Use long as implicit type in chibicc

This makes it possible to write 64-bit C without headers and prototypes.

third_party/chibicc/chibicc.c

@@ -689,7 +689,9 @@ static void OnCtrlC(int sig, siginfo_t *si, void *ctx) {
 }
 
 int chibicc(int argc, char **argv) {
+#ifndef NDEBUG
   ShowCrashReports();
+#endif
   atexit(chibicc_cleanup);
   sigaction(SIGINT, &(struct sigaction){.sa_sigaction = OnCtrlC}, NULL);
   for (int i = 1; i < argc; i++) {

third_party/chibicc/parse.c

@@ -22,11 +22,14 @@
 #include "libc/log/log.h"
 #include "libc/mem/mem.h"
 #include "libc/nexgen32e/ffs.h"
+#include "libc/stdio/stdio.h"
 #include "libc/testlib/testlib.h"
 #include "libc/x/xasprintf.h"
 #include "third_party/chibicc/chibicc.h"
 #include "third_party/chibicc/kw.h"
 
+#define IMPLICIT_FUNCTIONS
+
 typedef struct InitDesg InitDesg;
 typedef struct Initializer Initializer;
 typedef struct Scope Scope;
@@ -665,7 +668,7 @@ static Type *declspec(Token **rest, Token *tok, VarAttr *attr) {
     INT128 = 1 << 19,
   };
   unsigned char kw;
-  Type *ty = copy_type(ty_int);
+  Type *ty = copy_type(ty_long);  // [jart] use long as implicit type
   int counter = 0;
   bool is_const = false;
   bool is_atomic = false;
@@ -3508,14 +3511,17 @@ static Node *primary(Token **rest, Token *tok) {
   if (tok->kind == TK_IDENT) {
     // Variable or enum constant
     VarScope *sc = find_var(tok);
-    *rest = tok->next;
-#ifdef IMPLICIT_FUNCTIONS
+    // [jart] support implicit function declarations with `long` type
     if (!sc && EQUAL(tok->next, "(")) {
       Type *ty = func_type(ty_long);
       ty->is_variadic = true;
-      return new_var_node(new_gvar(strndup(tok->loc, tok->len), ty), tok);
+      Obj *fn = new_var(strndup(tok->loc, tok->len), ty);
+      fn->next = globals;
+      fn->is_function = true;
+      globals = fn;
+      sc = find_var(tok);
     }
-#endif
+    *rest = tok->next;
     // For "static inline" function
     if (sc && sc->var && sc->var->is_function) {
       if (current_fn) {

third_party/chibicc/test/implicit_test.c

@@ -0,0 +1,64 @@
+add(x, y) {
+  return x + y;
+}
+
+implicit_functions_are_long() {
+  if (add(0xffffffff, 0xffffffff) != 0x0001fffffffe) {
+    __builtin_trap();
+  }
+}
+
+external_functions_are_long() {
+  if (_bsrl(0x0001000000000000) != 48) {
+    __builtin_trap();
+  }
+}
+
+auto_variables_are_long() {
+  auto x, y, z;
+  x = 0x0101fffffffe;
+  y = 0x0201fffffffe;
+  z = x + y;
+  if (z != 0x0303fffffffc) {
+    __builtin_trap();
+  }
+}
+
+static_variables_are_long() {
+  static x, y, z;
+  x = 0x0101fffffffe;
+  y = 0x0201fffffffe;
+  z = x + y;
+  if (z != 0x0303fffffffc) {
+    __builtin_trap();
+  }
+}
+
+x_ = 0x0101fffffffe;
+y_ = 0x0201fffffffe;
+z_;
+
+globo_variables_are_long() {
+  z_ = x_ + y_;
+  if (z_ != 0x0303fffffffc) {
+    __builtin_trap();
+  }
+}
+
+implicit_function_string() {
+  auto lol = strdup("hello");
+  if (strlen(lol) != 5) {
+    __builtin_trap();
+  }
+  free(lol);
+}
+
+main() {
+  ShowCrashReports();
+  implicit_functions_are_long();
+  external_functions_are_long();
+  auto_variables_are_long();
+  static_variables_are_long();
+  globo_variables_are_long();
+  implicit_function_string();
+}