6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-07-29 10:25:12 +00:00
Code Issues Projects Releases Wiki Activity

Fix handling of the From parameter in StringRef::find.

Browse Source 
Enable bounds checking to catch this kind of bug earlier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142247 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Benjamin Kramer
2011-10-17 20:49:40 +00:00
parent 5bc85286ff
commit e7a0719161
1 changed files with 5 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
lib/Support/StringRef.cpp
View File

@@ -153,19 +153,22 @@ size_t StringRef::find(StringRef Str, size_t From) const {
return npos; return npos;
} }
if (From >= Length)
return npos;
// Build the bad char heuristic table, with uint8_t to reduce cache thrashing. // Build the bad char heuristic table, with uint8_t to reduce cache thrashing.
uint8_t BadCharSkip[256]; uint8_t BadCharSkip[256];
std::memset(BadCharSkip, N, 256); std::memset(BadCharSkip, N, 256);
for (unsigned i = 0; i != N-1; ++i) for (unsigned i = 0; i != N-1; ++i)
BadCharSkip[(uint8_t)Str[i]] = N-1-i; BadCharSkip[(uint8_t)Str[i]] = N-1-i;
unsigned Len = Length, Pos = min(From, Length); unsigned Len = Length-From, Pos = From;
while (Len >= N) { while (Len >= N) {
if (substr(Pos, N).equals(Str)) // See if this is the correct substring. if (substr(Pos, N).equals(Str)) // See if this is the correct substring.
return Pos; return Pos;
// Otherwise skip the appropriate number of bytes. // Otherwise skip the appropriate number of bytes.
uint8_t Skip = BadCharSkip[(uint8_t)Data[Pos+N-1]]; uint8_t Skip = BadCharSkip[(uint8_t)(*this)[Pos+N-1]];
Len -= Skip; Len -= Skip;
Pos += Skip; Pos += Skip;
} }