[[ Bug 21887 ]] Use auto classes to manage MCTextChunkIterator instances

runrevmark · runrevmark · commit 0b424e20d962 · 2019-03-26T11:51:06.000Z
This patch replaces the use of explicit deallocation of MCTextChunkIterator
instances with auto classes. By doing this memory leaks in the LCB
'is among the chars of' and 'the number of chars in' operators are eliminated.
diff --git a/docs/notes/bugfix-21887.md b/docs/notes/bugfix-21887.md
@@ -0,0 +1,2 @@
+# Fix memory leaks in LCB 'number of chars in' and 'is among the chars of' operators
+
diff --git a/engine/src/exec-keywords.cpp b/engine/src/exec-keywords.cpp
@@ -417,7 +417,7 @@ void MCKeywordsExecRepeatFor(MCExecContext& ctxt, MCStatement *statements, MCExp
     index_t t_sequenced_iterator;
     const byte_t *t_data_ptr;
     
-    MCTextChunkIterator *tci = nil;
+    MCAutoPointer<MCTextChunkIterator> tci;
     
     if (!ctxt . TryToEvaluateExpression(endcond, line, pos, EE_REPEAT_BADFORCOND, &t_condition))
         return;
@@ -551,7 +551,7 @@ void MCKeywordsExecRepeatFor(MCExecContext& ctxt, MCStatement *statements, MCExp
                 
             default:
             {
-                t_found = MCStringsTextChunkIteratorNext(ctxt, tci);
+                t_found = MCStringsTextChunkIteratorNext(ctxt, *tci);
                 endnext = tci -> IsExhausted();
                 
                 if (!t_found)
@@ -595,8 +595,6 @@ void MCKeywordsExecRepeatFor(MCExecContext& ctxt, MCStatement *statements, MCExp
         
         done = done || endnext;
     }
-    
-    delete tci;
 }
 
 void MCKeywordsExecRepeatWith(MCExecContext& ctxt, MCStatement *statements, MCExpression *step, MCExpression *startcond, MCExpression *endcond, MCVarref *loopvar, real8 stepval, uint2 line, uint2 pos)
diff --git a/engine/src/exec-strings-chunk.cpp b/engine/src/exec-strings-chunk.cpp
@@ -64,12 +64,11 @@ void MCStringsCountChunksInRange(MCExecContext& ctxt, Chunk_term p_chunk_type, M
         return;
     }
 
-    MCTextChunkIterator *tci;
+    MCAutoPointer<MCTextChunkIterator> tci;
     tci = MCStringsTextChunkIteratorCreateWithRange(ctxt, p_string, p_range, p_chunk_type);
     
     r_count = tci -> CountChunks();
     
-    delete tci;
     return;
 }
 
@@ -1145,9 +1144,7 @@ MCTextChunkIterator *MCStringsTextChunkIteratorCreate(MCExecContext& ctxt, MCStr
 {
     if (p_chunk_type == CT_TOKEN)
     {
-        MCTextChunkIterator *tci;
-        tci = new (nothrow) MCTextChunkIterator_Tokenized(p_text, MCChunkTypeFromChunkTerm(p_chunk_type));
-        return tci;
+        return new (nothrow) MCTextChunkIterator_Tokenized(p_text, MCChunkTypeFromChunkTerm(p_chunk_type));
     }
     
     return MCChunkCreateTextChunkIterator(p_text, nil, MCChunkTypeFromChunkTerm(p_chunk_type), ctxt . GetLineDelimiter(), ctxt . GetItemDelimiter(), ctxt . GetStringComparisonType());
@@ -1157,9 +1154,7 @@ MCTextChunkIterator *MCStringsTextChunkIteratorCreateWithRange(MCExecContext& ct
 {
     if (p_chunk_type == CT_TOKEN)
     {
-        MCTextChunkIterator *tci;
-        tci = new (nothrow) MCTextChunkIterator_Tokenized(p_text, MCChunkTypeFromChunkTerm(p_chunk_type), p_range);
-        return tci;
+        return new (nothrow) MCTextChunkIterator_Tokenized(p_text, MCChunkTypeFromChunkTerm(p_chunk_type), p_range);
     }
     
     return MCChunkCreateTextChunkIterator(p_text, &p_range, MCChunkTypeFromChunkTerm(p_chunk_type), ctxt . GetLineDelimiter(), ctxt . GetItemDelimiter(), ctxt . GetStringComparisonType());
diff --git a/engine/src/exec-strings.cpp b/engine/src/exec-strings.cpp
@@ -1531,13 +1531,12 @@ bool MCStringsEvalIsAmongTheChunksOf(MCExecContext& ctxt, MCStringRef p_chunk, M
     MCChunkType t_type;
     t_type = MCChunkTypeFromChunkTerm(p_chunk_type);
     
-    MCTextChunkIterator *tci;
-    tci = MCStringsTextChunkIteratorCreate(ctxt, p_text, p_chunk_type);
+    MCAutoPointer<MCTextChunkIterator> tci = 
+            MCStringsTextChunkIteratorCreate(ctxt, p_text, p_chunk_type);
 
     bool t_result;
     t_result = tci -> IsAmong(p_chunk);
     
-    delete tci;
     return t_result;
 
 }
@@ -1680,12 +1679,11 @@ __MCStringsEvalChunkOffset(MCExecContext& ctxt,
     MCChunkType t_type;
     t_type = MCChunkTypeFromChunkTerm(p_chunk_type);
     
-    MCTextChunkIterator *tci;
-    tci = MCStringsTextChunkIteratorCreate(ctxt, p_string, p_chunk_type);
+    MCAutoPointer<MCTextChunkIterator> tci =
+            MCStringsTextChunkIteratorCreate(ctxt, p_string, p_chunk_type);
     
     uindex_t t_offset = tci -> ChunkOffset(p_chunk, p_start_offset, nil, ctxt . GetWholeMatches());
     
-    delete tci;
     return t_offset;
 }
 
diff --git a/libscript/src/module-char.cpp b/libscript/src/module-char.cpp
@@ -48,8 +48,8 @@ bool MCCharStoreChunk(MCStringRef &x_target, MCStringRef p_value, MCRange p_grap
 
 extern "C" MC_DLLEXPORT_DEF void MCCharEvalNumberOfCharsIn(MCStringRef p_target, index_t& r_output)
 {
-    MCTextChunkIterator *tci;
-    tci = MCChunkCreateTextChunkIterator(p_target, nil, kMCChunkTypeCharacter, nil, nil, kMCStringOptionCompareExact);
+    MCAutoPointer<MCTextChunkIterator> tci =
+            MCChunkCreateTextChunkIterator(p_target, nil, kMCChunkTypeCharacter, nil, nil, kMCStringOptionCompareExact);
     r_output = tci -> CountChunks();
 }
 
@@ -65,8 +65,8 @@ extern "C" MC_DLLEXPORT_DEF void MCCharEvalIsAmongTheCharsOf(MCStringRef p_needl
         return;
     }
     
-    MCTextChunkIterator *tci;
-    tci = MCChunkCreateTextChunkIterator(p_target, nil, kMCChunkTypeCharacter, nil, nil, kMCStringOptionCompareExact);
+    MCAutoPointer<MCTextChunkIterator> tci =
+            MCChunkCreateTextChunkIterator(p_target, nil, kMCChunkTypeCharacter, nil, nil, kMCStringOptionCompareExact);
     r_output = tci -> IsAmong(p_needle);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+# Fix memory leaks in LCB 'number of chars in' and 'is among the chars of' operators`
	`2`	`+`
Original file line number	Diff line number	Diff line change
`@@ -417,7 +417,7 @@ void MCKeywordsExecRepeatFor(MCExecContext& ctxt, MCStatement *statements, MCExp`
`417`	`417`	`index_t t_sequenced_iterator;`
`418`	`418`	`const byte_t *t_data_ptr;`
`419`	`419`
`420`		`- MCTextChunkIterator *tci = nil;`
	`420`	`+ MCAutoPointer<MCTextChunkIterator> tci;`
`421`	`421`
`422`	`422`	`if (!ctxt . TryToEvaluateExpression(endcond, line, pos, EE_REPEAT_BADFORCOND, &t_condition))`
`423`	`423`	`return;`
`@@ -551,7 +551,7 @@ void MCKeywordsExecRepeatFor(MCExecContext& ctxt, MCStatement *statements, MCExp`
`551`	`551`
`552`	`552`	`default:`
`553`	`553`	`{`
`554`		`- t_found = MCStringsTextChunkIteratorNext(ctxt, tci);`
	`554`	`+ t_found = MCStringsTextChunkIteratorNext(ctxt, *tci);`
`555`	`555`	`endnext = tci -> IsExhausted();`
`556`	`556`
`557`	`557`	`if (!t_found)`
`@@ -595,8 +595,6 @@ void MCKeywordsExecRepeatFor(MCExecContext& ctxt, MCStatement *statements, MCExp`
`595`	`595`
`596`	`596`	`done = done \|\| endnext;`
`597`	`597`	`}`
`598`		`-`
`599`		`- delete tci;`
`600`	`598`	`}`
`601`	`599`
`602`	`600`	`void MCKeywordsExecRepeatWith(MCExecContext& ctxt, MCStatement statements, MCExpression step, MCExpression startcond, MCExpression endcond, MCVarref *loopvar, real8 stepval, uint2 line, uint2 pos)`
Original file line number	Diff line number	Diff line change
`@@ -64,12 +64,11 @@ void MCStringsCountChunksInRange(MCExecContext& ctxt, Chunk_term p_chunk_type, M`
`64`	`64`	`return;`
`65`	`65`	`}`
`66`	`66`
`67`		`- MCTextChunkIterator *tci;`
	`67`	`+ MCAutoPointer<MCTextChunkIterator> tci;`
`68`	`68`	`tci = MCStringsTextChunkIteratorCreateWithRange(ctxt, p_string, p_range, p_chunk_type);`
`69`	`69`
`70`	`70`	`r_count = tci -> CountChunks();`
`71`	`71`
`72`		`- delete tci;`
`73`	`72`	`return;`
`74`	`73`	`}`
`75`	`74`
`@@ -1145,9 +1144,7 @@ MCTextChunkIterator *MCStringsTextChunkIteratorCreate(MCExecContext& ctxt, MCStr`
`1145`	`1144`	`{`
`1146`	`1145`	`if (p_chunk_type == CT_TOKEN)`
`1147`	`1146`	`{`
`1148`		`- MCTextChunkIterator *tci;`
`1149`		`- tci = new (nothrow) MCTextChunkIterator_Tokenized(p_text, MCChunkTypeFromChunkTerm(p_chunk_type));`
`1150`		`- return tci;`
	`1147`	`+ return new (nothrow) MCTextChunkIterator_Tokenized(p_text, MCChunkTypeFromChunkTerm(p_chunk_type));`
`1151`	`1148`	`}`
`1152`	`1149`
`1153`	`1150`	`return MCChunkCreateTextChunkIterator(p_text, nil, MCChunkTypeFromChunkTerm(p_chunk_type), ctxt . GetLineDelimiter(), ctxt . GetItemDelimiter(), ctxt . GetStringComparisonType());`
`@@ -1157,9 +1154,7 @@ MCTextChunkIterator *MCStringsTextChunkIteratorCreateWithRange(MCExecContext& ct`
`1157`	`1154`	`{`
`1158`	`1155`	`if (p_chunk_type == CT_TOKEN)`
`1159`	`1156`	`{`
`1160`		`- MCTextChunkIterator *tci;`
`1161`		`- tci = new (nothrow) MCTextChunkIterator_Tokenized(p_text, MCChunkTypeFromChunkTerm(p_chunk_type), p_range);`
`1162`		`- return tci;`
	`1157`	`+ return new (nothrow) MCTextChunkIterator_Tokenized(p_text, MCChunkTypeFromChunkTerm(p_chunk_type), p_range);`
`1163`	`1158`	`}`
`1164`	`1159`
`1165`	`1160`	`return MCChunkCreateTextChunkIterator(p_text, &p_range, MCChunkTypeFromChunkTerm(p_chunk_type), ctxt . GetLineDelimiter(), ctxt . GetItemDelimiter(), ctxt . GetStringComparisonType());`
Original file line number	Diff line number	Diff line change
`@@ -48,8 +48,8 @@ bool MCCharStoreChunk(MCStringRef &x_target, MCStringRef p_value, MCRange p_grap`
`48`	`48`
`49`	`49`	`extern "C" MC_DLLEXPORT_DEF void MCCharEvalNumberOfCharsIn(MCStringRef p_target, index_t& r_output)`
`50`	`50`	`{`
`51`		`- MCTextChunkIterator *tci;`
`52`		`- tci = MCChunkCreateTextChunkIterator(p_target, nil, kMCChunkTypeCharacter, nil, nil, kMCStringOptionCompareExact);`
	`51`	`+ MCAutoPointer<MCTextChunkIterator> tci =`
	`52`	`+ MCChunkCreateTextChunkIterator(p_target, nil, kMCChunkTypeCharacter, nil, nil, kMCStringOptionCompareExact);`
`53`	`53`	`r_output = tci -> CountChunks();`
`54`	`54`	`}`
`55`	`55`
`@@ -65,8 +65,8 @@ extern "C" MC_DLLEXPORT_DEF void MCCharEvalIsAmongTheCharsOf(MCStringRef p_needl`
`65`	`65`	`return;`
`66`	`66`	`}`
`67`	`67`
`68`		`- MCTextChunkIterator *tci;`
`69`		`- tci = MCChunkCreateTextChunkIterator(p_target, nil, kMCChunkTypeCharacter, nil, nil, kMCStringOptionCompareExact);`
	`68`	`+ MCAutoPointer<MCTextChunkIterator> tci =`
	`69`	`+ MCChunkCreateTextChunkIterator(p_target, nil, kMCChunkTypeCharacter, nil, nil, kMCStringOptionCompareExact);`
`70`	`70`	`r_output = tci -> IsAmong(p_needle);`
`71`	`71`	`}`
`72`	`72`