Re: [PATCH] gdb: Respect CXXFLAGS when building with C++ compiler

[Simon Marchi <simon dot marchi at ericsson dot com>]

On 16-01-20 06:07 AM, Pedro Alves wrote:
> Currently, even when built with --enable-build-with-cxx, gdb uses
> CFLAGS instead of CXXFLAGS.  This commit fixes it.
> 
> CXXFLAGS set in the environment when configure was run is now honored
> in the generated gdb/Makefile, and you can also override CXXFLAGS in
> the command like at make time, with the usual 'make CXXFLAGS="..."'
> 
> Objects built with a C compiler (e.g., gnulib) still honor CFLAGS
> instead.
> 
> gdb/ChangeLog:
> 2016-01-20  Pedro Alves  <palves@redhat.com>
> 
> 	* Makefile.in (COMPILER_CFLAGS): New.
> 	(CXXFLAGS): Get it from configure.
> 	(INTERNAL_CFLAGS_BASE, INTERNAL_LDFLAGS): Use COMPILER_CFLAGS
> 	instead of CFLAGS.
> 	* build-with-cxx.m4 (GDB_AC_BUILD_WITH_CXX): Set and AC_SUBST
> 	COMPILER_CFLAGS.
> 	* configure: Regenerate.
> 
> gdb/gdbserver/ChangeLog:
> 2016-01-20  Pedro Alves  <palves@redhat.com>
> 
> 	* Makefile.in (COMPILER_CFLAGS, CXXFLAGS): New.
> 	(INTERNAL_CFLAGS_BASE, INTERNAL_LDFLAGS): Use COMPILER_CFLAGS
> 	instead of CFLAGS.
> 	* configure: Regenerate.
> ---
>  gdb/Makefile.in           | 18 +++++++++---------
>  gdb/build-with-cxx.m4     |  3 +++
>  gdb/configure             |  4 ++++
>  gdb/gdbserver/Makefile.in |  7 +++++--
>  gdb/gdbserver/configure   |  4 ++++
>  5 files changed, 25 insertions(+), 11 deletions(-)
> 
> diff --git a/gdb/Makefile.in b/gdb/Makefile.in
> index 895ece6..5e8eb9a 100644
> --- a/gdb/Makefile.in
> +++ b/gdb/Makefile.in
> @@ -81,6 +81,8 @@ CATALOGS = @CATALOGS@
>  
>  # The name of the compiler to use.
>  COMPILER = @COMPILER@
> +# Set to CFLAGS or CXXFLAGS, depending on compiler/language.
> +COMPILER_CFLAGS = @COMPILER_CFLAGS@
>  
>  # If you are compiling with GCC, make sure that either 1) You have the
>  # fixed include files where GCC can reach them, or 2) You use the
> @@ -551,9 +553,10 @@ GLOBAL_CFLAGS = $(MH_CFLAGS)
>  
>  PROFILE_CFLAGS = @PROFILE_CFLAGS@
>  
> -# CFLAGS is specifically reserved for setting from the command line
> -# when running make.  I.E.  "make CFLAGS=-Wmissing-prototypes".
> +# These are specifically reserved for setting from the command line
> +# when running make.  I.E.: "make CFLAGS=-Wmissing-prototypes".
>  CFLAGS = @CFLAGS@
> +CXXFLAGS = @CXXFLAGS@
>  
>  # Set by configure, for e.g. expat.  Python installations are such that
>  # C headers are included using their basename (for example, we #include
> @@ -563,14 +566,9 @@ CFLAGS = @CFLAGS@
>  # a bit the consequences by putting the Python includes last in the list.
>  INTERNAL_CPPFLAGS = @CPPFLAGS@ @GUILE_CPPFLAGS@ @PYTHON_CPPFLAGS@
>  
> -# Need to pass this to testsuite for "make check".  Probably should be
> -# consistent with top-level Makefile.in and gdb/testsuite/Makefile.in
> -# so "make check" has the same result no matter where it is run.
> -CXXFLAGS = -g -O
> -
>  # INTERNAL_CFLAGS is the aggregate of all other *CFLAGS macros.
>  INTERNAL_CFLAGS_BASE = \
> -	$(CFLAGS) $(GLOBAL_CFLAGS) $(PROFILE_CFLAGS) \
> +	$(COMPILER_CFLAGS) $(GLOBAL_CFLAGS) $(PROFILE_CFLAGS) \
>  	$(GDB_CFLAGS) $(OPCODES_CFLAGS) $(READLINE_CFLAGS) $(ZLIBINC) \
>  	$(BFD_CFLAGS) $(INCLUDE_CFLAGS) $(LIBDECNUMBER_CFLAGS) \
>  	$(INTL_CFLAGS) $(INCGNU) $(ENABLE_CFLAGS) $(INTERNAL_CPPFLAGS)
> @@ -585,7 +583,9 @@ LDFLAGS = @LDFLAGS@
>  # I think it's perfectly reasonable for a user to set -pg in CFLAGS
>  # and have it work; that's why CFLAGS is here.
>  # PROFILE_CFLAGS is _not_ included, however, because we use monstartup.
> -INTERNAL_LDFLAGS = $(CFLAGS) $(GLOBAL_CFLAGS) $(MH_LDFLAGS) $(LDFLAGS) $(CONFIG_LDFLAGS)
> +INTERNAL_LDFLAGS = \
> +	$(COMPILER_CFLAGS) $(GLOBAL_CFLAGS) $(MH_LDFLAGS) \
> +	$(LDFLAGS) $(CONFIG_LDFLAGS)
>  
>  # If your system is missing alloca(), or, more likely, it's there but
>  # it doesn't work, then refer to libiberty.
> diff --git a/gdb/build-with-cxx.m4 b/gdb/build-with-cxx.m4
> index d282092..6eb9143 100644
> --- a/gdb/build-with-cxx.m4
> +++ b/gdb/build-with-cxx.m4
> @@ -33,8 +33,11 @@ AC_DEFUN([GDB_AC_BUILD_WITH_CXX],
>  
>    if test "$enable_build_with_cxx" = "yes"; then
>      COMPILER='$(CXX)'
> +    COMPILER_CFLAGS='$(CXXFLAGS)'
>     else
>      COMPILER='$(CC)'
> +    COMPILER_CFLAGS='$(CFLAGS)'
>    fi
>    AC_SUBST(COMPILER)
> +  AC_SUBST(COMPILER_CFLAGS)
>  ])
> diff --git a/gdb/configure b/gdb/configure
> index 56deb9c..34d6539 100755
> --- a/gdb/configure
> +++ b/gdb/configure
> @@ -731,6 +731,7 @@ MAKE
>  CCDEPMODE
>  DEPDIR
>  am__leading_dot
> +COMPILER_CFLAGS
>  COMPILER
>  INSTALL_STRIP_PROGRAM
>  STRIP
> @@ -5015,12 +5016,15 @@ fi
>  
>    if test "$enable_build_with_cxx" = "yes"; then
>      COMPILER='$(CXX)'
> +    COMPILER_CFLAGS='$(CXXFLAGS)'
>     else
>      COMPILER='$(CC)'
> +    COMPILER_CFLAGS='$(CFLAGS)'
>    fi
>  
>  
>  
> +
>  # Dependency checking.
>  rm -rf .tst 2>/dev/null
>  mkdir .tst 2>/dev/null
> diff --git a/gdb/gdbserver/Makefile.in b/gdb/gdbserver/Makefile.in
> index 4719e48..f9b9dbe 100644
> --- a/gdb/gdbserver/Makefile.in
> +++ b/gdb/gdbserver/Makefile.in
> @@ -51,6 +51,8 @@ RANLIB = @RANLIB@
>  
>  # The name of the compiler to use.
>  COMPILER = @COMPILER@
> +# Set to CFLAGS or CXXFLAGS, depending on compiler/language.
> +COMPILER_CFLAGS = @COMPILER_CFLAGS@

Maybe call this COMPILER_FLAGS?

Otherwise, LGTM.