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changeset 33:890a8f688889
Basic parsing of local variable decls
| author | lost@l-w.ca |
|---|---|
| date | Thu, 03 Feb 2011 22:15:57 -0700 |
| parents | 49d608aecc4d |
| children | bfea77812e64 |
| files | lwbasic/lexer.c lwbasic/lwbasic.h lwbasic/parser.c |
| diffstat | 3 files changed, 43 insertions(+), 3 deletions(-) [+] |
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--- a/lwbasic/lexer.c Thu Feb 03 22:00:47 2011 -0700 +++ b/lwbasic/lexer.c Thu Feb 03 22:15:57 2011 -0700 @@ -58,6 +58,7 @@ { "integer", token_kw_integer }, { "endsub", token_kw_endsub }, { "endfunction", token_kw_endfunction }, + { "dim", token_kw_dim }, { NULL } };
--- a/lwbasic/lwbasic.h Thu Feb 03 22:00:47 2011 -0700 +++ b/lwbasic/lwbasic.h Thu Feb 03 22:15:57 2011 -0700 @@ -85,6 +85,7 @@ token_kw_integer, /* INTEGER keyword */ token_kw_endsub, /* ENDSUB keyword */ token_kw_endfunction, /* ENDFUNCTION keyword */ + token_kw_dim, /* DIM keyword */ token_identifier, /* an identifier (variable, function, etc. */ token_char, /* single character; fallback */ token_uint, /* unsigned integer up to 32 bits */
--- a/lwbasic/parser.c Thu Feb 03 22:00:47 2011 -0700 +++ b/lwbasic/parser.c Thu Feb 03 22:15:57 2011 -0700 @@ -62,10 +62,48 @@ static void parse_decls(cstate *state) { /* declarations */ - switch (state -> lexer_token) + /* the first thing that doesn't look like a declaration is assumed */ + /* to be a statement and will trigger a bailout */ + int vt; + char *vn; + symtab_entry_t *se; + + for (;;) { - default: - return; + switch (state -> lexer_token) + { + /* DIM keyword */ + case token_kw_dim: + lexer(state); + if (state -> lexer_token != token_identifier) + { + lwb_error("Expecting identifier, got %s\n", lexer_return_token(state)); + } + vn = lw_strdup(state -> lexer_token_string); + lexer(state); + if (state -> lexer_token != token_kw_as) + { + lwb_error("Expecting AS, got %s\n", lexer_return_token(state)); + } + lexer(state); + vt = parse_type(state); + + se = symtab_find(state -> local_syms, vn); + if (se) + { + lwb_error("Multiply defined local variable %s", vn); + } + state -> framesize += sizeof_type(vt); + symtab_register(state -> local_syms, vn, -(state -> framesize), symtype_var, NULL); + + lw_free(vn); + break; + default: + return; + } + if (state -> lexer_token != token_eol) + lwb_error("Expecting end of line; got %s", lexer_return_token(state)); + lexer(state); } }