Make "make variables" config attributes for overridable flags

With the support of "make variables" comes the possibility for the
user to override them.  However, we need to make a difference between
defaults that we use (and that should be overridable by the user) and
flags that are crucial for building OpenSSL (should not be
overridable).

Typically, overridable flags are those setting optimization levels,
warnings levels, that kind of thing, while non-overridable flags are,
for example, macros that indicate aspects of how the config target
should be treated, such as L_ENDIAN and B_ENDIAN.

We do that differentiation by allowing upper case attributes in the
config targets, named exactly like the "make variables" we support,
and reserving the lower case attributes for non-overridable project
flags.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5534)

15 files changed, 787 insertions, 459 deletions

diff --git a/Configurations/00-base-templates.conf b/Configurations/00-base-templates.conf
index 0350997ff7..310a37091e 100644
--- a/Configurations/00-base-templates.conf
+++ b/Configurations/00-base-templates.conf
@@ -46,16 +46,16 @@ my %targets=(
 	build_scheme	=> [ "unified", "unix" ],
 	build_file	=> "Makefile",
 
-	ar		=> "ar",
-	arflags		=> "r",
-	cc		=> "cc",
-	hashbangperl	=> "/usr/bin/env perl",
-	ranlib		=> sub { which("$config{cross_compile_prefix}ranlib")
+	AR		=> "ar",
+	ARFLAGS		=> "r",
+	CC		=> "cc",
+	HASHBANGPERL	=> "/usr/bin/env perl",
+	RANLIB		=> sub { which("$config{cross_compile_prefix}ranlib")
                                      ? "ranlib" : "" },
-	rc		=> "windres",
+	RC		=> "windres",
 
 	#### THESE WILL BE ENABLED IN OpenSSL 1.2
-	#hashbangperl	=> "PERL", # Only Unix actually cares
+	#HASHBANGPERL	=> "PERL", # Only Unix actually cares
     },
 
     BASE_common => {
@@ -84,19 +84,19 @@ my %targets=(
         inherit_from    => [ "BASE_common" ],
         template        => 1,
 
-        ar              => "ar",
-        arflags         => "r",
-        cc              => "cc",
+        AR              => "ar",
+        ARFLAGS         => "r",
+        CC              => "cc",
         lflags          =>
             sub { $withargs{zlib_lib} ? "-L".$withargs{zlib_lib} : () },
         ex_libs         =>
             sub { !defined($disabled{zlib})
                   && defined($disabled{"zlib-dynamic"})
                   ? "-lz" : () },
-        hashbangperl    => "/usr/bin/env perl", # Only Unix actually cares
-        ranlib          => sub { which("$config{cross_compile_prefix}ranlib")
+        HASHBANGPERL    => "/usr/bin/env perl", # Only Unix actually cares
+        RANLIB          => sub { which("$config{cross_compile_prefix}ranlib")
                                      ? "ranlib" : "" },
-        rc              => "windres",
+        RC              => "windres",
 
         build_scheme    => [ "unified", "unix" ],
         build_file      => "Makefile",
@@ -116,16 +116,16 @@ my %targets=(
                 return ();
             },
 
-        ld              => "link",
-        lflags          => "/nologo",
-        loutflag        => "/out:",
-        ar              => "lib",
-        arflags         => "/nologo",
+        LD              => "link",
+        LDFLAGS         => "/nologo",
+        ldoutflag       => "/out:",
+        AR              => "lib",
+        ARFLAGS         => "/nologo",
         aroutflag       => "/out:",
-        rc               => "rc",
+        RC               => "rc",
         rcoutflag        => "/fo",
-        mt              => "mt",
-        mtflags         => "-nologo",
+        MT              => "mt",
+        MTFLAGS         => "-nologo",
         mtinflag        => "-manifest ",
         mtoutflag       => "-outputresource:",
 
diff --git a/Configurations/10-main.conf b/Configurations/10-main.conf
index 7f07752511..277ec26625 100644
--- a/Configurations/10-main.conf
+++ b/Configurations/10-main.conf
@@ -6,16 +6,19 @@ my $vc_win64a_info = {};
 sub vc_win64a_info {
     unless (%$vc_win64a_info) {
         if (`nasm -v 2>NUL` =~ /NASM version ([0-9]+\.[0-9]+)/ && $1 >= 2.0) {
-            $vc_win64a_info = { as        => "nasm",
-                                asflags   => "-f win64 -DNEAR -Ox -g",
+            $vc_win64a_info = { AS        => "nasm",
+                                ASFLAGS   => "-g",
+                                asflags   => "-Ox -f win64 -DNEAR",
                                 asoutflag => "-o" };
         } elsif ($disabled{asm}) {
-            $vc_win64a_info = { as        => "ml64",
-                                asflags   => "/c /Cp /Cx /Zi",
+            $vc_win64a_info = { AS        => "ml64",
+                                ASFLAGS   => "/Zi",
+                                asflags   => "/c /Cp /Cx",
                                 asoutflag => "/Fo" };
         } else {
             $die->("NASM not found - please read INSTALL and NOTES.WIN for further details\n");
-            $vc_win64a_info = { as        => "{unknown}",
+            $vc_win64a_info = { AS        => "{unknown}",
+                                ASFLAGS   => "",
                                 asflags   => "",
                                 asoutflag => "" };
         }
@@ -29,18 +32,21 @@ sub vc_win32_info {
         my $ver=`nasm -v 2>NUL`;
         my $vew=`nasmw -v 2>NUL`;
         if ($ver ne "" || $vew ne "") {
-            $vc_win32_info = { as        => $ver ge $vew ? "nasm" : "nasmw",
+            $vc_win32_info = { AS        => $ver ge $vew ? "nasm" : "nasmw",
+                               ASFLAGS   => "",
                                asflags   => "-f win32",
                                asoutflag => "-o",
                                perlasm_scheme => "win32n" };
         } elsif ($disabled{asm}) {
-            $vc_win32_info = { as        => "ml",
-                               asflags   => "/nologo /Cp /coff /c /Cx /Zi",
+            $vc_win32_info = { AS        => "ml",
+                               ASFLAGS   => "/nologo /Zi",
+                               asflags   => "/Cp /coff /c /Cx",
                                asoutflag => "/Fo",
                                perlasm_scheme => "win32" };
         } else {
             $die->("NASM not found - please read INSTALL and NOTES.WIN for further details\n");
-            $vc_win32_info = { as        => "{unknown}",
+            $vc_win32_info = { AS        => "{unknown}",
+                               ASFLAGS   => "",
                                asflags   => "",
                                asoutflag => "",
                                perlasm_scheme => "win32" };
@@ -150,8 +156,9 @@ sub vms_info {
         if ($config{target} =~ /-ia64/) {
             `PIPE ias -H 2> NL:`;
             if ($? == 0) {
-                $vms_info->{as} = "ias";
-                $vms_info->{asflags} = '-d debug "-N" vms_upcase';
+                $vms_info->{AS} = "ias";
+                $vms_info->{ASFLAGS} = '-d debug';
+                $vms_info->{asflags} = '"-N" vms_upcase';
                 $vms_info->{asoutflag} = "-o";
                 $vms_info->{perlasm_scheme} = "ias";
             }
@@ -165,24 +172,24 @@ my %targets = (
 #### Basic configs that should work on any 32-bit box
     "gcc" => {
         inherit_from     => [ "BASE_unix" ],
-        cc               => "gcc",
-        cflags           => picker(debug   => "-O0 -g",
+        CC               => "gcc",
+        CFLAGS           => picker(debug   => "-O0 -g",
                                    release => "-O3"),
         thread_scheme    => "(unknown)",
         bn_ops           => "BN_LLONG",
     },
     "cc" => {
         inherit_from     => [ "BASE_unix" ],
-        cc               => "cc",
-        cflags           => "-O",
+        CC               => "cc",
+        CFLAGS           => "-O",
         thread_scheme    => "(unknown)",
     },
 
 #### VOS Configurations
     "vos-gcc" => {
         inherit_from     => [ "BASE_unix" ],
-        cc               => "gcc",
-        cflags           => picker(default => "-Wall",
+        CC               => "gcc",
+        CFLAGS           => picker(default => "-Wall",
                                    debug   => "-O0 -g",
                                    release => "-O3"),
         cppflags         => "-D_POSIX_C_SOURCE=200112L -D_BSD -D_VOS_EXTENDED_NAMES -DB_ENDIAN",
@@ -210,11 +217,11 @@ my %targets = (
         # /usr/ccs/bin/as. Failure to comply will result in compile
         # failures [at least] in 32-bit build.
         inherit_from     => [ "solaris-common", asm("x86_elf_asm") ],
-        cc               => "gcc",
-        cflags           => add_before(picker(default => "-Wall",
+        CC               => "gcc",
+        CFLAGS           => add_before(picker(default => "-Wall",
                                               debug   => "-O0 -g",
-                                              release => "-O3 -fomit-frame-pointer"),
-                                       threads("-pthread")),
+                                              release => "-O3 -fomit-frame-pointer")),
+        cflags           => add(threads("-pthread")),
         cppflags         => add("-DL_ENDIAN"),
         ex_libs          => add(threads("-pthread")),
         bn_ops           => "BN_LLONG",
@@ -231,11 +238,11 @@ my %targets = (
         # to consider using gcc shared build even with vendor compiler:-)
         #                        -- <appro@openssl.org>
         inherit_from     => [ "solaris-common", asm("x86_64_asm") ],
-        cc               => "gcc",
-        cflags           => add_before(picker(default => "-m64 -Wall",
+        CC               => "gcc",
+        CFLAGS           => add_before(picker(default => "-Wall",
                                               debug   => "-O0 -g",
-                                              release => "-O3"),
-                                       threads("-pthread")),
+                                              release => "-O3")),
+        cflags           => add_before("-m64", threads("-pthread")),
         cppflags         => add("-DL_ENDIAN"),
         ex_libs          => add(threads("-pthread")),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
@@ -260,10 +267,10 @@ my %targets = (
     #
     "solaris64-x86_64-cc" => {
         inherit_from     => [ "solaris-common", asm("x86_64_asm") ],
-        cc               => "cc",
-        cflags           => add_before(picker(default => "-xarch=generic64 -xstrconst -Xa",
-                                              debug   => "-g",
+        CC               => "cc",
+        CFLAGS           => add_before(picker(debug   => "-g",
                                               release => "-xO5 -xdepend -xbuiltin")),
+        cflags           => add_before("-xarch=generic64 -xstrconst -Xa"),
         cppflags         => add("-DL_ENDIAN", threads("-D_REENTRANT")),
         thread_scheme    => "pthreads",
         lflags           => add(threads("-mt")),
@@ -278,11 +285,11 @@ my %targets = (
 #### SPARC Solaris with GNU C setups
     "solaris-sparcv7-gcc" => {
         inherit_from     => [ "solaris-common" ],
-        cc               => "gcc",
-        cflags           => add_before(picker(default => "-Wall",
+        CC               => "gcc",
+        CFLAGS           => add_before(picker(default => "-Wall",
                                               debug   => "-O0 -g",
-                                              release => "-O3"),
-                                       threads("-pthread")),
+                                              release => "-O3")),
+        cflags           => add(threads("-pthread")),
         cppflags         => add("-DB_ENDIAN -DBN_DIV2W"),
         ex_libs          => add(threads("-pthread")),
         bn_ops           => "BN_LLONG RC4_CHAR",
@@ -312,10 +319,10 @@ my %targets = (
 # SC5.0 note: Compiler common patch 107357-01 or later is required!
     "solaris-sparcv7-cc" => {
         inherit_from     => [ "solaris-common" ],
-        cc               => "cc",
-        cflags           => add_before(picker(default => "-xstrconst -Xa",
-                                              debug   => "-g",
+        CC               => "cc",
+        CFLAGS           => add_before(picker(debug   => "-g",
                                               release => "-xO5 -xdepend")),
+        cflags           => add_before("-xstrconst -Xa"),
         cppflags         => add("-DB_ENDIAN -DBN_DIV2W",
                                 threads("-D_REENTRANT")),
         lflags           => add(threads("-mt")),
@@ -344,10 +351,10 @@ my %targets = (
 # Only N32 and N64 ABIs are supported.
     "irix-mips3-gcc" => {
         inherit_from     => [ "BASE_unix", asm("mips64_asm") ],
-        cc               => "gcc",
-        cflags           => combine(picker(default => "-mabi=n32",
-                                           debug   => "-g -O0",
-                                           release => "-O3")),
+        CC               => "gcc",
+        CFLAGS           => picker(debug   => "-g -O0",
+                                   release => "-O3"),
+        cflags           => "-mabi=n32",
         cppflags         => combine("-DB_ENDIAN -DBN_DIV3W",
                                     threads("-D_SGI_MP_SOURCE")),
         ex_libs          => add(threads("-lpthread")),
@@ -361,10 +368,10 @@ my %targets = (
     },
     "irix-mips3-cc" => {
         inherit_from     => [ "BASE_unix", asm("mips64_asm") ],
-        cc               => "cc",
-        cflags           => combine(picker(default => "-n32 -mips3 -use_readonly_const -G0 -rdata_shared",
-                                           debug   => "-g -O0",
-                                           release => "-O2")),
+        CC               => "cc",
+        CFLAGS           => picker(debug   => "-g -O0",
+                                   release => "-O2"),
+        cflags           => "-n32 -mips3 -use_readonly_const -G0 -rdata_shared",
         cppflags         => combine("-DB_ENDIAN -DBN_DIV3W",
                                     threads("-D_SGI_MP_SOURCE")),
         ex_libs          => add(threads("-lpthread")),
@@ -379,10 +386,10 @@ my %targets = (
     # N64 ABI builds.
     "irix64-mips4-gcc" => {
         inherit_from     => [ "BASE_unix", asm("mips64_asm") ],
-        cc               => "gcc",
-        cflags           => combine(picker(default => "-mabi=64 -mips4",
-                                           debug   => "-g -O0",
-                                           release => "-O3")),
+        CC               => "gcc",
+        CFLAGS           => picker(debug   => "-g -O0",
+                                   release => "-O3"),
+        cflags           => "-mabi=64 -mips4",
         cppflags         => combine("-DB_ENDIAN -DBN_DIV3W",
                                     threads("-D_SGI_MP_SOURCE")),
         ex_libs          => add(threads("-lpthread")),
@@ -396,13 +403,14 @@ my %targets = (
     },
     "irix64-mips4-cc" => {
         inherit_from     => [ "BASE_unix", asm("mips64_asm") ],
-        cc               => "cc",
-        cflags           => combine(picker(default => "-64 -mips4 -use_readonly_const -G0 -rdata_shared",
-                                           debug   => "-g -O0",
-                                           release => "-O2")),
+        CC               => "cc",
+        CFLAGS           => picker(debug   => "-g -O0",
+                                   release => "-O2"),
+        cppflags         => threads("-D_SGI_MP_SOURCE"),
+        cflags           => "-64 -mips4 -use_readonly_const -G0 -rdata_shared",
         cppflags         => combine("-DB_ENDIAN -DBN_DIV3W",
                                     threads("-D_SGI_MP_SOURCE")),
-        ex_libs          => add(threads("-lpthread")),
+        ex_libs          => threads("-lpthread"),
         bn_ops           => "RC4_CHAR SIXTY_FOUR_BIT_LONG",
         thread_scheme    => "pthreads",
         perlasm_scheme   => "64",
@@ -441,10 +449,10 @@ my %targets = (
 #   thus adequate performance is provided even with PA-RISC 1.1 build.
     "hpux-parisc-gcc" => {
         inherit_from     => [ "BASE_unix" ],
-        cc               => "gcc",
-        cflags           => combine(picker(debug   => "-O0 -g",
-                                           release => "-O3"),
-                                    threads("-pthread")),
+        CC               => "gcc",
+        CFLAGS           => picker(debug   => "-O0 -g",
+                                   release => "-O3"),
+        cflags           => add(threads("-pthread")),
         cppflags         => "-DB_ENDIAN -DBN_DIV2W",
         ex_libs          => add("-Wl,+s -ldld", threads("-pthread")),
         bn_ops           => "BN_LLONG",
@@ -461,8 +469,8 @@ my %targets = (
     },
     "hpux64-parisc2-gcc" => {
         inherit_from     => [ "BASE_unix", asm("parisc20_64_asm") ],
-        cc               => "gcc",
-        cflags           => combine(picker(debug   => "-O0 -g",
+        CC               => "gcc",
+        CFLAGS           => combine(picker(debug   => "-O0 -g",
                                            release => "-O3")),
         cppflags         => combine("-DB_ENDIAN", threads("-D_REENTRANT")),
         ex_libs          => add("-ldl"),
@@ -479,10 +487,10 @@ my %targets = (
     # More attempts at unified 10.X and 11.X targets for HP C compiler.
     "hpux-parisc-cc" => {
         inherit_from     => [ "BASE_unix" ],
-        cc               => "cc",
-        cflags           => combine(picker(default => "+Optrs_strongly_typed -Ae +ESlit",
-                                           debug   => "+O0 +d -g",
-                                           release => "+O3")),
+        CC               => "cc",
+        CFLAGS           => picker(debug   => "+O0 +d -g",
+                                   release => "+O3"),
+        cflags           => "+Optrs_strongly_typed -Ae +ESlit",
         cppflags         => combine("-DB_ENDIAN -DBN_DIV2W -DMD32_XARRAY",
                                     threads("-D_REENTRANT")),
         ex_libs          => add("-Wl,+s -ldld",threads("-lpthread")),
@@ -501,10 +509,10 @@ my %targets = (
     },
     "hpux64-parisc2-cc" => {
         inherit_from     => [ "BASE_unix", asm("parisc20_64_asm") ],
-        cc               => "cc",
-        cflags           => combine(picker(default => "+DD64 +Optrs_strongly_typed -Ae +ESlit",
-                                           debug   => "+O0 +d -g",
-                                           release => "+O3")),
+        CC               => "cc",
+        CFLAGS           => picker(debug   => "+O0 +d -g",
+                                   release => "+O3") ,
+        cflags           => "+DD64 +Optrs_strongly_typed -Ae +ESlit",
         cppflags         => combine("-DB_ENDIAN -DMD32_XARRAY",
                                     threads("-D_REENTRANT")),
         ex_libs          => add("-ldl",threads("-lpthread")),
@@ -521,10 +529,10 @@ my %targets = (
     # HP/UX IA-64 targets
     "hpux-ia64-cc" => {
         inherit_from     => [ "BASE_unix", asm("ia64_asm") ],
-        cc               => "cc",
-        cflags           => combine(picker(default => "-Ae +DD32 +Olit=all -z",
-                                           debug   => "+O0 +d -g",
-                                           release => "+O2")),
+        CC               => "cc",
+        CFLAGS           => picker(debug   => "+O0 +d -g",
+                                   release => "+O2"),
+        cflags           => "-Ae +DD32 +Olit=all -z",
         cppflags         => combine("-DB_ENDIAN", threads("-D_REENTRANT")),
         ex_libs          => add("-ldl",threads("-lpthread")),
         bn_ops           => "SIXTY_FOUR_BIT",
@@ -538,10 +546,10 @@ my %targets = (
     },
     "hpux64-ia64-cc" => {
         inherit_from     => [ "BASE_unix", asm("ia64_asm") ],
-        cc               => "cc",
-        cflags           => combine(picker(default => "-Ae +DD64 +Olit=all -z",
-                                           debug   => "+O0 +d -g",
-                                           release => "+O3")),
+        CC               => "cc",
+        CFLAGS           => picker(debug   => "+O0 +d -g",
+                                   release => "+O3"),
+        cflags           => "-Ae +DD64 +Olit=all -z",
         cppflags         => combine("-DB_ENDIAN", threads("-D_REENTRANT")),
         ex_libs          => add("-ldl", threads("-lpthread")),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
@@ -556,10 +564,10 @@ my %targets = (
     # GCC builds...
     "hpux-ia64-gcc" => {
         inherit_from     => [ "BASE_unix", asm("ia64_asm") ],
-        cc               => "gcc",
-        cflags           => combine(picker(debug   => "-O0 -g",
-                                           release => "-O3"),
-                                    threads("-pthread")),
+        CC               => "gcc",
+        CFLAGS           => picker(debug   => "-O0 -g",
+                                   release => "-O3"),
+        cflags           => add(threads("-pthread")),
         cppflags         => "-DB_ENDIAN",
         ex_libs          => add("-ldl", threads("-pthread")),
         bn_ops           => "SIXTY_FOUR_BIT",
@@ -573,11 +581,10 @@ my %targets = (
     },
     "hpux64-ia64-gcc" => {
         inherit_from     => [ "BASE_unix", asm("ia64_asm") ],
-        cc               => "gcc",
-        cflags           => combine(picker(default => "-mlp64",
-                                           debug   => "-O0 -g",
-                                           release => "-O3"),
-                                    threads("-pthread")),
+        CC               => "gcc",
+        CFLAGS           => picker(debug   => "-O0 -g",
+                                   release => "-O3"),
+        cflags           => combine("-mlp64", threads("-pthread")),
         cppflags         => "-DB_ENDIAN",
         ex_libs          => add("-ldl", threads("-pthread")),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
@@ -593,8 +600,8 @@ my %targets = (
 #### HP MPE/iX http://jazz.external.hp.com/src/openssl/
     "MPE/iX-gcc" => {
         inherit_from     => [ "BASE_unix" ],
-        cc               => "gcc",
-        cflags           => "-O3",
+        CC               => "gcc",
+        CFLAGS           => "-O3",
         cppflags         => "-D_ENDIAN -DBN_DIV2W -D_POSIX_SOURCE -D_SOCKET_SOURCE",
         includes         => add("/SYSLOG/PUB"),
         sys_id           => "MPE",
@@ -610,8 +617,9 @@ my %targets = (
 #### but not anymore...
     "tru64-alpha-gcc" => {
         inherit_from     => [ "BASE_unix", asm("alpha_asm") ],
-        cc               => "gcc",
-        cflags           => combine("-std=c9x -O3", threads("-pthread")),
+        CC               => "gcc",
+        CFLAGS           => "-O3",
+        cflags           => add("-std=c9x", threads("-pthread")),
         cppflags         => "-D_XOPEN_SOURCE=500 -D_OSF_SOURCE",
         ex_libs          => add("-lrt", threads("-pthread")), # for mlock(2)
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
@@ -622,9 +630,10 @@ my %targets = (
     },
     "tru64-alpha-cc" => {
         inherit_from     => [ "BASE_unix", asm("alpha_asm") ],
-        cc               => "cc",
-        cflags           => combine("-std1 -tune host -fast -readonly_strings",
-                                    threads("-pthread")),
+        CC               => "cc",
+        CFLAGS           => "-tune host -fast",
+        cflags           => add("-std1 -readonly_strings",
+                                threads("-pthread")),
         cppflags         => "-D_XOPEN_SOURCE=500 -D_OSF_SOURCE",
         ex_libs          => add("-lrt", threads("-pthread")), # for mlock(2)
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
@@ -642,16 +651,16 @@ my %targets = (
 # throw in -D[BL]_ENDIAN, whichever appropriate...
     "linux-generic32" => {
         inherit_from     => [ "BASE_unix" ],
-        cc               => "gcc",
-        cxx              => "g++",
-        cflags           => combine(picker(default => "-Wall",
-                                           debug   => "-O0 -g",
-                                           release => "-O3"),
-                                    threads("-pthread")),
-        cxxflags         => combine(picker(default => "-std=c++11 -Wall",
-                                           debug   => "-O0 -g",
-                                           release => "-O3"),
-                                    threads("-pthread")),
+        CC               => "gcc",
+        CXX              => "g++",
+        CFLAGS           => picker(default => "-Wall",
+                                   debug   => "-O0 -g",
+                                   release => "-O3"),
+        CXXFLAGS         => picker(default => "-Wall",
+                                   debug   => "-O0 -g",
+                                   release => "-O3"),
+        cflags           => threads("-pthread"),
+        cxxflags         => combine("-std=c++11", threads("-pthread")),
         cppflags         => "-DOPENSSL_USE_NODELETE",
         ex_libs          => add("-ldl", threads("-pthread")),
         bn_ops           => "BN_LLONG RC4_CHAR",
@@ -762,14 +771,14 @@ my %targets = (
     #### machines where gcc doesn't understand -m32 and -m64
     "linux-elf" => {
         inherit_from     => [ "linux-generic32", asm("x86_elf_asm") ],
-        cflags           => add(picker(release => "-fomit-frame-pointer")),
+        CFLAGS           => add(picker(release => "-fomit-frame-pointer")),
         cppflags         => add("-DL_ENDIAN"),
         bn_ops           => "BN_LLONG",
     },
     "linux-aout" => {
         inherit_from     => [ "BASE_unix", asm("x86_asm") ],
-        cc               => "gcc",
-        cflags           => add(picker(default => "-Wall",
+        CC               => "gcc",
+        CFLAGS           => add(picker(default => "-Wall",
                                        debug   => "-O0 -g",
                                        release => "-O3 -fomit-frame-pointer")),
         cppflags         => add("-DL_ENDIAN"),
@@ -781,17 +790,17 @@ my %targets = (
     #### X86 / X86_64 targets
     "linux-x86" => {
         inherit_from     => [ "linux-generic32", asm("x86_asm") ],
-        cflags           => add(picker(default => "-m32",
-                                       release => "-fomit-frame-pointer")),
+        CFLAGS           => add(picker(release => "-fomit-frame-pointer")),
+        cflags           => add("-m32"),
         cppflags         => add("-DL_ENDIAN"),
         bn_ops           => "BN_LLONG",
         perlasm_scheme   => "elf",
     },
     "linux-x86-clang" => {
         inherit_from     => [ "linux-x86" ],
-        cc               => "clang",
-        cxx              => "clang++",
-        cflags           => add("-Wextra"),
+        CC               => "clang",
+        CXX              => "clang++",
+        CFLAGS           => add("-Wextra"),
     },
     "linux-x86_64" => {
         inherit_from     => [ "linux-generic64", asm("x86_64_asm") ],
@@ -803,9 +812,9 @@ my %targets = (
     },
     "linux-x86_64-clang" => {
         inherit_from     => [ "linux-x86_64" ],
-        cc               => "clang",
-        cxx              => "clang++",
-        cflags           => add("-Wextra"),
+        CC               => "clang",
+        CXX              => "clang++",
+        CFLAGS           => add("-Wextra"),
     },
     "linux-x32" => {
         inherit_from     => [ "linux-generic32", asm("x86_64_asm") ],
@@ -857,34 +866,35 @@ my %targets = (
     "linux-sparcv8" => {
         inherit_from     => [ "linux-generic32", asm("sparcv8_asm") ],
         cflags           => add("-mcpu=v8"),
-        cppflags         => add("-DB_ENDIAN -DBN_DIV2W"),
+        lib_cppflags     => add("-DB_ENDIAN -DBN_DIV2W"),
     },
     "linux-sparcv9" => {
         # it's a real mess with -mcpu=ultrasparc option under Linux,
         # but -Wa,-Av8plus should do the trick no matter what.
         inherit_from     => [ "linux-generic32", asm("sparcv9_asm") ],
         cflags           => add("-m32 -mcpu=ultrasparc -Wa,-Av8plus"),
-        cppflags         => add("-DB_ENDIAN -DBN_DIV2W"),
+        lib_cppflags     => add("-DB_ENDIAN -DBN_DIV2W"),
     },
     "linux64-sparcv9" => {
         # GCC 3.1 is a requirement
         inherit_from     => [ "linux-generic64", asm("sparcv9_asm") ],
         cflags           => add("-m64 -mcpu=ultrasparc"),
-        cppflags         => add("-DB_ENDIAN"),
+        lib_cppflags     => add("-DB_ENDIAN"),
         bn_ops           => "BN_LLONG RC4_CHAR",
         multilib         => "64",
     },
 
     "linux-alpha-gcc" => {
         inherit_from     => [ "linux-generic64", asm("alpha_asm") ],
-        cppflags         => add("-DL_ENDIAN"),
+        lib_cppflags     => add("-DL_ENDIAN"),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
     },
     "linux-c64xplus" => {
         inherit_from     => [ "BASE_unix" ],
         # TI_CGT_C6000_7.3.x is a requirement
-        cc               => "cl6x",
-        cflags           => "--linux -ea=.s -eo=.o -mv6400+ -o2 -ox -ms -pden",
+        CC               => "cl6x",
+        CFLAGS           => "-o2 -ox -ms",
+        cflags           => "--linux -ea=.s -eo=.o -mv6400+ -pden",
         cppflags         => combine("-DOPENSSL_SMALL_FOOTPRINT",
                                     threads("-D_REENTRANT")),
         bn_ops           => "BN_LLONG",
@@ -937,7 +947,7 @@ my %targets = (
     },
     "android-x86" => {
         inherit_from     => [ "android", asm("x86_asm") ],
-        cflags           => add(picker(release => "-fomit-frame-pointer")),
+        CFLAGS           => add(picker(release => "-fomit-frame-pointer")),
         bn_ops           => "BN_LLONG",
         perlasm_scheme   => "android",
     },
@@ -1007,11 +1017,11 @@ my %targets = (
         # -D_THREAD_SAFE and sometimes -D_REENTRANT. FreeBSD 5.x
         # expands it as -lc_r, which seems to be sufficient?
         inherit_from     => [ "BASE_unix" ],
-        cc               => "cc",
-        cflags           => combine(picker(default => "-Wall",
-                                           debug   => "-O0 -g",
-                                           release => "-O3"),
-                                    threads("-pthread")),
+        CC               => "cc",
+        CFLAGS           => picker(default => "-Wall",
+                                   debug   => "-O0 -g",
+                                   release => "-O3"),
+        cflags           => threads("-pthread"),
         cppflags         => threads("-D_THREAD_SAFE -D_REENTRANT"),
         ex_libs          => add(threads("-pthread")),
         enable           => add("devcryptoeng"),
@@ -1029,7 +1039,7 @@ my %targets = (
 
     "BSD-x86" => {
         inherit_from     => [ "BSD-generic32", asm("x86_asm") ],
-        cflags           => add(picker(release => "-fomit-frame-pointer")),
+        CFLAGS           => add(picker(release => "-fomit-frame-pointer")),
         cppflags         => add("-DL_ENDIAN"),
         bn_ops           => "BN_LLONG",
         shared_target    => "bsd-shared",
@@ -1069,8 +1079,8 @@ my %targets = (
 
     "bsdi-elf-gcc" => {
         inherit_from     => [ "BASE_unix", asm("x86_elf_asm") ],
-        cc               => "gcc",
-        cflags           => "-fomit-frame-pointer -O3 -Wall",
+        CC               => "gcc",
+        CFLAGS           => "-fomit-frame-pointer -O3 -Wall",
         cppflags         => "-DPERL5 -DL_ENDIAN",
         ex_libs          => add("-ldl"),
         bn_ops           => "BN_LLONG",
@@ -1083,16 +1093,16 @@ my %targets = (
 
     "nextstep" => {
         inherit_from     => [ "BASE_unix" ],
-        cc               => "cc",
-        cflags           => "-O -Wall",
+        CC               => "cc",
+        CFLAGS           => "-O -Wall",
         unistd           => "<libc.h>",
         bn_ops           => "BN_LLONG",
         thread_scheme    => "(unknown)",
     },
     "nextstep3.3" => {
         inherit_from     => [ "BASE_unix" ],
-        cc               => "cc",
-        cflags           => "-O3 -Wall",
+        CC               => "cc",
+        CFLAGS           => "-O3 -Wall",
         unistd           => "<libc.h>",
         bn_ops           => "BN_LLONG",
         thread_scheme    => "(unknown)",
@@ -1101,14 +1111,14 @@ my %targets = (
 # QNX
     "qnx4" => {
         inherit_from     => [ "BASE_unix" ],
-        cc               => "cc",
-        cflags           => "",
+        CC               => "cc",
+        CFLAGS           => "",
         cppflags         => "-DL_ENDIAN -DTERMIO",
         thread_scheme    => "(unknown)",
     },
     "QNX6" => {
         inherit_from     => [ "BASE_unix" ],
-        cc               => "gcc",
+        CC               => "gcc",
         ex_libs          => add("-lsocket"),
         dso_scheme       => "dlfcn",
         shared_target    => "bsd-gcc-shared",
@@ -1117,8 +1127,8 @@ my %targets = (
     },
     "QNX6-i386" => {
         inherit_from     => [ "BASE_unix", asm("x86_elf_asm") ],
-        cc               => "gcc",
-        cflags           => "-O2 -Wall",
+        CC               => "gcc",
+        CFLAGS           => "-O2 -Wall",
         cppflags         => "-DL_ENDIAN",
         ex_libs          => add("-lsocket"),
         dso_scheme       => "dlfcn",
@@ -1140,24 +1150,26 @@ my %targets = (
 # UnixWare 2.0x fails destest with -O.
     "unixware-2.0" => {
         inherit_from     => [ "BASE_unix" ],
-        cc               => "cc",
-        cflags           => combine(threads("-Kthread")),
+        CC