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Rewrite memory management of local RVTs

Browse Source 
The psvi slot of RVTs documents is used to store ownership information.

XSLT_RVT_LOCAL for RVTs that are destroyed after the current instructions
ends.

XSLT_RVT_VARIABLE for RVTs that are part of a local variable and are
destroyed after the variable goes out of scope.

XSLT_RVT_FUNC_RESULT for RVTs that are part of results returned with
func:result. These RVTs won't be destroyed after exiting a template and
will be reset to XSLT_RVT_LOCAL or XSLT_RVT_VARIABLE in the template
that receives the return value.

XSLT_RVT_GLOBAL for RVTs that are part of a global variable.

The function xsltFlagRVTs is used for the following ownership
transitions:

- LOCAL or VARIABLE to FUNC_RESULT when returning a value with
  func:result.
- FUNC_RESULT to LOCAL or VARIABLE when receiving a func:result.
- LOCAL to GLOBAL after evaluating global variables or parameters.

This obsoletes the element localRVTBase in the context struct and the
xsltExtensionInstructionResultRegister function. Aside from the
func:result implementation, the only reason for the old mechanism was
to protect RVTs (which can only be returned from extension functions)
in global variables from being destroyed too early. This is done
automatically now, so there's no need for extension authors to call
this function anymore.

The function xsltExtensionInstructionResultFinalize is unsupported
now. To the best of my knowledge, it isn't used outside of libxslt.

Another benefit is that, in some cases, RVTs are freed earlier now.

Also fixes bug #602531.
This commit is contained in:
Nick Wellnhofer
2016-04-20 11:50:07 +02:00
parent fe54d5e02b
commit 470b173461
15 changed files with 224 additions and 173 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
libexslt/common.c
View File

@@ -60,12 +60,6 @@ exsltNodeSetFunction (xmlXPathParserContextPtr ctxt, int nargs) {
xsltTransformError(tctxt, NULL, tctxt->inst, xsltTransformError(tctxt, NULL, tctxt->inst,
"exsltNodeSetFunction: Failed to create a node set object.\n"); "exsltNodeSetFunction: Failed to create a node set object.\n");
tctxt->state = XSLT_STATE_STOPPED; tctxt->state = XSLT_STATE_STOPPED;
} else {
/*
* Mark it as a function result in order to avoid garbage
* collecting of tree fragments
*/
xsltExtensionInstructionResultRegister(tctxt, obj);
} }
if (strval != NULL) if (strval != NULL)
xmlFree (strval); xmlFree (strval);

3
libexslt/dynamic.c
View File

@@ -216,7 +216,6 @@ exsltDynMapFunction(xmlXPathParserContextPtr ctxt, int nargs)
xmlXPathNodeSetAddUnique(ret->nodesetval, xmlXPathNodeSetAddUnique(ret->nodesetval,
cur); cur);
} }
xsltExtensionInstructionResultRegister(tctxt, ret);
} }
break; break;
case XPATH_NUMBER: case XPATH_NUMBER:
@@ -239,7 +238,6 @@ exsltDynMapFunction(xmlXPathParserContextPtr ctxt, int nargs)
xmlXPathNodeSetAddUnique(ret->nodesetval, xmlXPathNodeSetAddUnique(ret->nodesetval,
cur); cur);
} }
xsltExtensionInstructionResultRegister(tctxt, ret);
} }
break; break;
case XPATH_STRING: case XPATH_STRING:
@@ -257,7 +255,6 @@ exsltDynMapFunction(xmlXPathParserContextPtr ctxt, int nargs)
xmlXPathNodeSetAddUnique(ret->nodesetval, xmlXPathNodeSetAddUnique(ret->nodesetval,
cur); cur);
} }
xsltExtensionInstructionResultRegister(tctxt, ret);
} }
break; break;
default: default:

23
libexslt/functions.c
View File

@@ -35,7 +35,6 @@ struct _exsltFuncData {
xmlHashTablePtr funcs; /* pointer to the stylesheet module data */ xmlHashTablePtr funcs; /* pointer to the stylesheet module data */
xmlXPathObjectPtr result; /* returned by func:result */ xmlXPathObjectPtr result; /* returned by func:result */
int error; /* did an error occur? */ int error; /* did an error occur? */
xmlDocPtr RVT; /* result tree fragment */
}; };
typedef struct _exsltFuncResultPreComp exsltFuncResultPreComp; typedef struct _exsltFuncResultPreComp exsltFuncResultPreComp;
@@ -428,6 +427,12 @@ exsltFuncFunctionFunction (xmlXPathParserContextPtr ctxt, int nargs) {
if (data->result != NULL) { if (data->result != NULL) {
ret = data->result; ret = data->result;
/*
* IMPORTANT: This enables previously tree fragments marked as
* being results of a function, to be garbage-collected after
* the calling process exits.
*/
xsltFlagRVTs(tctxt, ret, XSLT_RVT_LOCAL);
} else } else
ret = xmlXPathNewCString(""); ret = xmlXPathNewCString("");
@@ -452,12 +457,6 @@ exsltFuncFunctionFunction (xmlXPathParserContextPtr ctxt, int nargs) {
valuePush(ctxt, ret); valuePush(ctxt, ret);
error: error:
/*
* IMPORTANT: This enables previously tree fragments marked as
* being results of a function, to be garbage-collected after
* the calling process exits.
*/
xsltExtensionInstructionResultFinalize(tctxt);
tctxt->funcLevel--; tctxt->funcLevel--;
} }
@@ -724,7 +723,7 @@ exsltFuncResultElem (xsltTransformContextPtr ctxt,
* Mark it as a function result in order to avoid garbage * Mark it as a function result in order to avoid garbage
* collecting of tree fragments before the function exits. * collecting of tree fragments before the function exits.
*/ */
xsltExtensionInstructionResultRegister(ctxt, ret); xsltFlagRVTs(ctxt, ret, XSLT_RVT_FUNC_RESULT);
} else if (inst->children != NULL) { } else if (inst->children != NULL) {
/* If the func:result element does not have a select attribute /* If the func:result element does not have a select attribute
* and has non-empty content (i.e. the func:result element has * and has non-empty content (i.e. the func:result element has
@@ -741,7 +740,8 @@ exsltFuncResultElem (xsltTransformContextPtr ctxt,
data->error = 1; data->error = 1;
return; return;
} }
xsltRegisterLocalRVT(ctxt, container); /* Mark as function result. */
container->psvi = XSLT_RVT_FUNC_RESULT;
oldInsert = ctxt->insert; oldInsert = ctxt->insert;
ctxt->insert = (xmlNodePtr) container; ctxt->insert = (xmlNodePtr) container;
@@ -756,11 +756,6 @@ exsltFuncResultElem (xsltTransformContextPtr ctxt,
data->error = 1; data->error = 1;
} else { } else {
ret->boolval = 0; /* Freeing is not handled there anymore */ ret->boolval = 0; /* Freeing is not handled there anymore */
/*
* Mark it as a function result in order to avoid garbage
* collecting of tree fragments before the function exits.
*/
xsltExtensionInstructionResultRegister(ctxt, ret);
} }
} else { } else {
/* If the func:result element has empty content and does not /* If the func:result element has empty content and does not

11
libexslt/strings.c
View File

@@ -111,11 +111,6 @@ exsltStrTokenizeFunction(xmlXPathParserContextPtr ctxt, int nargs)
xmlAddChild((xmlNodePtr) container, node); xmlAddChild((xmlNodePtr) container, node);
xmlXPathNodeSetAddUnique(ret->nodesetval, node); xmlXPathNodeSetAddUnique(ret->nodesetval, node);
} }
/*
* Mark it as a function result in order to avoid garbage
* collecting of tree fragments
*/
xsltExtensionInstructionResultRegister(tctxt, ret);
} }
} }
@@ -222,11 +217,6 @@ exsltStrSplitFunction(xmlXPathParserContextPtr ctxt, int nargs) {
xmlAddChild((xmlNodePtr) container, node); xmlAddChild((xmlNodePtr) container, node);
xmlXPathNodeSetAddUnique(ret->nodesetval, node); xmlXPathNodeSetAddUnique(ret->nodesetval, node);
} }
/*
* Mark it as a function result in order to avoid garbage
* collecting of tree fragments
*/
xsltExtensionInstructionResultRegister(tctxt, ret);
} }
} }
@@ -543,7 +533,6 @@ exsltStrReturnString(xmlXPathParserContextPtr ctxt, const xmlChar *str,
return(-1); return(-1);
} }
xsltExtensionInstructionResultRegister(tctxt, ret);
valuePush(ctxt, ret); valuePush(ctxt, ret);
return(0); return(0);

93
libxslt/transform.c
View File

@@ -56,6 +56,7 @@
#ifdef WITH_XSLT_DEBUG #ifdef WITH_XSLT_DEBUG
#define WITH_XSLT_DEBUG_EXTRA #define WITH_XSLT_DEBUG_EXTRA
#define WITH_XSLT_DEBUG_PROCESS #define WITH_XSLT_DEBUG_PROCESS
#define WITH_XSLT_DEBUG_VARIABLE
#endif #endif
#define XSLT_GENERATE_HTML_DOCTYPE #define XSLT_GENERATE_HTML_DOCTYPE
@@ -2299,30 +2300,28 @@ xsltReleaseLocalRVTs(xsltTransformContextPtr ctxt, xmlDocPtr base)
{ {
xmlDocPtr cur = ctxt->localRVT, tmp; xmlDocPtr cur = ctxt->localRVT, tmp;
while ((cur != NULL) && (cur != base)) { if (cur == base)
if (cur->psvi == (void *) ((long) 1)) { return;
cur = (xmlDocPtr) cur->next; if (cur->prev != NULL)
} else { xsltTransformError(ctxt, NULL, NULL, "localRVT not head of list\n");
tmp = cur;
cur = (xmlDocPtr) cur->next;
if (tmp == ctxt->localRVT) do {
ctxt->localRVT = cur; tmp = cur;
cur = (xmlDocPtr) cur->next;
if (tmp->psvi == XSLT_RVT_LOCAL) {
xsltReleaseRVT(ctxt, tmp);
} else if (tmp->psvi == XSLT_RVT_GLOBAL) {
xsltRegisterPersistRVT(ctxt, tmp);
} else if (tmp->psvi != XSLT_RVT_FUNC_RESULT) {
xmlGenericError(xmlGenericErrorContext,
"xsltReleaseLocalRVTs: Unexpected RVT flag %p\n",
tmp->psvi);
}
} while (cur != base);
/* if (base != NULL)
* We need ctxt->localRVTBase for extension instructions base->prev = NULL;
* which return values (like EXSLT's function). ctxt->localRVT = base;
*/
if (tmp == ctxt->localRVTBase)
ctxt->localRVTBase = cur;
if (tmp->prev)
tmp->prev->next = (xmlNodePtr) cur;
if (cur)
cur->prev = tmp->prev;
xsltReleaseRVT(ctxt, tmp);
}
}
} }
/** /**
@@ -2348,7 +2347,7 @@ xsltApplySequenceConstructor(xsltTransformContextPtr ctxt,
xmlNodePtr oldInsert, oldInst, oldCurInst, oldContextNode; xmlNodePtr oldInsert, oldInst, oldCurInst, oldContextNode;
xmlNodePtr cur, insert, copy = NULL; xmlNodePtr cur, insert, copy = NULL;
int level = 0, oldVarsNr; int level = 0, oldVarsNr;
xmlDocPtr oldLocalFragmentTop, oldLocalFragmentBase; xmlDocPtr oldLocalFragmentTop;
#ifdef XSLT_REFACTORED #ifdef XSLT_REFACTORED
xsltStylePreCompPtr info; xsltStylePreCompPtr info;
@@ -2676,16 +2675,9 @@ xsltApplySequenceConstructor(xsltTransformContextPtr ctxt,
cur->name)); cur->name));
#endif #endif
ctxt->insert = insert; ctxt->insert = insert;
/*
* We need the fragment base for extension instructions
* which return values (like EXSLT's function).
*/
oldLocalFragmentBase = ctxt->localRVTBase;
ctxt->localRVTBase = NULL;
func(ctxt, contextNode, cur, cur->psvi); func(ctxt, contextNode, cur, cur->psvi);
ctxt->localRVTBase = oldLocalFragmentBase;
/* /*
* Cleanup temporary tree fragments. * Cleanup temporary tree fragments.
*/ */
@@ -2749,12 +2741,9 @@ xsltApplySequenceConstructor(xsltTransformContextPtr ctxt,
oldCurInst = ctxt->inst; oldCurInst = ctxt->inst;
ctxt->inst = cur; ctxt->inst = cur;
ctxt->insert = insert; ctxt->insert = insert;
oldLocalFragmentBase = ctxt->localRVTBase;
ctxt->localRVTBase = NULL;
info->func(ctxt, contextNode, cur, (xsltElemPreCompPtr) info); info->func(ctxt, contextNode, cur, (xsltElemPreCompPtr) info);
ctxt->localRVTBase = oldLocalFragmentBase;
/* /*
* Cleanup temporary tree fragments. * Cleanup temporary tree fragments.
*/ */
@@ -2869,12 +2858,6 @@ xsltApplySequenceConstructor(xsltTransformContextPtr ctxt,
#endif #endif
ctxt->insert = insert; ctxt->insert = insert;
/*
* We need the fragment base for extension instructions
* which return values (like EXSLT's function).
*/
oldLocalFragmentBase = ctxt->localRVTBase;
ctxt->localRVTBase = NULL;
function(ctxt, contextNode, cur, cur->psvi); function(ctxt, contextNode, cur, cur->psvi);
/* /*
@@ -2883,7 +2866,6 @@ xsltApplySequenceConstructor(xsltTransformContextPtr ctxt,
if (oldLocalFragmentTop != ctxt->localRVT) if (oldLocalFragmentTop != ctxt->localRVT)
xsltReleaseLocalRVTs(ctxt, oldLocalFragmentTop); xsltReleaseLocalRVTs(ctxt, oldLocalFragmentTop);
ctxt->localRVTBase = oldLocalFragmentBase;
ctxt->insert = oldInsert; ctxt->insert = oldInsert;
} }
@@ -3059,7 +3041,7 @@ xsltApplyXSLTTemplate(xsltTransformContextPtr ctxt,
long start = 0; long start = 0;
xmlNodePtr cur; xmlNodePtr cur;
xsltStackElemPtr tmpParam = NULL; xsltStackElemPtr tmpParam = NULL;
xmlDocPtr oldUserFragmentTop, oldLocalFragmentTop; xmlDocPtr oldUserFragmentTop;
#ifdef XSLT_REFACTORED #ifdef XSLT_REFACTORED
xsltStyleItemParamPtr iparam; xsltStyleItemParamPtr iparam;
@@ -3122,7 +3104,6 @@ xsltApplyXSLTTemplate(xsltTransformContextPtr ctxt,
oldUserFragmentTop = ctxt->tmpRVT; oldUserFragmentTop = ctxt->tmpRVT;
ctxt->tmpRVT = NULL; ctxt->tmpRVT = NULL;
oldLocalFragmentTop = ctxt->localRVT;
/* /*
* Initiate a distinct scope of local params/variables. * Initiate a distinct scope of local params/variables.
@@ -3223,31 +3204,6 @@ xsltApplyXSLTTemplate(xsltTransformContextPtr ctxt,
xsltTemplateParamsCleanup(ctxt); xsltTemplateParamsCleanup(ctxt);
ctxt->varsBase = oldVarsBase; ctxt->varsBase = oldVarsBase;
/*
* Clean up remaining local tree fragments.
* This also frees fragments which are the result of
* extension instructions. Should normally not be hit; but
* just for the case xsltExtensionInstructionResultFinalize()
* was not called by the extension author.
*/
if (oldLocalFragmentTop != ctxt->localRVT) {
xmlDocPtr curdoc = ctxt->localRVT, tmp;
do {
tmp = curdoc;
curdoc = (xmlDocPtr) curdoc->next;
/* Need to housekeep localRVTBase */
if (tmp == ctxt->localRVTBase)
ctxt->localRVTBase = curdoc;
if (tmp->prev)
tmp->prev->next = (xmlNodePtr) curdoc;
if (curdoc)
curdoc->prev = tmp->prev;
xsltReleaseRVT(ctxt, tmp);
} while (curdoc != oldLocalFragmentTop);
}
ctxt->localRVT = oldLocalFragmentTop;
/* /*
* Release user-created fragments stored in the scope * Release user-created fragments stored in the scope
* of xsl:template. Note that this mechanism is deprecated: * of xsl:template. Note that this mechanism is deprecated:
@@ -6040,6 +5996,9 @@ xsltApplyStylesheetInternal(xsltStylesheetPtr style, xmlDocPtr doc,
xsltEvalGlobalVariables(ctxt); xsltEvalGlobalVariables(ctxt);
/* Clean up any unused RVTs. */
xsltReleaseLocalRVTs(ctxt, NULL);
ctxt->node = (xmlNodePtr) doc; ctxt->node = (xmlNodePtr) doc;
ctxt->output = res; ctxt->output = res;
ctxt->insert = (xmlNodePtr) res; ctxt->insert = (xmlNodePtr) res;

171
libxslt/variables.c
View File

@@ -43,8 +43,8 @@ const xmlChar *xsltDocFragFake = (const xmlChar *) " fake node libxslt";
const xmlChar *xsltComputingGlobalVarMarker = const xmlChar *xsltComputingGlobalVarMarker =
(const xmlChar *) " var/param being computed"; (const xmlChar *) " var/param being computed";
#define XSLT_VAR_GLOBAL 1<<0 #define XSLT_VAR_GLOBAL (1<<0)
#define XSLT_VAR_IN_SELECT 1<<1 #define XSLT_VAR_IN_SELECT (1<<1)
#define XSLT_TCTXT_VARIABLE(c) ((xsltStackElemPtr) (c)->contextVariable) #define XSLT_TCTXT_VARIABLE(c) ((xsltStackElemPtr) (c)->contextVariable)
/************************************************************************ /************************************************************************
@@ -122,6 +122,9 @@ xsltRegisterTmpRVT(xsltTransformContextPtr ctxt, xmlDocPtr RVT)
if ((ctxt == NULL) || (RVT == NULL)) if ((ctxt == NULL) || (RVT == NULL))
return(-1); return(-1);
RVT->prev = NULL;
RVT->psvi = XSLT_RVT_VARIABLE;
/* /*
* We'll restrict the lifetime of user-created fragments * We'll restrict the lifetime of user-created fragments
* insinde an xsl:variable and xsl:param to the lifetime of the * insinde an xsl:variable and xsl:param to the lifetime of the
@@ -159,15 +162,18 @@ xsltRegisterLocalRVT(xsltTransformContextPtr ctxt,
if ((ctxt == NULL) || (RVT == NULL)) if ((ctxt == NULL) || (RVT == NULL))
return(-1); return(-1);
RVT->prev = NULL;
/* /*
* When evaluating "select" expressions of xsl:variable * When evaluating "select" expressions of xsl:variable
* and xsl:param, we need to bind newly created tree fragments * and xsl:param, we need to bind newly created tree fragments
* to the variable itself; otherwise the tragment will be * to the variable itself; otherwise the fragment will be
* freed before we leave the scope of a var. * freed before we leave the scope of a var.
*/ */
if ((ctxt->contextVariable != NULL) && if ((ctxt->contextVariable != NULL) &&
(XSLT_TCTXT_VARIABLE(ctxt)->flags & XSLT_VAR_IN_SELECT)) (XSLT_TCTXT_VARIABLE(ctxt)->flags & XSLT_VAR_IN_SELECT))
{ {
RVT->psvi = XSLT_RVT_VARIABLE;
RVT->next = (xmlNodePtr) XSLT_TCTXT_VARIABLE(ctxt)->fragment; RVT->next = (xmlNodePtr) XSLT_TCTXT_VARIABLE(ctxt)->fragment;
XSLT_TCTXT_VARIABLE(ctxt)->fragment = RVT; XSLT_TCTXT_VARIABLE(ctxt)->fragment = RVT;
return(0); return(0);
@@ -177,19 +183,11 @@ xsltRegisterLocalRVT(xsltTransformContextPtr ctxt,
* If not reference by a returning instruction (like EXSLT's function), * If not reference by a returning instruction (like EXSLT's function),
* then this fragment will be freed, when the instruction exits. * then this fragment will be freed, when the instruction exits.
*/ */
RVT->psvi = XSLT_RVT_LOCAL;
RVT->next = (xmlNodePtr) ctxt->localRVT; RVT->next = (xmlNodePtr) ctxt->localRVT;
if (ctxt->localRVT != NULL) if (ctxt->localRVT != NULL)
ctxt->localRVT->prev = (xmlNodePtr) RVT; ctxt->localRVT->prev = (xmlNodePtr) RVT;
ctxt->localRVT = RVT; ctxt->localRVT = RVT;
/*
* We need to keep track of the first registered fragment
* for extension instructions which return fragments
* (e.g. EXSLT'S function), in order to let
* xsltExtensionInstructionResultFinalize() clear the
* preserving flag on the fragments.
*/
if (ctxt->localRVTBase == NULL)
ctxt->localRVTBase = RVT;
return(0); return(0);
} }
@@ -204,26 +202,16 @@ xsltRegisterLocalRVT(xsltTransformContextPtr ctxt,
* collector will free them after the function-calling process exits. * collector will free them after the function-calling process exits.
* *
* Returns 0 in case of success and -1 in case of API or internal errors. * Returns 0 in case of success and -1 in case of API or internal errors.
*
* This function is unsupported in newer releases of libxslt.
*/ */
int int
xsltExtensionInstructionResultFinalize(xsltTransformContextPtr ctxt) xsltExtensionInstructionResultFinalize(xsltTransformContextPtr ctxt)
{ {
xmlDocPtr cur; xmlGenericError(xmlGenericErrorContext,
"xsltExtensionInstructionResultFinalize is unsupported "
if (ctxt == NULL) "in this release of libxslt.\n");
return(-1); return(-1);
if (ctxt->localRVTBase == NULL)
return(0);
/*
* Enable remaining local tree fragments to be freed
* by the fragment garbage collector.
*/
cur = ctxt->localRVTBase;
do {
cur->psvi = NULL;
cur = (xmlDocPtr) cur->next;
} while (cur != NULL);
return(0);
} }
/** /**
@@ -238,11 +226,35 @@ xsltExtensionInstructionResultFinalize(xsltTransformContextPtr ctxt)
* tree fragments (via xsltCreateRVT()) with xsltRegisterLocalRVT(). * tree fragments (via xsltCreateRVT()) with xsltRegisterLocalRVT().
* *
* Returns 0 in case of success and -1 in case of error. * Returns 0 in case of success and -1 in case of error.
*
* It isn't necessary to call this function in newer releases of
* libxslt.
*/ */
int int
xsltExtensionInstructionResultRegister(xsltTransformContextPtr ctxt, xsltExtensionInstructionResultRegister(xsltTransformContextPtr ctxt,
xmlXPathObjectPtr obj) xmlXPathObjectPtr obj)
{ {
return(0);
}
/**
* xsltFlagRVTs:
* @ctxt: an XSLT transformation context
* @obj: an XPath object to be inspected for result tree fragments
* @val: the flag value
*
* Updates ownership information of RVTs in @obj according to @val.
*
* @val = XSLT_RVT_FUNC_RESULT for the result of an extension function, so its
* RVTs won't be destroyed after leaving the returning scope.
* @val = XSLT_RVT_LOCAL for the result of an extension function to reset
* the state of its RVTs after it was returned to a new scope.
* @val = XSLT_RVT_GLOBAL for parts of global variables.
*
* Returns 0 in case of success and -1 in case of error.
*/
int
xsltFlagRVTs(xsltTransformContextPtr ctxt, xmlXPathObjectPtr obj, void *val) {
int i; int i;
xmlNodePtr cur; xmlNodePtr cur;
xmlDocPtr doc; xmlDocPtr doc;
@@ -275,36 +287,59 @@ xsltExtensionInstructionResultRegister(xsltTransformContextPtr ctxt,
doc = cur->doc; doc = cur->doc;
} else { } else {
xsltTransformError(ctxt, NULL, ctxt->inst, xsltTransformError(ctxt, NULL, ctxt->inst,
"Internal error in " "Internal error in xsltFlagRVTs(): "
"xsltExtensionInstructionResultRegister(): "
"Cannot retrieve the doc of a namespace node.\n"); "Cannot retrieve the doc of a namespace node.\n");
goto error; return(-1);
} }
} else { } else {
doc = cur->doc; doc = cur->doc;
} }
if (doc == NULL) { if (doc == NULL) {
xsltTransformError(ctxt, NULL, ctxt->inst, xsltTransformError(ctxt, NULL, ctxt->inst,
"Internal error in " "Internal error in xsltFlagRVTs(): "
"xsltExtensionInstructionResultRegister(): "
"Cannot retrieve the doc of a node.\n"); "Cannot retrieve the doc of a node.\n");
goto error; return(-1);
} }
if (doc->name && (doc->name[0] == ' ')) { if (doc->name && (doc->name[0] == ' ') &&
doc->psvi != XSLT_RVT_GLOBAL) {
/* /*
* This is a result tree fragment. * This is a result tree fragment.
* We'll use the @psvi field for reference counting. * We store ownership information in the @psvi field.
* TODO: How do we know if this is a value of a * TODO: How do we know if this is a doc acquired via the
* global variable or a doc acquired via the
* document() function? * document() function?
*/ */
doc->psvi = (void *) ((long) 1); #ifdef WITH_XSLT_DEBUG_VARIABLE
XSLT_TRACE(ctxt,XSLT_TRACE_VARIABLES,xsltGenericDebug(xsltGenericDebugContext,
"Flagging RVT %p: %p -> %p\n", doc, doc->psvi, val));
#endif
if (val == XSLT_RVT_LOCAL) {
if (doc->psvi != XSLT_RVT_FUNC_RESULT) {
xmlGenericError(xmlGenericErrorContext,
"xsltFlagRVTs: Invalid transition %p => LOCAL\n",
doc->psvi);
return(-1);
}
xsltRegisterLocalRVT(ctxt, doc);
} else if (val == XSLT_RVT_GLOBAL) {
if (doc->psvi != XSLT_RVT_LOCAL) {
xmlGenericError(xmlGenericErrorContext,
"xsltFlagRVTs: Invalid transition %p => GLOBAL\n",
doc->psvi);
doc->psvi = XSLT_RVT_GLOBAL;
return(-1);
}
/* Will be registered as persistant in xsltReleaseLocalRVTs. */
doc->psvi = XSLT_RVT_GLOBAL;
} else if (val == XSLT_RVT_FUNC_RESULT) {
doc->psvi = val;
}
} }
} }
return(0); return(0);
error:
return(-1);
} }
/** /**
@@ -350,9 +385,9 @@ xsltReleaseRVT(xsltTransformContextPtr ctxt, xmlDocPtr RVT)
} }
/* /*
* Reset the reference counter. * Reset the ownership information.
*/ */
RVT->psvi = 0; RVT->psvi = NULL;
RVT->next = (xmlNodePtr) ctxt->cache->RVT; RVT->next = (xmlNodePtr) ctxt->cache->RVT;
ctxt->cache->RVT = RVT; ctxt->cache->RVT = RVT;
@@ -391,6 +426,8 @@ xsltRegisterPersistRVT(xsltTransformContextPtr ctxt, xmlDocPtr RVT)
{ {
if ((ctxt == NULL) || (RVT == NULL)) return(-1); if ((ctxt == NULL) || (RVT == NULL)) return(-1);
RVT->psvi = XSLT_RVT_GLOBAL;
RVT->prev = NULL;
RVT->next = (xmlNodePtr) ctxt->persistRVT; RVT->next = (xmlNodePtr) ctxt->persistRVT;
if (ctxt->persistRVT != NULL) if (ctxt->persistRVT != NULL)
ctxt->persistRVT->prev = (xmlNodePtr) RVT; ctxt->persistRVT->prev = (xmlNodePtr) RVT;
@@ -541,35 +578,21 @@ xsltFreeStackElem(xsltStackElemPtr elem) {
/* /*
* Release the list of temporary Result Tree Fragments. * Release the list of temporary Result Tree Fragments.
*/ */
if (elem->fragment) { if (elem->context) {
xmlDocPtr cur; xmlDocPtr cur;
while (elem->fragment != NULL) { while (elem->fragment != NULL) {
cur = elem->fragment; cur = elem->fragment;
elem->fragment = (xmlDocPtr) cur->next; elem->fragment = (xmlDocPtr) cur->next;
if (elem->context && if (cur->psvi == XSLT_RVT_VARIABLE) {
(cur->psvi == (void *) ((long) 1)))
{
/*
* This fragment is a result of an extension instruction
* (e.g. XSLT's function) and needs to be preserved until
* the instruction exits.
* Example: The fragment of the variable must not be freed
* since it is returned by the EXSLT function:
* <f:function name="foo">
* <xsl:variable name="bar">
* <bar/>
* </xsl:variable>
* <f:result select="$bar"/>
* </f:function>
*
*/
xsltRegisterLocalRVT(elem->context, cur);
} else {
xsltReleaseRVT((xsltTransformContextPtr) elem->context, xsltReleaseRVT((xsltTransformContextPtr) elem->context,
cur); cur);
} } else if (cur->psvi != XSLT_RVT_FUNC_RESULT) {
xmlGenericError(xmlGenericErrorContext,
"xsltFreeStackElem: Unexpected RVT flag %p\n",
cur->psvi);
}
} }
} }
/* /*
@@ -963,6 +986,7 @@ xsltEvalVariable(xsltTransformContextPtr ctxt, xsltStackElemPtr variable,
* the Result Tree Fragment. * the Result Tree Fragment.
*/ */
variable->fragment = container; variable->fragment = container;
container->psvi = XSLT_RVT_VARIABLE;
oldOutput = ctxt->output; oldOutput = ctxt->output;
oldInsert = ctxt->insert; oldInsert = ctxt->insert;
@@ -1149,16 +1173,23 @@ xsltEvalGlobalVariable(xsltStackElemPtr elem, xsltTransformContextPtr ctxt)
xsltTransformError(ctxt, NULL, comp->inst, xsltTransformError(ctxt, NULL, comp->inst,
"Evaluating global variable %s failed\n", elem->name); "Evaluating global variable %s failed\n", elem->name);
ctxt->state = XSLT_STATE_STOPPED; ctxt->state = XSLT_STATE_STOPPED;
goto error;
}
/*
* Mark all RVTs that are referenced from result as part
* of this variable so they won't be freed too early.
*/
xsltFlagRVTs(ctxt, result, XSLT_RVT_GLOBAL);
#ifdef WITH_XSLT_DEBUG_VARIABLE #ifdef WITH_XSLT_DEBUG_VARIABLE
#ifdef LIBXML_DEBUG_ENABLED #ifdef LIBXML_DEBUG_ENABLED
} else { if ((xsltGenericDebugContext == stdout) ||
if ((xsltGenericDebugContext == stdout) || (xsltGenericDebugContext == stderr))
(xsltGenericDebugContext == stderr)) xmlXPathDebugDumpObject((FILE *)xsltGenericDebugContext,
xmlXPathDebugDumpObject((FILE *)xsltGenericDebugContext, result, 0);
result, 0);
#endif #endif
#endif #endif
}
} else { } else {
if (elem->tree == NULL) { if (elem->tree == NULL) {
result = xmlXPathNewCString(""); result = xmlXPathNewCString("");

9
libxslt/variables.h
View File

@@ -34,6 +34,15 @@ extern "C" {
xsltRegisterAllElement(ctxt); \ xsltRegisterAllElement(ctxt); \
(ctxt)->xpathCtxt->extra = ctxt (ctxt)->xpathCtxt->extra = ctxt
/*
* Flags for memory management of RVTs
*/
#define XSLT_RVT_LOCAL ((void *)1)
#define XSLT_RVT_VARIABLE ((void *)2)
#define XSLT_RVT_FUNC_RESULT ((void *)3)
#define XSLT_RVT_GLOBAL ((void *)4)
/* /*
* Interfaces for the variable module. * Interfaces for the variable module.
*/ */

7
libxslt/xsltInternals.h
View File

@@ -1783,7 +1783,7 @@ struct _xsltTransformContext {
xmlDocPtr localRVT; /* list of local tree fragments; will be freed when xmlDocPtr localRVT; /* list of local tree fragments; will be freed when
the instruction which created the fragment the instruction which created the fragment
exits */ exits */
xmlDocPtr localRVTBase; xmlDocPtr localRVTBase; /* Obsolete */
int keyInitLevel; /* Needed to catch recursive keys issues */ int keyInitLevel; /* Needed to catch recursive keys issues */
int funcLevel; /* Needed to catch recursive functions issues */ int funcLevel; /* Needed to catch recursive functions issues */
int maxTemplateDepth; int maxTemplateDepth;
@@ -1906,6 +1906,11 @@ XSLTPUBFUN int XSLTCALL
XSLTPUBFUN int XSLTCALL XSLTPUBFUN int XSLTCALL
xsltExtensionInstructionResultFinalize( xsltExtensionInstructionResultFinalize(
xsltTransformContextPtr ctxt); xsltTransformContextPtr ctxt);
XSLTPUBFUN int XSLTCALL
xsltFlagRVTs(
xsltTransformContextPtr ctxt,
xmlXPathObjectPtr obj,
void *val);
XSLTPUBFUN void XSLTCALL XSLTPUBFUN void XSLTCALL
xsltFreeRVTs (xsltTransformContextPtr ctxt); xsltFreeRVTs (xsltTransformContextPtr ctxt);
XSLTPUBFUN void XSLTCALL XSLTPUBFUN void XSLTCALL

1
tests/docs/bug-192.xml Normal file
View File

@@ -0,0 +1 @@
<doc/>

3
tests/exslt/functions/Makefile.am
View File

@@ -13,7 +13,8 @@ EXTRA_DIST = \
function.7.out function.7.xml function.7.xsl \ function.7.out function.7.xml function.7.xsl \
function.8.out function.8.xml function.8.xsl \ function.8.out function.8.xml function.8.xsl \
function.9.out function.9.xml function.9.xsl \ function.9.out function.9.xml function.9.xsl \
function.10.out function.10.xml function.10.xsl function.10.out function.10.xml function.10.xsl \
function.11.out function.11.xml function.11.xsl
CLEANFILES = .memdump CLEANFILES = .memdump

2
tests/exslt/functions/function.11.out Normal file
View File

@@ -0,0 +1,2 @@
<?xml version="1.0"?>
<a><b/></a>

2
tests/exslt/functions/function.11.xml Normal file
View File

@@ -0,0 +1,2 @@
<?xml version="1.0"?>
<doc/>

32
tests/exslt/functions/function.11.xsl Normal file
View File

@@ -0,0 +1,32 @@
<?xml version="1.0"?>
<xsl:stylesheet
version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:func="http://exslt.org/functions"
xmlns:test="test"
extension-element-prefixes="func"
>
<func:function name="test:fragment">
<func:result>
<a>
<b/>
</a>
</func:result>
</func:function>
<func:function name="test:func1">
<xsl:variable name="var" select="test:fragment()"/>
<func:result select="$var"/>
</func:function>
<func:function name="test:func2">
<xsl:variable name="var" select="test:func1()"/>
<func:result select="$var"/>
</func:function>
<xsl:template match="/">
<xsl:copy-of select="test:func2()"/>
</xsl:template>
</xsl:stylesheet>

1
tests/general/bug-192.out Normal file
View File

@@ -0,0 +1 @@
assert 'success!' == 'success!'

33
tests/general/bug-192.xsl Normal file
View File

@@ -0,0 +1,33 @@
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl='http://www.w3.org/1999/XSL/Transform'
xmlns:func='http://exslt.org/functions'
xmlns:foo='http://foo.com/'
extension-element-prefixes='func'
>
<xsl:output method="text" />
<!-- $func-value should have the value 'success!' but instead reports an
empty string -->
<xsl:variable name="func-value" select="foo:get-value()" />
<xsl:variable name="dummy-value" select="$func-value" />
<xsl:variable name="template-value">
<xsl:call-template name="get-dummy" />
</xsl:variable>
<func:function name="foo:get-value">
<func:result>success!</func:result>
</func:function>
<xsl:template name="get-dummy">
<xsl:value-of select="$dummy-value" />
</xsl:template>
<xsl:template match="/">
<xsl:text>assert 'success!' == '</xsl:text>
<xsl:value-of select="$func-value" />
<xsl:text>'
</xsl:text>
</xsl:template>
</xsl:stylesheet>