| /* buffers.h -- Version 1.11 */ |
| |
| /* The following abbreviations are used at start of parameter names |
| * to indicate the type of data: |
| * s string (char * or WCHAR *) [PV] |
| * sw wide string (WCHAR *) [PV] |
| * p pointer (usually to some structure) [PV] |
| * a array (packed array as in C) (usually of some structure) [PV] |
| * called a "vector" or "vect" in some places. |
| * n generic number [IV, UV, or NV] |
| * iv signed integral value [IV] |
| * u unsigned integral value [UV] |
| * d floating-point number (double) [NV] |
| * b boolean (bool) [IV] |
| * c count of items [UV] |
| * l length (in bytes) [UV] |
| * lw length in WCHARs [UV] |
| * h a handle [IV] |
| * r record (structure) [PV] |
| * sv Perl scalar (s, i, u, d, n, or rv) [SV] |
| * rv Perl reference (usually to scalar) [RV] |
| * hv reference to Perl hash [HV] |
| * av reference to Perl array [AV] |
| * cv Perl code reference [PVCV] |
| * |
| * Unusual combined types: |
| * pp single pointer (to non-Perl data) packed into string [PV] |
| * pap vector of pointers (to non-Perl data) packed into string [PV] |
| * |
| * Whether a parameter is for input data, output data, or both is usually |
| * not reflected by the data type prefix. In cases where this is not |
| * obvious nor reflected in the variable name proper, you can use |
| * the following in front of the data type prefix: |
| * i an input parameter given to API (usually omitted) |
| * o an Output parameter taken from API |
| * io Input given to API then overwritten with Output taken from API |
| */ |
| |
| /* Buffer arguments are usually followed by an argument (or two) specifying |
| * their size and/or returning the size of data written. The size can be |
| * measured in bytes ["lSize"] or in characters [for (char *) buffers such as |
| * for *A() routines, these sizes are also called "lSize", but are called |
| * "lwSize" for (WCHAR *) buffers, UNICODE strings, such as for *W() routines]. |
| * |
| * Before calling the actual C function, you must make sure the Perl variable |
| * actually has a big enough buffer allocated, and, if the user didn't want |
| * to specify a buffer size, set the buffer size to be correct. This is what |
| * the grow_*() macros are for. They also handle special meanings of the |
| * buffer size argument [described below]. |
| * |
| * Once the actual C function returns, you must set the Perl variable to know |
| * the size of the written data. This is what the trunc_*() macros are for. |
| * |
| * The size sometimes does and sometimes doesn't include the trailing '\0' |
| * [or L'\0'], so we always add or subtract 1 in the appropriate places so |
| * we don't care about this detail. |
| * |
| * A call may 1) request a pointer to the buffer size which means that |
| * the buffer size will be overwritten with the size of the data written; |
| * 2) have an extra argument which is a pointer to the place to write the |
| * size of the written data; 3) provide the size of the written data in |
| * the function's return value; 4) format the data so that the length |
| * can be determined by examining the data [such as with '\0'-terminated |
| * strings]; or 5) write fixed-length data [usually sizeof(STRUCT)]. |
| * This obviously determines what you should use in the trunc_*() macro |
| # to specify the size of the output value. |
| * |
| * The user can pass in an empty list reference, C<[]>, to indicate C<NULL> |
| * for the pointer to the buffer which means that they don't want that data. |
| * |
| * The user can pass in C<[]> or C<0> to indicate that they don't care about |
| * the buffer size [we aren't programming in C here, after all] and just try |
| * to get the data. This will work if either the buffer already allocated for |
| * the SV [scalar value] is large enough to hold the data or the API provides |
| * an easy way to determine the required size [and the XS code uses it]. |
| * |
| * If the user passes in a numeric value for a buffer size, then the XS |
| * code makes sure that the buffer is at least large enough to hold a value |
| * of that size and then passes in how large the buffer is. So the buffer |
| * size passed to the API call is the larger of the size requested by the |
| * user and the size of the buffer aleady allocated to the SV. |
| * |
| * The user can also pass in a string consisting of a leading "=" followed |
| * by digits for a buffer size. This means just use the size specified after |
| * the equals sign, even if the allocated buffer is larger. The XS code will |
| * still allocate a large enough buffer before the first call. |
| * |
| * If the function is nice enough to tell us that a buffer was too small |
| * [usually via ERROR_MORE_DATA] _and_ how large the buffer needs to be, |
| * then the XS code should enlarge the buffer(s) and repeat the call [once]. |
| * This resizing is _not_ done for buffers whose size was specified with a |
| * leading "=". |
| * |
| * Only grow_buf() and perhaps trunc_buf() can be used in a typemap file. |
| * The other macros would be used in the parameter declarations or INPUT: |
| * section [grow_*()], the INIT: section [init_*()], or the OUTPUT: section |
| * [trunc_*()]. |
| * |
| * Buffer arguments should be initialised with C<= NO_INIT> [or C<= NULL;>]. |
| * |
| * See also the F<typemap> file. C<oDWORD>, for example, is for an output- |
| * only parameter of type C<DWORD> and you should simply C<#define> it to be |
| * C<DWORD>. In F<typemap>, C<oDWORD> is treated differently than C<DWORD> |
| * in two ways. |
| * |
| * First, if C<undef> is passed in, a C<DWORD> could generate a warning |
| * when it gets converted to 0 while C<oDWORD> will never generate such a |
| * warning for C<undef>. This first difference doesn't apply if specific |
| * initialization is specified for the variable, as in C<= init_buf_l($var);>. |
| * In particular, the init_*() macros also convert C<undef> to 0 without |
| * ever producing a warning. |
| * |
| * Second, passing in a read-only SV for a C<oDWORD> parameter will generate |
| * a fatal error on output when we try to update the SV. For C<DWORD>, we |
| * won't update a read-only SV since passing in a literal constant for a |
| * buffer size is a useful thing to do even though it prevents us from |
| * returning the size of data written via that SV. Since we should use a |
| * trunc_*() macro to output the actual data, the user should be able to |
| * determine the size of data written based on the size of the scalar we |
| * output anyway. |
| * |
| * This second difference doesn't apply unless the parameter is listed in |
| * the OUTPUT: section without specific output instructions. We define |
| * no macros for outputting buffer length parameters so be careful to use |
| * C<oDWORD> [for example] for them if and only if they are output-only. |
| * |
| * Note that C<oDWORD> is the same as C<DWORD> in that, if a defined value |
| * is passed in, it is used [and can generate a warning if the value is |
| * "not numeric"]. So although C<oDWORD> is for output-only parameters, |
| * we still initialize the C variable before calling the API. This is good |
| * in case the parameter isn't always strictly output-only due to upgrades, |
| * bugs, etc. |
| * |
| * Here is a made-up example that shows several cases: |
| * |
| * # Actual GetDataW() returns length of data written to ioswName, not bool. |
| * bool |
| * GetDataW( ioswName, ilwName, oswText, iolwText, opJunk, opRec, ilRec, olRec ) |
| * WCHAR * ioswName = NO_INIT |
| * DWORD ilwName = NO_INIT |
| * WCHAR * oswText = NO_INIT |
| * DWORD &iolwText = init_buf_l($arg); |
| * void * opJunk = NO_INIT |
| * BYTE * opRec = NO_INIT |
| * DWORD ilRec = init_buf_l($arg); |
| * oDWORD &olRec |
| * PREINIT: |
| * DWORD olwName; |
| * INIT: |
| * grow_buf_lw( ioswName,ST(0), ilwName,ST(1) ); |
| * grow_buf_lw( oswText,ST(2), iolwText,ST(3) ); |
| * grow_buf_typ( opJunk,ST(4),void *, LONG_STRUCT_TYPEDEF ); |
| * grow_buf_l( opRec,ST(5),BYTE *, ilRec,ST(6) ); |
| * CODE: |
| * olwName= GetDataW( ioswName, ilwName, oswText, &iolwText, |
| * (LONG_STRUCT_TYPEDEF *)opJunk, opRec, &iolRec ); |
| * if( 0 == olwName && ERROR_MORE_DATA == GetLastError() |
| * && ( autosize(ST(1)) || autosize(ST(3)) || autosize(ST(6)) ) ) { |
| * if( autosize(ST(1)) ) |
| * grow_buf_lw( ioswName,ST(0), ilwName,ST(1) ); |
| * if( autosize(ST(3)) ) |
| * grow_buf_lw( oswText,ST(2), iolwText,ST(3) ); |
| * if( autosize(ST(6)) ) |
| * grow_buf_l( opRec,ST(5),BYTE *, iolRec,ST(6) ); |
| * olwName= GetDataW( ioswName, ilwName, oswText, &iolwText, |
| * (LONG_STRUCT_TYPEDEF *)opJunk, opRec, &iolRec ); |
| * } |
| * RETVAL= 0 != olwName; |
| * OUTPUT: |
| * RETVAL |
| * ioswName trunc_buf_lw( RETVAL, ioswName,ST(0), olwName ); |
| * oswText trunc_buf_lw( RETVAL, oswText,ST(2), iolwText ); |
| * iolwText |
| * opJunk trunc_buf_typ(RETVAL,opJunk,ST(4),LONG_STRUCT_TYPEDEF); |
| * opRec trunc_buf_l( RETVAL, opRec,ST(5), olRec ); |
| * olRec |
| * |
| * The above example would be more complex and less efficient if we used |
| * C<DWORD * iolwText> in place of C<DWORD &iolwText>. The only possible |
| * advantage would be that C<NULL> would be passed in for C<iolwText> if |
| * _both_ C<$oswText> and C<$iolwText> were specified as C<[]>. The *_pl*() |
| * macros are defined [and C<DWORD *> specified in F<typemap>] so we can |
| * handle those cases but it is usually better to use the *_l*() macros |
| * instead by specifying C<&> instead of C<*>. Using C<&> instead of C<*> |
| * is usually better when dealing with scalars, even if they aren't buffer |
| * sizes. But you must use C<*> if it is important for that parameter to |
| * be able to pass C<NULL> to the underlying API. |
| * |
| * In Win32API::, we try to use C<*> for buffer sizes of optional buffers |
| * and C<&> for buffer sizes of required buffers. |
| * |
| * For parameters that are pointers to things other than buffers or buffer |
| * sizes, we use C<*> for "important" parameters [so that using C<[]> |
| * generates an error rather than fetching the value and just throwing it |
| * away], and for optional parameters [in case specifying C<NULL> is or |
| * becomes important]. Otherwise we use C<&> [for "unimportant" but |
| * required parameters] so the user can specify C<[]> if they don't care |
| * about it. The output handle of an "open" routine is "important". |
| */ |
| |
| #ifndef Debug |
| # define Debug(list) /*Nothing*/ |
| #endif |
| |
| /*#ifndef CAST |
| *# ifdef __cplusplus |
| *# define CAST(type,expr) static_cast<type>(expr) |
| *# else*/ |
| # define CAST(type,expr) (type)(expr) |
| /*# endif |
| *#endif*/ |
| |
| /* Is an argument C<[]>, meaning we should pass C<NULL>? */ |
| #define null_arg(sv) ( SvROK(sv) && SVt_PVAV == SvTYPE(SvRV(sv)) \ |
| && -1 == av_len((AV*)SvRV(sv)) ) |
| |
| #define PV_or_null(sv) ( null_arg(sv) ? NULL : SvPV_nolen(sv) ) |
| |
| /* Minimum buffer size to use when no buffer existed: */ |
| #define MIN_GROW_SIZE 128 |
| |
| #ifdef Debug |
| /* Used in Debug() messages to show which macro call is involved: */ |
| #define string(arg) #arg |
| #endif |
| |
| /* Simplify using SvGROW() for byte-sized buffers: */ |
| #define lSvGROW(sv,n) SvGROW( sv, 0==(n) ? MIN_GROW_SIZE : (n)+1 ) |
| |
| /* Simplify using SvGROW() for WCHAR-sized buffers: */ |
| #define lwSvGROW(sv,n) CAST( WCHAR *, \ |
| SvGROW( sv, sizeof(WCHAR)*( 0==(n) ? MIN_GROW_SIZE : (n)+1 ) ) ) |
| |
| /* Whether the buffer size we got lets us change what buffer size we use: */ |
| #define autosize(sv) (!( SvOK(sv) && ! SvROK(sv) \ |
| && SvPV_nolen(sv) && '=' == *SvPV_nolen(sv) )) |
| |
| /* Get the IV/UV for a parameter that might be C<[]> or C<undef>: */ |
| #define optIV(sv) ( null_arg(sv) ? 0 : !SvOK(sv) ? 0 : SvIV(sv) ) |
| #define optUV(sv) ( null_arg(sv) ? 0 : !SvOK(sv) ? 0 : SvUV(sv) ) |
| |
| /* Allocate temporary storage that will automatically be freed later: */ |
| #ifndef TempAlloc /* Can be C<#define>d to be C<_alloca>, for example */ |
| # define TempAlloc( size ) sv_grow( sv_newmortal(), size ) |
| #endif |
| |
| /* Initialize a buffer size argument of type (DWORD *): */ |
| #define init_buf_pl( plSize, svSize, tpSize ) STMT_START { \ |
| if( null_arg(svSize) ) \ |
| plSize= NULL; \ |
| else { \ |
| STRLEN n_a; \ |
| *( plSize= CAST( tpSize, TempAlloc(sizeof(*plSize)) ) )= \ |
| autosize(svSize) ? optUV(svSize) \ |
| : strtoul( 1+SvPV(svSize,n_a), NULL, 10 ); \ |
| } } STMT_END |
| /* In INPUT section put ": init_buf_pl($var,$arg,$type);" after var name. */ |
| |
| /* Initialize a buffer size argument of type DWORD: */ |
| #define init_buf_l( svSize ) \ |
| ( null_arg(svSize) ? 0 : autosize(svSize) ? optUV(svSize) \ |
| : strtoul( 1+SvPV_nolen(svSize), NULL, 10 ) ) |
| /* In INPUT section put "= init_buf_l($arg);" after variable name. */ |
| |
| /* Lengths in WCHARs are initialized the same as lengths in bytes: */ |
| #define init_buf_plw init_buf_pl |
| #define init_buf_lw init_buf_l |
| |
| /* grow_buf_pl() and grow_buf_plw() are included so you can define |
| * parameters of type C<DWORD *>, for example. In practice, it is |
| * usually better to define such parameters as "DWORD &". */ |
| |
| /* Grow a buffer where we have a pointer to its size in bytes: */ |
| #define grow_buf_pl( sBuf,svBuf,tpBuf, plSize,svSize,tpSize ) STMT_START { \ |
| Debug(("grow_buf_pl( %s==0x%lX,[%s:%ld/%ld, %s==0x%lX:%ld,[%s )\n",\ |
| string(sBuf),sBuf,strchr(string(svBuf),'('),SvPOK(svBuf)? \ |
| SvCUR(svBuf):-1,SvPOK(svBuf)?SvLEN(svBuf):-1,string(plSize), \ |
| plSize,plSize?*plSize:-1,strchr(string(svSize),'('))); \ |
| if( null_arg(svBuf) ) { \ |
| sBuf= NULL; \ |
| } else { \ |
| STRLEN n_a; \ |
| if( NULL == plSize ) \ |
| *( plSize= CAST(tpSize,TempAlloc(sizeof(*plSize))) )= 0;\ |
| if( ! SvOK(svBuf) ) sv_setpvn(svBuf,"",0); \ |
| (void) SvPV_force( svBuf, n_a ); \ |
| sBuf= CAST( tpBuf, lSvGROW( svBuf, *plSize ) ); \ |
| if( autosize(svSize) ) *plSize= SvLEN(svBuf) - 1; \ |
| Debug(("more buf_pl( %s==0x%lX,[%s:%ld/%ld, %s==0x%lX:%ld,[%s )\n",\ |
| string(sBuf),sBuf,strchr(string(svBuf),'('),SvPOK(svBuf)? \ |
| SvCUR(svBuf):-1,SvPOK(svBuf)?SvLEN(svBuf):-1,string(plSize),\ |
| plSize,plSize?*plSize:-1,strchr(string(svSize),'('))); \ |
| } } STMT_END |
| |
| /* Grow a buffer where we have a pointer to its size in WCHARs: */ |
| #define grow_buf_plw( sBuf,svBuf, plwSize,svSize,tpSize ) STMT_START { \ |
| if( null_arg(svBuf) ) { \ |
| sBuf= NULL; \ |
| } else { \ |
| STRLEN n_a; \ |
| if( NULL == plwSize ) \ |
| *( plwSize= CAST(tpSize,TempAlloc(sizeof(*plwSize))) )= 0;\ |
| if( ! SvOK(svBuf) ) sv_setpvn(svBuf,"",0); \ |
| (void) SvPV_force( svBuf, n_a ); \ |
| sBuf= lwSvGROW( svBuf, *plwSize ); \ |
| if( autosize(svSize) ) \ |
| *plwSize= SvLEN(svBuf)/sizeof(WCHAR) - 1; \ |
| } } STMT_END |
| |
| /* Grow a buffer where we have its size in bytes: */ |
| #define grow_buf_l( sBuf,svBuf,tpBuf, lSize,svSize ) STMT_START { \ |
| if( null_arg(svBuf) ) { \ |
| sBuf= NULL; \ |
| } else { \ |
| STRLEN n_a; \ |
| if( ! SvOK(svBuf) ) sv_setpvn(svBuf,"",0); \ |
| (void) SvPV_force( svBuf, n_a ); \ |
| sBuf= CAST( tpBuf, lSvGROW( svBuf, lSize ) ); \ |
| if( autosize(svSize) ) lSize= SvLEN(svBuf) - 1; \ |
| } } STMT_END |
| |
| /* Grow a buffer where we have its size in WCHARs: */ |
| #define grow_buf_lw( swBuf,svBuf, lwSize,svSize ) STMT_START { \ |
| if( null_arg(svBuf) ) { \ |
| swBuf= NULL; \ |
| } else { \ |
| STRLEN n_a; \ |
| if( ! SvOK(svBuf) ) sv_setpvn(svBuf,"",0); \ |
| (void) SvPV_force( svBuf, n_a ); \ |
| swBuf= lwSvGROW( svBuf, lwSize ); \ |
| if( autosize(svSize) ) \ |
| lwSize= SvLEN(svBuf)/sizeof(WCHAR) - 1; \ |
| } } STMT_END |
| |
| /* Grow a buffer that contains the declared fixed data type: */ |
| #define grow_buf( pBuf,svBuf, tpBuf ) STMT_START { \ |
| if( null_arg(svBuf) ) { \ |
| pBuf= NULL; \ |
| } else { \ |
| STRLEN n_a; \ |
| if( ! SvOK(svBuf) ) sv_setpvn(svBuf,"",0); \ |
| (void) SvPV_force( svBuf, n_a ); \ |
| pBuf= CAST( tpBuf, SvGROW( svBuf, sizeof(*pBuf) ) ); \ |
| } } STMT_END |
| |
| /* Grow a buffer that contains a fixed data type other than that declared: */ |
| #define grow_buf_typ( pBuf,svBuf,tpBuf, Type ) STMT_START { \ |
| if( null_arg(svBuf) ) { \ |
| pBuf= NULL; \ |
| } else { \ |
| STRLEN n_a; \ |
| if( ! SvOK(svBuf) ) sv_setpvn(svBuf,"",0); \ |
| (void) SvPV_force( svBuf, n_a ); \ |
| pBuf= CAST( tpBuf, SvGROW( svBuf, sizeof(Type) ) ); \ |
| } } STMT_END |
| |
| /* Grow a buffer that contains a list of items of the declared data type: */ |
| #define grow_vect( pBuf,svBuf,tpBuf, cItems ) STMT_START { \ |
| if( null_arg(svBuf) ) { \ |
| pBuf= NULL; \ |
| } else { \ |
| STRLEN n_a; \ |
| if( ! SvOK(svBuf) ) sv_setpvn(svBuf,"",0); \ |
| (void) SvPV_force( svBuf, n_a ); \ |
| pBuf= CAST( tpBuf, SvGROW( svBuf, sizeof(*pBuf)*cItems ) ); \ |
| } } STMT_END |
| |
| /* If call succeeded, set data length to returned length (in bytes): */ |
| #define trunc_buf_l( bOkay, sBuf,svBuf, lSize ) STMT_START { \ |
| if( bOkay && NULL != sBuf ) { \ |
| SvPOK_only( svBuf ); \ |
| SvCUR_set( svBuf, lSize ); \ |
| } } STMT_END |
| |
| /* Same as above except we have a pointer to the returned length: */ |
| #define trunc_buf_pl( bOkay, sBuf,svBuf, plSize ) \ |
| trunc_buf_l( bOkay, sBuf,svBuf, *plSize ) |
| |
| /* If call succeeded, set data length to returned length (in WCHARs): */ |
| #define trunc_buf_lw( bOkay, sBuf,svBuf, lwSize ) STMT_START { \ |
| if( bOkay && NULL != sBuf ) { \ |
| SvPOK_only( svBuf ); \ |
| SvCUR_set( svBuf, (lwSize)*sizeof(WCHAR) ); \ |
| } } STMT_END |
| |
| /* Same as above except we have a pointer to the returned length: */ |
| #define trunc_buf_plw( bOkay, swBuf,svBuf, plwSize ) \ |
| trunc_buf_lw( bOkay, swBuf,svBuf, *plwSize ) |
| |
| /* Set data length for a buffer that contains the declared fixed data type: */ |
| #define trunc_buf( bOkay, pBuf,svBuf ) STMT_START { \ |
| if( bOkay && NULL != pBuf ) { \ |
| SvPOK_only( svBuf ); \ |
| SvCUR_set( svBuf, sizeof(*pBuf) ); \ |
| } } STMT_END |
| |
| /* Set data length for a buffer that contains some other fixed data type: */ |
| #define trunc_buf_typ( bOkay, pBuf,svBuf, Type ) STMT_START { \ |
| if( bOkay && NULL != pBuf ) { \ |
| SvPOK_only( svBuf ); \ |
| SvCUR_set( svBuf, sizeof(Type) ); \ |
| } } STMT_END |
| |
| /* Set length for buffer that contains list of items of the declared type: */ |
| #define trunc_vect( bOkay, pBuf,svBuf, cItems ) STMT_START { \ |
| if( bOkay && NULL != pBuf ) { \ |
| SvPOK_only( svBuf ); \ |
| SvCUR_set( svBuf, sizeof(*pBuf)*cItems ); \ |
| } } STMT_END |
| |
| /* Set data length for a buffer where a '\0'-terminate string was stored: */ |
| #define trunc_buf_z( bOkay, sBuf,svBuf ) STMT_START { \ |
| if( bOkay && NULL != sBuf ) { \ |
| SvPOK_only( svBuf ); \ |
| SvCUR_set( svBuf, strlen(sBuf) ); \ |
| } } STMT_END |
| |
| /* Set data length for a buffer where a L'\0'-terminate string was stored: */ |
| #define trunc_buf_zw( bOkay, sBuf,svBuf ) STMT_START { \ |
| if( bOkay && NULL != sBuf ) { \ |
| SvPOK_only( svBuf ); \ |
| SvCUR_set( svBuf, wcslen(sBuf)*sizeof(WCHAR) ); \ |
| } } STMT_END |
