Merge bitcoin-core/secp256k1#1292: refactor: Make 64-bit shift explicit

d1e48e5 refactor: Make 64-bit shift explicit (Hennadii Stepanov)
b2e29e4 ci: Treat all compiler warnings as errors in "Windows (VS 2022)" task (Hennadii Stepanov)

Pull request description:

ACKs for top commit:
  real-or-random:
    utACK d1e48e5
  jonasnick:
    ACK d1e48e5

Tree-SHA512: fd07c8c136b1c947900d45b5a4ad4963e2c29884aca62a26be07713dfd1b0c5e7655f07a0b99217fc055bf3266e71cb5edabbd4d5c145a172b4be5d10f7ad51c

.cirrus.yml

@@ -397,7 +397,7 @@ task:
     - PowerShell -NoLogo -Command if ($env:CIRRUS_PR -ne $null) { git fetch $env:CIRRUS_REPO_CLONE_URL pull/$env:CIRRUS_PR/merge; git reset --hard FETCH_HEAD; }
   configure_script:
     - '%x64_NATIVE_TOOLS%'
-    - cmake -G "Visual Studio 17 2022" -A x64 -S . -B build -DSECP256K1_ENABLE_MODULE_RECOVERY=ON -DSECP256K1_BUILD_EXAMPLES=ON
+    - cmake -E env CFLAGS="/WX" cmake -G "Visual Studio 17 2022" -A x64 -S . -B build -DSECP256K1_ENABLE_MODULE_RECOVERY=ON -DSECP256K1_BUILD_EXAMPLES=ON
   build_script:
     - '%x64_NATIVE_TOOLS%'
     - cmake --build build --config RelWithDebInfo -- -property:UseMultiToolTask=true;CL_MPcount=5

src/ecmult_impl.h

@@ -680,7 +680,7 @@ static int secp256k1_ecmult_pippenger_batch(const secp256k1_callback* error_call
     }
     state_space->ps = (struct secp256k1_pippenger_point_state *) secp256k1_scratch_alloc(error_callback, scratch, entries * sizeof(*state_space->ps));
     state_space->wnaf_na = (int *) secp256k1_scratch_alloc(error_callback, scratch, entries*(WNAF_SIZE(bucket_window+1)) * sizeof(int));
-    buckets = (secp256k1_gej *) secp256k1_scratch_alloc(error_callback, scratch, (1<<bucket_window) * sizeof(*buckets));
+    buckets = (secp256k1_gej *) secp256k1_scratch_alloc(error_callback, scratch, ((size_t)1 << bucket_window) * sizeof(*buckets));
     if (state_space->ps == NULL || state_space->wnaf_na == NULL || buckets == NULL) {
         secp256k1_scratch_apply_checkpoint(error_callback, scratch, scratch_checkpoint);
         return 0;

src/tests.c

@@ -2221,7 +2221,7 @@ static void scalar_test(void) {
         for (i = 0; i < 100; ++i) {
             int low;
             int shift = 1 + secp256k1_testrand_int(15);
-            int expected = r.d[0] % (1 << shift);
+            int expected = r.d[0] % (1ULL << shift);
             low = secp256k1_scalar_shr_int(&r, shift);
             CHECK(expected == low);
         }