[codeview] Truncate records to maximum record size near 64KB
If we don't truncate, LLVM asserts when the label difference doesn't fit
in a 16 bit field. This patch truncates two kinds of data: trailing null
terminated names in symbol records, and inline line tables. The inline
line table test that I have is too large (many MB), so I'm not checking
it in.
Hopefully fixes PR28264.
llvm-svn: 283403
diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index 1850a30..a305e3d 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -432,10 +432,13 @@
}
static void emitNullTerminatedSymbolName(MCStreamer &OS, StringRef S) {
- // Microsoft's linker seems to have trouble with symbol names longer than
- // 0xffd8 bytes.
- S = S.substr(0, 0xffd8);
- SmallString<32> NullTerminatedString(S);
+ // The maximum CV record length is 0xFF00. Most of the strings we emit appear
+ // after a fixed length portion of the record. The fixed length portion should
+ // always be less than 0xF00 (3840) bytes, so truncate the string so that the
+ // overall record size is less than the maximum allowed.
+ unsigned MaxFixedRecordLength = 0xF00;
+ SmallString<32> NullTerminatedString(
+ S.take_front(MaxRecordLength - MaxFixedRecordLength - 1));
NullTerminatedString.push_back('\0');
OS.EmitBytes(NullTerminatedString);
}