Fixed a problem with variable declarations in inner blocks giving errors. bug#82.

git-svn-id: http://picoc.googlecode.com/svn/trunk@470 21eae674-98b7-11dd-bd71-f92a316d2d60

expression.c

@@ -767,7 +767,7 @@ void ExpressionInfixOperator(struct ParseState *Parser, struct ExpressionStack *
         else if (Op == TokenAssign && TopInt == 0)
         {
             /* assign a NULL pointer */
-            HeapUnpopStack(sizeof(struct Value));   /* XXX - possible bug if lvalue is a temp value and takes more than sizeof(struct Value) */
+            HeapUnpopStack(sizeof(struct Value));
             ExpressionAssign(Parser, BottomValue, TopValue, FALSE, NULL, 0, FALSE);
             ExpressionStackPushValueNode(Parser, StackTop, BottomValue);
         }
@@ -785,7 +785,7 @@ void ExpressionInfixOperator(struct ParseState *Parser, struct ExpressionStack *
             else
                 Pointer = (void *)((char *)Pointer - TopInt * Size);
 
-            HeapUnpopStack(sizeof(struct Value));   /* XXX - possible bug if lvalue is a temp value and takes more than sizeof(struct Value) */
+            HeapUnpopStack(sizeof(struct Value));
             BottomValue->Val->Pointer = Pointer;
             ExpressionStackPushValueNode(Parser, StackTop, BottomValue);
         }
@@ -963,7 +963,7 @@ void ExpressionGetStructElement(struct ParseState *Parser, struct ExpressionStac
         if (StructType->Base != TypeStruct && StructType->Base != TypeUnion)
             ProgramFail(Parser, "can't use '%s' on something that's not a struct or union %s : it's a %t", (Token == TokenDot) ? "." : "->", (Token == TokenArrow) ? "pointer" : "", ParamVal->Typ);
             
-        if (!TableGet(StructType->Members, Ident->Val->Identifier, &MemberValue))
+        if (!TableGet(StructType->Members, Ident->Val->Identifier, &MemberValue, NULL, NULL))
             ProgramFail(Parser, "doesn't have a member called '%s'", Ident->Val->Identifier);
         
         /* pop the value - assume it'll still be there until we're done */

lex.c

@@ -755,7 +755,7 @@ void LexHashIfdef(struct ParseState *Parser, int IfNot)
         ProgramFail(Parser, "identifier expected");
     
     /* is the identifier defined? */
-    IsDefined = TableGet(&GlobalTable, IdentValue->Val->Identifier, &SavedValue);
+    IsDefined = TableGet(&GlobalTable, IdentValue->Val->Identifier, &SavedValue, NULL, NULL);
     if (Parser->HashIfEvaluateToLevel == Parser->HashIfLevel && ( (IsDefined && !IfNot) || (!IsDefined && IfNot)) )
     {
         /* #if is active, evaluate to this new level */
@@ -777,7 +777,7 @@ void LexHashIf(struct ParseState *Parser)
     if (Token == TokenIdentifier)
     {
         /* look up a value from a macro definition */
-        if (!TableGet(&GlobalTable, IdentValue->Val->Identifier, &SavedValue))
+        if (!TableGet(&GlobalTable, IdentValue->Val->Identifier, &SavedValue, NULL, NULL))
             ProgramFail(Parser, "'%s' is undefined", IdentValue->Val->Identifier);
         
         if (SavedValue->Typ->Base != TypeMacro)

parse.c

@@ -128,7 +128,7 @@ struct Value *ParseFunctionDefinition(struct ParseState *Parser, struct ValueTyp
         FuncValue->Val->FuncDef.Body.Pos = LexCopyTokens(&FuncBody, Parser);
 
         /* is this function already in the global table? */
-        if (TableGet(&GlobalTable, Identifier, &OldFuncValue))
+        if (TableGet(&GlobalTable, Identifier, &OldFuncValue, NULL, NULL))
         {
             if (OldFuncValue->Val->FuncDef.Body.Pos == NULL)
                 TableDelete(&GlobalTable, Identifier);   /* override an old function prototype */
@@ -137,7 +137,7 @@ struct Value *ParseFunctionDefinition(struct ParseState *Parser, struct ValueTyp
         }
     }
 
-    if (!TableSet(&GlobalTable, Identifier, FuncValue))
+    if (!TableSet(&GlobalTable, Identifier, FuncValue, Parser->Line, Parser->CharacterPos))
         ProgramFail(Parser, "'%s' is already defined", Identifier);
         
     return FuncValue;
@@ -227,7 +227,7 @@ int ParseDeclaration(struct ParseState *Parser, enum LexToken Token)
                     ProgramFail(Parser, "can't define a void variable");
                     
                 if (Parser->Mode == RunModeRun)
-                    NewVariable = VariableDefine(Parser, Identifier, NULL, Typ, TRUE);
+                    NewVariable = VariableDefineButIgnoreIdentical(Parser, Identifier, Typ);
                 
                 if (LexGetToken(Parser, NULL, FALSE) == TokenAssign)
                 {
@@ -304,7 +304,7 @@ void ParseMacroDefinition(struct ParseState *Parser)
     LexToEndOfLine(Parser);
     MacroValue->Val->MacroDef.Body.Pos = LexCopyTokens(&MacroValue->Val->MacroDef.Body, Parser);
     
-    if (!TableSet(&GlobalTable, MacroNameStr, MacroValue))
+    if (!TableSet(&GlobalTable, MacroNameStr, MacroValue, Parser->Line, Parser->CharacterPos))
         ProgramFail(Parser, "'%s' is already defined", MacroNameStr);
 }
 

picoc.h

@@ -208,6 +208,9 @@ struct Value
 struct TableEntry
 {
     struct TableEntry *Next;        /* next item in this hash chain */
+    unsigned short DeclLine;        /* where the variable was declared */
+    unsigned short DeclColumn;
+
     union TableEntryPayload
     {
         struct ValueEntry
@@ -321,8 +324,8 @@ void TableInit();
 char *TableStrRegister(const char *Str);
 char *TableStrRegister2(const char *Str, int Len);
 void TableInitTable(struct Table *Tbl, struct TableEntry **HashTable, int Size, int OnHeap);
-int TableSet(struct Table *Tbl, char *Key, struct Value *Val);
+int TableSet(struct Table *Tbl, char *Key, struct Value *Val, int DeclLine, int DeclColumn);
-int TableGet(struct Table *Tbl, const char *Key, struct Value **Val);
+int TableGet(struct Table *Tbl, const char *Key, struct Value **Val, int *DeclLine, int *DeclColumn);
 struct Value *TableDelete(struct Table *Tbl, const char *Key);
 char *TableSetIdentifier(struct Table *Tbl, const char *Ident, int IdentLen);
 void TableStrFree();
@@ -394,6 +397,7 @@ struct Value *VariableAllocValueFromType(struct ParseState *Parser, struct Value
 struct Value *VariableAllocValueFromExistingData(struct ParseState *Parser, struct ValueType *Typ, union AnyValue *FromValue, int IsLValue, struct Value *LValueFrom);
 struct Value *VariableAllocValueShared(struct ParseState *Parser, struct Value *FromValue);
 struct Value *VariableDefine(struct ParseState *Parser, char *Ident, struct Value *InitValue, struct ValueType *Typ, int MakeWritable);
+struct Value *VariableDefineButIgnoreIdentical(struct ParseState *Parser, char *Ident, struct ValueType *Typ);
 int VariableDefined(const char *Ident);
 void VariableGet(struct ParseState *Parser, const char *Ident, struct Value **LVal);
 void VariableDefinePlatformVar(struct ParseState *Parser, char *Ident, struct ValueType *Typ, union AnyValue *FromValue, int IsWritable);

table.c

@@ -56,7 +56,7 @@ static struct TableEntry *TableSearch(struct Table *Tbl, const char *Key, int *A
 
 /* set an identifier to a value. returns FALSE if it already exists. 
  * Key must be a shared string from TableStrRegister() */
-int TableSet(struct Table *Tbl, char *Key, struct Value *Val)
+int TableSet(struct Table *Tbl, char *Key, struct Value *Val, int DeclLine, int DeclColumn)
 {
     int AddAt;
     struct TableEntry *FoundEntry = TableSearch(Tbl, Key, &AddAt);
@@ -64,6 +64,8 @@ int TableSet(struct Table *Tbl, char *Key, struct Value *Val)
     if (FoundEntry == NULL)
     {   /* add it to the table */
         struct TableEntry *NewEntry = VariableAlloc(NULL, sizeof(struct TableEntry), Tbl->OnHeap);
+        NewEntry->DeclLine = DeclLine;
+        NewEntry->DeclColumn = DeclColumn;
         NewEntry->p.v.Key = Key;
         NewEntry->p.v.Val = Val;
         NewEntry->Next = Tbl->HashTable[AddAt];
@@ -76,7 +78,7 @@ int TableSet(struct Table *Tbl, char *Key, struct Value *Val)
 
 /* find a value in a table. returns FALSE if not found. 
  * Key must be a shared string from TableStrRegister() */
-int TableGet(struct Table *Tbl, const char *Key, struct Value **Val)
+int TableGet(struct Table *Tbl, const char *Key, struct Value **Val, int *DeclLine, int *DeclColumn)
 {
     int AddAt;
     struct TableEntry *FoundEntry = TableSearch(Tbl, Key, &AddAt);
@@ -84,6 +86,13 @@ int TableGet(struct Table *Tbl, const char *Key, struct Value **Val)
         return FALSE;
     
     *Val = FoundEntry->p.v.Val;
+    
+    if (DeclLine != NULL)
+    {
+        *DeclLine = FoundEntry->DeclLine;
+        *DeclColumn = FoundEntry->DeclColumn;
+    }
+    
     return TRUE;
 }
 
@@ -132,7 +141,7 @@ char *TableSetIdentifier(struct Table *Tbl, const char *Ident, int IdentLen)
         return &FoundEntry->p.Key[0];
     else
     {   /* add it to the table - we economise by not allocating the whole structure here */
-        struct TableEntry *NewEntry = HeapAllocMem(sizeof(struct TableEntry *) + IdentLen + 1);
+        struct TableEntry *NewEntry = HeapAllocMem(sizeof(struct TableEntry) - sizeof(union TableEntryPayload) + IdentLen + 1);
         if (NewEntry == NULL)
             ProgramFail(NULL, "out of memory");
             

tests/44_scoped_declarations.c

@@ -0,0 +1,10 @@
+#include <stdio.h>
+
+int a;
+
+for (a = 0; a < 2; a++)
+{
+    int b = a;
+}
+
+printf("it's all good\n");

tests/44_scoped_declarations.expect

@@ -0,0 +1 @@
+it's all good

tests/Makefile

@@ -38,7 +38,8 @@ TESTS=	00_assignment.test \
 	39_typedef.test \
 	40_stdio.test \
 	41_hashif.test \
-	43_void_param.test
+	43_void_param.test \
+	44_scoped_declarations.test
 
 %.test: %.expect %.c
 	@echo Test: $*...

type.c

@@ -233,7 +233,7 @@ void TypeParseStruct(struct ParseState *Parser, struct ValueType **Typ, int IsSt
                 (*Typ)->Sizeof = TypeSizeValue(MemberValue);
         }
         
-        if (!TableSet((*Typ)->Members, MemberIdentifier, MemberValue))
+        if (!TableSet((*Typ)->Members, MemberIdentifier, MemberValue, Parser->Line, Parser->CharacterPos))
             ProgramFail(Parser, "member '%s' already defined", &MemberIdentifier);
             
         if (LexGetToken(Parser, NULL, TRUE) != TokenSemicolon)

variable.c

@@ -161,20 +161,34 @@ struct Value *VariableDefine(struct ParseState *Parser, char *Ident, struct Valu
     
     AssignValue->IsLValue = MakeWritable;
         
-    if (!TableSet((TopStackFrame == NULL) ? &GlobalTable : &TopStackFrame->LocalTable, Ident, AssignValue))
+    if (!TableSet((TopStackFrame == NULL) ? &GlobalTable : &TopStackFrame->LocalTable, Ident, AssignValue, Parser ? Parser->Line : 0, Parser ? Parser->CharacterPos : 0))
         ProgramFail(Parser, "'%s' is already defined", Ident);
     
     return AssignValue;
 }
 
+/* define a variable. Ident must be registered. If it's a redefinition from the same declaration don't throw an error */
+struct Value *VariableDefineButIgnoreIdentical(struct ParseState *Parser, char *Ident, struct ValueType *Typ)
+{
+    struct Value *ExistingValue;
+    int DeclLine;
+    int DeclColumn;
+    
+    if (Parser->Line != 0 && TableGet((TopStackFrame == NULL) ? &GlobalTable : &TopStackFrame->LocalTable, Ident, &ExistingValue, &DeclLine, &DeclColumn)
+            && DeclLine == Parser->Line && DeclColumn == Parser->CharacterPos)
+        return ExistingValue;
+    else
+        return VariableDefine(Parser, Ident, NULL, Typ, TRUE);
+}
+
 /* check if a variable with a given name is defined. Ident must be registered */
 int VariableDefined(const char *Ident)
 {
     struct Value *FoundValue;
     
-    if (TopStackFrame == NULL || !TableGet(&TopStackFrame->LocalTable, Ident, &FoundValue))
+    if (TopStackFrame == NULL || !TableGet(&TopStackFrame->LocalTable, Ident, &FoundValue, NULL, NULL))
     {
-        if (!TableGet(&GlobalTable, Ident, &FoundValue))
+        if (!TableGet(&GlobalTable, Ident, &FoundValue, NULL, NULL))
             return FALSE;
     }
 
@@ -184,9 +198,9 @@ int VariableDefined(const char *Ident)
 /* get the value of a variable. must be defined. Ident must be registered */
 void VariableGet(struct ParseState *Parser, const char *Ident, struct Value **LVal)
 {
-    if (TopStackFrame == NULL || !TableGet(&TopStackFrame->LocalTable, Ident, LVal))
+    if (TopStackFrame == NULL || !TableGet(&TopStackFrame->LocalTable, Ident, LVal, NULL, NULL))
     {
-        if (!TableGet(&GlobalTable, Ident, LVal))
+        if (!TableGet(&GlobalTable, Ident, LVal, NULL, NULL))
             ProgramFail(Parser, "'%s' is undefined", Ident);
     }
 }
@@ -198,7 +212,7 @@ void VariableDefinePlatformVar(struct ParseState *Parser, char *Ident, struct Va
     SomeValue->Typ = Typ;
     SomeValue->Val = FromValue;
     
-    if (!TableSet((TopStackFrame == NULL) ? &GlobalTable : &TopStackFrame->LocalTable, TableStrRegister(Ident), SomeValue))
+    if (!TableSet((TopStackFrame == NULL) ? &GlobalTable : &TopStackFrame->LocalTable, TableStrRegister(Ident), SomeValue, Parser ? Parser->Line : 0, Parser ? Parser->CharacterPos : 0))
         ProgramFail(Parser, "'%s' is already defined", Ident);
 }
 
@@ -261,7 +275,7 @@ struct Value *VariableStringLiteralGet(char *Ident)
 {
     struct Value *LVal = NULL;
 
-    if (TableGet(&StringLiteralTable, Ident, &LVal))
+    if (TableGet(&StringLiteralTable, Ident, &LVal, NULL, NULL))
         return LVal;
     else
         return NULL;
@@ -270,7 +284,7 @@ struct Value *VariableStringLiteralGet(char *Ident)
 /* define a string literal. assumes that Ident is already registered */
 void VariableStringLiteralDefine(char *Ident, struct Value *Val)
 {
-    TableSet(&StringLiteralTable, Ident, Val);
+    TableSet(&StringLiteralTable, Ident, Val, 0, 0);
 }
 
 /* check a pointer for validity and dereference it for use */