perf: Dispatch hasInvalidAmount on type tag instead of dynamic_cast

hasInvalidAmount runs on the per-transaction invariant-checking path
(ValidAmounts::finalize) and at preflight, walking every field of every
modified entry. The previous implementation tried a dynamic_cast chain
(STAmount, STObject, STArray) on each field, so every scalar non-amount
field paid three failed RTTI casts.

Dispatch on the serialized type tag via getSType() and a switch instead.
The object-like tags all denote STObject subclasses (STLedgerEntry, STTx),
so the downcast is sound; safeDowncast keeps a dynamic_cast validity
assert in debug builds while compiling to static_cast in release.

cspell.config.yaml

@@ -134,6 +134,7 @@ words:
   - iou
   - ious
   - isrdc
+  - isystem
   - itype
   - jemalloc
   - jlog

docker/check-tools.sh

@@ -8,11 +8,13 @@ clang++ --version
 clang-format --version
 cmake --version
 conan --version
+curl --version
 g++ --version
 gcc --version
 gcov --version
 gcovr --version
 git --version
+gpg --version
 less --version
 make --version
 mold --version

docker/test_files/cpp_sources/asan.cpp

@@ -2,6 +2,13 @@
 #include <cstddef>
 #include <iostream>
 
+// Regression test: the compiler-rt sanitizer interface headers must be on the
+// include path. A bare on-PATH clang in the Nix CI env doesn't get them
+// propagated automatically, so this include would fail to compile with clang++
+// if the env isn't wired up correctly. abseil hits the same include during
+// sanitizer builds. LeakSanitizer ships with AddressSanitizer.
+#include <sanitizer/lsan_interface.h>
+
 #if defined(__clang__) || defined(__GNUC__)
 __attribute__((noinline))
 #elif defined(_MSC_VER)

nix/ci-env.nix

@@ -94,6 +94,14 @@ let
       ln -s "${customCompilerRt.out}/lib" "$rsrc/lib"
       ln -s "${customCompilerRt.out}/share" "$rsrc/share" || true
       echo "-resource-dir=$rsrc" >> $out/nix-support/cc-cflags
+      # compiler-rt ships the sanitizer/profile/xray interface headers (e.g.
+      # <sanitizer/lsan_interface.h>) in its `dev` output. In a normal Nix
+      # build these reach the include path because compiler-rt is propagated
+      # via depsTargetTargetPropagated and stdenv's setup hooks add its
+      # dev/include. The CI image runs clang outside a Nix stdenv (binaries
+      # on PATH, no setup hooks), so that never happens; add the headers
+      # explicitly. gcc ships its own copy, which is why this is clang-only.
+      echo "-isystem ${customCompilerRt.dev}/include" >> $out/nix-support/cc-cflags
     '';
   };
 

nix/packages.nix

@@ -11,9 +11,11 @@ in
     ccache
     cmake
     conan
+    curlMinimal # needed for codecov/codecov-action
     gcovr
     git
     gnumake
+    gnupg # needed for signing commits & codecov/codecov-action
     llvmPackages_22.clang-tools
     less # needed for git diff
     mold

src/libxrpl/protocol/STAmount.cpp

@@ -1250,16 +1250,30 @@ hasInvalidAmount(STBase const& field, int depth, beast::Journal j)
         return true;
     }
 
-    if (auto const amount = dynamic_cast<STAmount const*>(&field))
-        return !isLegalMPT(*amount) || !isLegalNet(*amount);
+    // Dispatch on the serialized type tag rather than RTTI: this is on the invariant-checking path
+    // and a dynamic_cast chain over every field of every modified entry is measurably expensive.
+    // The object-like tags below all denote STObject subclasses (STLedgerEntry, STTx), so the
+    // downcast is sound; nested fields are only ever plain STI_OBJECT / STI_ARRAY containers.
+    // safeDowncast keeps a dynamic_cast validity assert in debug builds while compiling to
+    // static_cast in release.
+    switch (field.getSType())
+    {
+        case STI_AMOUNT: {
+            auto const& amount = safeDowncast<STAmount const&>(field);
+            return !isLegalMPT(amount) || !isLegalNet(amount);
+        }
 
-    if (auto const object = dynamic_cast<STObject const*>(&field))
-        return hasInvalidAmount(*object, depth + 1, j);
+        case STI_OBJECT:
+        case STI_LEDGERENTRY:
+        case STI_TRANSACTION:
+            return hasInvalidAmount(safeDowncast<STObject const&>(field), depth + 1, j);
 
-    if (auto const array = dynamic_cast<STArray const*>(&field))
-        return hasInvalidAmount(*array, depth + 1, j);
+        case STI_ARRAY:
+            return hasInvalidAmount(safeDowncast<STArray const&>(field), depth + 1, j);
 
-    return false;
+        default:
+            return false;
+    }
 }
 
 bool