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Check formatted string structure at load time

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If we have a bug, or somebody edits the project file manually, we
can end up with a very wrong string, such as a null-terminated
string that isn't, or a DCI string that has a mix of high and low
ASCII from start to finish.  We now check all incoming strings for
validity, and discard any that fail the test.  The verification
code is shared with the extension script inline data formatter.

Also, added a comment to an F8-ROM symbol I stumbled over.
This commit is contained in:
Andy McFadden
2019-10-06 17:07:07 -07:00
parent c4fe759efc
commit 8c87ce3004
6 changed files with 154 additions and 90 deletions
Download Patch File Download Diff File Expand all files Collapse all files
SourceGen/CodeAnalysis.cs
+3 -62
View File
@@ -1086,7 +1086,9 @@ namespace SourceGen {
}
if (isStringType) {
if (!VerifyStringData(offset, length, fmt)) {
if (!DataAnalysis.VerifyStringData(mFileData, offset, length, fmt,
out string failMsg)) {
LogW(offset, failMsg);
return false;
}
} else if (type == DataType.Fill) {
@@ -1111,67 +1113,6 @@ namespace SourceGen {
return true;
}
/// <summary>
/// Verifies that the string data is what is expected. Does not attempt to check
/// the character encoding, just the structure.
/// </summary>
/// <returns>True if all is well.</returns>
private bool VerifyStringData(int offset, int length, FormatDescriptor.Type type) {
switch (type) {
case FormatDescriptor.Type.StringGeneric:
case FormatDescriptor.Type.StringReverse:
return true;
case FormatDescriptor.Type.StringNullTerm:
// must end in null byte, and have no null bytes before the end
int chk = offset;
while (length-- != 0) {
byte val = mFileData[chk++];
if (val == 0x00) {
if (length != 0) {
LogW(offset, "found null in middle of null-term string");
return false;
} else {
return true;
}
}
}
LogW(offset, "no null at end of null-term string");
return false;
case FormatDescriptor.Type.StringL8:
if (mFileData[offset] != length - 1) {
LogW(offset, "L1 string with mismatched length");
return false;
}
return true;
case FormatDescriptor.Type.StringL16:
int len = RawData.GetWord(mFileData, offset, 2, false);
if (len != length - 2) {
LogW(offset, "L2 string with mismatched length");
return false;
}
return true;
case FormatDescriptor.Type.StringDci:
if (length < 2) {
LogW(offset, "DCI string is too short");
return false;
}
byte first = (byte) (mFileData[offset] & 0x80);
for (int i = offset + 1; i < offset + length - 1; i++) {
if ((mFileData[i] & 0x80) != first) {
LogW(offset, "mixed DCI string");
return false;
}
}
if ((mFileData[offset + length - 1] & 0x80) == first) {
LogW(offset, "DCI string did not end");
return false;
}
return true;
default:
Debug.Assert(false);
return false;
}
}
private bool VerifyFillData(int offset, int length) {
byte first = mFileData[offset];