[Flang] malloc(1) on AIX as malloc(0) returns nullptr

[madanial0]

On AIX malloc(0) reutrns nullptr, which fails test case Evaluate/ISO-Fortran-binding.test, using malloc(1) in AIX for consistent behaviour

[llvmbot]

@llvm/pr-subscribers-flang-runtime

Author: None (madanial0)

Changes

On AIX malloc(0) reutrns nullptr, which fails test case Evaluate/ISO-Fortran-binding.test, using malloc(1) in AIX for consistent behaviour

---

Full diff: https://github.com/llvm/llvm-project/pull/73878.diff

1 Files Affected:

• (modified) flang/runtime/ISO_Fortran_binding.cpp (+5-1)

diff --git a/flang/runtime/ISO_Fortran_binding.cpp b/flang/runtime/ISO_Fortran_binding.cpp
index ce146844533a064..f354430d6106fb9 100644
--- a/flang/runtime/ISO_Fortran_binding.cpp
+++ b/flang/runtime/ISO_Fortran_binding.cpp
@@ -75,7 +75,11 @@ RT_API_ATTRS int CFI_allocate(CFI_cdesc_t *descriptor,
     dim->sm = byteSize;
     byteSize *= extent;
   }
-  void *p{std::malloc(byteSize)};
+  void *p;
+  if (_AIX && !byteSize)
+    p = std::malloc(1);
+  else
+    p = std::malloc(byteSize);
   if (!p && byteSize) {
     return CFI_ERROR_MEM_ALLOCATION;
   }

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[jeanPerier]

Thanks