skip bounds test with GCC < 12

known GCC bug

Author: scivision

src/bounds/bounds.c

@@ -0,0 +1,74 @@
+#include <iostream>
+#include <ISO_Fortran_binding.h>
+
+#include "bounds.h"
+
+// ==================== 1D Version ====================
+bool c_bounder(CFI_cdesc_t* a,
+               CFI_index_t fortran_lower,
+               CFI_index_t fortran_upper)
+{
+    std::cout << "=== C++: c_bounder (1D) called ===\n";
+
+    if (a == nullptr) {
+        std::cerr << "ERROR: nullptr descriptor\n";
+        return false;
+    }
+
+    if (a->rank != 1) {
+        std::cerr << "ERROR: Expected rank 1, got " << a->rank << "\n";
+        return false;
+    }
+
+    const CFI_dim_t& dim = a->dim[0];
+    const CFI_index_t c_lower = dim.lower_bound;
+    const CFI_index_t extent   = dim.extent;
+    const CFI_index_t c_upper  = c_lower + extent - 1;
+
+    std::cout << "C Descriptor:   lower=" << c_lower << ", upper=" << c_upper << ", extent=" << extent << "\n";
+    std::cout << "Fortran Array:  lower=" << fortran_lower << ", upper=" << fortran_upper << "\n";
+
+    if (c_lower != 0) {
+        std::cerr << "WARNING: C lower bound is not 0 (got " << c_lower << ")\n";
+    }
+
+    if (extent != (fortran_upper - fortran_lower + 1)) {
+        std::cerr << "ERROR: Extent mismatch! Expected " << (fortran_upper - fortran_lower + 1) << ", got " << extent << "\n";
+        return false;
+    }
+
+    std::cout << "✓ Extent check PASSED\n";
+
+    return true;
+}
+
+// ==================== 2D Version ====================
+bool c_bounder_2d(CFI_cdesc_t* a,
+                  CFI_index_t fl1, CFI_index_t fu1,
+                  CFI_index_t fl2, CFI_index_t fu2)
+{
+    std::cout << "=== C++: c_bounder_2d called ===\n";
+
+    if (a == nullptr || a->rank != 2) {
+        std::cerr << "ERROR: Expected rank 2\n";
+        return false;
+    }
+
+    // Check dimensions
+    const CFI_index_t extent1 = a->dim[0].extent;
+    const CFI_index_t extent2 = a->dim[1].extent;
+
+    if (extent1 != (fu1 - fl1 + 1)) {
+        std::cerr << "ERROR: Dim1 extent mismatch\n";
+        return false;
+    }
+
+    if (extent2 != (fu2 - fl2 + 1)) {
+        std::cerr << "ERROR: Dim2 extent mismatch\n";
+        return false;
+    }
+
+    std::cout << "✓ 2D Extent check PASSED: [" << fl1 << ":" << fu1 << ", " << fl2 << ":" << fu2 << "]\n";
+
+    return true;
+}

src/bounds/bounds.cpp

@@ -1,6 +1,6 @@
-#if defined(__STDC_VERSION__) && __STDC_VERSION__ < 202311L
-#include <stdbool.h>
-#endif
+#include <ISO_Fortran_binding.h>
 
+extern "C" {
 bool c_bounder(CFI_cdesc_t*, CFI_index_t, CFI_index_t);
 bool c_bounder_2d(CFI_cdesc_t*, CFI_index_t, CFI_index_t, CFI_index_t, CFI_index_t);
+}

src/bounds/bounds.h

@@ -4,6 +4,13 @@ if(NOT HAVE_ISO_FORTRAN_BINDING_H)
   return()
 endif()
 
-add_executable(bounds_fortran bounds.f90 ${PROJECT_SOURCE_DIR}/src/bounds/bounds.c)
-target_include_directories(bounds_fortran INTERFACE ${PROJECT_SOURCE_DIR}/src/bounds)
+if(CMAKE_Fortran_COMPILER_ID STREQUAL "GNU" AND
+  CMAKE_Fortran_COMPILER_VERSION VERSION_LESS 12)
+    message(STATUS "GNU Fortran < 12 has known bugs in non-default array bounds. Skipping bounds tests.")
+  return()
+endif()
+
+add_executable(bounds_fortran bounds.f90 ${PROJECT_SOURCE_DIR}/src/bounds/bounds.cpp)
+target_include_directories(bounds_fortran PRIVATE ${PROJECT_SOURCE_DIR}/src/bounds)
+
 add_test(NAME BoundsFortran COMMAND bounds_fortran)