Fix cert leaks in s_server
[openssl.git] / Configurations / 10-main.conf
index 3b904031b6b20e43b531a3ef8525d4c7b75ebe32..576ac45ce7ea35558820f8426f6ddfbacac6f59c 100644 (file)
@@ -1,31 +1,46 @@
 ## -*- mode: perl; -*-
 ## Standard openssl configuration targets.
 
+sub picker {
+    my %opts = @_;
+    return sub { add($opts{default} || (),
+                     $opts{$config{build_type}} || ())->(); }
+}
+
+sub threads {
+    my @flags = @_;
+    return sub { add($disabled{threads} ? () : @flags)->(); }
+}
+
+sub combine {
+    my @stuff = @_;
+    return sub { add(@stuff)->(); }
+}
+
 %targets = (
 
 #### Basic configs that should work on any 32-bit box
     "gcc" => {
         cc               => "gcc",
-        cflags           => "",
-        debug_cflags     => "-O0 -g",
-        release_cflags   => "-O3",
-        thread_cflag     => "(unknown)",
+        cflags           => picker(debug   => "-O0 -g",
+                                   release => "-O3"),
+        thread_scheme    => "(unknown)",
         bn_ops           => "BN_LLONG",
     },
     "cc" => {
         cc               => "cc",
         cflags           => "-O",
-        thread_cflag     => "(unknown)",
+        thread_scheme    => "(unknown)",
     },
 
 #### VOS Configurations
     "vos-gcc" => {
         inherit_from     => [ "BASE_unix" ],
         cc               => "gcc",
-        cflags           => "-Wall -DOPENSSL_SYS_VOS -D_POSIX_C_SOURCE=200112L -D_BSD -D_VOS_EXTENDED_NAMES -DB_ENDIAN",
-        debug_cflags     => "-O0 -g -DBN_DEBUG -DREF_DEBUG -DCONF_DEBUG",
-        release_cflags   => "-O3",
-        thread_cflag     => "(unknown)",
+        cflags           => picker(default => "-Wall -DOPENSSL_SYS_VOS -D_POSIX_C_SOURCE=200112L -D_BSD -D_VOS_EXTENDED_NAMES -DB_ENDIAN",
+                                   debug   => "-O0 -g -DBN_DEBUG -DREF_DEBUG -DCONF_DEBUG",
+                                   release => "-O3"),
+        thread_scheme    => "(unknown)",
         sys_id           => "VOS",
         lflags           => "-Wl,-map",
         bn_ops           => "BN_LLONG",
@@ -39,6 +54,7 @@
         cflags           => "-DFILIO_H",
         ex_libs          => add("-lresolv -lsocket -lnsl -ldl"),
         dso_scheme       => "dlfcn",
+        thread_scheme    => "pthreads",
         shared_target    => "solaris-shared",
         shared_extension => ".so.\$(SHLIB_MAJOR).\$(SHLIB_MINOR)",
     },
         # with "Illegal mnemonic" error message.
         inherit_from     => [ "solaris-common", asm("x86_elf_asm") ],
         cc               => "gcc",
-        cflags           => add_before("-Wall -DL_ENDIAN -DOPENSSL_NO_INLINE_ASM"),
-        debug_cflags     => "-O0 -g",
-        release_cflags   => "-O3 -fomit-frame-pointer",
-        thread_cflag     => "-pthread",
+        cflags           => add_before(picker(default => "-Wall -DL_ENDIAN -DOPENSSL_NO_INLINE_ASM",
+                                              debug   => "-O0 -g",
+                                              release => "-O3 -fomit-frame-pointer"),
+                                       threads("-pthread")),
         bn_ops           => "BN_LLONG",
         shared_cflag     => "-fPIC",
         shared_ldflag    => "-shared",
         #                                      <appro@fy.chalmers.se>
         inherit_from     => [ "solaris-common", asm("x86_64_asm") ],
         cc               => "gcc",
-        cflags           => add_before("-m64 -Wall -DL_ENDIAN"),
-        debug_cflags     => "-O0 -g",
-        release_cflags   => "-O3",
-        thread_cflag     => "-pthread",
+        cflags           => add_before(picker(default => "-m64 -Wall -DL_ENDIAN",
+                                              debug   => "-O0 -g",
+                                              release => "-O3"),
+                                       threads("-pthread")),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
         perlasm_scheme   => "elf",
         shared_cflag     => "-fPIC",
     "solaris-x86-cc" => {
         inherit_from     => [ "solaris-common" ],
         cc               => "cc",
-        cflags           => add_before("-xarch=generic -xstrconst -Xa -DL_ENDIAN"),
-        debug_cflags     => "-g",
-        release_cflags   => "-xO5 -xregs=frameptr -xdepend -xbuiltin",
-        thread_cflag     => "-D_REENTRANT",
-        lflags           => add("-mt"),
-        ex_libs          => add("-lpthread"),
+        cflags           => add_before(picker(default => "-xarch=generic -xstrconst -Xa -DL_ENDIAN",
+                                              debug   => "-g",
+                                              release => "-xO5 -xregs=frameptr -xdepend -xbuiltin"),
+                                       threads("-D_REENTRANT")),
+        lflags           => add(threads("-mt")),
+        ex_libs          => add(threads("-lpthread")),
         bn_ops           => "BN_LLONG RC4_CHAR",
         shared_cflag     => "-KPIC",
         shared_ldflag    => "-G -dy -z text",
     "solaris64-x86_64-cc" => {
         inherit_from     => [ "solaris-common", asm("x86_64_asm") ],
         cc               => "cc",
-        cflags           => add_before("-xarch=generic64 -xstrconst -Xa -DL_ENDIAN"),
-        debug_cflags     => "-g",
-        release_cflags   => "-xO5 -xdepend -xbuiltin",
-        thread_cflag     => "-D_REENTRANT",
-        lflags           => add("-mt"),
-        ex_libs          => add("-lpthread"),
+        cflags           => add_before(picker(default => "-xarch=generic64 -xstrconst -Xa -DL_ENDIAN",
+                                              debug   => "-g",
+                                              release => "-xO5 -xdepend -xbuiltin"),
+                                       threads("-D_REENTRANT")),
+        thread_scheme    => "pthreads",
+        lflags           => add(threads("-mt")),
+        ex_libs          => add(threads("-lpthread")),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
         perlasm_scheme   => "elf",
         shared_cflag     => "-KPIC",
     "solaris-sparcv7-gcc" => {
         inherit_from     => [ "solaris-common" ],
         cc               => "gcc",
-        cflags           => add_before("-Wall -DB_ENDIAN -DBN_DIV2W"),
-        debug_cflags     => "-O0 -g",
-        release_cflags   => "-O3",
-        thread_cflag     => "-pthread",
+        cflags           => add_before(picker(default => "-Wall -DB_ENDIAN -DBN_DIV2W",
+                                              debug   => "-O0 -g",
+                                              release => "-O3"),
+                                       threads("-pthread")),
         bn_ops           => "BN_LLONG RC4_CHAR",
         shared_cflag     => "-fPIC",
         shared_ldflag    => "-shared",
         # -m32 should be safe to add as long as driver recognizes
         # -mcpu=ultrasparc
         inherit_from     => [ "solaris-sparcv7-gcc", asm("sparcv9_asm") ],
-        cflags           => add_before("-m32 -mcpu=ultrasparc"),
-        debug_cflags     => "-DBN_DEBUG -DREF_DEBUG -DCONF_DEBUG -DBN_CTX_DEBUG -DPEDANTIC -O -g -pedantic -ansi -Wshadow -Wno-long-long -D__EXTENSIONS__",
+        cflags           => add_before(picker(default => "-m32 -mcpu=ultrasparc",
+                                              debug   => "-DBN_DEBUG -DREF_DEBUG -DCONF_DEBUG -DBN_CTX_DEBUG -DPEDANTIC -O -g -pedantic -ansi -Wshadow -Wno-long-long -D__EXTENSIONS__")),
     },
     "solaris64-sparcv9-gcc" => {
         inherit_from     => [ "solaris-sparcv9-gcc" ],
     "solaris-sparcv7-cc" => {
         inherit_from     => [ "solaris-common" ],
         cc               => "cc",
-        cflags           => add_before("-xstrconst -Xa -DB_ENDIAN -DBN_DIV2W"),
-        debug_cflags     => "-g -DBN_DEBUG -DREF_DEBUG -DCONF_DEBUG -DBN_CTX_DEBUG",
-        release_cflags   => "-xO5 -xdepend",
-        thread_cflag     => "-D_REENTRANT",
-        lflags           => add("-mt"),
-        ex_libs          => add("-lpthread"),
+        cflags           => add_before(picker(default => "-xstrconst -Xa -DB_ENDIAN -DBN_DIV2W",
+                                              debug   => "-g -DBN_DEBUG -DREF_DEBUG -DCONF_DEBUG -DBN_CTX_DEBUG",
+                                              release => "-xO5 -xdepend"),
+                                       threads("-D_REENTRANT")),
+        lflags           => add(threads("-mt")),
+        ex_libs          => add(threads("-lpthread")),
         bn_ops           => "BN_LLONG RC4_CHAR",
         shared_cflag     => "-KPIC",
         shared_ldflag    => "-G -dy -z text",
     "irix-gcc" => {
         inherit_from     => [ "BASE_unix", asm("mips32_asm") ],
         cc               => "gcc",
-        cflags           => "-DB_ENDIAN",
-        debug_cflags     => "-g -O0",
-        release_cflags   => "-O3",
-        thread_cflag     => "(unknown)",
+        cflags           => picker(default => "-DB_ENDIAN",
+                                   debug   => "-g -O0",
+                                   release => "-O3"),
         bn_ops           => "BN_LLONG RC4_CHAR",
+        thread_scheme    => "(unknown)",
         perlasm_scheme   => "o32",
         dso_scheme       => "dlfcn",
         shared_target    => "irix-shared",
     "irix-cc" => {
         inherit_from     => [ "BASE_unix", asm("mips32_asm") ],
         cc               => "cc",
-        cflags           => "-use_readonly_const -DB_ENDIAN",
-        debug_cflags     => "-g -O0",
-        release_cflags   => "-O2",
-        thread_cflag     => "(unknown)",
+        cflags           => picker(default => "-use_readonly_const -DB_ENDIAN",
+                                   debug   => "-g -O0",
+                                   release => "-O2"),
         bn_ops           => "BN_LLONG RC4_CHAR",
+        thread_scheme    => "(unknown)",
         perlasm_scheme   => "o32",
         dso_scheme       => "dlfcn",
         shared_target    => "irix-shared",
     "irix-mips3-gcc" => {
         inherit_from     => [ "BASE_unix", asm("mips64_asm") ],
         cc               => "gcc",
-        cflags           => "-mabi=n32 -DB_ENDIAN -DBN_DIV3W",
-        debug_cflags     => "-g -O0",
-        release_cflags   => "-O3",
-        thread_cflag     => "-D_SGI_MP_SOURCE -pthread",
+        cflags           => combine(picker(default => "-mabi=n32 -DB_ENDIAN -DBN_DIV3W",
+                                           debug   => "-g -O0",
+                                           release => "-O3"),
+                                    threads("-D_SGI_MP_SOURCE -pthread")),
         bn_ops           => "RC4_CHAR SIXTY_FOUR_BIT",
+        thread_scheme    => "pthreads",
         perlasm_scheme   => "n32",
         dso_scheme       => "dlfcn",
         shared_target    => "irix-shared",
     "irix-mips3-cc" => {
         inherit_from     => [ "BASE_unix", asm("mips64_asm") ],
         cc               => "cc",
-        cflags           => "-n32 -mips3 -use_readonly_const -G0 -rdata_shared -DB_ENDIAN -DBN_DIV3W",
-        debug_cflags     => "-g -O0",
-        release_cflags   => "-O2",
-        thread_cflag     => "-D_SGI_MP_SOURCE",
-        ex_libs          => add("-lpthread"),
+        cflags           => combine(picker(default => "-n32 -mips3 -use_readonly_const -G0 -rdata_shared -DB_ENDIAN -DBN_DIV3W",
+                                           debug   => "-g -O0",
+                                           release => "-O2"),
+                                    threads("-D_SGI_MP_SOURCE")),
+        ex_libs          => add(threads("-lpthread")),
         bn_ops           => "RC4_CHAR SIXTY_FOUR_BIT",
+        thread_scheme    => "pthreads",
         perlasm_scheme   => "n32",
         dso_scheme       => "dlfcn",
         shared_target    => "irix-shared",
     "irix64-mips4-gcc" => {
         inherit_from     => [ "BASE_unix", asm("mips64_asm") ],
         cc               => "gcc",
-        cflags           => "-mabi=64 -mips4 -DB_ENDIAN -DBN_DIV3W",
-        debug_cflags     => "-g -O0",
-        release_cflags   => "-O3",
-        thread_cflag     => "-D_SGI_MP_SOURCE",
+        cflags           => combine(picker(default => "-mabi=64 -mips4 -DB_ENDIAN -DBN_DIV3W",
+                                           debug   => "-g -O0",
+                                           release => "-O3"),
+                                    threads("-D_SGI_MP_SOURCE")),
         bn_ops           => "RC4_CHAR SIXTY_FOUR_BIT_LONG",
+        thread_scheme    => "pthreads",
         perlasm_scheme   => "64",
         dso_scheme       => "dlfcn",
         shared_target    => "irix-shared",
     "irix64-mips4-cc" => {
         inherit_from     => [ "BASE_unix", asm("mips64_asm") ],
         cc               => "cc",
-        cflags           => "-64 -mips4 -use_readonly_const -G0 -rdata_shared -DB_ENDIAN -DBN_DIV3W",
-        debug_cflags     => "-g -O0",
-        release_cflags   => "-O2",
-        thread_cflag     => "-D_SGI_MP_SOURCE",
-        ex_libs          => add("-lpthread"),
+        cflags           => combine(picker(default => "-64 -mips4 -use_readonly_const -G0 -rdata_shared -DB_ENDIAN -DBN_DIV3W",
+                                           debug   => "-g -O0",
+                                           release => "-O2"),
+                                    threads("-D_SGI_MP_SOURCE")),
+        ex_libs          => add(threads("-lpthread")),
         bn_ops           => "RC4_CHAR SIXTY_FOUR_BIT_LONG",
+        thread_scheme    => "pthreads",
         perlasm_scheme   => "64",
         dso_scheme       => "dlfcn",
         shared_target    => "irix-shared",
     "hpux-parisc-gcc" => {
         inherit_from     => [ "BASE_unix" ],
         cc               => "gcc",
-        cflags           => "-DB_ENDIAN -DBN_DIV2W",
-        debug_cflags     => "-O0 -g",
-        release_cflags   => "-O3",
-        thread_cflag     => "-pthread",
+        cflags           => combine(picker(default => "-DB_ENDIAN -DBN_DIV2W",
+                                           debug   => "-O0 -g",
+                                           release => "-O3"),
+                                    threads("-pthread")),
         ex_libs          => add("-Wl,+s -ldld"),
         bn_ops           => "BN_LLONG",
+        thread_scheme    => "pthreads",
         dso_scheme       => "dl",
         shared_target    => "hpux-shared",
         shared_cflag     => "-fPIC",
     "hpux64-parisc2-gcc" => {
         inherit_from     => [ "BASE_unix", asm("parisc20_64_asm") ],
         cc               => "gcc",
-        cflags           => "-DB_ENDIAN",
-        debug_cflags     => "-O0 -g",
-        release_cflags   => "-O3",
-        thread_cflag     => "-D_REENTRANT",
+        cflags           => combine(picker(default => "-DB_ENDIAN",
+                                           debug   => "-O0 -g",
+                                           release => "-O3"),
+                                    threads("-D_REENTRANT")),
         ex_libs          => add("-ldl"),
         bn_ops           => "SIXTY_FOUR_BIT_LONG RC4_CHAR",
+        thread_scheme    => "pthreads",
         dso_scheme       => "dlfcn",
         shared_target    => "hpux-shared",
         shared_cflag     => "-fpic",
     "hpux-parisc-cc" => {
         inherit_from     => [ "BASE_unix" ],
         cc               => "cc",
-        cflags           => "+Optrs_strongly_typed -Ae +ESlit -DB_ENDIAN -DBN_DIV2W -DMD32_XARRAY",
-        debug_cflags      => "+O0 +d -g",
-        release_cflags   => "+O3",
-        thread_cflag     => "-D_REENTRANT",
-        ex_libs          => add("-Wl,+s -ldld -lpthread"),
+        cflags           => combine(picker(default => "+Optrs_strongly_typed -Ae +ESlit -DB_ENDIAN -DBN_DIV2W -DMD32_XARRAY",
+                                           debug   => "+O0 +d -g",
+                                           release => "+O3"),
+                                    threads("-D_REENTRANT")),
+        ex_libs          => add("-Wl,+s -ldld",threads("-lpthread")),
         bn_ops           => "RC4_CHAR",
+        thread_scheme    => "pthreads",
         dso_scheme       => "dl",
         shared_target    => "hpux-shared",
         shared_cflag     => "+Z",
     "hpux64-parisc2-cc" => {
         inherit_from     => [ "BASE_unix", asm("parisc20_64_asm") ],
         cc               => "cc",
-        cflags           => "+DD64 +Optrs_strongly_typed -Ae +ESlit -DB_ENDIAN -DMD32_XARRAY",
-        debug_cflags      => "+O0 +d -g",
-        release_cflags   => "+O3",
-        thread_cflag     => "-D_REENTRANT",
-        ex_libs          => add("-ldl -lpthread"),
+        cflags           => combine(picker(default => "+DD64 +Optrs_strongly_typed -Ae +ESlit -DB_ENDIAN -DMD32_XARRAY",
+                                           debug   => "+O0 +d -g",
+                                           release => "+O3"),
+                                    threads("-D_REENTRANT")),
+        ex_libs          => add("-ldl",threads("-lpthread")),
         bn_ops           => "SIXTY_FOUR_BIT_LONG RC4_CHAR",
+        thread_scheme    => "pthreads",
         dso_scheme       => "dlfcn",
         shared_target    => "hpux-shared",
         shared_cflag     => "+Z",
     "hpux-ia64-cc" => {
         inherit_from     => [ "BASE_unix", asm("ia64_asm") ],
         cc               => "cc",
-        cflags           => "-Ae +DD32 +Olit=all -z -DB_ENDIAN",
-        debug_cflags     => "+O0 +d -g",
-        release_cflags   => "+O2",
-        thread_cflag     => "-D_REENTRANT",
-        ex_libs          => add("-ldl -lpthread"),
+        cflags           => combine(picker(default => "-Ae +DD32 +Olit=all -z -DB_ENDIAN",
+                                           debug   => "+O0 +d -g",
+                                           release => "+O2"),
+                                    threads("-D_REENTRANT")),
+        ex_libs          => add("-ldl",threads("-lpthread")),
         bn_ops           => "SIXTY_FOUR_BIT",
+        thread_scheme    => "pthreads",
         dso_scheme       => "dlfcn",
         shared_target    => "hpux-shared",
         shared_cflag     => "+Z",
     "hpux64-ia64-cc" => {
         inherit_from     => [ "BASE_unix", asm("ia64_asm") ],
         cc               => "cc",
-        cflags           => "-Ae +DD64 +Olit=all -z -DB_ENDIAN",
-        debug_cflags     => "+O0 +d -g",
-        release_cflags   => "+O3",
-        thread_cflag     => "-D_REENTRANT",
-        ex_libs          => add("-ldl -lpthread"),
+        cflags           => combine(picker(default => "-Ae +DD64 +Olit=all -z -DB_ENDIAN",
+                                           debug   => "+O0 +d -g",
+                                           release => "+O3"),
+                                    threads("-D_REENTRANT")),
+        ex_libs          => add("-ldl", threads("-lpthread")),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
+        thread_scheme    => "pthreads",
         dso_scheme       => "dlfcn",
         shared_target    => "hpux-shared",
         shared_cflag     => "+Z",
     "hpux-ia64-gcc" => {
         inherit_from     => [ "BASE_unix", asm("ia64_asm") ],
         cc               => "gcc",
-        cflags           => "-DB_ENDIAN",
-        debug_cflags     => "-O0 -g",
-        release_cflags   => "-O3",
-        thread_cflag     => "-pthread",
+        cflags           => combine(picker(default => "-DB_ENDIAN",
+                                           debug   => "-O0 -g",
+                                           release => "-O3"),
+                                    threads("-pthread")),
         ex_libs          => add("-ldl"),
         bn_ops           => "SIXTY_FOUR_BIT",
+        thread_scheme    => "pthreads",
         dso_scheme       => "dlfcn",
         shared_target    => "hpux-shared",
         shared_cflag     => "-fpic",
     "hpux64-ia64-gcc" => {
         inherit_from     => [ "BASE_unix", asm("ia64_asm") ],
         cc               => "gcc",
-        cflags           => "-mlp64 -DB_ENDIAN",
-        debug_cflags     => "-O0 -g",
-        release_cflags   => "-O3",
-        thread_cflag     => "-pthread",
+        cflags           => picker(default => "-mlp64 -DB_ENDIAN",
+                                   debug   => "-O0 -g",
+                                   release => "-O3",
+                                   threads("-pthread")),
         ex_libs          => add("-ldl"),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
+        thread_scheme    => "pthreads",
         dso_scheme       => "dlfcn",
         shared_target    => "hpux-shared",
         shared_cflag     => "-fpic",
         inherit_from     => [ "BASE_unix" ],
         cc               => "gcc",
         cflags           => "-D_ENDIAN -DBN_DIV2W -O3 -D_POSIX_SOURCE -D_SOCKET_SOURCE -I/SYSLOG/PUB",
-        thread_cflag     => "(unknown)",
         sys_id           => "MPE",
         ex_libs          => add("-L/SYSLOG/PUB -lsyslog -lsocket -lcurses"),
+        thread_scheme    => "(unknown)",
         bn_ops           => "BN_LLONG",
     },
 
         inherit_from     => [ "BASE_unix", asm("alpha_asm") ],
         cc               => "gcc",
         cflags           => "-O3",
-        thread_cflag     => "(unknown)",
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
+        thread_scheme    => "(unknown)",
         dso_scheme       => "dlfcn",
         shared_target    => "alpha-osf1-shared",
         shared_extension => ".so",
         inherit_from     => [ "BASE_unix", asm("alpha_asm") ],
         cc               => "cc",
         cflags           => "-std1 -tune host -O4 -readonly_strings",
-        thread_cflag     => "(unknown)",
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
+        thread_scheme    => "(unknown)",
         dso_scheme       => "dlfcn",
         shared_target    => "alpha-osf1-shared",
         shared_extension => ".so",
     "tru64-alpha-cc" => {
         inherit_from     => [ "BASE_unix", asm("alpha_asm") ],
         cc               => "cc",
-        cflags           => "-std1 -tune host -fast -readonly_strings",
-        thread_cflag     => "-pthread",
+        cflags           => combine("-std1 -tune host -fast -readonly_strings",
+                                    threads("-pthread")),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
+        thread_scheme    => "pthreads",
         dso_scheme       => "dlfcn",
         shared_target    => "alpha-osf1-shared",
         shared_ldflag    => "-msym",
     "linux-generic32" => {
         inherit_from     => [ "BASE_unix" ],
         cc               => "gcc",
-        cflags           => "-Wall",
-        debug_cflags     => "-O0 -g -DBN_DEBUG -DREF_DEBUG -DCONF_DEBUG",
-        release_cflags   => "-O3",
-        thread_cflag     => "-pthread",
+        cflags           => combine(picker(default => "-Wall",
+                                           debug   => "-O0 -g -DBN_DEBUG -DREF_DEBUG -DCONF_DEBUG",
+                                           release => "-O3"),
+                                    threads("-pthread")),
         ex_libs          => add("-ldl"),
         bn_ops           => "BN_LLONG RC4_CHAR",
+        thread_scheme    => "pthreads",
         dso_scheme       => "dlfcn",
         shared_target    => "linux-shared",
         shared_cflag     => "-fPIC",
     },
     "linux-ppc64" => {
         inherit_from     => [ "linux-generic64", asm("ppc64_asm") ],
-        cflags           => "-m64 -Wall -DB_ENDIAN",
+        cflags           => add("-m64 -DB_ENDIAN"),
         perlasm_scheme   => "linux64",
         shared_ldflag    => "-m64",
         multilib         => "64",
     },
     "linux-ppc64le" => {
         inherit_from     => [ "linux-generic64", asm("ppc64_asm") ],
-        cflags           => "-m64 -Wall -DL_ENDIAN",
+        cflags           => add("-m64 -DL_ENDIAN"),
         perlasm_scheme   => "linux64le",
         shared_ldflag    => "-m64",
     },
     },
     "linux-arm64ilp32" => {  # https://wiki.linaro.org/Platform/arm64-ilp32
         inherit_from     => [ "linux-generic32", asm("aarch64_asm") ],
-        cflags           => "-mabi=ilp32 -Wall",
+        cflags           => add("-mabi=ilp32"),
         bn_ops           => "SIXTY_FOUR_BIT RC4_CHAR",
         perlasm_scheme   => "linux64",
         shared_ldflag    => "-mabi=ilp32",
         # Configure script adds minimally required -march for assembly
         # support, if no -march was specified at command line.
         inherit_from     => [ "linux-generic32", asm("mips32_asm") ],
-        cflags           => "-mabi=32 -Wall -DBN_DIV3W",
+        cflags           => add("-mabi=32 -DBN_DIV3W"),
         perlasm_scheme   => "o32",
         shared_ldflag    => "-mabi=32",
     },
     # specifications, MIPS32 and MIPS64, rather than to kernel bitness.
     "linux-mips64" => {
         inherit_from     => [ "linux-generic32", asm("mips64_asm") ],
-        cflags           => "-mabi=n32 -Wall -DBN_DIV3W",
+        cflags           => add("-mabi=n32 -DBN_DIV3W"),
         bn_ops           => "SIXTY_FOUR_BIT RC4_CHAR",
         perlasm_scheme   => "n32",
         shared_ldflag    => "-mabi=n32",
     },
     "linux64-mips64" => {
         inherit_from     => [ "linux-generic64", asm("mips64_asm") ],
-        cflags           => "-mabi=64 -O3 -Wall -DBN_DIV3W",
+        cflags           => add("-mabi=64 -DBN_DIV3W"),
         perlasm_scheme   => "64",
         shared_ldflag    => "-mabi=64",
         multilib         => "64",
     #### IA-32 targets...
     "linux-elf" => {
         inherit_from     => [ "linux-generic32", asm("x86_elf_asm") ],
-        cc               => "gcc",
-        cflags           => "-DL_ENDIAN -Wall",
-        debug_cflags     => "-O0 -g -DBN_DEBUG -DREF_DEBUG -DCONF_DEBUG -DBN_CTX_DEBUG",
-        release_cflags   => "-O3 -fomit-frame-pointer",
-        debug_ex_libs    => "-lefence",
+        cflags           => add(picker(default => "-DL_ENDIAN",
+                                       release => "-fomit-frame-pointer")),
+        ex_libs          => add(picker(debug => "-lefence")),
         bn_ops           => "BN_LLONG",
     },
     "linux-aout" => {
         inherit_from     => [ "BASE_unix", asm("x86_asm") ],
         cc               => "gcc",
-        cflags           => "-DL_ENDIAN -Wall",
-        debug_cflags     => "-O0 -g",
-        release_cflags   => "-O3 -fomit-frame-pointer",
-        thread_cflag     => "(unknown)",
+        cflags           => add(picker(default => "-DL_ENDIAN -Wall",
+                                       debug   => "-O0 -g",
+                                       release => "-O3 -fomit-frame-pointer")),
         bn_ops           => "BN_LLONG",
+        thread_scheme    => "(unknown)",
         perlasm_scheme   => "a.out",
     },
 
     "linux-x86_64" => {
         inherit_from     => [ "linux-generic64", asm("x86_64_asm") ],
-        cflags           => "-m64 -DL_ENDIAN -Wall",
+        cflags           => add("-m64 -DL_ENDIAN"),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
         perlasm_scheme   => "elf",
         shared_ldflag    => "-m64",
     "linux-x86_64-clang" => {
         inherit_from     => [ "linux-x86_64" ],
         cc               => "clang",
-        cflags           => "-m64 -DL_ENDIAN -Wall -Wextra -Qunused-arguments",
+        cflags           => add("-Wextra -Qunused-arguments"),
     },
     "linux-x32" => {
         inherit_from     => [ "linux-generic32", asm("x86_64_asm") ],
-        cflags           => "-mx32 -DL_ENDIAN -Wall",
+        cflags           => add("-mx32 -DL_ENDIAN"),
         bn_ops           => "SIXTY_FOUR_BIT",
         perlasm_scheme   => "elf",
         shared_ldflag    => "-mx32",
 
     "linux64-s390x" => {
         inherit_from     => [ "linux-generic64", asm("s390x_asm") ],
-        cflags           => "-m64 -Wall -DB_ENDIAN",
+        cflags           => add("-m64 -DB_ENDIAN"),
         perlasm_scheme   => "64",
         shared_ldflag    => "-m64",
         multilib         => "64",
         # sysdeps/s390/dl-procinfo.c affecting ldconfig and ld.so.1...
         #
         inherit_from     => [ "linux-generic32", asm("s390x_asm") ],
-        cflags           => "-m31 -Wall -Wa,-mzarch -DB_ENDIAN",
+        cflags           => add("-m31 -Wa,-mzarch -DB_ENDIAN"),
         bn_obj           => sub { my $r=join(" ",@_); $r=~s/bn\-s390x/bn_asm/; $r; },
         perlasm_scheme   => "31",
         shared_ldflag    => "-m31",
     # patiently assisted with debugging of following two configs.
     "linux-sparcv8" => {
         inherit_from     => [ "linux-generic32", asm("sparcv8_asm") ],
-        cflags           => "-mcpu=v8 -Wall -DB_ENDIAN -DBN_DIV2W",
+        cflags           => add("-mcpu=v8 -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           => "-m32 -mcpu=ultrasparc -Wall -Wa,-Av8plus -DB_ENDIAN -DBN_DIV2W",
+        cflags           => add("-m32 -mcpu=ultrasparc -Wa,-Av8plus -DB_ENDIAN -DBN_DIV2W"),
         shared_ldflag    => "-m32",
     },
     "linux64-sparcv9" => {
         # GCC 3.1 is a requirement
         inherit_from     => [ "linux-generic64", asm("sparcv9_asm") ],
-        cflags           => "-m64 -mcpu=ultrasparc -Wall -DB_ENDIAN",
+        cflags           => add("-m64 -mcpu=ultrasparc -DB_ENDIAN"),
         bn_ops           => "BN_LLONG RC4_CHAR",
         shared_ldflag    => "-m64",
         multilib         => "64",
 
     "linux-alpha-gcc" => {
         inherit_from     => [ "linux-generic64", asm("alpha_asm") ],
-        cflags           => "-DL_ENDIAN",
+        cflags           => 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 -DOPENSSL_SMALL_FOOTPRINT",
-        thread_cflag     => "-D_REENTRANT",
+        cflags           => combine("--linux -ea=.s -eo=.o -mv6400+ -o2 -ox -ms -pden -DOPENSSL_SMALL_FOOTPRINT",
+                                    threads("-D_REENTRANT")),
         bn_ops           => "BN_LLONG",
         cpuid_asm_src    => "c64xpluscpuid.s",
         bn_asm_src       => "asm/bn-c64xplus.asm c64xplus-gf2m.s",
         modes_asm_src    => "ghash-c64xplus.s",
         chacha_asm_src   => "chacha-c64xplus.s",
         poly1305_asm_src => "poly1305-c64xplus.s",
+        thread_scheme    => "pthreads",
         perlasm_scheme   => "void",
         dso_scheme       => "dlfcn",
         shared_target    => "linux-shared",
         # systems are perfectly capable of executing binaries targeting
         # Froyo. Keep in mind that in the nutshell Android builds are
         # about JNI, i.e. shared libraries, not applications.
-        cflags           => "-mandroid -fPIC --sysroot=\$(CROSS_SYSROOT) -Wa,--noexecstack -Wall",
-        debug_cflags     => "-O0 -g",
+        cflags           => picker(default => "-mandroid -fPIC --sysroot=\$(CROSS_SYSROOT) -Wa,--noexecstack -Wall",
+                                   debug   => "-O0 -g",
+                                   release => "-O3"),
         lflags           => "-pie",
         shared_cflag     => "",
     },
     "android-x86" => {
         inherit_from     => [ "android", asm("x86_asm") ],
-        release_cflags   => "-O3 -fomit-frame-pointer",
+        cflags           => add(picker(release => "-fomit-frame-pointer")),
         bn_ops           => "BN_LLONG",
         perlasm_scheme   => "android",
     },
 
     "android64" => {
         inherit_from     => [ "linux-generic64" ],
-        cflags           => "-mandroid -fPIC --sysroot=\$(CROSS_SYSROOT) -Wa,--noexecstack -Wall",
-        debug_cflags     => "-O0 -g",
+        cflags           => picker(default => "-mandroid -fPIC --sysroot=\$(CROSS_SYSROOT) -Wa,--noexecstack -Wall",
+                                   debug   => "-O0 -g",
+                                   release => "-O3"),
         lflags           => "-pie",
         shared_cflag     => "",
     },
 
 #### *BSD
     "BSD-generic32" => {
-        # As for thread_cflag. Idea is to maintain "collective" set of
+        # As for thread cflag. Idea is to maintain "collective" set of
         # flags, which would cover all BSD flavors. -pthread applies
         # to them all, but is treated differently. OpenBSD expands is
         # as -D_POSIX_THREAD -lc_r, which is sufficient. FreeBSD 4.x
         # expands it as -lc_r, which seems to be sufficient?
         inherit_from     => [ "BASE_unix" ],
         cc               => "cc",
-        cflags           => "-Wall",
-        debug_cflags     => "-O0 -g",
-        release_cflags   => "-O3",
-        thread_cflag     => "-pthread -D_THREAD_SAFE -D_REENTRANT",
+        cflags           => combine(picker(default => "-Wall",
+                                           debug   => "-O0 -g",
+                                           release => "-O3"),
+                                    threads("-pthread -D_THREAD_SAFE -D_REENTRANT")),
         bn_ops           => "BN_LLONG",
+        thread_scheme    => "pthreads",
         dso_scheme       => "dlfcn",
         shared_target    => "bsd-gcc-shared",
         shared_cflag     => "-fPIC",
 
     "BSD-x86" => {
         inherit_from     => [ "BSD-generic32", asm("x86_asm") ],
-        cflags           => "-DL_ENDIAN -Wall",
-        release_cflags   => "-O3 -fomit-frame-pointer",
+        cflags           => add(picker(default => "-DL_ENDIAN",
+                                       release => "-fomit-frame-pointer")),
         bn_ops           => "BN_LLONG",
         shared_target    => "bsd-shared",
         perlasm_scheme   => "a.out",
 
     "BSD-sparcv8" => {
         inherit_from     => [ "BSD-generic32", asm("sparcv8_asm") ],
-        cflags           => "-mcpu=v8 -Wall -DB_ENDIAN",
+        cflags           => add("-mcpu=v8 -DB_ENDIAN"),
     },
     "BSD-sparc64" => {
         # -DMD32_REG_T=int doesn't actually belong in sparc64 target, it
         # simply *happens* to work around a compiler bug in gcc 3.3.3,
         # triggered by RIPEMD160 code.
         inherit_from     => [ "BSD-generic64", asm("sparcv9_asm") ],
-        cflags           => "-DB_ENDIAN -DMD32_REG_T=int -Wall",
+        cflags           => add("-DB_ENDIAN -DMD32_REG_T=int"),
         bn_ops           => "BN_LLONG",
     },
 
     "BSD-ia64" => {
         inherit_from     => [ "BSD-generic64", asm("ia64_asm") ],
-        cflags           => "-DL_ENDIAN -Wall",
+        cflags           => add_before("-DL_ENDIAN"),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
     },
 
     "BSD-x86_64" => {
         inherit_from     => [ "BSD-generic64", asm("x86_64_asm") ],
-        cflags           => "-DL_ENDIAN -Wall",
+        cflags           => add_before("-DL_ENDIAN"),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
         perlasm_scheme   => "elf",
     },
         inherit_from     => [ "BASE_unix", asm("x86_elf_asm") ],
         cc               => "gcc",
         cflags           => "-DPERL5 -DL_ENDIAN -fomit-frame-pointer -O3 -Wall",
-        thread_cflag     => "(unknown)",
         ex_libs          => add("-ldl"),
         bn_ops           => "BN_LLONG",
+        thread_scheme    => "(unknown)",
         dso_scheme       => "dlfcn",
         shared_target    => "bsd-gcc-shared",
         shared_cflag     => "-fPIC",
         cc               => "cc",
         cflags           => "-O -Wall",
         unistd           => "<libc.h>",
-        thread_cflag     => "(unknown)",
         bn_ops           => "BN_LLONG",
+        thread_scheme    => "(unknown)",
     },
     "nextstep3.3" => {
         inherit_from     => [ "BASE_unix" ],
         cc               => "cc",
         cflags           => "-O3 -Wall",
         unistd           => "<libc.h>",
-        thread_cflag     => "(unknown)",
         bn_ops           => "BN_LLONG",
+        thread_scheme    => "(unknown)",
     },
 
 # QNX
         inherit_from     => [ "BASE_unix" ],
         cc               => "cc",
         cflags           => "-DL_ENDIAN -DTERMIO",
-        thread_cflag     => "(unknown)",
+        thread_scheme    => "(unknown)",
     },
     "QNX6" => {
         inherit_from     => [ "BASE_unix" ],
     "unixware-2.0" => {
         inherit_from     => [ "BASE_unix" ],
         cc               => "cc",
-        cflags           => "-DFILIO_H -DNO_STRINGS_H",
-        thread_cflag     => "-Kthread",
+        cflags           => combine("-DFILIO_H -DNO_STRINGS_H",
+                                    threads("-Kthread")),
         ex_libs          => add("-lsocket -lnsl -lresolv -lx"),
+        thread_scheme    => "uithreads",
     },
     "unixware-2.1" => {
         inherit_from     => [ "BASE_unix" ],
         cc               => "cc",
-        cflags           => "-O -DFILIO_H",
-        thread_cflag     => "-Kthread",
+        cflags           => combine("-O -DFILIO_H",
+                                    threads("-Kthread")),
         ex_libs          => add("-lsocket -lnsl -lresolv -lx"),
+        thread_scheme    => "uithreads",
     },
     "unixware-7" => {
         inherit_from     => [ "BASE_unix", asm("x86_elf_asm") ],
         cc               => "cc",
-        cflags           => "-O -DFILIO_H -Kalloca",
-        thread_cflag     => "-Kthread",
+        cflags           => combine("-O -DFILIO_H -Kalloca",
+                                    threads("-Kthread")),
         ex_libs          => add("-lsocket -lnsl"),
+        thread_scheme    => "uithreads",
         bn_ops           => "BN_LLONG",
         perlasm_scheme   => "elf-1",
         dso_scheme       => "dlfcn",
     "unixware-7-gcc" => {
         inherit_from     => [ "BASE_unix", asm("x86_elf_asm") ],
         cc               => "gcc",
-        cflags           => "-DL_ENDIAN -DFILIO_H -O3 -fomit-frame-pointer -Wall",
-        thread_cflag     => "-D_REENTRANT",
+        cflags           => combine("-DL_ENDIAN -DFILIO_H -O3 -fomit-frame-pointer -Wall",
+                                    threads("-D_REENTRANT")),
         ex_libs          => add("-lsocket -lnsl"),
         bn_ops           => "BN_LLONG",
+        thread_scheme    => "pthreads",
         perlasm_scheme   => "elf-1",
         dso_scheme       => "dlfcn",
         shared_target    => "gnu-shared",
         inherit_from     => [ "BASE_unix", asm("x86_elf_asm") ],
         cc               => "cc",
         cflags           => "-belf",
-        thread_cflag     => "(unknown)",
         ex_libs          => add("-lsocket -lnsl"),
+        thread_scheme    => "(unknown)",
         perlasm_scheme   => "elf-1",
         dso_scheme       => "dlfcn",
         shared_target    => "svr3-shared",
         inherit_from     => [ "BASE_unix", asm("x86_elf_asm") ],
         cc               => "gcc",
         cflags           => "-O3 -fomit-frame-pointer",
-        thread_cflag     => "(unknown)",
         ex_libs          => add("-lsocket -lnsl"),
         bn_ops           => "BN_LLONG",
+        thread_scheme    => "(unknown)",
         perlasm_scheme   => "elf-1",
         dso_scheme       => "dlfcn",
         shared_target    => "svr3-shared",
     "aix-gcc" => {
         inherit_from     => [ "BASE_unix", asm("ppc32_asm") ],
         cc               => "gcc",
-        cflags           => "-DB_ENDIAN",
-        debug_cflags     => "-O0 -g",
-        release_cflags   => "-O",
-        thread_cflag     => "-pthread",
+        cflags           => combine(picker(default => "-DB_ENDIAN",
+                                           debug   => "-O0 -g",
+                                           release => "-O"),
+                                    threads("-pthread")),
         sys_id           => "AIX",
         bn_ops           => "BN_LLONG RC4_CHAR",
+        thread_scheme    => "pthreads",
         perlasm_scheme   => "aix32",
         dso_scheme       => "dlfcn",
         shared_target    => "aix-shared",
     "aix64-gcc" => {
         inherit_from     => [ "BASE_unix", asm("ppc64_asm") ],
         cc               => "gcc",
-        cflags           => "-maix64 -DB_ENDIAN",
-        debug_cflags     => "-O0 -g",
-        release_cflags   => "-O",
-        thread_cflag     => "-pthread",
+        cflags           => combine(picker(default => "-maix64 -DB_ENDIAN",
+                                           debug   => "-O0 -g",
+                                           release => "-O"),
+                                    threads("-pthread")),
         sys_id           => "AIX",
         bn_ops           => "SIXTY_FOUR_BIT_LONG RC4_CHAR",
+        thread_scheme    => "pthreads",
         perlasm_scheme   => "aix64",
         dso_scheme       => "dlfcn",
         shared_target    => "aix-shared",
     "aix-cc" => {
         inherit_from     => [ "BASE_unix", asm("ppc32_asm") ],
         cc               => "cc",
-        cflags           => "-q32 -DB_ENDIAN -qmaxmem=16384 -qro -qroconst",
-        debug_cflags     => "",
-        release_cflags   => "-O",
-        thread_cflag     => "-qthreaded -D_THREAD_SAFE",
+        cflags           => combine(picker(default => "-q32 -DB_ENDIAN -qmaxmem=16384 -qro -qroconst",
+                                           debug   => "-O0 -g",
+                                           release => "-O"),
+                                    threads("-qthreaded -D_THREAD_SAFE")),
         sys_id           => "AIX",
         bn_ops           => "BN_LLONG RC4_CHAR",
+        thread_scheme    => "pthreads",
         perlasm_scheme   => "aix32",
         dso_scheme       => "dlfcn",
         shared_target    => "aix-shared",
     "aix64-cc" => {
         inherit_from     => [ "BASE_unix", asm("ppc64_asm") ],
         cc               => "cc",
-        cflags           => "-q64 -DB_ENDIAN -qmaxmem=16384 -qro -qroconst",
-        debug_cflags     => "",
-        release_cflags   => "-O",
-        thread_cflag     => "-qthreaded -D_THREAD_SAFE",
+        cflags           => combine(picker(default => "-q64 -DB_ENDIAN -qmaxmem=16384 -qro -qroconst",
+                                           debug   => "-O0 -g",
+                                           release => "-O"),
+                                    threads("-qthreaded -D_THREAD_SAFE")),
         sys_id           => "AIX",
         bn_ops           => "SIXTY_FOUR_BIT_LONG RC4_CHAR",
+        thread_scheme    => "pthreads",
         perlasm_scheme   => "aix64",
         dso_scheme       => "dlfcn",
         shared_target    => "aix-shared",
         inherit_from     => [ "BASE_unix" ],
         cc               => "c89",
         cflags           => "-O -XLLML -XLLMK -XL -DB_ENDIAN -DCHARSET_EBCDIC",
-        thread_cflag     => "(unknown)",
         ex_libs          => add("-lsocket -lnsl"),
         bn_ops           => "THIRTY_TWO_BIT RC4_CHAR",
+        thread_scheme    => "(unknown)",
     },
 
 # OS/390 Unix an EBCDIC-based Unix system on IBM mainframe
         inherit_from     => [ "BASE_unix" ],
         cc               => "c89.sh",
         cflags           => "-O -DB_ENDIAN -DCHARSET_EBCDIC -DNO_SYS_PARAM_H  -D_ALL_SOURCE",
-        thread_cflag     => "(unknown)",
         bn_ops           => "THIRTY_TWO_BIT RC4_CHAR",
+        thread_scheme    => "(unknown)",
     },
 
 #### Visual C targets
         inherit_from     => [ "BASE_unix", asm("x86_asm"),
                               sub { $disabled{shared} ? () : "x86_uplink" } ],
         cc               => "gcc",
-        cflags           => "-DL_ENDIAN -DWIN32_LEAN_AND_MEAN -DUNICODE -D_UNICODE -m32 -Wall",
-        debug_cflags     => "-g -O0",
-        release_cflags   => "-O3 -fomit-frame-pointer",
-        thread_cflag     => "-D_MT",
+        cflags           => combine(picker(default => "-DL_ENDIAN -DWIN32_LEAN_AND_MEAN -DUNICODE -D_UNICODE -m32 -Wall",
+                                           debug   => "-g -O0",
+                                           release => "-O3 -fomit-frame-pointer"),
+                                    threads("-D_MT")),
         sys_id           => "MINGW32",
         ex_libs          => add("-lws2_32 -lgdi32 -lcrypt32"),
         bn_ops           => "BN_LLONG EXPORT_VAR_AS_FN",
+        thread_scheme    => "winthreads",
         perlasm_scheme   => "coff",
         dso_scheme       => "win32",
         shared_target    => "mingw-shared",
         # Applink is never engaged and can as well be omitted.
         inherit_from     => [ "BASE_unix", asm("x86_64_asm") ],
         cc               => "gcc",
-        cflags           => "-DL_ENDIAN -DWIN32_LEAN_AND_MEAN -DUNICODE -D_UNICODE -m64 -Wall",
-        debug_cflags     => "-g -O0",
-        release_cflags   => "-O3",
-        thread_cflag     => "-D_MT",
+        cflags           => combine(picker(default => "-DL_ENDIAN -DWIN32_LEAN_AND_MEAN -DUNICODE -D_UNICODE -m64 -Wall",
+                                           debug   => "-g -O0",
+                                           release => "-O3"),
+                                    threads("-D_MT")),
         sys_id           => "MINGW64",
         ex_libs          => add("-lws2_32 -lgdi32 -lcrypt32"),
         bn_ops           => "SIXTY_FOUR_BIT EXPORT_VAR_AS_FN",
+        thread_scheme    => "winthreads",
         perlasm_scheme   => "mingw64",
         dso_scheme       => "win32",
         shared_target    => "mingw-shared",
     "Cygwin-x86" => {
         inherit_from     => [ "BASE_unix", asm("x86_asm") ],
         cc               => "gcc",
-        cflags           => "-DTERMIOS -DL_ENDIAN -Wall",
-        debug_cflags     => "-g -O0",
-        release_cflags   => "-O3 -fomit-frame-pointer",
+        cflags           => picker(default => "-DTERMIOS -DL_ENDIAN -Wall",
+                                   debug   => "-g -O0",
+                                   release => "-O3 -fomit-frame-pointer"),
         sys_id           => "CYGWIN",
         bn_ops           => "BN_LLONG",
         perlasm_scheme   => "coff",
     "Cygwin-x86_64" => {
         inherit_from     => [ "BASE_unix", asm("x86_64_asm") ],
         cc               => "gcc",
-        cflags           => "-DTERMIOS -DL_ENDIAN -Wall",
-        debug_cflags     => "-g -O0",
-        release_cflags   => "-O3",
+        cflags           => picker(default => "-DTERMIOS -DL_ENDIAN -Wall",
+                                   debug   => "-g -O0",
+                                   release => "-O3"),
         sys_id           => "CYGWIN",
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
         perlasm_scheme   => "mingw64",
         inherit_from     => [ "BASE_unix" ],
         cc               => "cc",
         cflags           => "-std1 -O -Olimit 2500 -DL_ENDIAN",
-        thread_cflag     => "(unknown)",
+        thread_scheme    => "(unknown)",
     },
     "ultrix-gcc" => {
         inherit_from     => [ "BASE_unix" ],
         cc               => "gcc",
         cflags           => "-O3 -DL_ENDIAN",
-        thread_cflag     => "(unknown)",
         bn_ops           => "BN_LLONG",
+        thread_scheme    => "(unknown)",
     },
 # K&R C is no longer supported; you need gcc on old Ultrix installations
 ##"ultrix","cc:-O2 -DNOPROTO -DNOCONST -DL_ENDIAN::(unknown):::::::",
         inherit_from     => [ "BASE_unix" ],
         template         => 1,
         cc               => "cc",
-        cflags           => "",
-        debug_cflags     => "-g -O0",
-        release_cflags   => "-O3",
-        thread_cflag     => "-D_REENTRANT",
+        cflags           => combine(picker(default => "",
+                                           debug   => "-g -O0",
+                                           release => "-O3"),
+                                   threads("-D_REENTRANT")),
         sys_id           => "MACOSX",
         plib_lflags      => "-Wl,-search_paths_first",
         bn_ops           => "BN_LLONG RC4_CHAR",
+        thread_scheme    => "pthreads",
         perlasm_scheme   => "osx32",
         dso_scheme       => "dlfcn",
+        ranlib           => "ranlib -c",
         shared_target    => "darwin-shared",
-        shared_cflag     => "-fPIC -fno-common",
+        shared_cflag     => "-fPIC",
         shared_ldflag    => "-dynamiclib",
         shared_extension => ".\$(SHLIB_MAJOR).\$(SHLIB_MINOR).dylib",
     },
     "darwin-ppc-cc" => {
         inherit_from     => [ "darwin-common", asm("ppc32_asm") ],
-        cflags           => "-arch ppc -DB_ENDIAN -Wa,-force_cpusubtype_ALL",
+        cflags           => add("-arch ppc -DB_ENDIAN -Wa,-force_cpusubtype_ALL"),
         perlasm_scheme   => "osx32",
         shared_ldflag    => "-arch ppc -dynamiclib",
     },
     "darwin64-ppc-cc" => {
         inherit_from     => [ "darwin-common", asm("ppc64_asm") ],
-        cflags           => "-arch ppc64 -DB_ENDIAN",
+        cflags           => add("-arch ppc64 -DB_ENDIAN"),
         bn_ops           => "SIXTY_FOUR_BIT_LONG RC4_CHAR",
         perlasm_scheme   => "osx64",
         shared_ldflag    => "-arch ppc64 -dynamiclib",
     },
     "darwin-i386-cc" => {
         inherit_from     => [ "darwin-common", asm("x86_asm") ],
-        cflags           => "-arch i386 -DL_ENDIAN",
-        release_cflags   => "-O3 -fomit-frame-pointer",
+        cflags           => add(picker(default => "-arch i386 -DL_ENDIAN",
+                                       release => "-fomit-frame-pointer")),
         bn_ops           => "BN_LLONG RC4_INT",
         perlasm_scheme   => "macosx",
         shared_ldflag    => "-arch i386 -dynamiclib",
     },
     "darwin64-x86_64-cc" => {
         inherit_from     => [ "darwin-common", asm("x86_64_asm") ],
-        cflags           => "-arch x86_64 -DL_ENDIAN -Wall",
+        cflags           => add("-arch x86_64 -DL_ENDIAN -Wall"),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
         perlasm_scheme   => "macosx",
         shared_ldflag    => "-arch x86_64 -dynamiclib",
 #
     "iphoneos-cross" => {
         inherit_from     => [ "darwin-common" ],
-        cflags           => "-isysroot \$(CROSS_TOP)/SDKs/\$(CROSS_SDK) -fno-common",
+        cflags           => add("-isysroot \$(CROSS_TOP)/SDKs/\$(CROSS_SDK) -fno-common"),
         sys_id           => "iOS",
     },
     "ios-cross" => {
         # It should be possible to go below iOS 6 and even add -arch armv6,
         # thus targeting iPhone pre-3GS, but it's assumed to be irrelevant
         # at this point.
-        cflags           => "-arch armv7 -mios-version-min=6.0.0 -isysroot \$(CROSS_TOP)/SDKs/\$(CROSS_SDK) -fno-common",
+        cflags           => add("-arch armv7 -mios-version-min=6.0.0 -isysroot \$(CROSS_TOP)/SDKs/\$(CROSS_SDK) -fno-common"),
         sys_id           => "iOS",
         perlasm_scheme   => "ios32",
     },
     "ios64-cross" => {
         inherit_from     => [ "darwin-common", asm("aarch64_asm") ],
-        cflags           => "-arch arm64 -mios-version-min=7.0.0 -isysroot \$(CROSS_TOP)/SDKs/\$(CROSS_SDK) -fno-common",
+        cflags           => add("-arch arm64 -mios-version-min=7.0.0 -isysroot \$(CROSS_TOP)/SDKs/\$(CROSS_SDK) -fno-common"),
         sys_id           => "iOS",
         bn_ops           => "SIXTY_FOUR_BIT_LONG RC4_CHAR",
         perlasm_scheme   => "ios64",
         inherit_from     => [ "BASE_unix" ],
         inherit_from     => [ asm("x86_elf_asm") ],
         cc               => "gcc",
-        cflags           => "-DL_ENDIAN -O3 -fomit-frame-pointer -Wall",
-        thread_cflag     => "-pthread",
+        cflags           => combine("-DL_ENDIAN -O3 -fomit-frame-pointer -Wall",
+                                    threads("-pthread")),
         ex_libs          => add("-ldl"),
         bn_ops           => "BN_LLONG",
+        thread_scheme    => "pthreads",
         dso_scheme       => "dlfcn",
         shared_target    => "linux-shared",
         shared_cflag     => "-fPIC",
     "vxworks-mips" => {
         inherit_from     => [ "BASE_unix", asm("mips32_asm") ],
         cc               => "ccmips",
-        cflags           => "-mrtp -mips2 -O -G 0 -B\$(WIND_BASE)/host/\$(WIND_HOST_TYPE)/lib/gcc-lib/ -D_VSB_CONFIG_FILE=\"\$(WIND_BASE)/target/lib/h/config/vsbConfig.h\" -DCPU=MIPS32 -msoft-float -mno-branch-likely -DTOOL_FAMILY=gnu -DTOOL=gnu -fno-builtin -fno-defer-pop -DNO_STRINGS_H -I\$(WIND_BASE)/target/usr/h -I\$(WIND_BASE)/target/h/wrn/coreip",
-        thread_cflag     => "-D_REENTRANT",
+        cflags           => combine("-mrtp -mips2 -O -G 0 -B\$(WIND_BASE)/host/\$(WIND_HOST_TYPE)/lib/gcc-lib/ -D_VSB_CONFIG_FILE=\"\$(WIND_BASE)/target/lib/h/config/vsbConfig.h\" -DCPU=MIPS32 -msoft-float -mno-branch-likely -DTOOL_FAMILY=gnu -DTOOL=gnu -fno-builtin -fno-defer-pop -DNO_STRINGS_H -I\$(WIND_BASE)/target/usr/h -I\$(WIND_BASE)/target/h/wrn/coreip",
+                                    threads("-D_REENTRANT")),
         sys_id           => "VXWORKS",
         ex_libs          => add("-Wl,--defsym,__wrs_rtp_base=0xe0000000 -L \$(WIND_BASE)/target/usr/lib/mips/MIPSI32/sfcommon"),
+        thread_scheme    => "pthreads",
         perlasm_scheme   => "o32",
         ranlib           => "ranlibmips",
     },
     "uClinux-dist" => {
         inherit_from     => [ "BASE_unix" ],
         cc               => "$ENV{'CC'}",
-        cflags           => "\$(CFLAGS)",
-        thread_cflag     => "-D_REENTRANT",
+        cflags           => combine("\$(CFLAGS)",
+                                    threads("-D_REENTRANT")),
         plib_lflags      => "\$(LDFLAGS)",
         ex_libs          => add("\$(LDLIBS)"),
         bn_ops           => "BN_LLONG",
+        thread_scheme    => "pthreads",
         dso_scheme       => "$ENV{'LIBSSL_dlfcn'}",
         shared_target    => "linux-shared",
         shared_cflag     => "-fPIC",
     "uClinux-dist64" => {
         inherit_from     => [ "BASE_unix" ],
         cc               => "$ENV{'CC'}",
-        cflags           => "\$(CFLAGS)",
-        thread_cflag     => "-D_REENTRANT",
+        cflags           => combine("\$(CFLAGS)",
+                                    threads("-D_REENTRANT")),
         plib_lflags      => "\$(LDFLAGS)",
         ex_libs          => add("\$(LDLIBS)"),
         bn_ops           => "SIXTY_FOUR_BIT_LONG",
+        thread_scheme    => "pthreads",
         dso_scheme       => "$ENV{'LIBSSL_dlfcn'}",
         shared_target    => "linux-shared",
         shared_cflag     => "-fPIC",
         inherit_from     => [ "BASE_VMS" ],
         template         => 1,
         cc               => "CC/DECC",
-        cflags           => "/STANDARD=RELAXED/NOLIST/PREFIX=ALL/NAMES=(AS_IS,SHORTENED)",
-        debug_cflags     => "/NOOPTIMIZE/DEBUG",
-        release_cflags   => "/OPTIMIZE/NODEBUG",
-        lflags           => "/MAP",
-        debug_lflags     => "/DEBUG/TRACEBACK",
-        release_lflags   => "/NODEBUG/NOTRACEBACK",
+        cflags           => picker(default => "/STANDARD=RELAXED/NOLIST/PREFIX=ALL/NAMES=(AS_IS,SHORTENED)",
+                                   debug   => "/NOOPTIMIZE/DEBUG",
+                                   release => "/OPTIMIZE/NODEBUG"),
+        lflags           => picker(default => "/MAP",
+                                   debug   => "/DEBUG/TRACEBACK",
+                                   release => "/NODEBUG/NOTRACEBACK"),
         shared_target    => "vms-shared",
+        thread_scheme    => "pthreads",
 
         apps_aux_src     => "vms_decc_init.c",
     },