# HG changeset patch
# User Jed Brown <jed@59A2.org>
# Date 1347290967 14400
# Node ID fa3c39414903ec37de9896eeacaf2db0f50329a1
# Parent  6a6027ef45156b7709fbcc40b9d1dc0fea6b5611
Refactor complex support to allow portable use of complex in otherwise real builds

diff --git a/include/petscmath.h b/include/petscmath.h
--- a/include/petscmath.h
+++ b/include/petscmath.h
@@ -49,8 +49,7 @@
 /*
     Complex number definitions
  */
-#if defined(PETSC_USE_COMPLEX)
-#if defined(PETSC_CLANGUAGE_CXX)
+#if defined(PETSC_CLANGUAGE_CXX) && defined(PETSC_HAVE_CXX_COMPLEX)
 /* C++ support of complex number */
 #if defined(PETSC_HAVE_CUSP)
 #define complexlib cusp
@@ -60,76 +59,81 @@
 #include <complex>
 #endif
 
-#define PetscRealPart(a)      (a).real()
-#define PetscImaginaryPart(a) (a).imag()
-#define PetscAbsScalar(a)     complexlib::abs(a)
-#define PetscConj(a)          complexlib::conj(a)
-#define PetscSqrtScalar(a)    complexlib::sqrt(a)
-#define PetscPowScalar(a,b)   complexlib::pow(a,b)
-#define PetscExpScalar(a)     complexlib::exp(a)
-#define PetscLogScalar(a)     complexlib::log(a)
-#define PetscSinScalar(a)     complexlib::sin(a)
-#define PetscCosScalar(a)     complexlib::cos(a)
+#define PetscRealPartComplex(a)      (a).real()
+#define PetscImaginaryPartComplex(a) (a).imag()
+#define PetscAbsScalarComplex(a)     complexlib::abs(a)
+#define PetscConjComplex(a)          complexlib::conj(a)
+#define PetscSqrtScalarComplex(a)    complexlib::sqrt(a)
+#define PetscPowScalarComplex(a,b)   complexlib::pow(a,b)
+#define PetscExpScalarComplex(a)     complexlib::exp(a)
+#define PetscLogScalarComplex(a)     complexlib::log(a)
+#define PetscSinScalarComplex(a)     complexlib::sin(a)
+#define PetscCosScalarComplex(a)     complexlib::cos(a)
 
 #if defined(PETSC_USE_REAL_SINGLE)
-typedef complexlib::complex<float> PetscScalar;
+typedef complexlib::complex<float> PetscComplex;
 #elif defined(PETSC_USE_REAL_DOUBLE)
-typedef complexlib::complex<double> PetscScalar;
+typedef complexlib::complex<double> PetscComplex;
 #elif defined(PETSC_USE_REAL___FLOAT128)
-typedef complexlib::complex<__float128> PetscScalar;
+typedef complexlib::complex<__float128> PetscComplex; /* Notstandard and not expected to work, use __complex128 */
 #endif  /* PETSC_USE_REAL_ */
 
-#else /* PETSC_CLANGUAGE_CXX */
+#elif defined(PETSC_CLANGUAGE_C) && defined(PETSC_HAVE_C99_COMPLEX)
 
-/*  C support of complex numbers: Requires C99 compliant compiler*/
+/* Use C99 _Complex for the type. Do not include complex.h by default to define "complex" because of symbol conflicts in Hypre. */
+/* Compilation units that can safely use complex should define PETSC_DESIRE_COMPLEX before including any headers */
+#if defined(PETSC_USE_COMPLEX) || defined(PETSC_DESIRE_COMPLEX)
 #include <complex.h>
+#endif
 
 #if defined(PETSC_USE_REAL_SINGLE)
-typedef float complex PetscScalar;
+typedef float _Complex PetscComplex;
 
-#define PetscRealPart(a)      crealf(a)
-#define PetscImaginaryPart(a) cimagf(a)
-#define PetscAbsScalar(a)     cabsf(a)
-#define PetscConj(a)          conjf(a)
-#define PetscSqrtScalar(a)    csqrtf(a)
-#define PetscPowScalar(a,b)   cpowf(a,b)
-#define PetscExpScalar(a)     cexpf(a)
-#define PetscLogScalar(a)     clogf(a)
-#define PetscSinScalar(a)     csinf(a)
-#define PetscCosScalar(a)     ccosf(a)
+#define PetscRealPartComplex(a)      crealf(a)
+#define PetscImaginaryPartComplex(a) cimagf(a)
+#define PetscAbsScalarComplex(a)     cabsf(a)
+#define PetscConjComplex(a)          conjf(a)
+#define PetscSqrtScalarComplex(a)    csqrtf(a)
+#define PetscPowScalarComplex(a,b)   cpowf(a,b)
+#define PetscExpScalarComplex(a)     cexpf(a)
+#define PetscLogScalarComplex(a)     clogf(a)
+#define PetscSinScalarComplex(a)     csinf(a)
+#define PetscCosScalarComplex(a)     ccosf(a)
 
 #elif defined(PETSC_USE_REAL_DOUBLE)
-typedef double complex PetscScalar;
+typedef double _Complex PetscComplex;
 
-#define PetscRealPart(a)      creal(a)
-#define PetscImaginaryPart(a) cimag(a)
-#define PetscAbsScalar(a)     cabs(a)
-#define PetscConj(a)          conj(a)
-#define PetscSqrtScalar(a)    csqrt(a)
-#define PetscPowScalar(a,b)   cpow(a,b)
-#define PetscExpScalar(a)     cexp(a)
-#define PetscLogScalar(a)     clog(a)
-#define PetscSinScalar(a)     csin(a)
-#define PetscCosScalar(a)     ccos(a)
+#define PetscRealPartComplex(a)      creal(a)
+#define PetscImaginaryPartComplex(a) cimag(a)
+#define PetscAbsScalarComplex(a)     cabs(a)
+#define PetscConjComplex(a)          conj(a)
+#define PetscSqrtScalarComplex(a)    csqrt(a)
+#define PetscPowScalarComplex(a,b)   cpow(a,b)
+#define PetscExpScalarComplex(a)     cexp(a)
+#define PetscLogScalarComplex(a)     clog(a)
+#define PetscSinScalarComplex(a)     csin(a)
+#define PetscCosScalarComplex(a)     ccos(a)
 
 #elif defined(PETSC_USE_REAL___FLOAT128)
-typedef __complex128 PetscScalar;
+typedef __complex128 PetscComplex;
 PETSC_EXTERN MPI_Datatype MPIU___FLOAT128;
 PETSC_EXTERN MPI_Datatype MPIU___COMPLEX128;
 #define MPIU_SCALAR MPIU___COMPLEX128
 
-#define PetscRealPart(a)      crealq(a)
-#define PetscImaginaryPart(a) cimagq(a)
-#define PetscAbsScalar(a)     cabsq(a)
-#define PetscConj(a)          conjq(a)
-#define PetscSqrtScalar(a)    csqrtq(a)
-#define PetscPowScalar(a,b)   cpowq(a,b)
-#define PetscExpScalar(a)     cexpq(a)
-#define PetscLogScalar(a)     clogq(a)
-#define PetscSinScalar(a)     csinq(a)
-#define PetscCosScalar(a)     ccosq(a)
+#define PetscRealPartComplex(a)      crealq(a)
+#define PetscImaginaryPartComplex(a) cimagq(a)
+#define PetscAbsScalarComplex(a)     cabsq(a)
+#define PetscConjComplex(a)          conjq(a)
+#define PetscSqrtScalarComplex(a)    csqrtq(a)
+#define PetscPowScalarComplex(a,b)   cpowq(a,b)
+#define PetscExpScalarComplex(a)     cexpq(a)
+#define PetscLogScalarComplex(a)     clogq(a)
+#define PetscSinScalarComplex(a)     csinq(a)
+#define PetscCosScalarComplex(a)     ccosq(a)
 
 #endif /* PETSC_USE_REAL_* */
+#elif defined(PETSC_USE_COMPLEX)
+#error "PETSc was configured --with-scalar-type=complex, but a language-appropriate complex library is not available"
 #endif /* PETSC_CLANGUAGE_CXX */
 
 #if defined(PETSC_HAVE_MPI_C_DOUBLE_COMPLEX)
@@ -140,6 +144,19 @@
 PETSC_EXTERN MPI_Datatype MPIU_C_COMPLEX;
 #endif /* PETSC_HAVE_MPI_C_DOUBLE_COMPLEX */
 
+#if defined(PETSC_USE_COMPLEX)
+typedef PetscComplex PetscScalar;
+#define PetscRealPart(a)      PetscRealPartComplex(a)
+#define PetscImaginaryPart(a) PetscImaginaryPartComplex(a)
+#define PetscAbsScalar(a)     PetscAbsScalarComplex(a)
+#define PetscConj(a)          PetscConjComplex(a)
+#define PetscSqrtScalar(a)    PetscSqrtScalarComplex(a)
+#define PetscPowScalar(a,b)   PetscPowScalarComplex(a,b)
+#define PetscExpScalar(a)     PetscExpScalarComplex(a)
+#define PetscLogScalar(a)     PetscLogScalarComplex(a)
+#define PetscSinScalar(a)     PetscSinScalarComplex(a)
+#define PetscCosScalar(a)     PetscCosScalarComplex(a)
+
 #if defined(PETSC_USE_REAL_SINGLE)
 #define MPIU_SCALAR MPIU_C_COMPLEX
 #elif defined(PETSC_USE_REAL_DOUBLE)
@@ -194,8 +211,10 @@
 */
 typedef enum { PETSC_SCALAR_DOUBLE,PETSC_SCALAR_SINGLE, PETSC_SCALAR_LONG_DOUBLE } PetscScalarPrecision;
 
+#if defined(PETSC_HAVE_C99_COMPLEX) || defined(PETSC_HAVE_CXX_COMPLEX)
 /* PETSC_i is the imaginary number, i */
-PETSC_EXTERN PetscScalar   PETSC_i;
+PETSC_EXTERN PetscComplex PETSC_i;
+#endif
 
 /*MC
    PetscMin - Returns minimum of two numbers
diff --git a/src/sys/objects/init.c b/src/sys/objects/init.c
--- a/src/sys/objects/init.c
+++ b/src/sys/objects/init.c
@@ -32,7 +32,7 @@
 PetscMPIInt  PetscGlobalRank = -1;
 PetscMPIInt  PetscGlobalSize = -1;
 
-#if defined(PETSC_USE_COMPLEX)
+#if (defined(PETSC_CLANGUAGE_C) && defined(PETSC_HAVE_C99_COMPLEX)) || (defined(PETSC_CLANGUAGE_CXX) && defined(PETSC_HAVE_CXX_COMPLEX))
 #if defined(PETSC_COMPLEX_INSTANTIATE)
 template <> class std::complex<double>; /* instantiate complex template class */
 #endif
@@ -40,9 +40,7 @@
 MPI_Datatype   MPIU_C_DOUBLE_COMPLEX;
 MPI_Datatype   MPIU_C_COMPLEX;
 #endif
-PetscScalar    PETSC_i;
-#else
-PetscScalar    PETSC_i = 0.0;
+PetscComplex    PETSC_i;
 #endif
 #if defined(PETSC_USE_REAL___FLOAT128)
 MPI_Datatype   MPIU___FLOAT128 = 0;
diff --git a/src/sys/objects/pinit.c b/src/sys/objects/pinit.c
--- a/src/sys/objects/pinit.c
+++ b/src/sys/objects/pinit.c
@@ -2,7 +2,7 @@
 /*
    This file defines the initialization of PETSc, including PetscInitialize()
 */
-
+#define PETSC_DESIRE_COMPLEX
 #include <petscsys.h>        /*I  "petscsys.h"   I*/
 
 #if defined(PETSC_HAVE_CUSP)
@@ -692,18 +692,17 @@
   ierr = MPI_Comm_rank(MPI_COMM_WORLD,&PetscGlobalRank);CHKERRQ(ierr);
   ierr = MPI_Comm_size(MPI_COMM_WORLD,&PetscGlobalSize);CHKERRQ(ierr);
 
-#if defined(PETSC_USE_COMPLEX)
-  /* 
+  /*
      Initialized the global complex variable; this is because with 
      shared libraries the constructors for global variables
      are not called; at least on IRIX.
   */
   {
-#if defined(PETSC_CLANGUAGE_CXX)
-    PetscScalar ic(0.0,1.0);
+#if defined(PETSC_CLANGUAGE_CXX) && defined(PETSC_HAVE_CXX_COMPLEX)
+    PetscComplex ic(0.0,1.0);
     PETSC_i = ic; 
-#else
-    PETSC_i = I;
+#elif defined(PETSC_CLANGUAGE_C) && defined(PETSC_HAVE_C99_COMPLEX)
+    PETSC_i = _Complex_I;
 #endif
   }
 
@@ -712,6 +711,7 @@
   ierr = MPI_Type_commit(&MPIU_C_DOUBLE_COMPLEX);CHKERRQ(ierr);
   ierr = MPI_Type_contiguous(2,MPI_FLOAT,&MPIU_C_COMPLEX);CHKERRQ(ierr);
   ierr = MPI_Type_commit(&MPIU_C_COMPLEX);CHKERRQ(ierr);
+#if defined(PETSC_USE_COMPLEX)
   ierr = MPI_Op_create(PetscSum_Local,1,&MPIU_SUM);CHKERRQ(ierr);
 #endif
 #endif