Fix integer random functions so they correctly handle all representable

ranges

4 files changed, 28 insertions, 16 deletions

diff --git a/builtins/integers.c b/builtins/integers.c
index ef9b5df4..d50c6573 100644
--- a/builtins/integers.c
+++ b/builtins/integers.c
@@ -51,14 +51,22 @@
         } \
         return bit_array; \
     } \
-    public c_type KindOfInt ## $random(int64_t min, int64_t max) { \
-        if (min > max) fail("Random min (%ld) is larger than max (%ld)", min, max); \
-        if (min < (int64_t)min_val) fail("Random min (%ld) is smaller than the minimum "#KindOfInt" value", min); \
-        if (max > (int64_t)max_val) fail("Random max (%ld) is smaller than the maximum "#KindOfInt" value", max); \
-        int64_t range = max - min; \
-        if (range > UINT32_MAX) fail("Random range (%ld) is larger than the maximum allowed (%ld)", range, UINT32_MAX); \
-        uint32_t r = arc4random_uniform((uint32_t)range); \
-        return min + (c_type)r; \
+    public c_type KindOfInt ## $random(c_type min, c_type max) { \
+        if (min > max) fail("Random minimum value (%ld) is larger than the maximum value (%ld)", min, max); \
+        if (min == max) return min; \
+        if (min == min_val && max == max_val) { \
+            c_type r; \
+            arc4random_buf(&r, sizeof(r)); \
+            return r; \
+        } \
+        uint64_t range = (uint64_t)max - (uint64_t)min + 1; \
+        uint64_t min_r = -range % range; \
+        uint64_t r; \
+        for (;;) { \
+            arc4random_buf(&r, sizeof(r)); \
+            if (r >= min_r) break; \
+        } \
+        return (c_type)((uint64_t)min + (r % range)); \
     } \
     public c_type KindOfInt ## $from_text(CORD text, CORD *the_rest) { \
         const char *str = CORD_to_const_char_star(text); \
diff --git a/builtins/integers.h b/builtins/integers.h
index 2e8f6721..2c638a4a 100644
--- a/builtins/integers.h
+++ b/builtins/integers.h
@@ -27,7 +27,7 @@
     CORD type_name ## $hex(c_type i, int64_t digits, bool uppercase, bool prefix); \
     CORD type_name ## $octal(c_type i, int64_t digits, bool prefix); \
     array_t type_name ## $bits(c_type x); \
-    c_type type_name ## $random(int64_t min, int64_t max); \
+    c_type type_name ## $random(c_type min, c_type max); \
     c_type type_name ## $from_text(CORD text, CORD *the_rest); \
     extern const c_type type_name ## $min, type_name##$max; \
     extern const TypeInfo $ ## type_name;
diff --git a/compile.c b/compile.c
index cd02e1f4..a9e55b9e 100644
--- a/compile.c
+++ b/compile.c
@@ -181,7 +181,11 @@ static CORD compile_lvalue(env_t *env, ast_t *ast)
         } else if (container_t->tag == TableType) {
             CORD target_code = compile_to_pointer_depth(env, index->indexed, 1, false);
             type_t *value_t = Match(container_t, TableType)->value_type;
-            return CORD_all("*(", compile_type(value_t), "*)Table$reserve_value(", target_code, ", ",
+            CORD key = compile(env, index->index);
+            if (!promote(env, &key, get_type(env, index->index), Match(container_t, TableType)->key_type))
+                code_err(index->index, "I couldn't promote this type from %T to %T",
+                         get_type(env, index->index), Match(container_t, TableType)->key_type);
+            return CORD_all("*(", compile_type(value_t), "*)Table$reserve_value(", target_code, ", (", compile_type(Match(container_t, TableType)->key_type), ")",
                             compile(env, index->index),", ", compile_type_info(env, container_t), ")");
         } else {
             code_err(ast, "I don't know how to assign to this target");
@@ -1671,12 +1675,12 @@ CORD compile(env_t *env, ast_t *ast)
     case Table: {
         auto table = Match(ast, Table);
         if (!table->entries) {
-            CORD code = "(table_t){";
+            CORD code = "((table_t){";
             if (table->fallback)
                 code = CORD_all(code, ".fallback=", compile(env, table->fallback),",");
             if (table->default_value)
                 code = CORD_all(code, ".default_value=heap(", compile(env, table->default_value),"),");
-            return CORD_cat(code, "}");
+            return CORD_cat(code, "})");
         }
 
         type_t *table_type = get_type(env, ast);
diff --git a/environment.c b/environment.c
index a5d935f3..c81156c5 100644
--- a/environment.c
+++ b/environment.c
@@ -74,7 +74,7 @@ env_t *new_compilation_unit(CORD *libname)
             {"format", "Int$format", "func(i:Int, digits=0)->Text"},
             {"hex", "Int$hex", "func(i:Int, digits=0, uppercase=yes, prefix=yes)->Text"},
             {"octal", "Int$octal", "func(i:Int, digits=0, prefix=yes)->Text"},
-            {"random", "Int$random", "func(min=0, max=0xffffffff)->Int"},
+            {"random", "Int$random", "func(min=-0x8000000000000000, max=0x7FFFFFFFFFFFFFFF)->Int"},
             {"from_text", "Int$from_text", "func(text:Text, the_rest=!&Text)->Int"},
             {"bits", "Int$bits", "func(x:Int)->[Bool]"},
             {"abs", "labs", "func(i:Int)->Int"},
@@ -85,7 +85,7 @@ env_t *new_compilation_unit(CORD *libname)
             {"format", "Int32$format", "func(i:Int32, digits=0)->Text"},
             {"hex", "Int32$hex", "func(i:Int32, digits=0, uppercase=yes, prefix=yes)->Text"},
             {"octal", "Int32$octal", "func(i:Int32, digits=0, prefix=yes)->Text"},
-            {"random", "Int32$random", "func(min=0, max=0xffffffff)->Int32"},
+            {"random", "Int32$random", "func(min=-0x80000000_i32, max=0x7FFFFFFF_i32)->Int32"},
             {"from_text", "Int$from_text", "func(text:Text, the_rest=!&Text)->Int32"},
             {"bits", "Int32$bits", "func(x:Int32)->[Bool]"},
             {"abs", "abs", "func(i:Int32)->Int32"},
@@ -96,7 +96,7 @@ env_t *new_compilation_unit(CORD *libname)
             {"format", "Int16$format", "func(i:Int16, digits=0)->Text"},
             {"hex", "Int16$hex", "func(i:Int16, digits=0, uppercase=yes, prefix=yes)->Text"},
             {"octal", "Int16$octal", "func(i:Int16, digits=0, prefix=yes)->Text"},
-            {"random", "Int16$random", "func(min=0, max=0xffffffff)->Int16"},
+            {"random", "Int16$random", "func(min=-0x8000_i16, max=0x7FFF_i16)->Int16"},
             {"from_text", "Int$from_text", "func(text:Text, the_rest=!&Text)->Int16"},
             {"bits", "Int16$bits", "func(x:Int16)->[Bool]"},
             {"abs", "abs", "func(i:Int16)->Int16"},
@@ -107,7 +107,7 @@ env_t *new_compilation_unit(CORD *libname)
             {"format", "Int8$format", "func(i:Int8, digits=0)->Text"},
             {"hex", "Int8$hex", "func(i:Int8, digits=0, uppercase=yes, prefix=yes)->Text"},
             {"octal", "Int8$octal", "func(i:Int8, digits=0, prefix=yes)->Text"},
-            {"random", "Int8$random", "func(min=0, max=0xffffffff)->Int8"},
+            {"random", "Int8$random", "func(min=-0x80_i8, max=0x7F_i8)->Int8"},
             {"from_text", "Int$from_text", "func(text:Text, the_rest=!&Text)->Int8"},
             {"bits", "Int8$bits", "func(x:Int8)->[Bool]"},
             {"abs", "abs", "func(i:Int8)->Int8"},