Merge pull request Mbed-TLS#816 from ARMmbed/development

Merge recent commits from development into 2.26.0-rc

CMakeLists.txt

@@ -179,6 +179,9 @@ if(CMAKE_COMPILER_IS_GNU)
     execute_process(COMMAND ${CMAKE_C_COMPILER} -dumpversion
                     OUTPUT_VARIABLE GCC_VERSION)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wwrite-strings")
+    if (GCC_VERSION VERSION_GREATER 3.0 OR GCC_VERSION VERSION_EQUAL 3.0)
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wformat=2 -Wno-format-nonliteral")
+    endif()
     if (GCC_VERSION VERSION_GREATER 4.3 OR GCC_VERSION VERSION_EQUAL 4.3)
         set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wvla")
     endif()
@@ -194,6 +197,9 @@ if(CMAKE_COMPILER_IS_GNU)
             set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wformat-signedness")
         endif()
     endif()
+    if (GCC_VERSION VERSION_GREATER 7.0 OR GCC_VERSION VERSION_EQUAL 7.0)
+      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wformat-overflow=2 -Wformat-truncation=2")
+    endif()
     set(CMAKE_C_FLAGS_RELEASE     "-O2")
     set(CMAKE_C_FLAGS_DEBUG       "-O0 -g3")
     set(CMAKE_C_FLAGS_COVERAGE    "-O0 -g3 --coverage")
@@ -204,7 +210,7 @@ if(CMAKE_COMPILER_IS_GNU)
 endif(CMAKE_COMPILER_IS_GNU)
 
 if(CMAKE_COMPILER_IS_CLANG)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wwrite-strings -Wpointer-arith -Wimplicit-fallthrough -Wshadow -Wvla")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wwrite-strings -Wpointer-arith -Wimplicit-fallthrough -Wshadow -Wvla -Wformat=2 -Wno-format-nonliteral")
     set(CMAKE_C_FLAGS_RELEASE     "-O2")
     set(CMAKE_C_FLAGS_DEBUG       "-O0 -g3")
     set(CMAKE_C_FLAGS_COVERAGE    "-O0 -g3 --coverage")

ChangeLog.d/fix-printf-specifiers.txt

@@ -0,0 +1,10 @@
+Bugfix
+   * Add printf function attributes to mbedtls_debug_print_msg to ensure we
+     get printf format specifier warnings.
+Changes
+   * Add extra printf compiler warning flags to builds.
+Requirement changes
+   * The library now uses the %zu format specifier with the printf() family of
+     functions, so requires a toolchain that supports it. This change does not
+     affect the maintained LTS branches, so when contributing changes please
+     bear this in mind and do not add them to backported code.

ChangeLog.d/fix_memsan_build_clang11.txt

@@ -0,0 +1,2 @@
+Changes
+   * Fix memsan build false positive in x509_crt.c with clang 11

include/mbedtls/debug.h

@@ -80,6 +80,50 @@
 
 #endif /* MBEDTLS_DEBUG_C */
 
+/**
+ * \def MBEDTLS_PRINTF_ATTRIBUTE
+ *
+ * Mark a function as having printf attributes, and thus enable checking
+ * via -wFormat and other flags. This does nothing on builds with compilers
+ * that do not support the format attribute
+ *
+ * Module:  library/debug.c
+ * Caller:
+ *
+ * This module provides debugging functions.
+ */
+#if defined(__has_attribute)
+#if __has_attribute(format)
+#define MBEDTLS_PRINTF_ATTRIBUTE(string_index, first_to_check)    \
+    __attribute__((format (printf, string_index, first_to_check)))
+#else /* __has_attribute(format) */
+#define MBEDTLS_PRINTF_ATTRIBUTE(string_index, first_to_check)
+#endif /* __has_attribute(format) */
+#else /* defined(__has_attribute) */
+#define MBEDTLS_PRINTF_ATTRIBUTE(string_index, first_to_check)
+#endif
+
+/**
+ * \def MBEDTLS_PRINTF_SIZET
+ *
+ * MBEDTLS_PRINTF_xxx: Due to issues with older window compilers
+ * and MinGW we need to define the printf specifier for size_t
+ * and long long per platform.
+ *
+ * Module:  library/debug.c
+ * Caller:
+ *
+ * This module provides debugging functions.
+ */
+#if defined(__MINGW32__) || (defined(_MSC_VER) && _MSC_VER < 1800)
+   #include <inttypes.h>
+   #define MBEDTLS_PRINTF_SIZET     PRIuPTR
+   #define MBEDTLS_PRINTF_LONGLONG  "I64d"
+#else /* defined(__MINGW32__) || (defined(_MSC_VER) && _MSC_VER < 1800) */
+   #define MBEDTLS_PRINTF_SIZET     "zu"
+   #define MBEDTLS_PRINTF_LONGLONG  "lld"
+#endif /* defined(__MINGW32__) || (defined(_MSC_VER) && _MSC_VER < 1800) */
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -118,7 +162,7 @@ void mbedtls_debug_set_threshold( int threshold );
  */
 void mbedtls_debug_print_msg( const mbedtls_ssl_context *ssl, int level,
                               const char *file, int line,
-                              const char *format, ... );
+                              const char *format, ... ) MBEDTLS_PRINTF_ATTRIBUTE(5, 6);
 
 /**
  * \brief   Print the return value of a function to the debug output. This