[PATCH] D77304: [llvm/Support] Don't crash on empty nullptr ranges when decoding LEBs

[Pavel Labath via Phabricator via llvm-commits]

labath updated this revision to Diff 254510.
labath added a comment.

Upload the diff properly


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D77304/new/

https://reviews.llvm.org/D77304

Files:
  llvm/include/llvm/Support/LEB128.h
  llvm/unittests/Support/LEB128Test.cpp


Index: llvm/unittests/Support/LEB128Test.cpp
===================================================================
--- llvm/unittests/Support/LEB128Test.cpp
+++ llvm/unittests/Support/LEB128Test.cpp
@@ -113,6 +113,9 @@
     EXPECT_EQ(EXPECTED, Actual); \
   } while (0)
 
+  // Don't crash
+  EXPECT_EQ(0u, decodeULEB128(nullptr, nullptr, nullptr));
+
   // Decode ULEB128
   EXPECT_DECODE_ULEB128_EQ(0u, "\x00");
   EXPECT_DECODE_ULEB128_EQ(1u, "\x01");
@@ -148,6 +151,9 @@
     EXPECT_EQ(EXPECTED, Actual); \
   } while (0)
 
+  // Don't crash
+  EXPECT_EQ(0, decodeSLEB128(nullptr, nullptr, nullptr));
+
   // Decode SLEB128
   EXPECT_DECODE_SLEB128_EQ(0L, "\x00");
   EXPECT_DECODE_SLEB128_EQ(1L, "\x01");
Index: llvm/include/llvm/Support/LEB128.h
===================================================================
--- llvm/include/llvm/Support/LEB128.h
+++ llvm/include/llvm/Support/LEB128.h
@@ -134,7 +134,7 @@
   if (error)
     *error = nullptr;
   do {
-    if (end && p == end) {
+    if (p == end) {
       if (error)
         *error = "malformed uleb128, extends past end";
       if (n)
@@ -168,7 +168,7 @@
   if (error)
     *error = nullptr;
   do {
-    if (end && p == end) {
+    if (p == end) {
       if (error)
         *error = "malformed sleb128, extends past end";
       if (n)


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