# External: Integer Set Library
set(ISL_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/isl")
set(ISL_BINARY_DIR "${CMAKE_CURRENT_BINARY_DIR}/isl")

# Determine version of isl
if (EXISTS "${ISL_SOURCE_DIR}/GIT_HEAD_ID")
  # The source comes from a 'make dist' archive
  file(READ "${ISL_SOURCE_DIR}/GIT_HEAD_ID" GIT_HEAD_ID)
  string(STRIP "${GIT_HEAD_ID}" GIT_HEAD_ID)
elseif (EXISTS "${ISL_SOURCE_DIR}/gitversion.h")
  # The source directory is preconfigured
  file(READ "${ISL_SOURCE_DIR}/gitversion.h" GITVERSION_H)
  string(REGEX REPLACE ".*\\\"([^\\\"]*)\\\".*" "\\1" GIT_HEAD_ID "${GITVERSION_H}")
elseif ()
  # Unknown revision
  # TODO: We could look for a .git and get the revision from HEAD
  set(GIT_HEAD_ID "UNKNOWN")
endif ()

message(STATUS "ISL version: ${GIT_HEAD_ID}")

# Enable small integer optimization and imath
set(USE_GMP_FOR_MP OFF)
set(USE_IMATH_FOR_MP ON)
set(USE_SMALL_INT_OPT ON)

# Determine compiler characteristics
include(CheckCSourceCompiles)

# Like check_c_source_compiles, but sets the result to either
# 0 (error while compiling) or 1 (compiled successfully)
# Required for compatibility with autotool's AC_CHECK_DECLS
function (check_c_source_compiles_numeric _prog _var)
  check_c_source_compiles("${_prog}" "${_var}")
  if ("${${_var}}")
    set("${_var}" 1 PARENT_SCOPE)
  else ()
    set("${_var}" 0 PARENT_SCOPE)
  endif ()
endfunction ()

# Check for the existance of a type
function (check_c_type_exists _type _files _variable)
  set(_includes "")
  foreach (file_name ${_files})
     set(_includes "${_includes}#include<${file_name}>\n")
  endforeach()
  check_c_source_compiles("
    ${_includes}
    ${_type} typeVar;
    int main() {
        return 0;
    }
    " ${_variable})
endfunction ()


check_c_source_compiles("
  int func(void) __attribute__((__warn_unused_result__));
  int main() { return 0; }
  " HAS_ATTRIBUTE_WARN_UNUSED_RESULT)
set(GCC_WARN_UNUSED_RESULT)
if (HAS_ATTRIBUTE_WARN_UNUSED_RESULT)
  set(GCC_WARN_UNUSED_RESULT "__attribute__((__warn_unused_result__))")
endif ()

check_c_source_compiles("
  static void foo(void) __attribute__ ((unused));
  int main() { return 0; }
  " HAVE___ATTRIBUTE__)


check_c_source_compiles_numeric("
  #include <strings.h>
  int main() { (void)ffs(0); return 0; }
  " HAVE_DECL_FFS)

check_c_source_compiles_numeric("
  int main() { __builtin_ffs(0); return 0; }
  " HAVE_DECL___BUILTIN_FFS)

check_c_source_compiles_numeric("
  #include <intrin.h>
  int main() { _BitScanForward(NULL, 0); return 0; }
  " HAVE_DECL__BITSCANFORWARD)

if (NOT HAVE_DECL_FFS AND
    NOT HAVE_DECL___BUILTIN_FFS AND
    NOT HAVE_DECL__BITSCANFORWARD)
  message(FATAL_ERROR "No ffs implementation found")
endif ()


check_c_source_compiles_numeric("
  #include <strings.h>
  int main() { (void)strcasecmp(\"\", \"\"); return 0; }
  " HAVE_DECL_STRCASECMP)

check_c_source_compiles_numeric("
  #include <string.h>
  int main() { _stricmp(\"\", \"\"); return 0; }
  " HAVE_DECL__STRICMP)

if (NOT HAVE_DECL_STRCASECMP AND NOT HAVE_DECL__STRICMP)
  message(FATAL_ERROR "No strcasecmp implementation found")
endif ()


check_c_source_compiles_numeric("
  #include <strings.h>
  int main() { (void)strncasecmp(\"\", \"\", 0); return 0; }
  " HAVE_DECL_STRNCASECMP)

check_c_source_compiles_numeric("
  #include <string.h>
  int main() { _strnicmp(\"\", \"\", 0); return 0; }
  " HAVE_DECL__STRNICMP)

if (NOT HAVE_DECL_STRNCASECMP AND NOT HAVE_DECL__STRNICMP)
  message(FATAL_ERROR "No strncasecmp implementation found")
endif ()


check_c_source_compiles_numeric("
  #include <stdio.h>
  int main() { snprintf((void*)0, 0, \"\"); return 0; }
  " HAVE_DECL_SNPRINTF)

check_c_source_compiles_numeric("
  #include <stdio.h>
  int main() { _snprintf((void*)0, 0, \"\"); return 0; }
  " HAVE_DECL__SNPRINTF)

if (NOT HAVE_DECL_SNPRINTF AND NOT HAVE_DECL__SNPRINTF)
  message(FATAL_ERROR "No snprintf implementation found")
endif ()


check_c_type_exists(uint8_t "" HAVE_UINT8T)
check_c_type_exists(uint8_t "stdint.h" HAVE_STDINT_H)
check_c_type_exists(uint8_t "inttypes.h" HAVE_INTTYPES_H)
check_c_type_exists(uint8_t "sys/types.h" HAVE_SYS_INTTYPES_H)
if (HAVE_UINT8T)
  set(INCLUDE_STDINT_H "")
elseif (HAVE_STDINT_H)
  set(INCLUDE_STDINT_H "#include <stdint.h>")
elseif (HAVE_INTTYPES_H)
  set(INCLUDE_STDINT_H "#include <inttypes.h>")
elseif (HAVE_SYS_INTTYPES_H)
  set(INCLUDE_STDINT_H "#include <sys/inttypes.h>")
else ()
  message(FATAL_ERROR "No stdint.h or compatible found")
endif ()

# Write configure result
# configure_file(... COPYONLY) avoids that the time stamp changes if the file is identical
file(WRITE "${ISL_BINARY_DIR}/gitversion.h.tmp"
     "#define GIT_HEAD_ID \"${GIT_HEAD_ID}\"")
configure_file("${ISL_BINARY_DIR}/gitversion.h.tmp"
               "${ISL_BINARY_DIR}/gitversion.h" COPYONLY)

file(WRITE "${ISL_BINARY_DIR}/include/isl/stdint.h.tmp"
     "${INCLUDE_STDINT_H}\n")
configure_file("${ISL_BINARY_DIR}/include/isl/stdint.h.tmp"
               "${ISL_BINARY_DIR}/include/isl/stdint.h" COPYONLY)

configure_file("isl_config.h.cmake" "${ISL_BINARY_DIR}/isl_config.h")

include_directories(BEFORE
  ${ISL_BINARY_DIR}
  ${ISL_SOURCE_DIR}/imath
  ${ISL_SOURCE_DIR}/include
  ${ISL_SOURCE_DIR}
)

# ISL files to compile
set (ISL_FILES
    isl/basis_reduction_tab.c
    isl/isl_aff.c
    isl/isl_affine_hull.c
    isl/isl_arg.c
    isl/isl_ast_build.c
    isl/isl_ast_build_expr.c
    isl/isl_ast.c
    isl/isl_ast_codegen.c
    isl/isl_ast_graft.c
    isl/isl_band.c
    isl/isl_bernstein.c
    isl/isl_blk.c
    isl/isl_bound.c
    isl/isl_coalesce.c
    isl/isl_constraint.c
    isl/isl_convex_hull.c
    isl/isl_ctx.c
    isl/isl_deprecated.c
    isl/isl_dim_map.c
    isl/isl_equalities.c
    isl/isl_factorization.c
    isl/isl_farkas.c
    isl/isl_ffs.c
    isl/isl_flow.c
    isl/isl_fold.c
    isl/isl_hash.c
    isl/isl_id.c
    isl/isl_id_to_ast_expr.c
    isl/isl_id_to_pw_aff.c
    isl/isl_ilp.c
    isl/isl_imath.c
    isl/isl_input.c
    isl/isl_int_sioimath.c
    isl/isl_local_space.c
    isl/isl_lp.c
    isl/isl_map.c
    isl/isl_map_list.c
    isl/isl_map_simplify.c
    isl/isl_map_subtract.c
    isl/isl_map_to_basic_set.c
    isl/isl_mat.c
    isl/isl_morph.c
    isl/isl_obj.c
    isl/isl_options.c
    isl/isl_output.c
    isl/isl_point.c
    isl/isl_polynomial.c
    isl/isl_printer.c
    isl/isl_range.c
    isl/isl_reordering.c
    isl/isl_sample.c
    isl/isl_scan.c
    isl/isl_schedule.c
    isl/isl_schedule_band.c
    isl/isl_schedule_node.c
    isl/isl_schedule_read.c
    isl/isl_schedule_tree.c
    isl/isl_scheduler.c
    isl/isl_seq.c
    isl/isl_set_list.c
    isl/isl_sort.c
    isl/isl_space.c
    isl/isl_stream.c
    isl/isl_tab.c
    isl/isl_tab_pip.c
    isl/isl_tarjan.c
    isl/isl_transitive_closure.c
    isl/isl_union_map.c
    isl/isl_val.c
    isl/isl_val_sioimath.c
    isl/isl_vec.c
    isl/isl_version.c
    isl/isl_vertices.c
    isl/print.c
    isl/imath/gmp_compat.c
    isl/imath/imath.c
    isl/imath/imrat.c
    )

add_polly_library(PollyISL FORCE_STATIC
  ${ISL_FILES}
)

# ISL requires at least C99 to compile. gcc < 5.0 use -std=gnu89 as default.
target_enable_c99(PollyISL)

# Define the FLAGS for the compilation of isl and imath
#
# We first set the visibility of all isl functions to hidden to ensure we do
# not clash with other isl versions that got linked into a program that uses
# Polly. (This happens e.g when linking Polly with dragonegg)
#
# This is the reason for the FORCE_STATIC flag above; without it, not even Polly
# could access ISL's symbols in shared library builds.
#
# We also disable warnings which should be coped with upstream.
if (NOT MSVC)
  set_target_properties(PollyISL PROPERTIES
    COMPILE_FLAGS "-fvisibility=hidden -w"
  )
endif ()