feat(ftrace): implement ftrace

Author: EmbroiderSnow

Makefile

@@ -25,6 +25,14 @@ itrace:
 	@echo "-------Start Debugging-------"
 	@$(SIM) $(T) --itrace
 
+ftrace: 
+	@echo "-------Build Simulator-------"
+	@$(MAKE) -C sim
+	@echo "-------Build Test-------"
+	@$(MAKE) -C test T=$(T)
+	@echo "-------Start Debugging-------"
+	@$(SIM) $(T) --ftrace
+
 unit_test:
 	@echo "------- Building and Running Simulator Unit Tests -------"
 	@$(MAKE) -C sim unit_test

sim/include/ftrace.h

@@ -20,7 +20,7 @@ void add_func_symbol(SymbolTable *table, uint64_t addr, const char *name);
 
 void sort_symbols_by_address(SymbolTable *table);
 
-const char* find_func_name(SymbolTable *table, uint64_t addr);
+const FuncSymbol* find_func(SymbolTable *table, uint64_t addr);
 
 void free_symbol_table(SymbolTable *table);
 

sim/src/cpu.c

@@ -2,9 +2,14 @@
 #include <decode.h>
 #include <memory.h>
 #include <disasm.h>
+#include "ftrace.h"
 
 extern int itrace_enabled;
+extern int ftrace_enabled;
+extern SymbolTable *sym_table;
 extern LLVMDisasmContextRef disasm_ctx;
+
+int indentaton_level = 0;
 CPU_state cpu = {};
 static int running = 1;
 
@@ -14,7 +19,29 @@ void init_cpu(){
     memset(cpu.csr, 0, sizeof(cpu.csr));
 }
 
- 
+static int is_call(uint32_t inst) {
+    uint32_t opcode = inst & 0x7f;
+    uint32_t rd = (inst >> 7) & 0x1f;
+    if (opcode == 0x6f && rd == 1) { // JAL && rd == x1 (ra)
+        return 1;
+    }
+    if (opcode == 0x67 && rd == 1) { // JALR && rd == x1 (ra)
+        return 1;
+    }
+    return 0;
+}
+
+static int is_ret(uint32_t inst) {
+    uint32_t opcode = inst & 0x7f;
+    uint32_t rs1 = (inst >> 15) & 0x1f;
+    uint32_t rd = (inst >> 7) & 0x1f;
+    uint32_t imm = (inst >> 20) & 0xfff; 
+    if (opcode == 0x67 && rs1 == 1 && rd == 0 && imm == 0) { // JALR x0, 0(x1)
+        return 1;
+    }
+    return 0;
+}
+
 void exec_once(){
     Decode s;
     s.pc   = cpu.pc;
@@ -30,6 +57,29 @@ void exec_once(){
         disassemble_inst(disasm_ctx, bytes, 4, s.pc, asm_buf, sizeof(asm_buf));
         printf("\33[1;34m0x%016lx\33[1;0m: %08x          %s\n", s.pc, s.inst, asm_buf);
     }
+    if (ftrace_enabled) {
+        if (is_call(s.inst)) {
+            const FuncSymbol *func_symbol = find_func(sym_table, s.pc);
+            const char *func_name = func_symbol ? func_symbol->name : "unknown_function";
+            const uint64_t func_addr = func_symbol ? func_symbol->address : 0;
+            printf("\33[1;34m0x%08lx\33[1;0m: ", s.pc);
+            for (int i = 0; i < indentaton_level; i++) {
+                printf("  ");
+            }
+            printf("call [%s@%08lx]\n", func_name, func_addr);
+            indentaton_level++;
+        } else if (is_ret(s.inst)) {
+            indentaton_level--;
+            if (indentaton_level < 0) indentaton_level = 0;
+            const FuncSymbol *func_symbol = find_func(sym_table, s.pc);
+            const char *func_name = func_symbol ? func_symbol->name : "unknown_function";
+            printf("\33[1;34m0x%08lx\33[1;0m: ", s.pc);
+            for (int i = 0; i < indentaton_level; i++) {
+                printf("  ");
+            }
+            printf("ret  [%s]\n", func_name);
+        }
+    }
     decode_exec(&s);
     cpu.pc = s.dnpc;
 }

sim/src/ftrace.c

@@ -48,8 +48,8 @@ void sort_symbols_by_address(SymbolTable *table) {
     qsort(table->symbols, table->count, sizeof(FuncSymbol), compare_symbols);
 }
 
-const char* find_func_name(SymbolTable *table, uint64_t addr) {
-    if (!table || table->count == 0) return "unknown_function";
+const FuncSymbol* find_func(SymbolTable *table, uint64_t addr) {
+    if (!table || table->count == 0) return NULL;
 
     int low = 0, high = table->count - 1;
     int best_match_idx = -1;
@@ -65,10 +65,10 @@ const char* find_func_name(SymbolTable *table, uint64_t addr) {
     }
 
     if (best_match_idx != -1) {
-        return table->symbols[best_match_idx].name;
+        return &(table->symbols[best_match_idx]);
     }
 
-    return "unknown_function";
+    return NULL;
 }
 
 

sim/src/main.c

@@ -6,8 +6,9 @@
 
 uint8_t *mem = NULL;
 int itrace_enabled = 0;
-LLVMDisasmContextRef disasm_ctx;
+int ftrace_enabled = 0;
 SymbolTable *sym_table = NULL;
+LLVMDisasmContextRef disasm_ctx;
 
 const char *help_string = "Usage: Simulator <img_file> [-d|-b]\n"
                                   "Options:\n"
@@ -40,6 +41,10 @@ int main(int argc, char *argv[]){
         init_llvm_disassembler();
         cpu_exec();
     }
+    else if (argc > 2 && strcmp(argv[2], "--ftrace") == 0) {
+        ftrace_enabled = 1;
+        cpu_exec();
+    }
     else {
         printf("%s", help_string);
         exit(0);

sim/src/memory.c

@@ -1,6 +1,7 @@
 #include <common.h>
 #include <gelf.h>
 #include <fcntl.h>
+#include <unistd.h>
 #include "ftrace.h"
 
 extern uint8_t* mem;