Author: Kadir Cetinkaya Date: 2020-11-13T17:01:07+01:00 New Revision: 6e7dd1e3e1170080b76b5dcc5716bdd974343233
URL: https://github.com/llvm/llvm-project/commit/6e7dd1e3e1170080b76b5dcc5716bdd974343233 DIFF: https://github.com/llvm/llvm-project/commit/6e7dd1e3e1170080b76b5dcc5716bdd974343233.diff LOG: [clangd] Assert on varint encoding 5th byte of a varint can't be bigger than 0x0f, fix a test and add an assertion. Differential Revision: https://reviews.llvm.org/D91405 Added: Modified: clang-tools-extra/clangd/index/Serialization.cpp clang-tools-extra/clangd/unittests/SerializationTests.cpp Removed: ################################################################################ diff --git a/clang-tools-extra/clangd/index/Serialization.cpp b/clang-tools-extra/clangd/index/Serialization.cpp index 0b82224fa715..8b0ae3925a2f 100644 --- a/clang-tools-extra/clangd/index/Serialization.cpp +++ b/clang-tools-extra/clangd/index/Serialization.cpp @@ -21,6 +21,7 @@ #include "llvm/Support/Endian.h" #include "llvm/Support/Error.h" #include "llvm/Support/raw_ostream.h" +#include <cstdint> #include <vector> namespace clang { @@ -81,12 +82,17 @@ class Reader { uint32_t consumeVar() { constexpr static uint8_t More = 1 << 7; - uint8_t B = consume8(); + + // Use a 32 bit unsigned here to prevent promotion to signed int (unless int + // is wider than 32 bits). + uint32_t B = consume8(); if (LLVM_LIKELY(!(B & More))) return B; uint32_t Val = B & ~More; for (int Shift = 7; B & More && Shift < 32; Shift += 7) { B = consume8(); + // 5th byte of a varint can only have lowest 4 bits set. + assert((Shift != 28 || B == (B & 0x0f)) && "Invalid varint encoding"); Val |= (B & ~More) << Shift; } return Val; diff --git a/clang-tools-extra/clangd/unittests/SerializationTests.cpp b/clang-tools-extra/clangd/unittests/SerializationTests.cpp index 94db6c9127a8..ca7d3ba7e3e1 100644 --- a/clang-tools-extra/clangd/unittests/SerializationTests.cpp +++ b/clang-tools-extra/clangd/unittests/SerializationTests.cpp @@ -366,9 +366,9 @@ TEST(SerializationTest, NoCrashOnBadArraySize) { Pos += FileDigest.size(); // Varints are little-endian base-128 numbers, where the top-bit of each byte - // indicates whether there are more. 8fffffff7f -> 0xffffffff. + // indicates whether there are more. ffffffff0f -> 0xffffffff. std::string CorruptSrcs = - (Srcs->Data.take_front(Pos) + llvm::fromHex("8fffffff7f") + + (Srcs->Data.take_front(Pos) + llvm::fromHex("ffffffff0f") + "some_random_garbage") .str(); Srcs->Data = CorruptSrcs; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
