silence MSVC with definitions and options (GPSBabel#859)

* deal with MSVC CRT security warnings in a consistent manner.

* correct cmake targets

* turn off some MSVC warnings for shapelib, zlib with cmake.

* fix msvc C4100 warning handling.

There was interference between our attempt to turn off the warning
with -wd4100 and win32-msvc mkspec changing the level of this
warning with -w34100.

CMakeLists.txt

@@ -352,7 +352,8 @@ if(WIN32)
 endif()
 
 if(MSVC)
-  target_compile_definitions(gpsbabel PRIVATE _CRT_SECURE_NO_DEPRECATE)
+  target_compile_definitions(gpsbabel PRIVATE _CRT_SECURE_NO_WARNINGS)
+  target_compile_definitions(gpsbabel PRIVATE _CRT_NONSTDC_NO_WARNINGS)
   target_compile_options(gpsbabel PRIVATE /MP -wd4100 -wd4267)
 endif()
 

GPSBabel.pro

@@ -338,9 +338,20 @@ win32 {
 }
 
 win32-msvc* {
-  DEFINES += _CRT_SECURE_NO_DEPRECATE
-  QMAKE_CFLAGS += /MP -wd4100 -wd4267
-  QMAKE_CXXFLAGS += /MP -wd4100 -wd4267
+  DEFINES += _CRT_SECURE_NO_WARNINGS
+  DEFINES += _CRT_NONSTDC_NO_WARNINGS
+  QMAKE_CFLAGS += /MP -wd4267
+  QMAKE_CXXFLAGS += /MP -wd4267
+  # The -wd (disable warning) and -w3 (change warning to level 3) options are exclusive.
+  # The win32-msvc makespec uses -w34100, which can interfer with -wd4100.
+  # Their are two qmake settings for warnings in CONFIG: warn_on and warn_off.
+  # This results in the warning showing with msbuild, but not with nmake, even if
+  # -wd4100 is included in QMAKE_CFLAGS and QMAKE_CXXFLAGS.
+  # Override win32-msvc, leaving these warnings at their default of level 4, which
+  # will not show up because we run at level 3.
+  # shapelib/shpopen.c can cause a C4100 error.
+  QMAKE_CFLAGS_WARN_ON -= -w34100
+  QMAKE_CXXFLAGS_WARN_ON -= -w34100
 }
 
 include(shapelib.pri)

defs.h

@@ -126,19 +126,6 @@ constexpr double KNOTS_TO_MPS(double a)  {return a * kMPSPerKnot;}
 #define CENTI_TO_MICRO(t) ((t) * 10000) /* Centiseconds to Microseconds */
 #define MICRO_TO_CENTI(t) ((t) / 10000) /* Centiseconds to Microseconds */
 
-#if __WIN32__
-#  ifndef fileno
-#    define fileno _fileno
-#  endif
-#  define strdup _strdup
-#endif
-
-#if __WIN32__
-#if !defined _CRT_SECURE_NO_DEPRECATE
-#  define _CRT_SECURE_NO_DEPRECATE 1
-#endif
-#endif
-
 /* Pathname separator character */
 #if __WIN32__
 #  define GB_PATHSEP '\\'

shapelib.cmake

@@ -19,6 +19,11 @@ else()
     # note gpsbabel has conditional code include "shapelib/shapefil.h",
     # so it doesn't actually rely on the include directory being PUBLIC/INTERFACE
     target_include_directories(shp PUBLIC shape)
+    if(MSVC)
+      target_compile_definitions(shp PRIVATE _CRT_SECURE_NO_WARNINGS)
+      target_compile_definitions(shp PRIVATE _CRT_NONSTDC_NO_WARNINGS)
+      target_compile_options(shp PRIVATE /MP -wd4100 -wd4267)
+    endif()
     list(APPEND LIBS shp)
   elseif(GPSBABEL_WITH_SHAPELIB STREQUAL "custom")
     message(STATUS "shapelib is enabled but but must be manually configured.")

zlib.cmake

@@ -54,6 +54,11 @@ else()
         target_compile_definitions(z PRIVATE HAVE_STDARG_H)
       endif()
     endif()
+    if(MSVC)
+      target_compile_definitions(z PRIVATE _CRT_SECURE_NO_WARNINGS)
+      target_compile_definitions(z PRIVATE _CRT_NONSTDC_NO_WARNINGS)
+      target_compile_options(z PRIVATE /MP -wd4100 -wd4267)
+    endif()
     target_include_directories(z PUBLIC zlib)
     list(APPEND LIBS z)
   elseif(GPSBABEL_WITH_ZLIB STREQUAL "custom")