fix(ci): address Ubuntu 26 compiler diagnostics

src/nanoarrow/common/utils_test.cc

@@ -267,36 +267,33 @@ TEST(DecimalTest, Decimal32Test) {
 
 #if defined(NANOARROW_BUILD_TESTS_WITH_ARROW) && ARROW_VERSION_MAJOR >= 18
   auto dec_pos = *Decimal32::FromString("12.345");
-  uint8_t bytes_pos[4];
+  // ArrowDecimalSetBytes() accepts buffers for all decimal widths. Allocate enough
+  // space for either branch so bounds-checking compilers do not diagnose the
+  // unreachable Decimal64 copy below.
+  uint8_t bytes_pos[sizeof(uint64_t)] = {};
   dec_pos.ToBytes(bytes_pos);
 
   auto dec_neg = *Decimal32::FromString("-34.567");
-  uint8_t bytes_neg[4];
+  uint8_t bytes_neg[sizeof(uint64_t)] = {};
   dec_neg.ToBytes(bytes_neg);
 #endif
 
   ArrowDecimalSetInt(&decimal, 12345);
   EXPECT_EQ(ArrowDecimalGetIntUnsafe(&decimal), 12345);
   EXPECT_EQ(ArrowDecimalSign(&decimal), 1);
 #if defined(NANOARROW_BUILD_TESTS_WITH_ARROW) && ARROW_VERSION_MAJOR >= 18
-  EXPECT_EQ(memcmp(decimal.words, bytes_pos, sizeof(bytes_pos)), 0);
-  ASSERT_EQ(decimal.n_words, 0);
-  // This duplicative assert suppresses array-bounds warnings with release builds
-  assert(decimal.n_words == 0);
+  EXPECT_EQ(memcmp(decimal.words, bytes_pos, sizeof(int32_t)), 0);
   ArrowDecimalSetBytes(&decimal, bytes_pos);
-  EXPECT_EQ(memcmp(decimal.words, bytes_pos, sizeof(bytes_pos)), 0);
+  EXPECT_EQ(memcmp(decimal.words, bytes_pos, sizeof(int32_t)), 0);
 #endif
 
   ArrowDecimalSetInt(&decimal, -34567);
   EXPECT_EQ(ArrowDecimalGetIntUnsafe(&decimal), -34567);
   EXPECT_EQ(ArrowDecimalSign(&decimal), -1);
 #if defined(NANOARROW_BUILD_TESTS_WITH_ARROW) && ARROW_VERSION_MAJOR >= 18
-  EXPECT_EQ(memcmp(decimal.words, bytes_neg, sizeof(bytes_neg)), 0);
-  ASSERT_EQ(decimal.n_words, 0);
-  // This duplicative assert suppresses array-bounds warnings with release builds
-  assert(decimal.n_words == 0);
+  EXPECT_EQ(memcmp(decimal.words, bytes_neg, sizeof(int32_t)), 0);
   ArrowDecimalSetBytes(&decimal, bytes_neg);
-  EXPECT_EQ(memcmp(decimal.words, bytes_neg, sizeof(bytes_neg)), 0);
+  EXPECT_EQ(memcmp(decimal.words, bytes_neg, sizeof(int32_t)), 0);
 #endif
 }
 

src/nanoarrow/hpp/view_test.cc

@@ -15,6 +15,8 @@
 // specific language governing permissions and limitations
 // under the License.
 
+#include <array>
+
 #include <gmock/gmock-matchers.h>
 #include <gtest/gtest.h>
 
@@ -107,9 +109,9 @@ TEST_P(BinaryViewTypeTestFixture, NanoarrowHppViewBinaryViewArrayAsBytesTest) {
   array->offset = offset;
   array->length = array->length - offset;
 
-  ArrowStringView expected[] = {"foo"_asv, ""_asv,
-                                "this_string_is_longer_than_inline"_asv, ""_asv,
-                                "here_is_another_string"_asv};
+  std::array<ArrowStringView, 5> expected = {"foo"_asv, ""_asv,
+                                             "this_string_is_longer_than_inline"_asv,
+                                             ""_asv, "here_is_another_string"_asv};
 
   nanoarrow::UniqueArrayView array_view{};
   ArrowArrayViewInitFromType(array_view.get(), type);
@@ -120,7 +122,7 @@ TEST_P(BinaryViewTypeTestFixture, NanoarrowHppViewBinaryViewArrayAsBytesTest) {
     if (i == 1 || i == 3) {
       EXPECT_EQ(slot, nanoarrow::NA);
     } else {
-      EXPECT_EQ(slot, expected[i]);
+      EXPECT_EQ(slot, expected.at(i));
     }
     ++i;
   }
@@ -130,7 +132,7 @@ TEST_P(BinaryViewTypeTestFixture, NanoarrowHppViewBinaryViewArrayAsBytesTest) {
     if (i == 1 || i == 3) {
       EXPECT_EQ(slot, nanoarrow::NA);
     } else {
-      EXPECT_EQ(slot, expected[i]);
+      EXPECT_EQ(slot, expected.at(i));
     }
     ++i;
   }

src/nanoarrow/integration/ipc_integration.cc

@@ -17,6 +17,7 @@
 
 #include <cstdlib>
 #include <sstream>
+#include <stdexcept>
 
 #include <nanoarrow/nanoarrow_ipc.hpp>
 #include <nanoarrow/nanoarrow_testing.hpp>
@@ -115,14 +116,25 @@ struct File {
   }
 
   std::string read() const {
-    fseek(file_, 0, SEEK_END);
-    std::string contents(ftell(file_), '\0');
-    rewind(file_);
+    if (fseek(file_, 0, SEEK_END) != 0) {
+      throw std::runtime_error("Could not seek to the end of the input file");
+    }
+
+    long file_size = ftell(file_);
+    if (file_size < 0) {
+      throw std::runtime_error("Could not determine the input file size");
+    }
 
-    size_t bytes_read = 0;
-    while (bytes_read < contents.size()) {
-      bytes_read += fread(&contents[bytes_read], 1, contents.size() - bytes_read, file_);
+    if (fseek(file_, 0, SEEK_SET) != 0) {
+      throw std::runtime_error("Could not seek to the beginning of the input file");
     }
+
+    std::string contents(static_cast<size_t>(file_size), '\0');
+    if (!contents.empty() &&
+        fread(&contents[0], 1, contents.size(), file_) != contents.size()) {
+      throw std::runtime_error("Could not read the complete input file");
+    }
+
     return contents;
   }