From 9159153caff99062e2a3cd150dc67ddae7cb6b76 Mon Sep 17 00:00:00 2001
From: Rolel <rolel@smile.fr>
Date: Tue, 31 Dec 2024 12:18:41 +0100
Subject: [PATCH] Segfault are often repeated massively. This adds a
 repeat_printf function that will not reprint the line but count them if
 repeated.

---
 src/lindbergh/hook.c | 104 ++++++++++++++++++++++++++++++++++++++++++-
 src/lindbergh/hook.h |   1 +
 2 files changed, 104 insertions(+), 1 deletion(-)

diff --git a/src/lindbergh/hook.c b/src/lindbergh/hook.c
index 84e1d9b..492020f 100644
--- a/src/lindbergh/hook.c
+++ b/src/lindbergh/hook.c
@@ -154,7 +154,7 @@ static void handleSegfault(int signal, siginfo_t *info, void *ptr)
     break;
 
     default:
-        printf("Warning: Skipping SEGFAULT %X\n", *code);
+        repeat_printf("Warning: Skipping SEGFAULT %X\n", *code);
         ctx->uc_mcontext.gregs[REG_EIP]++;
         // abort();
     }
@@ -1027,3 +1027,105 @@ char *__strdup(const char *string)
     }
     return ___strdup(string);
 }
+
+
+/**
+ * @brief Prints formatted text in a way that avoids spamming identical lines.
+ *
+ * This function behaves similarly to printf, but tracks the last printed message.
+ * If the newly formatted string is identical to the last one, the previous console
+ * line is overwritten and a repetition counter "(xN)" is appended instead of
+ * printing a new line.
+ *
+ * @details
+ * Usage:
+ *   1. Call `repeat_printf("Some message");` as you would call printf(...).
+ *   2. If the next call uses the exact same message, the console line updates
+ *      to "... (x2)", then "... (x3)", etc.
+ *   3. If the next call uses a different message, the old message is finalized
+ *      (a newline is printed) and the new message is printed on a fresh line.
+ *   4. Calling `live_printf("")` or `repeat_printf(NULL)` finalizes the current
+ *      message (if any) and resets the internal state.
+ *
+ * If the message ends with a newline ('\n'), the cursor is moved up one line
+ * after printing. This allows consecutive identical lines that end with '\n'
+ * to be updated in place, though note it may be visually confusing if your
+ * terminal is at the top line.
+ *
+ * @param format  A printf-style format string, or NULL. If NULL or an empty
+ *                string results from formatting, the current tracked message
+ *                is finalized (a newline is printed, and the internal state
+ *                is reset).
+ * @param ...     Variadic arguments for the format string.
+ *
+ * @return        (void) No return value.
+ */
+void repeat_printf(const char *format, ...)
+{
+    static char last_msg[256] = {0};
+    static u_int  repeat_count  = 0;
+
+    // If format is NULL, treat it as an empty string to trigger finalization.
+    if (format == NULL) {
+        format = "";
+    }
+
+    // Construct the new message using vsnprintf (like printf).
+    char msg[256];
+    va_list args;
+    va_start(args, format);
+    vsnprintf(msg, sizeof(msg), format, args);
+    va_end(args);
+
+    // If the constructed message is empty, finalize and reset.
+    if (msg[0] == '\0') {
+        if (repeat_count > 0) {
+            // Finalize the previous message with a newline.
+            printf("\n");
+            fflush(stdout);
+        }
+        // Reset tracking variables.
+        last_msg[0]  = '\0';
+        repeat_count = 0;
+        return;
+    }
+
+    // Check if the new message is the same as the last one.
+    if (strcmp(last_msg, msg) == 0) {
+        // Same message => increment counter, overwrite the line.
+        repeat_count++;
+
+        // If the message ends with new line, we go up one line
+        size_t len = strlen(msg);
+        int ends_with_newline = 0;
+        if (len > 0 && msg[len - 1] == '\n') {
+            printf("\033[1A");
+            ends_with_newline = 1;
+            msg[len - 1] = '\0';  // Remove the trailing '\n'
+        }
+        // Move cursor to the start of the line and clear it.
+        printf("\r\033[K");
+        // Print the message with the updated repeat count if > 1
+        if (repeat_count > 1) {
+            printf("%s (x%d)", msg, repeat_count);
+        } else {
+            // If repeat_count == 1, it means the first time for this message
+            // on this call. (Normally we shouldn't enter here with == 1 though.)
+            printf("%s", msg);
+        }
+        if (ends_with_newline) {
+            // Print a newline, then move cursor up one line
+            printf("\n");
+        }
+        fflush(stdout);
+    } else {
+        // Track the new message.
+        strncpy(last_msg, msg, sizeof(last_msg) - 1);
+        last_msg[sizeof(last_msg) - 1] = '\0';
+        repeat_count = 1;
+
+        // Print the new message on a fresh line.
+        printf("%s", msg);
+        fflush(stdout);
+    }
+}
diff --git a/src/lindbergh/hook.h b/src/lindbergh/hook.h
index 903c3dc..8880774 100644
--- a/src/lindbergh/hook.h
+++ b/src/lindbergh/hook.h
@@ -2,3 +2,4 @@
 #include <stddef.h>
 
 uint32_t get_crc32(const char *s, size_t  n);
+void repeat_printf(const char *format, ...);