Diagnostics: if a line is longer than 4096 characters, don't print it.
Specifically, don't print snippets, caret diagnostics, or ranges for
lines over 4096 characters. We copy the line around a few times in our
diagnostics machinery, and we have to print a caret line that's just as
long. This uses a lot of memory just to create a poor user experience as
we print out a line much too long for anyone to read...or spend extra
energy trying to fit it to -fmessage-length.
<rdar://problem/13106850>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173976 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/TextDiagnostic.cpp b/lib/Frontend/TextDiagnostic.cpp
index f7c0d60..c2562eb 100644
--- a/lib/Frontend/TextDiagnostic.cpp
+++ b/lib/Frontend/TextDiagnostic.cpp
@@ -1096,18 +1096,26 @@
unsigned LineNo = SM.getLineNumber(FID, FileOffset);
unsigned ColNo = SM.getColumnNumber(FID, FileOffset);
+
+ // Arbitrarily stop showing snippets when the line is too long.
+ static const unsigned MaxLineLength = 4096;
+ if (ColNo > MaxLineLength)
+ return;
// Rewind from the current position to the start of the line.
const char *TokPtr = BufStart+FileOffset;
const char *LineStart = TokPtr-ColNo+1; // Column # is 1-based.
-
// Compute the line end. Scan forward from the error position to the end of
// the line.
const char *LineEnd = TokPtr;
while (*LineEnd != '\n' && *LineEnd != '\r' && *LineEnd != '\0')
++LineEnd;
+ // Arbitrarily stop showing snippets when the line is too long.
+ if (LineEnd - LineStart > MaxLineLength)
+ return;
+
// Copy the line of code into an std::string for ease of manipulation.
std::string SourceLine(LineStart, LineEnd);