esmf-org · xylar · Jul 16, 2026 · Jul 18, 2026 · Jul 18, 2026 · Jul 19, 2026
diff --git a/build_config/MinGW.gfortran.default/build_rules.mk b/build_config/MinGW.gfortran.default/build_rules.mk
@@ -10,6 +10,20 @@ ESMF_F90DEFAULT         = gfortran
 ESMF_CXXDEFAULT         = g++
 ESMF_CDEFAULT           = gcc
 
+############################################################
+# Use the GNU dialect (gnu++/gnu) instead of strict ISO (c++/c). On MinGW the
+# strict -std=c++NN / -std=cNN flags define __STRICT_ANSI__, which makes the CRT
+# headers (<io.h>, <unistd.h>) hide their POSIX-named entry points (dup, dup2,
+# close, open, read, write, ...). ESMF's VM code uses those names, so the strict
+# dialect breaks the build. The GNU dialect keeps them visible.
+#
+ifneq ($(ESMF_CXXSTD),sysdefault)
+ESMF_CXXSTDFLAG         = -std=gnu++$(ESMF_CXXSTD)
+endif
+ifneq ($(ESMF_CSTD),sysdefault)
+ESMF_CSTDFLAG           = -std=gnu$(ESMF_CSTD)
+endif
+
 ############################################################
 # Default MPI setting.
 #
@@ -96,7 +110,20 @@ endif
 ifeq ($(ESMF_ABI),64)
 ESMF_ABISTRING := x86_64_small
 endif
-else
+endif
+# 64-bit MSYS2/MinGW reports `uname -m` as x86_64; accept it alongside the legacy
+# i686 label (mirrors the Linux.gfortran ABISTRING handling). ESMF_ABI still selects
+# the 32- vs 64-bit memory model.
+ifeq ($(ESMF_MACHINE),x86_64)
+ESMF_ABISTRING := x86_64_small
+ifeq ($(ESMF_ABI),32)
+ESMF_ABISTRING := x86_64_32
+endif
+ifeq ($(ESMF_ABI),64)
+ESMF_ABISTRING := x86_64_small
+endif
+endif
+ifeq ($(ESMF_ABISTRING),)
 $(error "ESMF_MACHINE = $(ESMF_MACHINE)" not recognized)
 endif
 
@@ -149,8 +176,10 @@ ESMF_CXXCOMPILECPPFLAGS += -DESMF_NO_SYSTEMCALL
 
 ############################################################
 # Windows does not have support for the times system call
+# (also define it for C: vendored Zoltan timer.c is C and includes sys/times.h)
 #
 ESMF_CXXCOMPILECPPFLAGS += -DNO_TIMES
+ESMF_CCOMPILECPPFLAGS   += -DNO_TIMES
 
 ############################################################
 # Windows does not have support for Pthreads
@@ -212,7 +241,14 @@ ESMF_CXXLINKLIBS += -lgfortran -lWs2_32
 ############################################################
 # Shared library options
 #
-ESMF_SL_LIBOPTS  += -shared
+# --export-all-symbols is required: parts of the tree (yaml-cpp, MOAB/mesquite,
+# MOAB Factory.cpp, verdict, ESMCI_Trace, nlohmann/json) decorate symbols with
+# __declspec(dllexport). As soon as ANY symbol is explicitly exported, MinGW ld
+# stops auto-exporting the rest, so the undecorated extern "C" ESMC_* / ESMF C API
+# (e.g. ESMC_Initialize) is absent from the DLL export table and ctypes can't find
+# it. Forcing all globals to be exported restores the Unix-.so-like behavior ESMPy
+# expects.
+ESMF_SL_LIBOPTS  += -shared -Wl,--export-all-symbols
 ESMF_SL_LIBLIBS       += $(ESMF_CXXLINKPATHS) $(ESMF_CXXLINKLIBS) -lgfortran
 
 ############################################################

diff --git a/src/Infrastructure/Base/interface/ESMF_Info.F90 b/src/Infrastructure/Base/interface/ESMF_Info.F90
@@ -893,7 +893,7 @@ subroutine ESMF_InfoGetI8(info, key, value, keywordEnforcer, default, idx, attne
   integer, intent(out), optional :: rc
 
   integer :: localrc
-  integer(C_LONG), target :: local_default
+  integer(ESMF_KIND_I8), target :: local_default
   integer(C_INT), target :: local_idx
   type(C_PTR) :: local_default_ptr, local_idx_ptr
   integer(C_INT) :: recursive, strlen_only

diff --git a/src/Infrastructure/Base/interface/ESMF_InfoCDef.F90 b/src/Infrastructure/Base/interface/ESMF_InfoCDef.F90
@@ -3,7 +3,7 @@
   function c_info_base_get(base_address) bind(C, name="ESMC_BaseGetInfo")
     use iso_c_binding
     implicit none
-    integer(C_LONG), intent(in) :: base_address
+    integer(C_LONG_LONG), intent(in) :: base_address
     type(C_PTR) :: c_info_base_get
   end function c_info_base_get
 
@@ -66,8 +66,8 @@ subroutine c_info_copyforattribute(isrc, idst, rc) bind(C, name="ESMC_InfoCopyFo
   subroutine c_info_copyforattribute_reference(src_base_address, dst_base_address, rc) bind(C, name="ESMC_InfoCopyForAttributeReference")
     use iso_c_binding
     implicit none
-    integer(C_LONG) :: src_base_address
-    integer(C_LONG) :: dst_base_address
+    integer(C_LONG_LONG) :: src_base_address
+    integer(C_LONG_LONG) :: dst_base_address
     integer(C_INT), intent(out) :: rc
   end subroutine
 
@@ -205,7 +205,7 @@ subroutine c_info_base_sync(inqstate, rootPet, vmAddress, markClean, rc) bind(C,
     implicit none
     type(C_PTR), value :: inqstate
     integer(C_INT), intent(in) :: rootPet
-    integer(C_LONG), intent(in) :: vmAddress
+    integer(C_LONG_LONG), intent(in) :: vmAddress
     integer(C_INT), intent(in) :: markClean
     integer(C_INT), intent(out) :: rc
   end subroutine

diff --git a/src/Infrastructure/Mesh/src/Moab/DiscreteGeometry/makefile b/src/Infrastructure/Mesh/src/Moab/DiscreteGeometry/makefile
@@ -3,7 +3,13 @@
 # leave alone.
 ALL: build_here 
 
-ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DLINUX -DUSE_MPI
+ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DUSE_MPI
+# -DLINUX selects MOAB's Unix code paths (dlfcn.h, dirent.h in Core.cpp).
+# Those headers do not exist on MinGW; leave LINUX undefined there so MOAB
+# uses its POSIX/Windows-safe fallbacks. Kept for Linux and Darwin.
+ifneq ($(ESMF_OS),MinGW)
+ESMF_CXXCOMPILECPPFLAGS += -DLINUX
+endif
 
 SOURCEC = \
   DGMSolver.cpp HiReconstruction.cpp

diff --git a/src/Infrastructure/Mesh/src/Moab/IntxMesh/makefile b/src/Infrastructure/Mesh/src/Moab/IntxMesh/makefile
@@ -3,7 +3,13 @@
 # leave alone.
 ALL: build_here 
 
-ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DLINUX -DUSE_MPI
+ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DUSE_MPI
+# -DLINUX selects MOAB's Unix code paths (dlfcn.h, dirent.h in Core.cpp).
+# Those headers do not exist on MinGW; leave LINUX undefined there so MOAB
+# uses its POSIX/Windows-safe fallbacks. Kept for Linux and Darwin.
+ifneq ($(ESMF_OS),MinGW)
+ESMF_CXXCOMPILECPPFLAGS += -DLINUX
+endif
 
 SOURCEC = \
   Intx2Mesh.cpp Intx2MeshInPlane.cpp Intx2MeshOnSphere.cpp \

diff --git a/src/Infrastructure/Mesh/src/Moab/LocalDiscretization/makefile b/src/Infrastructure/Mesh/src/Moab/LocalDiscretization/makefile
@@ -3,7 +3,13 @@
 # leave alone.
 ALL: build_here 
 
-ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DLINUX -DUSE_MPI
+ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DUSE_MPI
+# -DLINUX selects MOAB's Unix code paths (dlfcn.h, dirent.h in Core.cpp).
+# Those headers do not exist on MinGW; leave LINUX undefined there so MOAB
+# uses its POSIX/Windows-safe fallbacks. Kept for Linux and Darwin.
+ifneq ($(ESMF_OS),MinGW)
+ESMF_CXXCOMPILECPPFLAGS += -DLINUX
+endif
 
 SOURCEC = ElemEvaluator.cpp LinearHex.cpp LinearQuad.cpp \
   LinearTet.cpp LinearTri.cpp QuadraticHex.cpp 

diff --git a/src/Infrastructure/Mesh/src/Moab/io/makefile b/src/Infrastructure/Mesh/src/Moab/io/makefile
@@ -3,7 +3,13 @@
 # leave alone.
 ALL: build_here 
 
-ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DLINUX -DUSE_MPI
+ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DUSE_MPI
+# -DLINUX selects MOAB's Unix code paths (dlfcn.h, dirent.h in Core.cpp).
+# Those headers do not exist on MinGW; leave LINUX undefined there so MOAB
+# uses its POSIX/Windows-safe fallbacks. Kept for Linux and Darwin.
+ifneq ($(ESMF_OS),MinGW)
+ESMF_CXXCOMPILECPPFLAGS += -DLINUX
+endif
 
 SOURCEC = \
 	ExoIIUtil.cpp FileTokenizer.cpp GmshUtil.cpp \

diff --git a/src/Infrastructure/Mesh/src/Moab/makefile b/src/Infrastructure/Mesh/src/Moab/makefile
@@ -3,7 +3,13 @@
 # leave alone.
 ALL: build_here 
 
-ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DLINUX -DUSE_MPI
+ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DUSE_MPI
+# -DLINUX selects MOAB's Unix code paths (dlfcn.h, dirent.h in Core.cpp).
+# Those headers do not exist on MinGW; leave LINUX undefined there so MOAB
+# uses its POSIX/Windows-safe fallbacks. Kept for Linux and Darwin.
+ifneq ($(ESMF_OS),MinGW)
+ESMF_CXXCOMPILECPPFLAGS += -DLINUX
+endif
 
 SOURCEC = \
   AdaptiveKDTree.cpp AEntityFactory.cpp AffineXform.cpp AxisBox.cpp \

diff --git a/src/Infrastructure/Mesh/src/Moab/moab/Matrix3.hpp b/src/Infrastructure/Mesh/src/Moab/moab/Matrix3.hpp
@@ -71,7 +71,18 @@
 
 // We will rely on LAPACK directly
 
-#ifdef WIN32
+// RLO: Only use ESMF-internal LAPACK subroutines with ESMF internal LAPACK.
+//      It seems like only dgeev and dsyevd are currently in use with MOAB.
+//      ESMF-internal LAPACK does not currently support dsyevr, dgetrf, dgetri.
+//      NOTE: this must be checked before the WIN32 case below. MinGW predefines
+//      WIN32, but the ESMF-internal LAPACK still exposes only the esmf_-prefixed
+//      names, so they must be used on Windows too -- otherwise the link fails
+//      with undefined references to dgeev_/dsyevd_.
+#if defined ESMF_LAPACK_INTERNAL
+#define MOAB_dgeev  MOAB_FC_WRAPPER(esmf_dgeev, ESMF_DGEEV)
+#define MOAB_dsyevd MOAB_FC_WRAPPER(esmf_dsyevd, ESMF_DSYEVD)
+
+#elif defined( WIN32 )
 
 // Should use second form below for windows but
 // needed to do this to make it work.
@@ -82,31 +93,11 @@
 #define MOAB_dgetrf MOAB_FC_FUNC( dgetrf, DGETRF )
 #define MOAB_dgetri MOAB_FC_FUNC( dgetri, DGETRI )
 
-#else
-
-// RLO: Only use ESMF-internal LAPACK subroutines with ESMF internal LAPACK.
-//      It seems like only dgeev and dsyevd are currently in use with MOAB.
-//      ESMF-internal LAPACK does not currently support dsyevr, dgetrf, dgetri.
-#if defined ESMF_LAPACK_INTERNAL
-#define MOAB_dgeev  MOAB_FC_WRAPPER(esmf_dgeev, ESMF_DGEEV)
-#define MOAB_dsyevd MOAB_FC_WRAPPER(esmf_dsyevd, ESMF_DSYEVD)
 #elif defined ESMF_LAPACK
 #define MOAB_dgeev  MOAB_FC_WRAPPER(dgeev, DGEEV)
 #define MOAB_dsyevd MOAB_FC_WRAPPER(dsyevd, DSYEVD)
 #endif
 
-// #define MOAB_dsyevr MOAB_FC_FUNC(dsyevr, DSYEVR)
-// #define MOAB_dgetrf MOAB_FC_FUNC(dgetrf, DGETRF)
-// #define MOAB_dgetri MOAB_FC_FUNC(dgetri, DGETRI)
-
-// #define MOAB_dsyevd MOAB_FC_WRAPPER( dsyevd, DSYEVD )
-// #define MOAB_dsyevr MOAB_FC_WRAPPER( dsyevr, DSYEVR )
-// #define MOAB_dgeev  MOAB_FC_WRAPPER( dgeev, DGEEV )
-// #define MOAB_dgetrf MOAB_FC_WRAPPER( dgetrf, DGETRF )
-// #define MOAB_dgetri MOAB_FC_WRAPPER( dgetri, DGETRI )
-
-#endif
-
 extern "C" {
 
 // Computes all eigenvalues and, optionally, eigenvectors of a

diff --git a/src/Infrastructure/Mesh/src/Moab/parallel/makefile b/src/Infrastructure/Mesh/src/Moab/parallel/makefile
@@ -3,7 +3,13 @@
 # leave alone.
 ALL: build_here 
 
-ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DLINUX -DUSE_MPI
+ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DUSE_MPI
+# -DLINUX selects MOAB's Unix code paths (dlfcn.h, dirent.h in Core.cpp).
+# Those headers do not exist on MinGW; leave LINUX undefined there so MOAB
+# uses its POSIX/Windows-safe fallbacks. Kept for Linux and Darwin.
+ifneq ($(ESMF_OS),MinGW)
+ESMF_CXXCOMPILECPPFLAGS += -DLINUX
+endif
 
 SOURCEC = \
   gs.cpp ParallelComm.cpp ParallelData.cpp ParallelMergeMesh.cpp \

diff --git a/src/Infrastructure/Mesh/src/Moab/verdict/makefile b/src/Infrastructure/Mesh/src/Moab/verdict/makefile
@@ -3,7 +3,13 @@
 # leave alone.
 ALL: build_here 
 
-ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DLINUX -DUSE_MPI
+ESMF_CXXCOMPILECPPFLAGS += -DIS_BUILDING_MB -DHAVE_VSNPRINTF -DUSE_MPI
+# -DLINUX selects MOAB's Unix code paths (dlfcn.h, dirent.h in Core.cpp).
+# Those headers do not exist on MinGW; leave LINUX undefined there so MOAB
+# uses its POSIX/Windows-safe fallbacks. Kept for Linux and Darwin.
+ifneq ($(ESMF_OS),MinGW)
+ESMF_CXXCOMPILECPPFLAGS += -DLINUX
+endif
 
 SOURCEC = V_EdgeMetric.cpp VerdictVector.cpp VerdictWrapper.cpp \
   V_GaussIntegration.cpp V_HexMetric.cpp V_KnifeMetric.cpp \