diff --git a/programs/.gitignore b/programs/.gitignore
index 353a92d..5d3c5bd 100644
--- a/programs/.gitignore
+++ b/programs/.gitignore
@@ -53,6 +53,7 @@
 ssl/ssl_server2
 test/benchmark
 test/cpp_dummy_build
+test/cpp_dummy_build.cpp
 test/ecp-bench
 test/query_compile_time_config
 test/selftest
diff --git a/programs/Makefile b/programs/Makefile
index 35ef7ad..550887a 100644
--- a/programs/Makefile
+++ b/programs/Makefile
@@ -310,6 +310,10 @@
 	echo "  CC    test/benchmark.c"
 	$(CC) $(LOCAL_CFLAGS) $(CFLAGS) test/benchmark.c   $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
 
+test/cpp_dummy_build.cpp: test/generate_cpp_dummy_build.sh
+	echo "  Gen   test/cpp_dummy_build.cpp"
+	test/generate_cpp_dummy_build.sh
+
 test/cpp_dummy_build$(EXEXT): test/cpp_dummy_build.cpp $(DEP)
 	echo "  CXX   test/cpp_dummy_build.cpp"
 	$(CXX) $(LOCAL_CXXFLAGS) $(CXXFLAGS) test/cpp_dummy_build.cpp   $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@
@@ -374,10 +378,11 @@
 ifndef WINDOWS
 	rm -f $(APPS)
 	-rm -f ssl/ssl_pthread_server$(EXEXT)
-	-rm -f test/cpp_dummy_build$(EXEXT)
+	-rm -f test/cpp_dummy_build.cpp test/cpp_dummy_build$(EXEXT)
 else
 	if exist *.o del /Q /F *.o
 	if exist *.exe del /Q /F *.exe
+	if exist test\cpp_dummy_build.cpp del /Q /F test\cpp_dummy_build.cpp
 endif
 	$(MAKE) -C fuzz clean
 
diff --git a/programs/test/CMakeLists.txt b/programs/test/CMakeLists.txt
index 2b1e61e..04ec7fc 100644
--- a/programs/test/CMakeLists.txt
+++ b/programs/test/CMakeLists.txt
@@ -22,7 +22,17 @@
 )
 
 if(TEST_CPP)
-    list(APPEND executables_mbedcrypto cpp_dummy_build)
+    set(cpp_dummy_build_cpp "${CMAKE_CURRENT_BINARY_DIR}/cpp_dummy_build.cpp")
+    set(generate_cpp_dummy_build "${CMAKE_CURRENT_SOURCE_DIR}/generate_cpp_dummy_build.sh")
+    add_custom_command(
+        OUTPUT "${cpp_dummy_build_cpp}"
+        COMMAND "${generate_cpp_dummy_build}" "${cpp_dummy_build_cpp}"
+        DEPENDS "${generate_cpp_dummy_build}"
+        WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+    )
+    add_executable(cpp_dummy_build "${cpp_dummy_build_cpp}")
+    target_include_directories(cpp_dummy_build PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../../include)
+    target_link_libraries(cpp_dummy_build ${mbedcrypto_target})
 endif()
 
 foreach(exe IN LISTS executables_libs executables_mbedcrypto)
diff --git a/programs/test/cpp_dummy_build.cpp b/programs/test/cpp_dummy_build.cpp
deleted file mode 100644
index d052682..0000000
--- a/programs/test/cpp_dummy_build.cpp
+++ /dev/null
@@ -1,123 +0,0 @@
-/*
- *  This program is a dummy C++ program to ensure Mbed TLS library header files
- *  can be included and built with a C++ compiler.
- *
- *  Copyright The Mbed TLS Contributors
- *  SPDX-License-Identifier: Apache-2.0
- *
- *  Licensed under the Apache License, Version 2.0 (the "License"); you may
- *  not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *  http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- */
-
-#if !defined(MBEDTLS_CONFIG_FILE)
-#include "mbedtls/config.h"
-#else
-#include MBEDTLS_CONFIG_FILE
-#endif
-
-#include "mbedtls/aes.h"
-#include "mbedtls/aesni.h"
-#include "mbedtls/arc4.h"
-#include "mbedtls/aria.h"
-#include "mbedtls/asn1.h"
-#include "mbedtls/asn1write.h"
-#include "mbedtls/base64.h"
-#include "mbedtls/bignum.h"
-#include "mbedtls/blowfish.h"
-#include "mbedtls/bn_mul.h"
-#include "mbedtls/camellia.h"
-#include "mbedtls/ccm.h"
-#include "mbedtls/certs.h"
-#include "mbedtls/chacha20.h"
-#include "mbedtls/chachapoly.h"
-#include "mbedtls/check_config.h"
-#include "mbedtls/cipher.h"
-#include "mbedtls/cipher_internal.h"
-#include "mbedtls/cmac.h"
-#include "mbedtls/compat-1.3.h"
-#include "mbedtls/config_psa.h"
-#include "mbedtls/ctr_drbg.h"
-#include "mbedtls/debug.h"
-#include "mbedtls/des.h"
-#include "mbedtls/dhm.h"
-#include "mbedtls/ecdh.h"
-#include "mbedtls/ecdsa.h"
-#include "mbedtls/ecjpake.h"
-#include "mbedtls/ecp.h"
-#include "mbedtls/ecp_internal.h"
-#include "mbedtls/entropy.h"
-#include "mbedtls/entropy_poll.h"
-#include "mbedtls/error.h"
-#include "mbedtls/gcm.h"
-#include "mbedtls/havege.h"
-#include "mbedtls/hkdf.h"
-#include "mbedtls/hmac_drbg.h"
-#include "mbedtls/md.h"
-#include "mbedtls/md2.h"
-#include "mbedtls/md4.h"
-#include "mbedtls/md5.h"
-#include "mbedtls/md_internal.h"
-#include "mbedtls/net.h"
-#include "mbedtls/net_sockets.h"
-#include "mbedtls/nist_kw.h"
-#include "mbedtls/oid.h"
-#include "mbedtls/padlock.h"
-#include "mbedtls/pem.h"
-#include "mbedtls/pk.h"
-#include "mbedtls/pk_internal.h"
-#include "mbedtls/pkcs11.h"
-#include "mbedtls/pkcs12.h"
-#include "mbedtls/pkcs5.h"
-#include "mbedtls/platform_time.h"
-#include "mbedtls/platform_util.h"
-#include "mbedtls/poly1305.h"
-#include "mbedtls/psa_util.h"
-#include "mbedtls/ripemd160.h"
-#include "mbedtls/rsa.h"
-#include "mbedtls/rsa_internal.h"
-#include "mbedtls/sha1.h"
-#include "mbedtls/sha256.h"
-#include "mbedtls/sha512.h"
-#include "mbedtls/ssl.h"
-#include "mbedtls/ssl_cache.h"
-#include "mbedtls/ssl_ciphersuites.h"
-#include "mbedtls/ssl_cookie.h"
-#include "mbedtls/ssl_internal.h"
-#include "mbedtls/ssl_ticket.h"
-#include "mbedtls/threading.h"
-#include "mbedtls/timing.h"
-#include "mbedtls/version.h"
-#include "mbedtls/x509.h"
-#include "mbedtls/x509_crl.h"
-#include "mbedtls/x509_crt.h"
-#include "mbedtls/x509_csr.h"
-#include "mbedtls/xtea.h"
-
-#if defined(MBEDTLS_PLATFORM_C)
-#include "mbedtls/platform.h"
-#endif
-
-#if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
-#include "mbedtls/memory_buffer_alloc.h"
-#endif
-
-#include "psa/crypto.h"
-#include "psa/crypto_se_driver.h"
-#include "../library/psa_crypto_its.h"
-
-int main()
-{
-    mbedtls_platform_context *ctx = NULL;
-    mbedtls_platform_setup(ctx);
-    mbedtls_printf("CPP Build test\n");
-    mbedtls_platform_teardown(ctx);
-}
diff --git a/programs/test/generate_cpp_dummy_build.sh b/programs/test/generate_cpp_dummy_build.sh
new file mode 100755
index 0000000..90a181d
--- /dev/null
+++ b/programs/test/generate_cpp_dummy_build.sh
@@ -0,0 +1,97 @@
+#!/bin/sh
+
+DEFAULT_OUTPUT_FILE=programs/test/cpp_dummy_build.cpp
+
+if [ "$1" = "--help" ]; then
+    cat <<EOF
+Usage: $0 [OUTPUT]
+Generate a C++ dummy build program that includes all the headers.
+OUTPUT defaults to "programs/test/cpp_dummy_build.cpp".
+Run this program from the root of an Mbed TLS directory tree or from
+its "programs" or "programs/test" subdirectory.
+EOF
+    exit
+fi
+
+# Copyright The Mbed TLS Contributors
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -e
+
+# Ensure a reproducible order for *.h
+export LC_ALL=C
+
+print_cpp () {
+    cat <<'EOF'
+/* Automatically generated file. Do not edit.
+ *
+ *  This program is a dummy C++ program to ensure Mbed TLS library header files
+ *  can be included and built with a C++ compiler.
+ *
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include "mbedtls/config.h"
+
+EOF
+
+  for header in include/mbedtls/*.h include/psa/*.h; do
+    case ${header#include/} in
+      psa/crypto_config.h) :;; # not meant for direct inclusion
+      # Some of the psa/crypto_*.h headers are not meant to be included directly.
+      # They do have include guards that make them no-ops if psa/crypto.h
+      # has been included before. Since psa/crypto.h comes before psa/crypto_*.h
+      # in the wildcard enumeration, we don't need to skip those headers.
+      *) echo "#include \"${header#include/}\"";;
+    esac
+  done
+
+    cat <<'EOF'
+
+int main()
+{
+    mbedtls_platform_context *ctx = NULL;
+    mbedtls_platform_setup(ctx);
+    mbedtls_printf("CPP Build test passed\n");
+    mbedtls_platform_teardown(ctx);
+}
+EOF
+}
+
+if [ -d include/mbedtls ]; then
+    :
+elif [ -d ../include/mbedtls ]; then
+    cd ..
+elif [ -d ../../include/mbedtls ]; then
+    cd ../..
+else
+    echo >&2 "This script must be run from an Mbed TLS source tree."
+    exit 3
+fi
+
+print_cpp >"${1:-$DEFAULT_OUTPUT_FILE}"
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 98950c0..07503a2 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -1,4 +1,4 @@
-#! /usr/bin/env sh
+#! /usr/bin/env bash
 
 # all.sh
 #
@@ -59,6 +59,15 @@
 # This script must be invoked from the toplevel directory of a git
 # working copy of Mbed TLS.
 #
+# The behavior on an error depends on whether --keep-going (alias -k)
+# is in effect.
+#  * Without --keep-going: the script stops on the first error without
+#    cleaning up. This lets you work in the configuration of the failing
+#    component.
+#  * With --keep-going: the script runs all requested components and
+#    reports failures at the end. In particular the script always cleans
+#    up on exit.
+#
 # Note that the output is not saved. You may want to run
 #   script -c tests/scripts/all.sh
 # or
@@ -81,6 +90,12 @@
 #
 # Each component must start by invoking `msg` with a short informative message.
 #
+# Warning: due to the way bash detects errors, the failure of a command
+# inside 'if' or '!' is not detected. Use the 'not' function instead of '!'.
+#
+# Each component is executed in a separate shell process. The component
+# fails if any command in it returns a non-zero status.
+#
 # The framework performs some cleanup tasks after each component. This
 # means that components can assume that the working directory is in a
 # cleaned-up state, and don't need to perform the cleanup themselves.
@@ -91,19 +106,6 @@
 #   `tests/Makefile` and `programs/fuzz/Makefile` from git.
 #   This cleans up after an in-tree use of CMake.
 #
-# Any command that is expected to fail must be protected so that the
-# script keeps running in --keep-going mode despite `set -e`. In keep-going
-# mode, if a protected command fails, this is logged as a failure and the
-# script will exit with a failure status once it has run all components.
-# Commands can be protected in any of the following ways:
-# * `make` is a function which runs the `make` command with protection.
-#   Note that you must write `make VAR=value`, not `VAR=value make`,
-#   because the `VAR=value make` syntax doesn't work with functions.
-# * Put `report_status` before the command to protect it.
-# * Put `if_build_successful` before a command. This protects it, and
-#   additionally skips it if a prior invocation of `make` in the same
-#   component failed.
-#
 # The tests are roughly in order from fastest to slowest. This doesn't
 # have to be exact, but in general you should add slower tests towards
 # the end and fast checks near the beginning.
@@ -114,8 +116,9 @@
 #### Initialization and command line parsing
 ################################################################
 
-# Abort on errors (and uninitialised variables)
-set -eu
+# Abort on errors (even on the left-hand side of a pipe).
+# Treat uninitialised variables as errors.
+set -e -o pipefail -u
 
 pre_check_environment () {
     if [ -d library -a -d include -a -d tests ]; then :; else
@@ -126,9 +129,16 @@
 
 pre_initialize_variables () {
     CONFIG_H='include/mbedtls/config.h'
-    CONFIG_BAK="$CONFIG_H.bak"
     CRYPTO_CONFIG_H='include/psa/crypto_config.h'
-    CRYPTO_CONFIG_BAK="$CRYPTO_CONFIG_H.bak"
+
+    # Files that are clobbered by some jobs will be backed up. Use a different
+    # suffix from auxiliary scripts so that all.sh and auxiliary scripts can
+    # independently decide when to remove the backup file.
+    backup_suffix='.all.bak'
+    # Files clobbered by config.py
+    files_to_back_up="$CONFIG_H $CRYPTO_CONFIG_H"
+    # Files clobbered by in-tree cmake
+    files_to_back_up="$files_to_back_up Makefile library/Makefile programs/Makefile tests/Makefile programs/fuzz/Makefile"
 
     append_outcome=0
     MEMORY=0
@@ -176,8 +186,8 @@
 
     # Gather the list of available components. These are the functions
     # defined in this script whose name starts with "component_".
-    # Parse the script with sed, because in sh there is no way to list
-    # defined functions.
+    # Parse the script with sed. This way we get the functions in the order
+    # they are defined.
     ALL_COMPONENTS=$(sed -n 's/^ *component_\([0-9A-Z_a-z]*\) *().*/\1/p' <"$0")
 
     # Exclude components that are not supported on this platform.
@@ -194,6 +204,8 @@
 # Test whether the component $1 is included in the command line patterns.
 is_component_included()
 {
+    # Temporarily disable wildcard expansion so that $COMMAND_LINE_COMPONENTS
+    # only does word splitting.
     set -f
     for pattern in $COMMAND_LINE_COMPONENTS; do
         set +f
@@ -235,6 +247,11 @@
                         Prefix for a cross-compiler for arm-linux-gnueabi
                         (default: "${ARM_LINUX_GNUEABI_GCC_PREFIX}")
      --armcc            Run ARM Compiler builds (on by default).
+     --restore          First clean up the build tree, restoring backed up
+                        files. Do not run any components unless they are
+                        explicitly specified.
+     --error-test       Error test mode: run a failing function in addition
+                        to any specified component. May be repeated.
      --except           Exclude the COMPONENTs listed on the command line,
                         instead of running only those.
      --no-append-outcome    Write a new outcome file and analyze it (default).
@@ -263,13 +280,11 @@
 EOF
 }
 
-# remove built files as well as the cmake cache/config
+# Cleanup before/after running a component.
+# Remove built files as well as the cmake cache/config.
+# Does not remove generated source files.
 cleanup()
 {
-    if [ -n "${MBEDTLS_ROOT_DIR+set}" ]; then
-        cd "$MBEDTLS_ROOT_DIR"
-    fi
-
     command make clean
 
     # Remove CMake artefacts
@@ -280,21 +295,26 @@
               -iname CMakeCache.txt \) -exec rm {} \+
     # Recover files overwritten by in-tree CMake builds
     rm -f include/Makefile include/mbedtls/Makefile programs/*/Makefile
-    git update-index --no-skip-worktree Makefile library/Makefile programs/Makefile tests/Makefile programs/fuzz/Makefile
-    git checkout -- Makefile library/Makefile programs/Makefile tests/Makefile programs/fuzz/Makefile
 
     # Remove any artifacts from the component_test_cmake_as_subdirectory test.
     rm -rf programs/test/cmake_subproject/build
     rm -f programs/test/cmake_subproject/Makefile
     rm -f programs/test/cmake_subproject/cmake_subproject
 
-    if [ -f "$CONFIG_BAK" ]; then
-        mv "$CONFIG_BAK" "$CONFIG_H"
-    fi
+    # Restore files that may have been clobbered by the job
+    for x in $files_to_back_up; do
+        cp -p "$x$backup_suffix" "$x"
+    done
+}
 
-    if [ -f "$CRYPTO_CONFIG_BAK" ]; then
-        mv "$CRYPTO_CONFIG_BAK" "$CRYPTO_CONFIG_H"
-    fi
+# Final cleanup when this script exits (except when exiting on a failure
+# in non-keep-going mode).
+final_cleanup () {
+    cleanup
+
+    for x in $files_to_back_up; do
+        rm -f "$x$backup_suffix"
+    done
 }
 
 # Executed on exit. May be redefined depending on command line options.
@@ -303,7 +323,7 @@
 }
 
 fatal_signal () {
-    cleanup
+    final_cleanup
     final_report $1
     trap - $1
     kill -$1 $$
@@ -373,17 +393,11 @@
     done
 }
 
-check_headers_in_cpp () {
-    ls include/mbedtls | grep "\.h$" >headers.txt
-    <programs/test/cpp_dummy_build.cpp sed -n 's/"$//; s!^#include "mbedtls/!!p' |
-    sort |
-    diff headers.txt -
-    rm headers.txt
-}
-
 pre_parse_command_line () {
     COMMAND_LINE_COMPONENTS=
     all_except=0
+    error_test=0
+    restore_first=0
     no_armcc=
 
     # Note that legacy options are ignored instead of being omitted from this
@@ -397,6 +411,7 @@
             --armcc) no_armcc=;;
             --armc5-bin-dir) shift; ARMC5_BIN_DIR="$1";;
             --armc6-bin-dir) shift; ARMC6_BIN_DIR="$1";;
+            --error-test) error_test=$((error_test + 1));;
             --except) all_except=1;;
             --force|-f) FORCE=1;;
             --gnutls-cli) shift; GNUTLS_CLI="$1";;
@@ -422,6 +437,7 @@
             --quiet|-q) QUIET=1;;
             --random-seed) unset SEED;;
             --release-test|-r) SEED=$RELEASE_SEED;;
+            --restore) restore_first=1;;
             --seed|-s) shift; SEED="$1";;
             -*)
                 echo >&2 "Unknown option: $1"
@@ -434,7 +450,7 @@
     done
 
     # With no list of components, run everything.
-    if [ -z "$COMMAND_LINE_COMPONENTS" ]; then
+    if [ -z "$COMMAND_LINE_COMPONENTS" ] && [ $restore_first -eq 0 ]; then
         all_except=1
     fi
 
@@ -444,6 +460,32 @@
         COMMAND_LINE_COMPONENTS="$COMMAND_LINE_COMPONENTS *_armcc*"
     fi
 
+    # Error out if an explicitly requested component doesn't exist.
+    if [ $all_except -eq 0 ]; then
+        unsupported=0
+        # Temporarily disable wildcard expansion so that $COMMAND_LINE_COMPONENTS
+        # only does word splitting.
+        set -f
+        for component in $COMMAND_LINE_COMPONENTS; do
+            set +f
+            # If the requested name includes a wildcard character, don't
+            # check it. Accept wildcard patterns that don't match anything.
+            case $component in
+                *[*?\[]*) continue;;
+            esac
+            case " $SUPPORTED_COMPONENTS " in
+                *" $component "*) :;;
+                *)
+                    echo >&2 "Component $component was explicitly requested, but is not known or not supported."
+                    unsupported=$((unsupported + 1));;
+            esac
+        done
+        set +f
+        if [ $unsupported -ne 0 ]; then
+            exit 2
+        fi
+    fi
+
     # Build the list of components to run.
     RUN_COMPONENTS=
     for component in $SUPPORTED_COMPONENTS; do
@@ -479,9 +521,36 @@
     fi
 }
 
+pre_restore_files () {
+    # If the makefiles have been generated by a framework such as cmake,
+    # restore them from git. If the makefiles look like modifications from
+    # the ones checked into git, take care not to modify them. Whatever
+    # this function leaves behind is what the script will restore before
+    # each component.
+    case "$(head -n1 Makefile)" in
+        *[Gg]enerated*)
+            git update-index --no-skip-worktree Makefile library/Makefile programs/Makefile tests/Makefile programs/fuzz/Makefile
+            git checkout -- Makefile library/Makefile programs/Makefile tests/Makefile programs/fuzz/Makefile
+            ;;
+    esac
+}
+
+pre_back_up () {
+    for x in $files_to_back_up; do
+        cp -p "$x" "$x$backup_suffix"
+    done
+}
+
 pre_setup_keep_going () {
-    failure_summary=
-    failure_count=0
+    failure_count=0 # Number of failed components
+    last_failure_status=0 # Last failure status in this component
+
+    # See err_trap
+    previous_failure_status=0
+    previous_failed_command=
+    previous_failure_funcall_depth=0
+    unset report_failed_command
+
     start_red=
     end_color=
     if [ -t 1 ]; then
@@ -492,76 +561,106 @@
                 ;;
         esac
     fi
-    record_status () {
-        if "$@"; then
-            last_status=0
-        else
-            last_status=$?
-            text="$current_section: $* -> $last_status"
-            failure_summary="$failure_summary
-$text"
-            failure_count=$((failure_count + 1))
-            echo "${start_red}^^^^$text^^^^${end_color}" >&2
-        fi
-    }
-    make () {
-        case "$*" in
-            *test|*check)
-                if [ $build_status -eq 0 ]; then
-                    record_status command make "$@"
-                else
-                    echo "(skipped because the build failed)"
-                fi
-                ;;
-            *)
-                record_status command make "$@"
-                build_status=$last_status
-                ;;
+
+    # Keep a summary of failures in a file. We'll print it out at the end.
+    failure_summary_file=$PWD/all-sh-failures-$$.log
+    : >"$failure_summary_file"
+
+    # Whether it makes sense to keep a component going after the specified
+    # command fails (test command) or not (configure or build).
+    # This function normally receives the failing simple command
+    # ($BASH_COMMAND) as an argument, but if $report_failed_command is set,
+    # this is passed instead.
+    # This doesn't have to be 100% accurate: all failures are recorded anyway.
+    # False positives result in running things that can't be expected to
+    # work. False negatives result in things not running after something else
+    # failed even though they might have given useful feedback.
+    can_keep_going_after_failure () {
+        case "$1" in
+            "msg "*) false;;
+            "cd "*) false;;
+            *make*[\ /]tests*) false;; # make tests, make CFLAGS=-I../tests, ...
+            *test*) true;; # make test, tests/stuff, env V=v tests/stuff, ...
+            *make*check*) true;;
+            "grep "*) true;;
+            "[ "*) true;;
+            "! "*) true;;
+            *) false;;
         esac
     }
+
+    # This function runs if there is any error in a component.
+    # It must either exit with a nonzero status, or set
+    # last_failure_status to a nonzero value.
+    err_trap () {
+        # Save $? (status of the failing command). This must be the very
+        # first thing, before $? is overridden.
+        last_failure_status=$?
+        failed_command=${report_failed_command-$BASH_COMMAND}
+
+        if [[ $last_failure_status -eq $previous_failure_status &&
+              "$failed_command" == "$previous_failed_command" &&
+              ${#FUNCNAME[@]} == $((previous_failure_funcall_depth - 1)) ]]
+        then
+            # The same command failed twice in a row, but this time one level
+            # less deep in the function call stack. This happens when the last
+            # command of a function returns a nonzero status, and the function
+            # returns that same status. Ignore the second failure.
+            previous_failure_funcall_depth=${#FUNCNAME[@]}
+            return
+        fi
+        previous_failure_status=$last_failure_status
+        previous_failed_command=$failed_command
+        previous_failure_funcall_depth=${#FUNCNAME[@]}
+
+        text="$current_section: $failed_command -> $last_failure_status"
+        echo "${start_red}^^^^$text^^^^${end_color}" >&2
+        echo "$text" >>"$failure_summary_file"
+
+        # If the command is fatal (configure or build command), stop this
+        # component. Otherwise (test command) keep the component running
+        # (run more tests from the same build).
+        if ! can_keep_going_after_failure "$failed_command"; then
+            exit $last_failure_status
+        fi
+    }
+
     final_report () {
         if [ $failure_count -gt 0 ]; then
             echo
             echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
-            echo "${start_red}FAILED: $failure_count${end_color}$failure_summary"
+            echo "${start_red}FAILED: $failure_count components${end_color}"
+            cat "$failure_summary_file"
             echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
-            exit 1
         elif [ -z "${1-}" ]; then
             echo "SUCCESS :)"
         fi
         if [ -n "${1-}" ]; then
             echo "Killed by SIG$1."
         fi
+        rm -f "$failure_summary_file"
+        if [ $failure_count -gt 0 ]; then
+            exit 1
+        fi
     }
 }
 
+# record_status() and if_build_succeeded() are kept temporarily for backward
+# compatibility. Don't use them in new components.
+record_status () {
+    "$@"
+}
 if_build_succeeded () {
-    if [ $build_status -eq 0 ]; then
-        record_status "$@"
-    fi
+    "$@"
 }
 
-# to be used instead of ! for commands run with
-# record_status or if_build_succeeded
-not() {
-    ! "$@"
-}
-
-pre_setup_quiet_redirect () {
-    if [ $QUIET -ne 1 ]; then
-        redirect_out () {
-            "$@"
-        }
-        redirect_err () {
-            "$@"
-        }
-    else
-        redirect_out () {
-            "$@" >/dev/null
-        }
-        redirect_err () {
-            "$@" 2>/dev/null
-        }
+# '! true' does not trigger the ERR trap. Arrange to trigger it, with
+# a reasonably informative error message (not just "$@").
+not () {
+    if "$@"; then
+        report_failed_command="! $*"
+        false
+        unset report_failed_command
     fi
 }
 
@@ -686,28 +785,28 @@
 
 component_check_recursion () {
     msg "Check: recursion.pl" # < 1s
-    record_status tests/scripts/recursion.pl library/*.c
+    tests/scripts/recursion.pl library/*.c
 }
 
 component_check_generated_files () {
     msg "Check: freshness of generated source files" # < 1s
-    record_status tests/scripts/check-generated-files.sh
+    tests/scripts/check-generated-files.sh
 }
 
 component_check_doxy_blocks () {
     msg "Check: doxygen markup outside doxygen blocks" # < 1s
-    record_status tests/scripts/check-doxy-blocks.pl
+    tests/scripts/check-doxy-blocks.pl
 }
 
 component_check_files () {
     msg "Check: file sanity checks (permissions, encodings)" # < 1s
-    record_status tests/scripts/check_files.py
+    tests/scripts/check_files.py
 }
 
 component_check_changelog () {
     msg "Check: changelog entries" # < 1s
     rm -f ChangeLog.new
-    record_status scripts/assemble_changelog.py -o ChangeLog.new
+    scripts/assemble_changelog.py -o ChangeLog.new
     if [ -e ChangeLog.new ]; then
         # Show the diff for information. It isn't an error if the diff is
         # non-empty.
@@ -718,7 +817,7 @@
 
 component_check_names () {
     msg "Check: declared and exported names (builds the library)" # < 3s
-    record_status tests/scripts/check_names.py -v
+    tests/scripts/check_names.py -v
 }
 
 component_check_test_cases () {
@@ -728,13 +827,13 @@
     else
         opt=''
     fi
-    record_status tests/scripts/check_test_cases.py $opt
+    tests/scripts/check_test_cases.py $opt
     unset opt
 }
 
 component_check_doxygen_warnings () {
     msg "Check: doxygen warnings (builds the documentation)" # ~ 3s
-    record_status tests/scripts/doxygen.sh
+    tests/scripts/doxygen.sh
 }
 
 
@@ -754,7 +853,7 @@
     make test
 
     msg "selftest: make, default config (out-of-box)" # ~10s
-    if_build_succeeded programs/test/selftest
+    programs/test/selftest
 
     export MBEDTLS_TEST_OUTCOME_FILE="$SAVE_MBEDTLS_TEST_OUTCOME_FILE"
     unset SAVE_MBEDTLS_TEST_OUTCOME_FILE
@@ -769,16 +868,16 @@
     make test
 
     msg "test: selftest (ASan build)" # ~ 10s
-    if_build_succeeded programs/test/selftest
+    programs/test/selftest
 
     msg "test: ssl-opt.sh (ASan build)" # ~ 1 min
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 
     msg "test: compat.sh (ASan build)" # ~ 6 min
-    if_build_succeeded tests/compat.sh
+    tests/compat.sh
 
     msg "test: context-info.sh (ASan build)" # ~ 15 sec
-    if_build_succeeded tests/context-info.sh
+    tests/context-info.sh
 }
 
 component_test_full_cmake_gcc_asan () {
@@ -791,16 +890,16 @@
     make test
 
     msg "test: selftest (ASan build)" # ~ 10s
-    if_build_succeeded programs/test/selftest
+    programs/test/selftest
 
     msg "test: ssl-opt.sh (full config, ASan build)"
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 
     msg "test: compat.sh (full config, ASan build)"
-    if_build_succeeded tests/compat.sh
+    tests/compat.sh
 
     msg "test: context-info.sh (full config, ASan build)" # ~ 15 sec
-    if_build_succeeded tests/context-info.sh
+    tests/context-info.sh
 }
 
 component_test_psa_crypto_key_id_encodes_owner () {
@@ -838,7 +937,7 @@
     # Check that if a symbol is renamed by crypto_spe.h, the non-renamed
     # version is not present.
     echo "Checking for renamed symbols in the library"
-    if_build_succeeded check_renamed_symbols tests/include/spe/crypto_spe.h library/libmbedcrypto.a
+    check_renamed_symbols tests/include/spe/crypto_spe.h library/libmbedcrypto.a
 }
 
 component_test_psa_crypto_client () {
@@ -861,7 +960,7 @@
     make test
 
     msg "test: ssl-opt.sh (zlib, make)"
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 }
 support_test_zlib_make () {
     base=support_test_zlib_$$
@@ -885,7 +984,7 @@
     make test
 
     msg "test: ssl-opt.sh (zlib, cmake)"
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 }
 support_test_zlib_cmake () {
     support_test_zlib_make "$@"
@@ -903,7 +1002,7 @@
 component_test_ref_configs () {
     msg "test/build: ref-configs (ASan build)" # ~ 6 min 20s
     CC=gcc cmake -D CMAKE_BUILD_TYPE:String=Asan .
-    record_status tests/scripts/test-ref-configs.pl
+    tests/scripts/test-ref-configs.pl
 }
 
 component_test_sslv3 () {
@@ -916,14 +1015,14 @@
     make test
 
     msg "build: SSLv3 - compat.sh (ASan build)" # ~ 6 min
-    if_build_succeeded tests/compat.sh -m 'tls1 tls1_1 tls1_2 dtls1 dtls1_2'
-    if_build_succeeded env OPENSSL_CMD="$OPENSSL_LEGACY" tests/compat.sh -m 'ssl3'
+    tests/compat.sh -m 'tls1 tls1_1 tls1_2 dtls1 dtls1_2'
+    env OPENSSL_CMD="$OPENSSL_LEGACY" tests/compat.sh -m 'ssl3'
 
     msg "build: SSLv3 - ssl-opt.sh (ASan build)" # ~ 6 min
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 
     msg "build: SSLv3 - context-info.sh (ASan build)" # ~ 15 sec
-    if_build_succeeded tests/context-info.sh
+    tests/context-info.sh
 }
 
 component_test_no_renegotiation () {
@@ -936,7 +1035,7 @@
     make test
 
     msg "test: !MBEDTLS_SSL_RENEGOTIATION - ssl-opt.sh (ASan build)" # ~ 6 min
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 }
 
 component_test_no_pem_no_fs () {
@@ -952,7 +1051,7 @@
     make test
 
     msg "test: !MBEDTLS_PEM_PARSE_C !MBEDTLS_FS_IO - ssl-opt.sh (ASan build)" # ~ 6 min
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 }
 
 component_test_rsa_no_crt () {
@@ -965,13 +1064,13 @@
     make test
 
     msg "test: RSA_NO_CRT - RSA-related part of ssl-opt.sh (ASan build)" # ~ 5s
-    if_build_succeeded tests/ssl-opt.sh -f RSA
+    tests/ssl-opt.sh -f RSA
 
     msg "test: RSA_NO_CRT - RSA-related part of compat.sh (ASan build)" # ~ 3 min
-    if_build_succeeded tests/compat.sh -t RSA
+    tests/compat.sh -t RSA
 
     msg "test: RSA_NO_CRT - RSA-related part of context-info.sh (ASan build)" # ~ 15 sec
-    if_build_succeeded tests/context-info.sh
+    tests/context-info.sh
 }
 
 component_test_no_ctr_drbg_classic () {
@@ -990,10 +1089,10 @@
     # The SSL tests are slow, so run a small subset, just enough to get
     # confidence that the SSL code copes with HMAC_DRBG.
     msg "test: Full minus CTR_DRBG, classic crypto - ssl-opt.sh (subset)"
-    if_build_succeeded tests/ssl-opt.sh -f 'Default\|SSL async private.*delay=\|tickets enabled on server'
+    tests/ssl-opt.sh -f 'Default\|SSL async private.*delay=\|tickets enabled on server'
 
     msg "test: Full minus CTR_DRBG, classic crypto - compat.sh (subset)"
-    if_build_succeeded tests/compat.sh -m tls1_2 -t 'ECDSA PSK' -V NO -p OpenSSL
+    tests/compat.sh -m tls1_2 -t 'ECDSA PSK' -V NO -p OpenSSL
 }
 
 component_test_no_ctr_drbg_use_psa () {
@@ -1012,10 +1111,10 @@
     # The SSL tests are slow, so run a small subset, just enough to get
     # confidence that the SSL code copes with HMAC_DRBG.
     msg "test: Full minus CTR_DRBG, USE_PSA_CRYPTO - ssl-opt.sh (subset)"
-    if_build_succeeded tests/ssl-opt.sh -f 'Default\|SSL async private.*delay=\|tickets enabled on server'
+    tests/ssl-opt.sh -f 'Default\|SSL async private.*delay=\|tickets enabled on server'
 
     msg "test: Full minus CTR_DRBG, USE_PSA_CRYPTO - compat.sh (subset)"
-    if_build_succeeded tests/compat.sh -m tls1_2 -t 'ECDSA PSK' -V NO -p OpenSSL
+    tests/compat.sh -m tls1_2 -t 'ECDSA PSK' -V NO -p OpenSSL
 }
 
 component_test_no_hmac_drbg_classic () {
@@ -1037,12 +1136,12 @@
     # Test SSL with non-deterministic ECDSA. Only test features that
     # might be affected by how ECDSA signature is performed.
     msg "test: Full minus HMAC_DRBG, classic crypto - ssl-opt.sh (subset)"
-    if_build_succeeded tests/ssl-opt.sh -f 'Default\|SSL async private: sign'
+    tests/ssl-opt.sh -f 'Default\|SSL async private: sign'
 
     # To save time, only test one protocol version, since this part of
     # the protocol is identical in (D)TLS up to 1.2.
     msg "test: Full minus HMAC_DRBG, classic crypto - compat.sh (ECDSA)"
-    if_build_succeeded tests/compat.sh -m tls1_2 -t 'ECDSA'
+    tests/compat.sh -m tls1_2 -t 'ECDSA'
 }
 
 component_test_no_hmac_drbg_use_psa () {
@@ -1064,12 +1163,12 @@
     # Test SSL with non-deterministic ECDSA. Only test features that
     # might be affected by how ECDSA signature is performed.
     msg "test: Full minus HMAC_DRBG, USE_PSA_CRYPTO - ssl-opt.sh (subset)"
-    if_build_succeeded tests/ssl-opt.sh -f 'Default\|SSL async private: sign'
+    tests/ssl-opt.sh -f 'Default\|SSL async private: sign'
 
     # To save time, only test one protocol version, since this part of
     # the protocol is identical in (D)TLS up to 1.2.
     msg "test: Full minus HMAC_DRBG, USE_PSA_CRYPTO - compat.sh (ECDSA)"
-    if_build_succeeded tests/compat.sh -m tls1_2 -t 'ECDSA'
+    tests/compat.sh -m tls1_2 -t 'ECDSA'
 }
 
 component_test_psa_external_rng_no_drbg_classic () {
@@ -1093,7 +1192,7 @@
     make test
 
     msg "test: PSA_CRYPTO_EXTERNAL_RNG minus *_DRBG, classic crypto - ssl-opt.sh (subset)"
-    if_build_succeeded tests/ssl-opt.sh -f 'Default'
+    tests/ssl-opt.sh -f 'Default'
 }
 
 component_test_psa_external_rng_no_drbg_use_psa () {
@@ -1113,7 +1212,7 @@
     make test
 
     msg "test: PSA_CRYPTO_EXTERNAL_RNG minus *_DRBG, PSA crypto - ssl-opt.sh (subset)"
-    if_build_succeeded tests/ssl-opt.sh -f 'Default\|opaque'
+    tests/ssl-opt.sh -f 'Default\|opaque'
 }
 
 component_test_psa_external_rng_use_psa_crypto () {
@@ -1128,7 +1227,7 @@
     make test
 
     msg "test: full + PSA_CRYPTO_EXTERNAL_RNG + USE_PSA_CRYPTO minus CTR_DRBG"
-    if_build_succeeded tests/ssl-opt.sh -f 'Default\|opaque'
+    tests/ssl-opt.sh -f 'Default\|opaque'
 }
 
 component_test_ecp_no_internal_rng () {
@@ -1178,11 +1277,11 @@
     make test
 
     msg "test: new ECDH context - ECDH-related part of ssl-opt.sh (ASan build)" # ~ 5s
-    if_build_succeeded tests/ssl-opt.sh -f ECDH
+    tests/ssl-opt.sh -f ECDH
 
     msg "test: new ECDH context - compat.sh with some ECDH ciphersuites (ASan build)" # ~ 3 min
     # Exclude some symmetric ciphers that are redundant here to gain time.
-    if_build_succeeded tests/compat.sh -f ECDH -V NO -e 'ARCFOUR\|ARIA\|CAMELLIA\|CHACHA\|DES\|RC4'
+    tests/compat.sh -f ECDH -V NO -e 'ARCFOUR\|ARIA\|CAMELLIA\|CHACHA\|DES\|RC4'
 }
 
 component_test_everest () {
@@ -1196,11 +1295,11 @@
     make test
 
     msg "test: Everest ECDH context - ECDH-related part of ssl-opt.sh (ASan build)" # ~ 5s
-    if_build_succeeded tests/ssl-opt.sh -f ECDH
+    tests/ssl-opt.sh -f ECDH
 
     msg "test: Everest ECDH context - compat.sh with some ECDH ciphersuites (ASan build)" # ~ 3 min
     # Exclude some symmetric ciphers that are redundant here to gain time.
-    if_build_succeeded tests/compat.sh -f ECDH -V NO -e 'ARCFOUR\|ARIA\|CAMELLIA\|CHACHA\|DES\|RC4'
+    tests/compat.sh -f ECDH -V NO -e 'ARCFOUR\|ARIA\|CAMELLIA\|CHACHA\|DES\|RC4'
 }
 
 component_test_everest_curve25519_only () {
@@ -1230,7 +1329,7 @@
     make
 
     msg "test: small SSL_OUT_CONTENT_LEN - ssl-opt.sh MFL and large packet tests"
-    if_build_succeeded tests/ssl-opt.sh -f "Max fragment\|Large packet"
+    tests/ssl-opt.sh -f "Max fragment\|Large packet"
 }
 
 component_test_small_ssl_in_content_len () {
@@ -1241,7 +1340,7 @@
     make
 
     msg "test: small SSL_IN_CONTENT_LEN - ssl-opt.sh MFL tests"
-    if_build_succeeded tests/ssl-opt.sh -f "Max fragment"
+    tests/ssl-opt.sh -f "Max fragment"
 }
 
 component_test_small_ssl_dtls_max_buffering () {
@@ -1251,7 +1350,7 @@
     make
 
     msg "test: small MBEDTLS_SSL_DTLS_MAX_BUFFERING #0 - ssl-opt.sh specific reordering test"
-    if_build_succeeded tests/ssl-opt.sh -f "DTLS reordering: Buffer out-of-order hs msg before reassembling next, free buffered msg"
+    tests/ssl-opt.sh -f "DTLS reordering: Buffer out-of-order hs msg before reassembling next, free buffered msg"
 }
 
 component_test_small_mbedtls_ssl_dtls_max_buffering () {
@@ -1261,15 +1360,15 @@
     make
 
     msg "test: small MBEDTLS_SSL_DTLS_MAX_BUFFERING #1 - ssl-opt.sh specific reordering test"
-    if_build_succeeded tests/ssl-opt.sh -f "DTLS reordering: Buffer encrypted Finished message, drop for fragmented NewSessionTicket"
+    tests/ssl-opt.sh -f "DTLS reordering: Buffer encrypted Finished message, drop for fragmented NewSessionTicket"
 }
 
 component_test_psa_collect_statuses () {
   msg "build+test: psa_collect_statuses" # ~30s
   scripts/config.py full
-  record_status tests/scripts/psa_collect_statuses.py
+  tests/scripts/psa_collect_statuses.py
   # Check that psa_crypto_init() succeeded at least once
-  record_status grep -q '^0:psa_crypto_init:' tests/statuses.log
+  grep -q '^0:psa_crypto_init:' tests/statuses.log
   rm -f tests/statuses.log
 }
 
@@ -1283,16 +1382,16 @@
     make test
 
     msg "test: psa_constant_names (full config, clang)" # ~ 1s
-    record_status tests/scripts/test_psa_constant_names.py
+    tests/scripts/test_psa_constant_names.py
 
     msg "test: ssl-opt.sh default, ECJPAKE, SSL async (full config)" # ~ 1s
-    if_build_succeeded tests/ssl-opt.sh -f 'Default\|ECJPAKE\|SSL async private'
+    tests/ssl-opt.sh -f 'Default\|ECJPAKE\|SSL async private'
 
     msg "test: compat.sh RC4, DES, 3DES & NULL (full config)" # ~ 2 min
-    if_build_succeeded env OPENSSL_CMD="$OPENSSL_LEGACY" GNUTLS_CLI="$GNUTLS_LEGACY_CLI" GNUTLS_SERV="$GNUTLS_LEGACY_SERV" tests/compat.sh -e '^$' -f 'NULL\|DES\|RC4\|ARCFOUR'
+    env OPENSSL_CMD="$OPENSSL_LEGACY" GNUTLS_CLI="$GNUTLS_LEGACY_CLI" GNUTLS_SERV="$GNUTLS_LEGACY_SERV" tests/compat.sh -e '^$' -f 'NULL\|DES\|RC4\|ARCFOUR'
 
     msg "test: compat.sh ARIA + ChachaPoly"
-    if_build_succeeded env OPENSSL_CMD="$OPENSSL_NEXT" tests/compat.sh -e '^$' -f 'ARIA\|CHACHA'
+    env OPENSSL_CMD="$OPENSSL_NEXT" tests/compat.sh -e '^$' -f 'ARIA\|CHACHA'
 }
 
 component_test_memsan_constant_flow () {
@@ -1399,70 +1498,68 @@
   msg "build: make, crypto only"
   scripts/config.py crypto
   make CFLAGS='-O1 -Werror'
-  if_build_succeeded are_empty_libraries library/libmbedx509.* library/libmbedtls.*
+  are_empty_libraries library/libmbedx509.* library/libmbedtls.*
 }
 
 component_build_crypto_full () {
   msg "build: make, crypto only, full config"
   scripts/config.py crypto_full
   make CFLAGS='-O1 -Werror'
-  if_build_succeeded are_empty_libraries library/libmbedx509.* library/libmbedtls.*
+  are_empty_libraries library/libmbedx509.* library/libmbedtls.*
 }
 
 component_build_crypto_baremetal () {
   msg "build: make, crypto only, baremetal config"
   scripts/config.py crypto_baremetal
   make CFLAGS='-O1 -Werror'
-  if_build_succeeded are_empty_libraries library/libmbedx509.* library/libmbedtls.*
+  are_empty_libraries library/libmbedx509.* library/libmbedtls.*
 }
 
 component_test_depends_curves () {
     msg "test/build: curves.pl (gcc)" # ~ 4 min
-    record_status tests/scripts/curves.pl
+    tests/scripts/curves.pl
 }
 
 component_test_depends_curves_psa () {
     msg "test/build: curves.pl with MBEDTLS_USE_PSA_CRYPTO defined (gcc)"
     scripts/config.py set MBEDTLS_USE_PSA_CRYPTO
-    record_status tests/scripts/curves.pl
+    tests/scripts/curves.pl
 }
 
 component_test_depends_hashes () {
     msg "test/build: depends-hashes.pl (gcc)" # ~ 2 min
-    record_status tests/scripts/depends-hashes.pl
+    tests/scripts/depends-hashes.pl
 }
 
 component_test_depends_hashes_psa () {
     msg "test/build: depends-hashes.pl with MBEDTLS_USE_PSA_CRYPTO defined (gcc)"
     scripts/config.py set MBEDTLS_USE_PSA_CRYPTO
-    record_status tests/scripts/depends-hashes.pl
+    tests/scripts/depends-hashes.pl
 }
 
 component_test_depends_pkalgs () {
     msg "test/build: depends-pkalgs.pl (gcc)" # ~ 2 min
-    record_status tests/scripts/depends-pkalgs.pl
+    tests/scripts/depends-pkalgs.pl
 }
 
 component_test_depends_pkalgs_psa () {
     msg "test/build: depends-pkalgs.pl with MBEDTLS_USE_PSA_CRYPTO defined (gcc)"
     scripts/config.py set MBEDTLS_USE_PSA_CRYPTO
-    record_status tests/scripts/depends-pkalgs.pl
+    tests/scripts/depends-pkalgs.pl
 }
 
 component_build_key_exchanges () {
     msg "test/build: key-exchanges (gcc)" # ~ 1 min
-    record_status tests/scripts/key-exchanges.pl
+    tests/scripts/key-exchanges.pl
 }
 
-component_build_default_make_gcc_and_cxx () {
-    msg "build: Unix make, -Os (gcc)" # ~ 30s
-    make CC=gcc CFLAGS='-Werror -Wall -Wextra -Os'
+component_test_make_cxx () {
+    msg "build: Unix make, full, gcc + g++"
+    scripts/config.py full
+    make TEST_CPP=1 lib programs
 
-    msg "test: verify header list in cpp_dummy_build.cpp"
-    record_status check_headers_in_cpp
-
-    msg "build: Unix make, incremental g++"
-    make TEST_CPP=1
+    msg "test: cpp_dummy_build"
+    programs/test/cpp_dummy_build
 }
 
 component_test_no_use_psa_crypto_full_cmake_asan() {
@@ -1482,16 +1579,16 @@
     make test
 
     msg "test: ssl-opt.sh (full minus MBEDTLS_USE_PSA_CRYPTO)"
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 
     msg "test: compat.sh default (full minus MBEDTLS_USE_PSA_CRYPTO)"
-    if_build_succeeded tests/compat.sh
+    tests/compat.sh
 
     msg "test: compat.sh RC4, DES & NULL (full minus MBEDTLS_USE_PSA_CRYPTO)"
-    if_build_succeeded env OPENSSL_CMD="$OPENSSL_LEGACY" GNUTLS_CLI="$GNUTLS_LEGACY_CLI" GNUTLS_SERV="$GNUTLS_LEGACY_SERV" tests/compat.sh -e '3DES\|DES-CBC3' -f 'NULL\|DES\|RC4\|ARCFOUR'
+    env OPENSSL_CMD="$OPENSSL_LEGACY" GNUTLS_CLI="$GNUTLS_LEGACY_CLI" GNUTLS_SERV="$GNUTLS_LEGACY_SERV" tests/compat.sh -e '3DES\|DES-CBC3' -f 'NULL\|DES\|RC4\|ARCFOUR'
 
     msg "test: compat.sh ARIA + ChachaPoly (full minus MBEDTLS_USE_PSA_CRYPTO)"
-    if_build_succeeded env OPENSSL_CMD="$OPENSSL_NEXT" tests/compat.sh -e '^$' -f 'ARIA\|CHACHA'
+    env OPENSSL_CMD="$OPENSSL_NEXT" tests/compat.sh -e '^$' -f 'ARIA\|CHACHA'
 }
 
 component_test_psa_crypto_config_basic() {
@@ -2040,7 +2137,7 @@
 
     msg "test: ssl-opt.sh, MBEDTLS_MEMORY_BUFFER_ALLOC_C"
     # MBEDTLS_MEMORY_BUFFER_ALLOC is slow. Skip tests that tend to time out.
-    if_build_succeeded tests/ssl-opt.sh -e '^DTLS proxy'
+    tests/ssl-opt.sh -e '^DTLS proxy'
 }
 
 component_test_no_max_fragment_length () {
@@ -2051,7 +2148,7 @@
     make
 
     msg "test: ssl-opt.sh, MFL-related tests"
-    if_build_succeeded tests/ssl-opt.sh -f "Max fragment length"
+    tests/ssl-opt.sh -f "Max fragment length"
 }
 
 component_test_asan_remove_peer_certificate () {
@@ -2064,13 +2161,13 @@
     make test
 
     msg "test: ssl-opt.sh, !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE"
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 
     msg "test: compat.sh, !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE"
-    if_build_succeeded tests/compat.sh
+    tests/compat.sh
 
     msg "test: context-info.sh, !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE"
-    if_build_succeeded tests/context-info.sh
+    tests/context-info.sh
 }
 
 component_test_no_max_fragment_length_small_ssl_out_content_len () {
@@ -2082,10 +2179,10 @@
     make
 
     msg "test: MFL tests (disabled MFL extension case) & large packet tests"
-    if_build_succeeded tests/ssl-opt.sh -f "Max fragment length\|Large buffer"
+    tests/ssl-opt.sh -f "Max fragment length\|Large buffer"
 
     msg "test: context-info.sh (disabled MFL extension case)"
-    if_build_succeeded tests/context-info.sh
+    tests/context-info.sh
 }
 
 component_test_variable_ssl_in_out_buffer_len () {
@@ -2098,10 +2195,10 @@
     make test
 
     msg "test: ssl-opt.sh, MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH enabled"
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 
     msg "test: compat.sh, MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH enabled"
-    if_build_succeeded tests/compat.sh
+    tests/compat.sh
 }
 
 component_test_variable_ssl_in_out_buffer_len_CID () {
@@ -2116,10 +2213,10 @@
     make test
 
     msg "test: ssl-opt.sh, MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH and MBEDTLS_SSL_DTLS_CONNECTION_ID enabled"
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 
     msg "test: compat.sh, MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH and MBEDTLS_SSL_DTLS_CONNECTION_ID enabled"
-    if_build_succeeded tests/compat.sh
+    tests/compat.sh
 }
 
 component_test_variable_ssl_in_out_buffer_len_record_splitting () {
@@ -2134,10 +2231,10 @@
     make test
 
     msg "test: ssl-opt.sh, MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH and MBEDTLS_SSL_CBC_RECORD_SPLITTING enabled"
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 
     msg "test: compat.sh, MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH and MBEDTLS_SSL_CBC_RECORD_SPLITTING enabled"
-    if_build_succeeded tests/compat.sh
+    tests/compat.sh
 }
 
 component_test_ssl_alloc_buffer_and_mfl () {
@@ -2154,7 +2251,7 @@
     make test
 
     msg "test: MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH, MBEDTLS_MEMORY_BUFFER_ALLOC_C, MBEDTLS_MEMORY_DEBUG and MBEDTLS_SSL_MAX_FRAGMENT_LENGTH"
-    if_build_succeeded tests/ssl-opt.sh -f "Handshake memory usage"
+    tests/ssl-opt.sh -f "Handshake memory usage"
 }
 
 component_test_when_no_ciphersuites_have_mac () {
@@ -2168,7 +2265,7 @@
     make test
 
     msg "test ssl-opt.sh: !MBEDTLS_SSL_SOME_MODES_USE_MAC"
-    if_build_succeeded tests/ssl-opt.sh -f 'Default\|EtM' -e 'without EtM'
+    tests/ssl-opt.sh -f 'Default\|EtM' -e 'without EtM'
 }
 
 component_test_null_entropy () {
@@ -2220,7 +2317,7 @@
     msg "selftest: malloc(0) returns NULL (ASan+UBSan build)"
     # Just the calloc selftest. "make test" ran the others as part of the
     # test suites.
-    if_build_succeeded programs/test/selftest calloc
+    programs/test/selftest calloc
 
     msg "test ssl-opt.sh: malloc(0) returns NULL (ASan+UBSan build)"
     # Run a subset of the tests. The choice is a balance between coverage
@@ -2228,7 +2325,7 @@
     # The current choice is to skip tests whose description includes
     # "proxy", which is an approximation of skipping tests that use the
     # UDP proxy, which tend to be slower and flakier.
-    if_build_succeeded tests/ssl-opt.sh -e 'proxy'
+    tests/ssl-opt.sh -e 'proxy'
 }
 
 component_test_aes_fewer_tables () {
@@ -2396,7 +2493,7 @@
     make test
 
     msg "test ssl-opt.sh, i386, make, gcc-O1"
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 }
 support_test_m32_o1 () {
     support_test_m32_o0 "$@"
@@ -2412,11 +2509,11 @@
     make test
 
     msg "test: i386, Everest ECDH context - ECDH-related part of ssl-opt.sh (ASan build)" # ~ 5s
-    if_build_succeeded tests/ssl-opt.sh -f ECDH
+    tests/ssl-opt.sh -f ECDH
 
     msg "test: i386, Everest ECDH context - compat.sh with some ECDH ciphersuites (ASan build)" # ~ 3 min
     # Exclude some symmetric ciphers that are redundant here to gain time.
-    if_build_succeeded tests/compat.sh -f ECDH -V NO -e 'ARCFOUR\|ARIA\|CAMELLIA\|CHACHA\|DES\|RC4'
+    tests/compat.sh -f ECDH -V NO -e 'ARCFOUR\|ARIA\|CAMELLIA\|CHACHA\|DES\|RC4'
 }
 support_test_m32_everest () {
     support_test_m32_o0 "$@"
@@ -2556,7 +2653,7 @@
     scripts/config.py set MBEDTLS_NO_UDBL_DIVISION
     make CC="${ARM_NONE_EABI_GCC_PREFIX}gcc" AR="${ARM_NONE_EABI_GCC_PREFIX}ar" LD="${ARM_NONE_EABI_GCC_PREFIX}ld" CFLAGS='-std=c99 -Werror -Wall -Wextra' lib
     echo "Checking that software 64-bit division is not required"
-    if_build_succeeded not grep __aeabi_uldiv library/*.o
+    not grep __aeabi_uldiv library/*.o
 }
 
 component_build_arm_none_eabi_gcc_no_64bit_multiplication () {
@@ -2565,7 +2662,7 @@
     scripts/config.py set MBEDTLS_NO_64BIT_MULTIPLICATION
     make CC="${ARM_NONE_EABI_GCC_PREFIX}gcc" AR="${ARM_NONE_EABI_GCC_PREFIX}ar" LD="${ARM_NONE_EABI_GCC_PREFIX}ld" CFLAGS='-std=c99 -Werror -O1 -march=armv6-m -mthumb' lib
     echo "Checking that software 64-bit multiplication is not required"
-    if_build_succeeded not grep __aeabi_lmul library/*.o
+    not grep __aeabi_lmul library/*.o
 }
 
 component_build_armcc () {
@@ -2639,13 +2736,13 @@
     make test
 
     msg "test: ssl-opt.sh (MSan)" # ~ 1 min
-    if_build_succeeded tests/ssl-opt.sh
+    tests/ssl-opt.sh
 
     # Optional part(s)
 
     if [ "$MEMORY" -gt 0 ]; then
         msg "test: compat.sh (MSan)" # ~ 6 min 20s
-        if_build_succeeded tests/compat.sh
+        tests/compat.sh
     fi
 }
 
@@ -2661,17 +2758,17 @@
     # seem to receive signals under valgrind on OS X).
     if [ "$MEMORY" -gt 0 ]; then
         msg "test: ssl-opt.sh --memcheck (Release)"
-        if_build_succeeded tests/ssl-opt.sh --memcheck
+        tests/ssl-opt.sh --memcheck
     fi
 
     if [ "$MEMORY" -gt 1 ]; then
         msg "test: compat.sh --memcheck (Release)"
-        if_build_succeeded tests/compat.sh --memcheck
+        tests/compat.sh --memcheck
     fi
 
     if [ "$MEMORY" -gt 0 ]; then
         msg "test: context-info.sh --memcheck (Release)"
-        if_build_succeeded tests/context-info.sh --memcheck
+        tests/context-info.sh --memcheck
     fi
 }
 
@@ -2690,15 +2787,13 @@
     # "No such file or directory", which would indicate that some required
     # file is missing (ssl-opt.sh tolerates the absence of some files so
     # may exit with status 0 but emit errors).
-    if_build_succeeded ./tests/ssl-opt.sh -f 'Fallback SCSV: beginning of list' 2>ssl-opt.err
-    if [ -s ssl-opt.err ]; then
-        cat ssl-opt.err >&2
-        record_status [ ! -s ssl-opt.err ]
-        rm ssl-opt.err
-    fi
+    ./tests/ssl-opt.sh -f 'Fallback SCSV: beginning of list' 2>ssl-opt.err
+    cat ssl-opt.err >&2
+    # If ssl-opt.err is non-empty, record an error and keep going.
+    [ ! -s ssl-opt.err ]
+    rm ssl-opt.err
     cd "$MBEDTLS_ROOT_DIR"
     rm -rf "$OUT_OF_SOURCE_DIR"
-    unset MBEDTLS_ROOT_DIR
 }
 
 component_test_cmake_as_subdirectory () {
@@ -2708,7 +2803,7 @@
     cd programs/test/cmake_subproject
     cmake .
     make
-    if_build_succeeded ./cmake_subproject
+    ./cmake_subproject
 
     cd "$MBEDTLS_ROOT_DIR"
     unset MBEDTLS_ROOT_DIR
@@ -2733,9 +2828,9 @@
         for compiler in clang gcc; do
             msg "test: $compiler $optimization_flag, mbedtls_platform_zeroize()"
             make programs CC="$compiler" DEBUG=1 CFLAGS="$optimization_flag"
-            if_build_succeeded gdb -ex "$gdb_disable_aslr" -x tests/scripts/test_zeroize.gdb -nw -batch -nx 2>&1 | tee test_zeroize.log
-            if_build_succeeded grep "The buffer was correctly zeroized" test_zeroize.log
-            if_build_succeeded not grep -i "error" test_zeroize.log
+            gdb -ex "$gdb_disable_aslr" -x tests/scripts/test_zeroize.gdb -nw -batch -nx 2>&1 | tee test_zeroize.log
+            grep "The buffer was correctly zeroized" test_zeroize.log
+            not grep -i "error" test_zeroize.log
             rm -f test_zeroize.log
             make clean
         done
@@ -2746,7 +2841,7 @@
 
 component_check_python_files () {
     msg "Lint: Python scripts"
-    record_status tests/scripts/check-python-files.sh
+    tests/scripts/check-python-files.sh
 }
 
 component_check_generate_test_code () {
@@ -2754,7 +2849,7 @@
     # unittest writes out mundane stuff like number or tests run on stderr.
     # Our convention is to reserve stderr for actual errors, and write
     # harmless info on stdout so it can be suppress with --quiet.
-    record_status ./tests/scripts/test_generate_test_code.py 2>&1
+    ./tests/scripts/test_generate_test_code.py 2>&1
 }
 
 ################################################################
@@ -2763,7 +2858,7 @@
 
 post_report () {
     msg "Done, cleaning up"
-    cleanup
+    final_cleanup
 
     final_report
 }
@@ -2774,26 +2869,71 @@
 #### Run all the things
 ################################################################
 
+# Function invoked by --error-test to test error reporting.
+pseudo_component_error_test () {
+    msg "Testing error reporting $error_test_i"
+    if [ $KEEP_GOING -ne 0 ]; then
+        echo "Expect three failing commands."
+    fi
+    # If the component doesn't run in a subshell, changing error_test_i to an
+    # invalid integer will cause an error in the loop that runs this function.
+    error_test_i=this_should_not_be_used_since_the_component_runs_in_a_subshell
+    # Expected error: 'grep non_existent /dev/null -> 1'
+    grep non_existent /dev/null
+    # Expected error: '! grep -q . tests/scripts/all.sh -> 1'
+    not grep -q . "$0"
+    # Expected error: 'make unknown_target -> 2'
+    make unknown_target
+    false "this should not be executed"
+}
+
 # Run one component and clean up afterwards.
 run_component () {
-    # Back up the configuration in case the component modifies it.
-    # The cleanup function will restore it.
-    cp -p "$CONFIG_H" "$CONFIG_BAK"
-    cp -p "$CRYPTO_CONFIG_H" "$CRYPTO_CONFIG_BAK"
     current_component="$1"
     export MBEDTLS_TEST_CONFIGURATION="$current_component"
 
     # Unconditionally create a seedfile that's sufficiently long.
     # Do this before each component, because a previous component may
     # have messed it up or shortened it.
-    redirect_err dd if=/dev/urandom of=./tests/seedfile bs=64 count=1
+    local dd_cmd
+    dd_cmd=(dd if=/dev/urandom of=./tests/seedfile bs=64 count=1)
+    case $OSTYPE in
+        linux*|freebsd*|openbsd*|darwin*) dd_cmd+=(status=none)
+    esac
+    "${dd_cmd[@]}"
 
-    # Run the component code.
-    if [ $QUIET -eq 1 ]; then
-        # msg() is silenced, so just print the component name here
-        echo "${current_component#component_}"
+    # Run the component in a subshell, with error trapping and output
+    # redirection set up based on the relevant options.
+    if [ $KEEP_GOING -eq 1 ]; then
+        # We want to keep running if the subshell fails, so 'set -e' must
+        # be off when the subshell runs.
+        set +e
     fi
-    redirect_out "$@"
+    (
+        if [ $QUIET -eq 1 ]; then
+            # msg() will be silenced, so just print the component name here.
+            echo "${current_component#component_}"
+            exec >/dev/null
+        fi
+        if [ $KEEP_GOING -eq 1 ]; then
+            # Keep "set -e" off, and run an ERR trap instead to record failures.
+            set -E
+            trap err_trap ERR
+        fi
+        # The next line is what runs the component
+        "$@"
+        if [ $KEEP_GOING -eq 1 ]; then
+            trap - ERR
+            exit $last_failure_status
+        fi
+    )
+    component_status=$?
+    if [ $KEEP_GOING -eq 1 ]; then
+        set -e
+        if [ $component_status -ne 0 ]; then
+            failure_count=$((failure_count + 1))
+        fi
+    fi
 
     # Restore the build tree to a clean state.
     cleanup
@@ -2806,22 +2946,23 @@
 pre_parse_command_line "$@"
 
 pre_check_git
+pre_restore_files
+pre_back_up
 
 build_status=0
 if [ $KEEP_GOING -eq 1 ]; then
     pre_setup_keep_going
-else
-    record_status () {
-        "$@"
-    }
 fi
-pre_setup_quiet_redirect
 pre_prepare_outcome_file
 pre_print_configuration
 pre_check_tools
 cleanup
 
 # Run the requested tests.
+for ((error_test_i=1; error_test_i <= error_test; error_test_i++)); do
+    run_component pseudo_component_error_test
+done
+unset error_test_i
 for component in $RUN_COMPONENTS; do
     run_component "component_$component"
 done