ENH: Adding a cmake script to find which compiler return NULL on malloc(0)

diff --git a/src/gdcmjasper/CMakeLists.txt b/src/gdcmjasper/CMakeLists.txt
index 5298f6dc91f376a175b16295cadaeadc1a7c5366..5d81feb2f674e57f0c8294a47432d13d95b25dee 100644 (file)
--- a/src/gdcmjasper/CMakeLists.txt
+++ b/src/gdcmjasper/CMakeLists.txt
@@ -1,5 +1,35 @@
 PROJECT(GDCMJASPER C)
 
+#-----------------------------------------------------------------------------
+# Test how compiler handle the case of a malloc(0). If it returns 0
+# then we are doomed (jasper does not support this case)
+IF("NULL_ON_MALLOC_0" MATCHES "^NULL_ON_MALLOC_0$")
+  STRING(ASCII 35 POUND)
+  FILE(WRITE ${GDCMJASPER_BINARY_DIR}/jasperNULLmalloc.c
+    "${POUND}include <stdlib.h>\n"
+    "int main() { return (int)malloc(0); }")
+  MESSAGE(STATUS "Checking if compiler return NULL on malloc(0)")
+  TRY_RUN(RESULT_NULL_ON_MALLOC_0 COMPILE_NULL_ON_MALLOC_0
+      "${GDCMJASPER_BINARY_DIR}"
+      "${GDCMJASPER_BINARY_DIR}/jasperNULLmalloc.c"
+      OUTPUT_VARIABLE OUTPUT)
+  IF(NULL_ON_MALLOC_0)
+    MESSAGE(STATUS "Checking if compiler return NULL on malloc(0) -- yes")
+    SET(NULL_ON_MALLOC_0 1 CACHE INTERNAL "Check if compiler returns NULL on malloc(0)")
+    WRITE_FILE(${CMAKE_BINARY_DIR}/CMakeOutput.log
+      "Determining how compiler implement malloc(0)"
+      "passed with the following output:\n"
+      "${OUTPUT}\n" APPEND)
+  ELSE(NULL_ON_MALLOC_0)
+    MESSAGE(STATUS "Checking if ifreq has a sa_len -- no")
+    SET(NULL_ON_MALLOC_0 0 CACHE INTERNAL "Check if compiler returns NULL on malloc(0)")
+    WRITE_FILE(${CMAKE_BINARY_DIR}/CMakeError.log
+      "Determining how compiler implement malloc(0)"
+      "failed with the following output:\n"
+      "${OUTPUT}\n" APPEND)
+  ENDIF(NULL_ON_MALLOC_0)
+ENDIF("NULL_ON_MALLOC_0" MATCHES "^NULL_ON_MALLOC_0$")
+
 #OPTION(HAVE_LIBJPEG "Do you have ijg" OFF)
 IF(GDCM_SOURCE_DIR)
   SET(HAVE_LIBJPEG ON CACHE BOOL "Do you have ijg" FORCE)