[clang-tools-extra] 0b103ed - [clangd] Fix a hover crash on unsigned 64bit value

[Younan Zhang via cfe-commits]

Author: Younan Zhang
Date: 2023-03-27T10:27:11+08:00
New Revision: 0b103edf5b2c6178c2725a9ff085c6ccc866bccb

URL: https://github.com/llvm/llvm-project/commit/0b103edf5b2c6178c2725a9ff085c6ccc866bccb
DIFF: https://github.com/llvm/llvm-project/commit/0b103edf5b2c6178c2725a9ff085c6ccc866bccb.diff

LOG: [clangd] Fix a hover crash on unsigned 64bit value

This patch adapts to D140059, which makes an assumption that the
caller of `APSInt::getExtValue` promises no narrowing conversion
happens, i.e., from unsigned int64 to signed int64.

It also fixes clangd/clangd#1557.

Reviewed By: nridge

Differential Revision: https://reviews.llvm.org/D146874

Added: 
    

Modified: 
    clang-tools-extra/clangd/Hover.cpp
    clang-tools-extra/clangd/unittests/HoverTests.cpp

Removed: 
    


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diff  --git a/clang-tools-extra/clangd/Hover.cpp b/clang-tools-extra/clangd/Hover.cpp
index e240c22259f35..27663991a7f3c 100644
--- a/clang-tools-extra/clangd/Hover.cpp
+++ b/clang-tools-extra/clangd/Hover.cpp
@@ -400,9 +400,9 @@ void fillFunctionTypeAndParams(HoverInfo &HI, const Decl *D,
 // 100   => 0x64
 // Negative numbers are sign-extended to 32/64 bits
 // -2    => 0xfffffffe
-// -2^32 => 0xfffffffeffffffff
+// -2^32 => 0xffffffff00000000
 static llvm::FormattedNumber printHex(const llvm::APSInt &V) {
-  uint64_t Bits = V.getExtValue();
+  uint64_t Bits = V.getZExtValue();
   if (V.isNegative() && V.getSignificantBits() <= 32)
     return llvm::format_hex(uint32_t(Bits), 0);
   return llvm::format_hex(Bits, 0);

diff  --git a/clang-tools-extra/clangd/unittests/HoverTests.cpp b/clang-tools-extra/clangd/unittests/HoverTests.cpp
index 728f5444014dc..df46e2fa09951 100644
--- a/clang-tools-extra/clangd/unittests/HoverTests.cpp
+++ b/clang-tools-extra/clangd/unittests/HoverTests.cpp
@@ -3045,6 +3045,15 @@ TEST(Hover, NoCrash) {
     getHover(AST, P, format::getLLVMStyle(), nullptr);
 }
 
+TEST(Hover, NoCrashAPInt64) {
+  Annotations T(R"cpp(
+    constexpr unsigned long value = -1; // wrap around
+    void foo() { va^lue; }
+  )cpp");
+  auto AST = TestTU::withCode(T.code()).build();
+  getHover(AST, T.point(), format::getLLVMStyle(), nullptr);
+}
+
 TEST(Hover, DocsFromMostSpecial) {
   Annotations T(R"cpp(
   // doc1