Implement SIZE_FMT and vec_append_fmt

SIZE_FMT gets the size of a cstr with the given sprintf formatted
string and arguments using `snprintf`.

vec_append_fmt formats a cstr with the given sprintf arguments then
appends it to the given vector.

This simplifies a little bit of the wordy implementation of the
assembler.

1 files changed, 41 insertions, 48 deletions

diff --git a/assembler.c b/assembler.c
index 3c45a7b..cabca41 100644
--- a/assembler.c
+++ b/assembler.c
@@ -72,53 +72,49 @@ void asm_translate_nodes(vec_t *asm_buffer, struct PResult nodes,
   for (size_t i = 0; i < nodes.size; ++i)
   {
     node_t node = nodes.nodes[i];
-    if (node.type == LIN || node.type == LOUT)
+    // Something we can compile with only the information at hand
+    if (!(node.type == LIN || node.type == LOUT))
     {
-      // Translate the node-relative addresses to assembly-label-relative
-      // addresses
-      i64 cur_asm_label = 0, next_asm_label = 0;
-      ast_ref_to_asm_label(i, labels, nodes.labels * 2, &cur_asm_label,
-                           &next_asm_label);
-      if (cur_asm_label == -1 || next_asm_label == -1)
-      {
-        print_error(
-            src_name, node.row, node.col,
-            "[ASSEMBLY ERROR]: Could not find label for current jump!\n");
-        exit(1);
-      }
-
-      // Format labels
-      char current_label[128], next_label[128];
-
-      sprintf(current_label, ".L%lu", cur_asm_label);
-      sprintf(next_label, ".L%lu", next_asm_label);
-
-      // Setup format string for assembly jump code
-      char *format_string = NULL;
-      if (node.type == LIN)
-      {
-        format_string = "%s:\n"
-                        "  cmp byte [r9], 0\n"
-                        "  je %s\n";
-      }
-      else
-      {
-        format_string = "%s:\n"
-                        "  cmp byte [r9], 0\n"
-                        "  jne %s\n";
-      }
-      char formatted_string[snprintf(NULL, 0, format_string, current_label,
-                                     next_label) +
-                            1];
-      snprintf(formatted_string, sizeof(formatted_string), format_string,
-               current_label, next_label);
-      vec_append(asm_buffer, formatted_string, sizeof(formatted_string) - 1);
+      // I love tables so goddamn much
+      vec_append(asm_buffer, table[node.type].str, table[node.type].len);
+      continue;
+    }
+
+    // NOTE: Must be a label
+
+    // Translate the node-relative addresses to assembly-label-relative
+    // addresses
+    i64 cur_asm_label = 0, next_asm_label = 0;
+    ast_ref_to_asm_label(i, labels, nodes.labels * 2, &cur_asm_label,
+                         &next_asm_label);
+    if (cur_asm_label == -1 || next_asm_label == -1)
+    {
+      print_error(src_name, node.row, node.col,
+                  "[ASSEMBLY ERROR]: Could not find label for current jump!\n");
+      exit(1);
+    }
+
+    // Format labels
+    char current_label[128], next_label[128];
+
+    sprintf(current_label, ".L%lu", cur_asm_label);
+    sprintf(next_label, ".L%lu", next_asm_label);
+
+    // Setup format string for assembly jump code
+    char *format_string = NULL;
+    if (node.type == LIN)
+    {
+      format_string = "%s:\n"
+                      "  cmp byte [r9], 0\n"
+                      "  je %s\n";
     }
     else
     {
-      // I love tables so goddamn much
-      vec_append(asm_buffer, table[node.type].str, table[node.type].len);
+      format_string = "%s:\n"
+                      "  cmp byte [r9], 0\n"
+                      "  jne %s\n";
     }
+    vec_append_fmt(asm_buffer, format_string, current_label, next_label);
   }
   asm_write_exit(asm_buffer);
 }
@@ -151,10 +147,7 @@ void asm_write_init(vec_t *asm_buffer)
                                "global _start\n"
                                "_start:\n"
                                "  mov r9, memory\n";
-  char initial_assembly[snprintf(NULL, 0, format_string, MEMORY_DEFAULT) + 1];
-  snprintf(initial_assembly, sizeof(initial_assembly), format_string,
-           MEMORY_DEFAULT);
-  vec_append(asm_buffer, initial_assembly, sizeof(initial_assembly) - 1);
+  vec_append_fmt(asm_buffer, format_string, MEMORY_DEFAULT);
 }
 
 // Write the exit code for the assembly file
@@ -183,7 +176,7 @@ int asm_assemble(const char *asm_name, const char *objname)
 #else
   char *format_str = "yasm -f elf64 -o %s %s";
 #endif
-  char command[snprintf(NULL, 0, format_str, objname, asm_name) + 1];
+  char command[SIZE_FMT(format_str, objname, asm_name) + 1];
   sprintf(command, format_str, objname, asm_name);
   return system(command);
 }
@@ -191,7 +184,7 @@ int asm_assemble(const char *asm_name, const char *objname)
 int asm_link(const char *objname, const char *outname)
 {
   char *format_str = "ld -o %s %s";
-  char command[snprintf(NULL, 0, format_str, outname, objname) + 1];
+  char command[SIZE_FMT(format_str, outname, objname) + 1];
   sprintf(command, format_str, outname, objname);
   return system(command);
 }