diff options
| -rw-r--r-- | subx/035labels.cc | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/subx/035labels.cc b/subx/035labels.cc index a6da02eb..9f584425 100644 --- a/subx/035labels.cc +++ b/subx/035labels.cc @@ -48,11 +48,15 @@ void compute_addresses_for_labels(const segment& code, map<string, int32_t>& add ++current_byte; } else { + string label = drop_last(curr.data); + if (SIZE(label) <= 2) { + raise << "label '" << label << "' is too short; must be more than two characters long\n" << end(); + return; + } if (contains_any_operand_metadata(curr)) raise << "'" << to_string(inst) << "': label definition (':') not allowed in operand\n" << end(); if (j > 0) raise << "'" << to_string(inst) << "': labels can only be the first word in a line.\n" << end(); - string label = curr.data.substr(0, SIZE(curr.data)-1); put(address, label, current_byte); trace(99, "transform") << "label '" << label << "' is at address " << (current_byte+code.start) << end(); // no modifying current_byte; label definitions won't be in the final binary @@ -130,6 +134,10 @@ string data_to_string(const line& inst) { return out.str(); } +string drop_last(const string& s) { + return string(s.begin(), --s.end()); +} + //: Label definitions must be the first word on a line. No jumping inside //: instructions. //: They should also be the only word on a line. @@ -159,3 +167,13 @@ loop3: +transform: instruction after transform: 'eb f9' # second jump is to 0 (fall through) +transform: instruction after transform: 'eb 00' + +:(scenario label_too_short) +% Hide_errors = true; +== 0x1 + # instruction effective address operand displacement immediate + # op subop mod rm32 base index scale r32 + # 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes +xz: + 05 0x0d0c0b0a/imm32 # add to EAX ++error: label 'xz' is too short; must be more than two characters long |