11 files changed, 66 insertions, 15 deletions
diff --git a/config/arch/arc.in b/config/arch/arc.in
new file mode 100644
index 00000000..d7c6e043
--- /dev/null
+++ b/config/arch/arc.in
@@ -0,0 +1,16 @@
+# ARC specific configuration file
+
+## no-package
+## select ARCH_SUPPORTS_32
+## select ARCH_DEFAULT_32
+## select ARCH_SUPPORTS_BOTH_MMU
+## select ARCH_DEFAULT_HAS_MMU
+## select ARCH_SUPPORTS_EITHER_ENDIAN
+## select ARCH_DEFAULT_LE
+## select ARCH_SUPPORTS_WITH_CPU
+## select GCC_REQUIRE_7_or_later
+## select BINUTILS_REQUIRE_2_30_or_later
+## select LINUX_REQUIRE_4_8_or_later if KERNEL_LINUX
+##
+## help The Synopsys DesignWare ARC architecture, see more info here:
+## help     https://www.synopsys.com/designware-ip/processor-solutions/arc-processors.html
diff --git a/config/arch/arm.in b/config/arch/arm.in
index 7ce7ef0f..37575aa0 100644
--- a/config/arch/arm.in
+++ b/config/arch/arm.in
@@ -15,6 +15,7 @@
 ## select ARCH_SUPPORTS_WITH_FLOAT if ARCH_32
 ## select ARCH_SUPPORTS_WITH_FPU if ARCH_32
 ## select ARCH_SUPPORTS_SOFTFP if ARCH_32
+## select LINUX_REQUIRE_3_7_or_later if ARCH_64 && KERNEL_LINUX
 
 ## help The ARM architecture, as defined by:
 ## help     http://www.arm.com/
diff --git a/config/arch/riscv.in b/config/arch/riscv.in
index 4efde976..109556a7 100644
--- a/config/arch/riscv.in
+++ b/config/arch/riscv.in
@@ -4,9 +4,12 @@
 ## depends on EXPERIMENTAL
 ##
 ## select ARCH_SUPPORTS_32
+## select ARCH_SUPPORTS_64
 ## select ARCH_DEFAULT_32
+## select ARCH_SUPPORTS_BOTH_MMU
 ## select ARCH_SUPPORTS_WITH_ABI
 ## select ARCH_SUPPORTS_WITH_ARCH
+## select ARCH_SUPPORTS_WITH_TUNE
 ## select GCC_REQUIRE_7_or_later
 
 ## help The RISC-V architecture, as defined by:
diff --git a/config/cc/gcc.in b/config/cc/gcc.in
index 48ec5562..74fbb70a 100644
--- a/config/cc/gcc.in
+++ b/config/cc/gcc.in
@@ -11,8 +11,10 @@
 ## select ISL_REQUIRE_0_15_or_later if ISL_NEEDED && GCC_7_or_later
 # GCC6 requires ISL 0.14+ (it says 0.14-0.16, but accepts newer ISL as well)
 ## select ISL_REQUIRE_0_14_or_later if ISL_NEEDED && GCC_6_or_later
-# GCC5 requires ISL 0.12+ (again, it says 0.12-0.16, but also accepts newer ISL)
+# GCC5 requires ISL 0.12+ (again, it says 0.12-0.16, but also accepts newer ISL up to 0.18;
+# fails to compile with 0.19+)
 ## select ISL_REQUIRE_0_12_or_later if ISL_NEEDED && GCC_5_or_later
+## select ISL_REQUIRE_0_18_or_older if ISL_NEEDED && GCC_5_or_later && !GCC_6_or_later
 # GCC4.9 requires ISL 0.10..0.15
 # GCC4.8 requires ISL 0.10..0.14
 ## select ISL_REQUIRE_0_10_or_later if ISL_NEEDED && GCC_4_8_or_later
diff --git a/config/configure.in.in b/config/configure.in.in
index c8003a03..3d6a628b 100644
--- a/config/configure.in.in
+++ b/config/configure.in.in
@@ -45,5 +45,17 @@ config CONFIGURE_has_svn
 config CONFIGURE_has_git
     @KCONFIG_git@
 
+config CONFIGURE_has_md5sum
+    @KCONFIG_md5sum@
+
+config CONFIGURE_has_sha1sum
+    @KCONFIG_sha1sum@
+
+config CONFIGURE_has_sha256sum
+    @KCONFIG_sha256sum@
+
+config CONFIGURE_has_sha512sum
+    @KCONFIG_sha512sum@
+
 config CONFIGURE_has_install_with_strip_program
     @KCONFIG_install_with_strip_program@
diff --git a/config/debug/gdb.in b/config/debug/gdb.in
index 02882aa0..a9fab104 100644
--- a/config/debug/gdb.in
+++ b/config/debug/gdb.in
@@ -17,3 +17,10 @@ config GDB_HAS_PYTHON
 config GDB_INSTALL_GDBINIT
     bool
     default y if GDB_7_0_or_later
+
+# GDB 8.0 now requires C++ for build. GDB 7.12 offered a configure
+# switch to fall back to C. We want to use that option because
+# the conversion in 7.12 was incomplete and had some breakages.
+config GDB_HAS_DISABLE_CXX_BUILD
+    def_bool y
+    depends on GDB_7_12_or_later && !GDB_8_0_or_later
diff --git a/config/debug/gdb.in.gdbserver b/config/debug/gdb.in.gdbserver
index 8e999b41..d7f1bb81 100644
--- a/config/debug/gdb.in.gdbserver
+++ b/config/debug/gdb.in.gdbserver
@@ -16,7 +16,6 @@ config GDB_GDBSERVER_HAS_IPA_LIB
     depends on GDB_7_2_or_later
     default y
 
-# gdbserver is then linked with "-static -Wl,--dynamic-list=..." which
 config GDB_GDBSERVER_STATIC
     bool
     prompt "Build a static gdbserver"
diff --git a/config/global/download.in b/config/global/download.in
index 89b05cea..57f42e6f 100644
--- a/config/global/download.in
+++ b/config/global/download.in
@@ -135,6 +135,7 @@ endif # USE_MIRROR
 config VERIFY_DOWNLOAD_DIGEST
     bool "Verify download digests (checksums)"
     default y
+    depends on CONFIGURE_has_sha512sum || CONFIGURE_has_sha256sum || CONFIGURE_has_sha1sum || CONFIGURE_has_md5sum
 
 if VERIFY_DOWNLOAD_DIGEST
 
@@ -143,14 +144,18 @@ choice
 
 config VERIFY_DOWNLOAD_DIGEST_SHA512
     bool "SHA-512"
+    depends on CONFIGURE_has_sha512sum
 
 config VERIFY_DOWNLOAD_DIGEST_SHA256
+    depends on CONFIGURE_has_sha256sum
     bool "SHA-256"
 
 config VERIFY_DOWNLOAD_DIGEST_SHA1
+    depends on CONFIGURE_has_sha1sum
     bool "SHA-1"
 
 config VERIFY_DOWNLOAD_DIGEST_MD5
+    depends on CONFIGURE_has_md5sum
     bool "MD5"
 
 endchoice
diff --git a/config/global/extract.in b/config/global/extract.in
index 58f7b956..ba7f5f4c 100644
--- a/config/global/extract.in
+++ b/config/global/extract.in
@@ -40,19 +40,16 @@ config ONLY_EXTRACT
       Useful to look at the code before doing the build itself.
 
 choice
-    prompt "Patches origin"
-    bool
+    bool "Patches origin"
     default PATCH_BUNDLED
 
 config PATCH_BUNDLED
-    bool
-    prompt "Bundled only"
+    bool "Bundled only"
     help
       Only apply patches bundled with crosstool-NG.
 
 config PATCH_LOCAL
-    bool
-    prompt "Local only (EXPERIMENTAL)"
+    bool "Local only"
     select PATCH_USE_LOCAL
     depends on EXPERIMENTAL
     help
@@ -61,16 +58,14 @@ config PATCH_LOCAL
       copy them into your local directory if needed.
 
 config PATCH_BUNDLED_LOCAL
-    bool
-    prompt "Bundled, then local"
+    bool "Bundled, then local"
     select PATCH_USE_LOCAL
     help
       Apply the patches bundled with crosstool-NG, then apply your local
       patches.
 
 config PATCH_LOCAL_BUNDLED
-    bool
-    prompt "Local, then bundled"
+    bool "Local, then bundled"
     select PATCH_USE_LOCAL
     depends on EXPERIMENTAL
     help
@@ -79,8 +74,7 @@ config PATCH_LOCAL_BUNDLED
       to apply on top of your local patches.
 
 config PATCH_NONE
-    bool
-    prompt "None"
+    bool "None"
     depends on EXPERIMENTAL
     help
       Don't use any patch at all.
diff --git a/config/global/paths.in b/config/global/paths.in
index 39e15f35..b4e93ee0 100644
--- a/config/global/paths.in
+++ b/config/global/paths.in
@@ -42,7 +42,7 @@ config WORK_DIR
 
 config BUILD_TOP_DIR
     string
-    default "${CT_WORK_DIR}/${CT_HOST:+HOST-${CT_HOST}/}${CT_TARGET}"
+    default "${CT_WORK_DIR:-${CT_TOP_DIR}/.build}/${CT_HOST:+HOST-${CT_HOST}/}${CT_TARGET}"
 
 config PREFIX_DIR
     string
diff --git a/config/libc/glibc.in b/config/libc/glibc.in
index a297bb15..5916a83c 100644
--- a/config/libc/glibc.in
+++ b/config/libc/glibc.in
@@ -320,4 +320,16 @@ config GLIBC_MIN_KERNEL
     default LINUX_VERSION                 if GLIBC_KERNEL_VERSION_AS_HEADERS
     default GLIBC_MIN_KERNEL_VERSION      if GLIBC_KERNEL_VERSION_CHOSEN
 
+# All supported versions of glibc build cleanly with GCC7 and earlier.
+# GCC8-related fixes were only available in glibc 2.27.
+config GLIBC_ENABLE_WERROR
+    bool "Enable -Werror during the build"
+    default y if GCC_7_or_older
+    default y if GCC_8_or_later && GLIBC_2_27_or_later
+    help
+      By default, glibc enables strict warning checks during the build.
+      However, older version of glibc may not build with newer versions
+      of the compiler than there were available at the time of a glibc
+      release (because newer compilers typically have better diagnostics).
+
 endif # KERNEL_LINUX