| 1 | #include "lookup.h"
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| 2 | #include "messages.h"
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| 3 | #include "types.h"
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| 4 | #include "Node.h"
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| 5 | #include "SyntaxTree.h"
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| 6 | #include "Symbol.h"
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| 7 | #include "SymbolTable.h"
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| 8 | #include <assert.h>
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| 9 |
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| 10 | /* declared in comp.l */
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| 11 | extern int lineno;
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| 12 |
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| 13 | /* declared in comp.y */
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| 14 | extern SyntaxTree *tree;
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| 15 | extern SymbolTable *symtab;
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| 16 | extern Messages messages;
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| 17 | extern string mainScopeName;
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| 18 |
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| 19 | Symbol *lookup(const string& id, SymbolType default_type)
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| 20 | {
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| 21 | /* Lookup ID */
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| 22 | Symbol *symbol = symtab->GetSymbol(id);
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| 23 | if (symbol == NULL) {
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| 24 | /* Symbol not found */
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| 25 | messages.UndeclaredIdError(lineno, id);
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| 26 |
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| 27 | /* Add ID with return type error to avoid triggering error again */
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| 28 | symbol = new Symbol();
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| 29 | symbol->SetSymbolType(default_type);
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| 30 | symbol->SetName(id);
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| 31 | symbol->SetLine(lineno);
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| 32 | symbol->SetReturnType(RT_ERROR);
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| 33 | symtab->AddSymbol(symbol);
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| 34 | }
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| 35 | return symbol;
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| 36 | }
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| 37 |
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| 38 | /* Checks if the id already exists and gives an error if it does */
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| 39 | void check_id(const string& id)
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| 40 | {
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| 41 | /* check for program name */
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| 42 | if (id == mainScopeName) {
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| 43 | messages.DeclaredIdError(lineno, id, 0);
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| 44 | return;
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| 45 | }
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| 46 | /* check for local identifiers */
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| 47 | Symbol *symbol = symtab->GetSymbol(symtab->GetCurrentScopeName(), id, false);
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| 48 | if (symbol != NULL) {
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| 49 | messages.DeclaredIdError(lineno, id, symbol->GetLine());
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| 50 | return;
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| 51 | }
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| 52 | /* check for global identifiers */
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| 53 | symbol = symtab->GetSymbol(id);
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| 54 | if (symbol != NULL) {
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| 55 | SymbolType symboltype = symbol->GetSymbolType();
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| 56 | if (symboltype == ST_FUNCTION || symboltype == ST_PROCEDURE) {
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| 57 | messages.DeclaredIdError(lineno, id, symbol->GetLine());
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| 58 | return;
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| 59 | }
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| 60 | }
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| 61 | }
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