Changes between Version 16 and Version 17 of Guidelines/MaintenanceGuidelines

Timestamp:

Nov 6, 2009, 4:15:05 PM (13 years ago)

Author:

Paul A. Bristow

Comment:

Added some notes on warnings and suggested actions.

Guidelines/MaintenanceGuidelines

@@ -570 +570 @@
 1  Test compilation with the most pedantic setting for the compiler.
 
-For Microsoft Visual Studio, this means setting level to 4 (command line /W4),
-and disabling Microsoft language extensions
-Disable MS extensions = Yes, command line option /Za
+For Microsoft Visual Studio, this means setting level to 4 (command line /W4),[[BR]]
+and disabling Microsoft language extensions Disable MS extensions = Yes, command line option /Za
+
+(You might also consider using Microsoft /Wall if available.  You may find
+[http://www.geoffchappell.com/viewer.htm?doc=studies/msvc/cl/c1xx/warnings/index.htm&tx=2,27&ts=0,3820]
+a helpful guide to the byzantine complexity of warnings).[[BR]]
 
 For GCC this means -Wall -pendantic  
@@ -580 +583 @@
 -pedantic -Wall -Wno-long-long -Wno-unused-value
 
-but this is a global setting, so you need to document that these warning must be suppressed by users of this module.  This may be acceptable if they are building a library of entirely Boost modules.
+but this is a global setting, so you need to document that these warnings must be suppressed by users of this module.  This may be acceptable if they are building a library of entirely Boost modules.
 
 Using bjam add warnings=all to the invocation command line.
@@ -659 +662 @@
 
 
-
-
-
+=== Specific warnings and suggested actions. ===
+
+''These are just few for starters and need more especially for gcc. Suggestions may be wrong!  Also need reordering in a table.''
+
+'''Microsoft'''
+
+If you chose to suppress (rather than fix by recoding),
+localise the warnings as far as possible by using push'n'pop pragmas (see above).
+
+1  C4512 assignment operator could not be generated
+
+Suppress using push'n'pop for the module(s) causing the warning.
+//#  pragma warning(disable: 4512) // assignment operator could not be generated
+
+
+2  C4996 'putenv': The POSIX name for this item is deprecated.[[BR]]
+and many other messages about using secure versions.
+
+Unless you believe that the 'secure' versions are useful, suppress with 
+#  pragma warning(disable: 4996) // '' was declared deprecated
+
+3  C4127 conditional expression is constant[[BR]]
+
+Very common and many believe unhelpful, but a few find it informative, so do not suppress globally.
+
+Even while(true) can trigger this!  Suppress.[[BR]]
+
+ #  pragma warning(disable: 4127) // conditional expression is constant
+
+4 C4100 unreferenced formal parameter
+
+Either surround the parameter with C comments, for example: int */ my_variable */)
+or just delete if the variable name is uninformative.
+
+5 C4701 local variable may be used without having been initialized
+
+Best is to recode to avoid the message, but if you are '''very''' sure the message is misleading, suppress.
+
+ #  pragma warning(disable: 4701) // local variable may be used without having been initialized
+
+6 c4511  copy constructor could not be generated
+
+This can almost certainly be suppressed.
+ #  pragma warning(disable: 4511) // copy constructor could not be generated
+
+7 C4180  qualifier applied to function type has no meaning; ignored
+
+This can always be suppressed - but check that you didn't mean to put the const somewhere else.
+
+8 C4702  unreachable code
+
+Be very cautious about suppressing this, but use of macros may make this troublesome,
+so suppress with care, and always locally.
+
+ #pragma warning(disable: 4702) // unreachable code
+
+9 C4189 local variable is initialized but not referenced
+
+This probably indicates a redundant variable and assignment, so probably remove it.
+
+If you sure it is required (or has negligible cost for some documentation benefit), suppress.
+
+10  C4224 nonstandard extension used : formal parameter 'arg' was previously defined as a type.
+
+This will bite users who try to compile with Microsoft extensions disabled.
+So is most undesirable, but may be a major nuisance to change the names in code.
+However fixing is the Right Thing, but meanwhile suppressing may be helpful.
+
+ #  pragma warning(disable: 4224) // formal parameter 'arg' was previously defined as a type.
+
+11 C4510  default constructor could not be generated
+
+Suppress.
+
+12 C4800 int' : forcing value to bool 'true' or 'false'
+
+Suppress.
+
+13 C4244   // Conversion: possible loss of data.
+
+Fix, for example changing type or using static_cast is best, suppress with much caution.
+
+  # pragma warning(disable:4244)    // Conversion: possible loss of data.
+
+14  C4324  structure was padded due to __declspec(align())
+
+Suppress
+
+#pragma warning(disable:4324) // structure was padded due to __declspec(align())
+
+'''GCC'''
+
+1  class does not have a  virtual destructor
+
+Suppress or provide a virtual destructor.
+