Re: Issue 5720: Fix C++11 option (issue 579270051 by address@hidden)

[trueroad]

Reviewers: lemzwerg,

Message:
On 2020/02/01 07:10:17, lemzwerg wrote:
> Mhmm, wouldn't it be better to simply define `M_PI` if it is not
defined?  GNU
> options might not be available with other compilers...

`-std=c++11` cannot use not only `M_PI` but also POSIX functions such as
`strdup ()`.
Even if we define `M_PI`, an error raises since there is no `strdup ()`.


Description:
Fix C++11 option

On the Linux environments,
`M_PI` definition can be used with the `-std=c++11` option.
However, on the other environments (e.g. MinGW),
`M_PI` cannot be used with the `-std=c++11` option.

Originally `-std=c++11` is an option to follow the strict C++ standard,
and cannot use `M_PI` that is not in the C++ standard.
To use `M_PI`, `-std=gnu++11` instead of `-std=c++11` is required.

Also, the current default for g++ is `-std=gnu++14`, not `-std=c++14`.

Please review this at https://codereview.appspot.com/579270051/

Affected files (+1, -1 lines):
  M stepmake/stepmake/c++-vars.make


Index: stepmake/stepmake/c++-vars.make
diff --git a/stepmake/stepmake/c++-vars.make b/stepmake/stepmake/c++-vars.make
index 
73dd91e240170d11f7736424e7da81ba6c21453a..e7bf19217d3e45dbbdb27e92a7c16013c3c50d6f
 100644
--- a/stepmake/stepmake/c++-vars.make
+++ b/stepmake/stepmake/c++-vars.make
@@ -14,7 +14,7 @@ DO_O_DEP = rm -f $(o-dep-out); 
DEPENDENCIES_OUTPUT="$(o-dep-out) $(outdir)/$(not
 lo-dep-out = $(outdir)/$(subst .lo,.dep,$(notdir $@))#
 DO_LO_DEP = rm -f $(lo-dep-out); DEPENDENCIES_OUTPUT="$(lo-dep-out) 
$(outdir)/$(notdir $@)"
 
-EXTRA_CXXFLAGS = -std=c++11 -W -Wall -Wconversion -Woverloaded-virtual
+EXTRA_CXXFLAGS = -std=gnu++11 -W -Wall -Wconversion -Woverloaded-virtual
 #ifeq ($(MY_PATCH_LEVEL),)
 #EXTRA_CXXFLAGS += -Werror
 #endif