newlib: Override __assert and __assert_func

Default assert implementation calls fiprintf, which tries to acquire a
lock and fails if it is executing in critical section or ISR

components/newlib/assert.c

@@ -0,0 +1,97 @@
+// Copyright 2021 Espressif Systems (Shanghai) PTE LTD
+//
+// 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 <string.h>
+#include <sys/param.h>
+#include "esp_system.h"
+#include "esp_spi_flash.h"
+#include "soc/soc_memory_layout.h"
+
+#define ASSERT_STR              "assert failed: "
+#define CACHE_DISABLED_STR      "<cached disabled>"
+
+#if __XTENSA__
+#define INST_LEN         3
+#elif __riscv
+#define INST_LEN         4
+#endif
+
+static inline void ra_to_str(char *addr)
+{
+    addr[0] = '0';
+    addr[1] = 'x';
+    itoa((uint32_t)(__builtin_return_address(0) - INST_LEN), addr + 2, 16);
+}
+
+/* Overriding assert function so that whenever assert is called from critical section,
+ * it does not lead to a crash of its own.
+ */
+void __attribute__((noreturn)) __assert_func(const char *file, int line, const char *func, const char *expr)
+{
+#if CONFIG_COMPILER_OPTIMIZATION_ASSERTIONS_SILENT
+    char buff[sizeof(ASSERT_STR) + 11 + 1] = ASSERT_STR;
+
+    ra_to_str(&buff[sizeof(ASSERT_STR) - 1]);
+
+    esp_system_abort(buff);
+#else
+    char addr[11] = { 0 };
+    char buff[200];
+    char lbuf[5];
+    uint32_t rem_len = sizeof(buff) - 1;
+    uint32_t off = 0;
+
+    itoa(line, lbuf, 10);
+
+    if (!spi_flash_cache_enabled()) {
+       if (esp_ptr_in_drom(file)) {
+           file = CACHE_DISABLED_STR;
+       }
+
+       if (esp_ptr_in_drom(func)) {
+           ra_to_str(addr);
+           func = addr;
+       }
+
+       if (esp_ptr_in_drom(expr)) {
+           expr = CACHE_DISABLED_STR;
+       }
+    }
+
+    const char *str[] = {ASSERT_STR, func ? func : "\b", " ", file, ":", lbuf, " (", expr, ")"};
+
+    for (int i = 0; i < sizeof(str) / sizeof(str[0]); i++) {
+        uint32_t len = strlen(str[i]);
+        uint32_t cpy_len = MIN(len, rem_len);
+        memcpy(buff + off, str[i], cpy_len);
+        rem_len -= cpy_len;
+        off += cpy_len;
+        if (rem_len == 0) {
+            break;
+        }
+    }
+    buff[off] = '\0';
+    esp_system_abort(buff);
+#endif  /* CONFIG_COMPILER_OPTIMIZATION_ASSERTIONS_SILENT */
+}
+
+void __attribute__((noreturn)) __assert(const char *file, int line, const char *failedexpr)
+{
+    __assert_func(file, line, NULL, failedexpr);
+}
+
+/* No-op function, used to force linker to include these changes */
+void newlib_include_assert_impl(void)
+{
+}