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lib/mem.c

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+#include "debug_config.h"
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include "mem.h"
+
+#ifndef BOUNDARY_CHECK_SIZE
+#define BOUNDARY_CHECK_SIZE 256
+#endif
+
+#define CANARY 0xDEADBEEF
+#define PADDING_FILL 0xAA
+#define METADATA_SIZE 128
+#define POINTER_SIZE sizeof(void*)
+#define LOCATION_MAX (METADATA_SIZE - POINTER_SIZE)
+#define NEXT_OFFSET LOCATION_MAX
+
+#if defined(__linux__) || defined(__APPLE__)
+#include <execinfo.h>
+#include <pthread.h>
+#define BACKTRACE_ENABLED 1
+#elif defined(_WIN32)
+#include <windows.h>
+#include <dbghelp.h>
+#define BACKTRACE_ENABLED 1
+#else
+#define BACKTRACE_ENABLED 0
+#endif
+
+#if defined(__linux__) || defined(__APPLE__)
+static pthread_mutex_t alloc_mutex = PTHREAD_MUTEX_INITIALIZER;
+#define LOCK() pthread_mutex_lock(&alloc_mutex)
+#define UNLOCK() pthread_mutex_unlock(&alloc_mutex)
+#elif defined(_WIN32)
+static CRITICAL_SECTION alloc_mutex;
+static bool mutex_initialized = false;
+static void init_mutex() {
+    if (!mutex_initialized) {
+        InitializeCriticalSection(&alloc_mutex);
+        mutex_initialized = true;
+    }
+}
+#define LOCK() init_mutex(); EnterCriticalSection(&alloc_mutex)
+#define UNLOCK() LeaveCriticalSection(&alloc_mutex)
+#else
+#error "Unsupported platform for thread safety"
+#endif
+
+static void* allocated_head = NULL;
+static size_t allocated_count = 0;
+
+static void hex_dump(const void* mem, size_t len) {
+    const uint8_t* data = (const uint8_t*)mem;
+    for (size_t i = 0; i < len; i += 16) {
+        printf("%08zx: ", i);
+        for (size_t j = 0; j < 16; j++) {
+            if (i + j < len) {
+                printf("%02x ", data[i + j]);
+            } else {
+                printf("   ");
+            }
+        }
+        printf("  ");
+        for (size_t j = 0; j < 16; j++) {
+            if (i + j < len) {
+                uint8_t c = data[i + j];
+                printf("%c", (c >= 32 && c <= 126) ? c : '.');
+            } else {
+                printf(" ");
+            }
+        }
+        printf("\n");
+    }
+}
+
+void u_check(void* ptr, const char* text, const char* location) {
+    if (!ptr) return;
+    uint8_t* base = (uint8_t*)ptr - 8 - BOUNDARY_CHECK_SIZE - METADATA_SIZE;
+    char* alloc_loc = (char*)base;
+    uint8_t* prefix_start = base + METADATA_SIZE;
+    uint32_t* pre_canary = (uint32_t*)(prefix_start + BOUNDARY_CHECK_SIZE);
+    uint32_t size = *(uint32_t*)(prefix_start + BOUNDARY_CHECK_SIZE + 4);
+    uint32_t total = size + 12 + 2 * BOUNDARY_CHECK_SIZE + METADATA_SIZE;
+    uint8_t* user = (uint8_t*)ptr;
+    bool error = false;
+    for (size_t i = 0; i < BOUNDARY_CHECK_SIZE; i++) {
+        if (prefix_start[i] != PADDING_FILL) {
+            printf("%s: %s: underflow prefix corrupted at %p, byte %zu (expected 0x%02X, got 0x%02X)\n", location, text, ptr, i, PADDING_FILL, prefix_start[i]);
+            DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, "%s: %s: underflow prefix corrupted at %p, byte %zu (expected 0x%02X, got 0x%02X)\n", location, text, ptr, i, PADDING_FILL, prefix_start[i]);
+            error = true;
+        }
+    }
+    if (*pre_canary != CANARY) {
+        printf("%s: %s: underflow canary corrupted at %p (expected 0x%X, got 0x%X)\n", location, text, ptr, CANARY, *pre_canary);
+        DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, "%s: %s: underflow canary corrupted at %p (expected 0x%X, got 0x%X)\n", location, text, ptr, CANARY, *pre_canary);
+        error = true;
+    }
+    uint8_t* post_start = user + size + 4;
+    for (size_t i = 0; i < BOUNDARY_CHECK_SIZE; i++) {
+        if (post_start[i] != PADDING_FILL) {
+            printf("%s: %s: overflow prefix corrupted at %p, byte %zu (expected 0x%02X, got 0x%02X)\n", location, text, ptr, i, PADDING_FILL, post_start[i]);
+            DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, "%s: %s: overflow prefix corrupted at %p, byte %zu (expected 0x%02X, got 0x%02X)\n", location, text, ptr, i, PADDING_FILL, post_start[i]);
+            error = true;
+        }
+    }
+    uint32_t* post_canary = (uint32_t*)(user + size);
+    if (*post_canary != CANARY) {
+        printf("%s: %s: overflow canary corrupted at %p (expected 0x%X, got 0x%X)\n", location, text, ptr, CANARY, *post_canary);
+        DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, "%s: %s: overflow canary corrupted at %p (expected 0x%X, got 0x%X)\n", location, text, ptr, CANARY, *post_canary);
+        error = true;
+    }
+    if (error) {
+        printf("%s: %s: Allocated at: %s\n", location, text, alloc_loc);
+        printf("%s: %s: Memory block size (user): %u bytes, total allocated: %u bytes\n", location, text, size, total);
+        printf("%s: %s: Full memory dump at base %p:\n", location, text, base);
+        hex_dump(base, total);
+        exit(EXIT_FAILURE);
+    }
+}
+
+void* u_malloc_impl(uint32_t size, const char* location) {
+    uint32_t total = size + 12 + 2 * BOUNDARY_CHECK_SIZE + METADATA_SIZE;
+    uint8_t* base = (uint8_t*)malloc(total);
+    if (!base && size > 0) return NULL;
+    memset(base, PADDING_FILL, total);
+    // Set metadata
+    size_t loc_len = strlen(location);
+    size_t max_copy = (loc_len >= LOCATION_MAX) ? LOCATION_MAX - 1 : loc_len;
+    memcpy(base, location, max_copy);
+    base[max_copy] = 0;
+    // Set allocation data
+    uint8_t* prefix_start = base + METADATA_SIZE;
+    *(uint32_t*)(prefix_start + BOUNDARY_CHECK_SIZE) = CANARY;
+    *(uint32_t*)(prefix_start + BOUNDARY_CHECK_SIZE + 4) = size;
+    *(uint32_t*)(prefix_start + BOUNDARY_CHECK_SIZE + 8 + size) = CANARY;
+    // Add to list (thread-safe)
+    LOCK();
+    void** next_ptr = (void**)(base + NEXT_OFFSET);
+    *next_ptr = allocated_head;
+    allocated_head = base;
+    allocated_count++;
+    UNLOCK();
+    return prefix_start + BOUNDARY_CHECK_SIZE + 8;
+}
+
+void* u_calloc_impl(uint32_t nmemb, uint32_t size, const char* location) {
+    uint32_t total_size = nmemb * size;
+    void* ptr = u_malloc_impl(total_size, location);
+    if (ptr) memset(ptr, 0, total_size);
+    return ptr;
+}
+
+void* u_realloc_impl(void* ptr, uint32_t size, const char* location) {
+    if (!ptr) return u_malloc_impl(size, location);
+    if (size == 0) {
+        u_free_impl(ptr, location);
+        return NULL;
+    }
+    u_check(ptr, "u_realloc", location);
+    uint8_t* old_base = (uint8_t*)ptr - 8 - BOUNDARY_CHECK_SIZE - METADATA_SIZE;
+    uint32_t old_size = *(uint32_t*)(old_base + METADATA_SIZE + BOUNDARY_CHECK_SIZE + 4);
+    void* new_ptr = u_malloc_impl(size, location);
+    if (!new_ptr) return NULL;
+    uint32_t copy_size = (old_size < size) ? old_size : size;
+    memcpy(new_ptr, ptr, copy_size);
+    u_free_impl(ptr, location);
+    return new_ptr;
+}
+
+void u_free_impl(void* ptr, const char* location) {
+    if (!ptr) return;
+    u_check(ptr, "u_free", location);
+    uint8_t* base = (uint8_t*)ptr - 8 - BOUNDARY_CHECK_SIZE - METADATA_SIZE;
+    // Remove from linked list (thread-safe)
+    LOCK();
+    void* prev = NULL;
+    void* curr = allocated_head;
+    bool found = false;
+    while (curr) {
+        if (curr == base) {
+            if (prev) {
+                *(void**)((uint8_t*)prev + NEXT_OFFSET) = *(void**)((uint8_t*)curr + NEXT_OFFSET);
+            } else {
+                allocated_head = *(void**)((uint8_t*)curr + NEXT_OFFSET);
+            }
+            allocated_count--;
+            found = true;
+            break;
+        }
+        prev = curr;
+        curr = *(void**)((uint8_t*)curr + NEXT_OFFSET);
+    }
+    UNLOCK();
+    if (!found) {
+        printf("%s: u_free: Attempt to free unallocated or already freed pointer %p\n", location, ptr);
+        exit(EXIT_FAILURE);
+    }
+    free(base);
+}
+
+char* u_strdup_impl(const char* s, const char* location) {
+    if (!s) return NULL;
+    size_t len = strlen(s) + 1;
+    char* copy = (char*)u_malloc_impl((uint32_t)len, location);
+    if (copy) memcpy(copy, s, len);
+    return copy;
+}
+
+void u_report_unfreed_blocks(void) {
+    LOCK();
+    size_t count = allocated_count;
+    void* head = allocated_head;
+    UNLOCK();
+    if (count == 0) {
+        printf("No unfreed memory blocks.\n");
+        return;
+    }
+    printf("Unfreed memory blocks: %zu\n", count);
+    void* curr = head;
+    while (curr) {
+        char* alloc_loc = (char*)curr;
+        uint8_t* prefix_start = (uint8_t*)curr + METADATA_SIZE;
+        uint32_t size = *(uint32_t*)(prefix_start + BOUNDARY_CHECK_SIZE + 4);
+        void* user_ptr = prefix_start + BOUNDARY_CHECK_SIZE + 8;
+        u_check(user_ptr, "unfreed_check", "u_report_unfreed_blocks");
+        printf(" - Allocated at: %s, size: %u bytes\n", alloc_loc, size);
+        curr = *(void**)((uint8_t*)curr + NEXT_OFFSET);
+    }
+}