IDebugExpressionEvaluator3::Parse2

项目
11/04/2016

Applies to: Visual Studio Visual Studio for Mac

Note

This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here

Converts an expression string to a parsed expression given the symbol provider and the address of the evaluating frame.

Syntax

HRESULT Parse2 (
    LPCOLESTR                upstrExpression,
    PARSEFLAGS               dwFlags,
    UINT                     nRadix,
    IDebugSymbolProvider*    pSymbolProvider,
    IDebugAddress*           pAddress,
    BSTR*                    pbstrError,
    UINT*                    pichError,
    IDebugParsedExpression** ppParsedExpression
);

HRESULT Parse2 (
    string                     upstrExpression,
    enum_PARSEFLAGS            dwFlags,
    uint                       nRadix,
    IDebugSymbolProvider       pSymbolProvider,
    IDebugAddress              pAddress,
    out string                 pbstrError,
    out uint                   pichError,
    out IDebugParsedExpression ppParsedExpression
);

Parameters

upstrExpression
[in] The expression string to be parsed.

dwFlags
[in] A collection of PARSEFLAGS constants that determine how the expression is to be parsed.

nRadix
[in] Radix to be used to interpret any numerical information.

pSymbolProvider
[in] Interface of the symbol provider.

pAddress
[in] Address of the evaluating frame.

pbstrError
[out] Returns the error as human-readable text.

pichError
[out] Returns the character position of the start of the error in the expression string.

ppParsedExpression
[out] Returns the parsed expression in an IDebugParsedExpression object.

Return Value

If successful, returns S_OK; otherwise, returns an error code.

Remarks

This method produces a parsed expression, not an actual value. A parsed expression is ready to be evaluated, that is, converted to a value.

Example

The following example shows how to implement this method for a CEE object that exposes the IDebugExpressionEvaluator3 interface.

HRESULT CEE::Parse2 ( LPCOLESTR in_szExprText,
  PARSEFLAGS in_FLAGS,
  UINT in_RADIX,
  IDebugSymbolProvider *pSymbolProvider,
  IDebugAddress *pAddress,
  BSTR* out_pbstrError,
  UINT* inout_pichError,
  IDebugParsedExpression** out_ppParsedExpression )
{
    // precondition
    REQUIRE( NULL != in_szExprText );
    //REQUIRE( NULL != out_pbstrError );
    REQUIRE( NULL != inout_pichError );
    REQUIRE( NULL != out_ppParsedExpression );

    if (NULL == in_szExprText)
        return E_INVALIDARG;

    if (NULL == inout_pichError)
        return E_POINTER;

    if (NULL == out_ppParsedExpression)
        return E_POINTER;

    if (out_pbstrError)
        *out_pbstrError = NULL;

    *out_ppParsedExpression = NULL;

    INVARIANT( this );

    if (!this->ClassInvariant())
        return E_UNEXPECTED;

    // function body
    EEDomain::fParseExpression DomainVal =
    {
        this,                   // CEE*
        in_szExprText,          // LPCOLESTR
        in_FLAGS,               // EVALFLAGS
        in_RADIX,               // RADIX
        out_pbstrError,         // BSTR*
        inout_pichError,        // UINT*
        pSymbolProvider,
        out_ppParsedExpression  // Output
    };

    return (*m_LanguageSpecificUseCases.pfParseExpression)(DomainVal);
}

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