported, but it represents a pointer in a target's address space. It might not have any modifiers, and it uses the debugger's internal address formatting. The following additional conversion characters are supported.

Character Argument type Argument Text printed
%p ULONG64 Pointer in an address space. The value of the pointer.
%N DWORD_PTR (32 or 64 bits, depending on the host's architecture) Pointer in the host's virtual address space. The value of the pointer. (This is equivalent to the standard C %p character.)
%I ULONG64 Any 64-bit value. The specified value. If this is greater than 0xFFFFFFFF, it is printed as a 64-bit value; otherwise, it is printed as a 32-bit value.
%ma ULONG64 Address of a NULL-terminated ASCII string in the process's virtual address space. The specified string.
%mu ULONG64 Address of a NULL-terminated Unicode string in the process's virtual address space. The specified string.
%msa ULONG64 Address of an ANSI_STRING structure in the process's virtual address space. The specified string.
%msu ULONG64 Address of a UNICODE_STRING structure in the process's virtual address space. The specified string.
%y ULONG64 Address in the process's virtual address space of an item with symbol information. String that contains the name of the specified symbol (and displacement, if any).
%ly ULONG64 Address in the process's virtual address space of an item with symbol information. String that contains the name of the specified symbol (and displacement, if any), as well as any available source line information.
 

The %Y format specifier can be used to support the Debugger Markup Language (DML). For more information, see Customizing Debugger Output Using DML.

The following table summarizes the use of the %Y format specifier.

Character Argument type Argument Text printed
%Y{t} String Text Quoted string. Will convert text to DML if the output format (first arg) is DML.
%Y{T} String Text Quoted string. Will always convert text to DML regardless of the output format.
%Y{s} String Text Unquoted string. Will convert text to DML if the output format (first arg) is DML.
%Y{S} String Text Unquoted string. Will always convert text to DML regardless of the output format.
%Y{as} ULONG64 Debugger formatted pointer Adds either an empty string or 9 characters of spacing for padding the high 32-bit portion of debugger formatted pointer fields. The extra space outputs 9 spaces which includes the upper 8 zeros plus the ` character.
%Y{ps} ULONG64 Debugger formatted pointer Adds either an empty string or 8 characters of spacing for padding the high 32-bit portion of debugger formatted pointer fields.
%Y{l} ULONG64 Debugger formatted pointer Address as source line information.
 

This code snippet illustrates the use of the %Y format specifier.

HRESULT CALLBACK testout(_In_ PDEBUG_CLIENT pClient, _In_ PCWSTR /*pwszArgs*/)
{
    HRESULT hr = S_OK;

    ComPtr<IDebugControl4> spControl;
    IfFailedReturn(pClient->QueryInterface(IID_PPV_ARGS(&spControl)));

    spControl->ControlledOutputWide(DEBUG_OUTCTL_DML, DEBUG_OUTPUT_NORMAL, L"DML/NORMAL Y{t}: %Y{t}\n", L"Hello <World>");
    spControl->ControlledOutputWide(DEBUG_OUTCTL_DML, DEBUG_OUTPUT_NORMAL, L"DML/NORMAL Y{T}: %Y{T}\n", L"Hello <World>");
    spControl->ControlledOutputWide(DEBUG_OUTCTL_DML, DEBUG_OUTPUT_NORMAL, L"DML/NORMAL Y{s}: %Y{s}\n", L"Hello <World>");
    spControl->ControlledOutputWide(DEBUG_OUTCTL_DML, DEBUG_OUTPUT_NORMAL, L"DML/NORMAL Y{S}: %Y{S}\n", L"Hello <World>");

    spControl->ControlledOutputWide(0, DEBUG_OUTPUT_NORMAL, L"TEXT/NORMAL Y{t}: %Y{t}\n", L"Hello <World>");
    spControl->ControlledOutputWide(0, DEBUG_OUTPUT_NORMAL, L"TEXT/NORMAL Y{T}: %Y{T}\n", L"Hello <World>");
    spControl->ControlledOutputWide(0, DEBUG_OUTPUT_NORMAL, L"TEXT/NORMAL Y{s}: %Y{s}\n", L"Hello <World>");
    spControl->ControlledOutputWide(0, DEBUG_OUTPUT_NORMAL, L"TEXT/NORMAL Y{S}: %Y{S}\n", L"Hello <World>");

    spControl->ControlledOutputWide(DEBUG_OUTCTL_DML, DEBUG_OUTPUT_NORMAL, L"DML/NORMAL Y{a}: %Y{a}\n", (ULONG64)0x00007ffa7da163c0);
    spControl->ControlledOutputWide(DEBUG_OUTCTL_DML, DEBUG_OUTPUT_NORMAL, L"DML/NORMAL Y{as} 64bit   : '%Y{as}'\n", (ULONG64)0x00007ffa7da163c0);
    spControl->ControlledOutputWide(DEBUG_OUTCTL_DML, DEBUG_OUTPUT_NORMAL, L"DML/NORMAL Y{as} 32value : '%Y{as}'\n", (ULONG64)0x1);

    spControl->ControlledOutputWide(DEBUG_OUTCTL_DML, DEBUG_OUTPUT_NORMAL, L"DML/NORMAL Y{ps} 64bit   : '%Y{ps}'\n", (ULONG64)0x00007ffa7da163c0);
    spControl->ControlledOutputWide(DEBUG_OUTCTL_DML, DEBUG_OUTPUT_NORMAL, L"DML/NORMAL Y{ps} 32value : '%Y{ps}'\n", (ULONG64)0x1);

    spControl->ControlledOutputWide(DEBUG_OUTCTL_DML, DEBUG_OUTPUT_NORMAL, L"DML/NORMAL Y{l}: %Y{l}\n", (ULONG64)0x00007ffa7da163c0);

    return hr;

}

This sample code would generate the following output.

0:004> !testout
DML/NORMAL Y{t}: "Hello <World>"
DML/NORMAL Y{T}: "Hello <World>"
DML/NORMAL Y{s}: Hello <World>
DML/NORMAL Y{S}: Hello <World>
TEXT/NORMAL Y{t}: "Hello <World>"
TEXT/NORMAL Y{T}: &quot;Hello <World>&quot;
TEXT/NORMAL Y{s}: Hello <World>
TEXT/NORMAL Y{S}: Hello <World>
DML/NORMAL Y{a}: 00007ffa`7da163c0
DML/NORMAL Y{as} 64bit   : '         '
DML/NORMAL Y{as} 32value : '         '
DML/NORMAL Y{ps} 64bit   : '        '
DML/NORMAL Y{ps} 32value : '        '
DML/NORMAL Y{l}: [d:\th\minkernel\kernelbase\debug.c @ 443]

[in] Args

Specifies additional parameters that represent values to be inserted into the output during formatting. Args must be initialized using va_start. This method does not call va_end.

Return value

Return code Description
S_OK
The method was successful.
 

This method may also return error values. See Return Values for more details.

Remarks

When generating very large output strings, it is possible to reach the limits of the debugger engine or of the operating system. For example, some versions of the debugger engine have a 16K character limit for a single output. If you find that very large output is getting truncated, you might need to split your output into multiple requests.

The macros va_list, va_start, and va_end are defined in Stdarg.h.

Requirements

Requirement Value
Target Platform Desktop
Header dbgeng.h (include Dbgeng.h, Stdarg.h)

See also

ControlledOutput

IDebugControl

IDebugControl2

IDebugControl3

OutputVaList

dprintf