saturate, scope

Author: labath

llvm/lib/Object/SFrameParser.cpp

@@ -10,19 +10,21 @@
 #include "llvm/BinaryFormat/SFrame.h"
 #include "llvm/Object/Error.h"
 #include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/MathExtras.h"
 
 using namespace llvm;
 using namespace llvm::object;
 
 static Expected<ArrayRef<uint8_t>>
 getDataSlice(ArrayRef<uint8_t> Data, uint64_t Offset, uint64_t Size) {
-  // Check for overflow.
-  if (Offset + Size < Offset || Offset + Size < Size ||
-      Offset + Size > Data.size()) {
+  uint64_t End = SaturatingAdd(Offset, Size);
+  // Data.size() cannot be UINT64_MAX, as it would occupy the whole address
+  // space.
+  if (End > Data.size()) {
     return createStringError(
         formatv("unexpected end of data at offset {0:x} while reading [{1:x}, "
                 "{2:x})",
-                Data.size(), Offset, Offset + Size)
+                Data.size(), Offset, End)
             .str(),
         object_error::unexpected_eof);
   }

llvm/test/tools/llvm-readobj/ELF/sframe-fde.test

@@ -101,10 +101,11 @@ Sections:
 #  CASE1-NEXT:      Size: 0x1BE
 #  CASE1-NEXT:      Start FRE Offset: 0x10
 #  CASE1-NEXT:      Num FREs: 0
-#  CASE1-NEXT:      Info: 0x31
-#  CASE1-NEXT:      FRE Type: Addr2 (0x1)
-#  CASE1-NEXT:      FDE Type: PCMask (0x1)
-#  CASE1-NEXT:      PAuth Key (unused): 1
+#  CASE1-NEXT:      Info {
+#  CASE1-NEXT:        FRE Type: Addr2 (0x1)
+#  CASE1-NEXT:        FDE Type: PCMask (0x1)
+#  CASE1-NEXT:        Raw: 0x31
+#  CASE1-NEXT:      }
 #  CASE1-NEXT:      Repetitive block size: 0xDE
 #  CASE1-NEXT:      Padding2: 0xAD
 #  CASE1-NEXT:    }
@@ -160,10 +161,12 @@ Sections:
 #  CASE1-NEXT:      Size: 0x1BE
 #  CASE1-NEXT:      Start FRE Offset: 0x10
 #  CASE1-NEXT:      Num FREs: 0
-#  CASE1-NEXT:      Info: 0x2
-#  CASE1-NEXT:      FRE Type: Addr4 (0x2)
-#  CASE1-NEXT:      FDE Type: PCInc (0x0)
-#  CASE1-NEXT:      PAuth Key: A (0x0)
+#  CASE1-NEXT:      Info {
+#  CASE1-NEXT:        FRE Type: Addr4 (0x2)
+#  CASE1-NEXT:        FDE Type: PCInc (0x0)
+#  CASE1-NEXT:        PAuth Key: A (0x0)
+#  CASE1-NEXT:        Raw: 0x2
+#  CASE1-NEXT:      }
 #  CASE1-NEXT:      Repetitive block size (unused): 0xDE
 #  CASE1-NEXT:      Padding2: 0xAD
 #  CASE1-NEXT:    }
@@ -221,10 +224,12 @@ Sections:
 #  CASE2-NEXT:      Size: 0x1BE
 #  CASE2-NEXT:      Start FRE Offset: 0x10
 #  CASE2-NEXT:      Num FREs: 16
-#  CASE2-NEXT:      Info: 0x2
-#  CASE2-NEXT:      FRE Type: Addr4 (0x2)
-#  CASE2-NEXT:      FDE Type: PCInc (0x0)
-#  CASE2-NEXT:      PAuth Key: A (0x0)
+#  CASE2-NEXT:      Info {
+#  CASE2-NEXT:        FRE Type: Addr4 (0x2)
+#  CASE2-NEXT:        FDE Type: PCInc (0x0)
+#  CASE2-NEXT:        PAuth Key: A (0x0)
+#  CASE2-NEXT:        Raw: 0x2
+#  CASE2-NEXT:      }
 #  CASE2-NEXT:      Repetitive block size (unused): 0xDE
 #  CASE2-NEXT:      Padding2: 0xAD00
 #  CASE2-NEXT:    }

llvm/tools/llvm-readobj/ELFDumper.cpp

@@ -6498,18 +6498,22 @@ void ELFDumper<ELFT>::printSFrameFDEs(
     W.printHex("Start FRE Offset", It->StartFREOff);
     W.printNumber("Num FREs", It->NumFREs);
 
-    W.printHex("Info", It->Info);
-    W.printEnum("FRE Type", It->getFREType(), sframe::getFRETypes());
-    W.printEnum("FDE Type", It->getFDEType(), sframe::getFDETypes());
-    switch (Parser.getHeader().ABIArch) {
-    case sframe::ABI::AArch64EndianBig:
-    case sframe::ABI::AArch64EndianLittle:
-      W.printEnum("PAuth Key", sframe::AArch64PAuthKey(It->getPAuthKey()),
-                  sframe::getAArch64PAuthKeys());
-      break;
-    default:
-      W.printNumber("PAuth Key (unused)", It->getPAuthKey());
-      break;
+    {
+      DictScope InfoScope(W, "Info");
+      W.printEnum("FRE Type", It->getFREType(), sframe::getFRETypes());
+      W.printEnum("FDE Type", It->getFDEType(), sframe::getFDETypes());
+      switch (Parser.getHeader().ABIArch) {
+      case sframe::ABI::AArch64EndianBig:
+      case sframe::ABI::AArch64EndianLittle:
+        W.printEnum("PAuth Key", sframe::AArch64PAuthKey(It->getPAuthKey()),
+                    sframe::getAArch64PAuthKeys());
+        break;
+      case sframe::ABI::AMD64EndianLittle:
+        // unused
+        break;
+      }
+
+      W.printHex("Raw", It->Info);
     }
 
     W.printHex(