From bfe64192a3ca375f581d96857581a4a048572b7a Mon Sep 17 00:00:00 2001
From: Lawrence Kesteloot <lk@teamten.com>
Date: Thu, 2 Aug 2018 16:07:42 -0700
Subject: [PATCH] Parse ld65 map file for symbolic debugging.

---
 apple2e.cpp | 99 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 97 insertions(+), 2 deletions(-)

diff --git a/apple2e.cpp b/apple2e.cpp
index 3145d56..b969f81 100644
--- a/apple2e.cpp
+++ b/apple2e.cpp
@@ -45,6 +45,9 @@ APPLE2Einterface::ModeHistory mode_history;
 
 const float paddle_max_pulse_seconds = .00282;
 
+// Map from memory address to name of function (from the ld65 map file).
+static map<int,string> address_to_function_name;
+
 typedef unsigned long long clk_t;
 struct system_clock
 {
@@ -86,6 +89,73 @@ bool read_blob(char *name, unsigned char *b, size_t sz)
     return true;
 }
 
+/**
+ * Parse a map entry from an ld65 map file and add it to the address_to_function_name map.
+ */
+static void add_map_entry(char *line)
+{
+    // Find end of function name and terminate it.
+    char *s = line;
+    while (*s != ' ') {
+        s++;
+    }
+    *s = '\0';
+    string function_name = string(line);
+
+    // Parse hex address.
+    int address = strtol(line + 26, NULL, 16);
+
+    // See if we have a duplicate. We define our own symbols (like _pushax) as aliases
+    // to cc65-defined ones (like pushax) so we can access them from C.
+    string old_function_name = address_to_function_name[address];
+    if (old_function_name.size() != 0 && old_function_name.size() < function_name.size()) {
+        // Skip this one, we already have one that's shorter (probably without
+        // leading underscore).
+    } else {
+        // Add to map.
+        address_to_function_name[address] = line;
+    }
+}
+
+/**
+ * Read a map file generated by ld65. Puts symbols into the address_to_function_name map.
+ */
+static bool read_map(char *name)
+{
+    char line[100];
+    FILE *fp = fopen(name, "r");
+    int state = 0;
+
+    while (state != 3 && fgets(line, sizeof(line), fp) != NULL) {
+        switch (state) {
+            case 0:
+                if (strncmp(line, "Exports list by name:", 21) == 0) {
+                    // Found header.
+                    state = 1;
+                }
+                break;
+
+            case 1:
+                // Skip line with dashes.
+                state = 2;
+                break;
+
+            case 2:
+                // Parse table.
+                if (strlen(line) <= 76) {
+                    // End of table.
+                    state = 3;
+                }
+                add_map_entry(line);
+                add_map_entry(line + 40);
+                break;
+        }
+    }
+
+    fclose(fp);
+    return true;
+}
+
 struct SoftSwitch
 {
     string name;
@@ -1051,6 +1121,7 @@ struct MAINboard : board_base
                 disassemble_buffer = new unsigned char[data];
                 disassemble_size = data;
                 disassemble_index = 0;
+                printf("Size of buffer: %d bytes\n", disassemble_size);
             }
             return true;
         } else if (addr == 0xBFFF) {
@@ -1063,7 +1134,17 @@ struct MAINboard : board_base
                     string dis;
                     for (int i = 0; i < disassemble_size; i += bytes) {
                         tie(bytes, dis) = disassemble_6502(i, disassemble_buffer + i);
-                        printf("%s\n", dis.c_str());
+                        printf("%-32s", dis.c_str());
+                        if (bytes == 3) {
+                            // Print function name if we have it.
+                            int address = disassemble_buffer[i + 1] +
+                                (disassemble_buffer[i + 2] << 8);
+                            auto search = address_to_function_name.find(address);
+                            if (search != address_to_function_name.end()) {
+                                printf(" ; %s", search->second.c_str());
+                            }
+                        }
+                        printf("\n");
                     }
                     printf("---\n");
                     delete[] disassemble_buffer;
@@ -2695,7 +2776,7 @@ struct CPU6502
 void usage(char *progname)
 {
     printf("\n");
-    printf("usage: %s [-debugger] [-fast] ROM.bin\n", progname);
+    printf("usage: %s [-debugger] [-fast] [-map ld65.map] ROM.bin\n", progname);
     printf("\n");
     printf("\n");
 }
@@ -2933,6 +3014,7 @@ int main(int argc, char **argv)
     argc -= 1;
     argv += 1;
     char *diskII_rom_name = NULL, *floppy1_name = NULL, *floppy2_name = NULL;
+    char *map_name = NULL;
 
     while((argc > 0) && (argv[0][0] == '-')) {
 	if(strcmp(argv[0], "-debugger") == 0) {
@@ -2965,6 +3047,14 @@ int main(int argc, char **argv)
             }
             argv += 2;
             argc -= 2;
+	} else if(strcmp(argv[0], "-map") == 0) {
+            if(argc < 2) {
+                fprintf(stderr, "-map option requires an ld65 map filename.\n");
+                exit(EXIT_FAILURE);
+            }
+            map_name = argv[1];
+            argv += 2;
+            argc -= 2;
         } else if(
             (strcmp(argv[0], "-help") == 0) ||
             (strcmp(argv[0], "-h") == 0) ||
@@ -2996,6 +3086,11 @@ int main(int argc, char **argv)
             exit(EXIT_FAILURE);
     }
 
+    if(map_name != NULL) {
+        if(!read_map(map_name))
+            exit(EXIT_FAILURE);
+    }
+
     system_clock clk;
 
     MAINboard* mainboard;