Fixed conversion warnings from clang

Plus some other details. (Option '-Wuninitialized' was removed from
the makefile because it is already enabled by -Wall.)

lcode.c

@@ -1439,7 +1439,7 @@ static void finishbinexpval (FuncState *fs, expdesc *e1, expdesc *e2,
   e1->u.info = pc;
   e1->k = VRELOC;  /* all those operations are relocatable */
   luaK_fixline(fs, line);
-  luaK_codeABCk(fs, mmop, v1, v2, event, flip);  /* to call metamethod */
+  luaK_codeABCk(fs, mmop, v1, v2, cast_int(event), flip);  /* metamethod */
   luaK_fixline(fs, line);
 }
 

llex.c

@@ -349,9 +349,14 @@ static int readhexaesc (LexState *ls) {
 }
 
 
+/*
+** When reading a UTF-8 escape sequence, save everything to the buffer
+** for error reporting in case of errors; 'i' counts the number of
+** saved characters, so that they can be removed if case of success.
+*/
 static unsigned long readutf8esc (LexState *ls) {
   unsigned long r;
-  int i = 4;  /* chars to be removed: '\', 'u', '{', and first digit */
+  int i = 4;  /* number of chars to be removed: start with #"\u{X" */
   save_and_next(ls);  /* skip 'u' */
   esccheck(ls, ls->current == '{', "missing '{'");
   r = cast_ulong(gethexa(ls));  /* must have at least one digit */

lmem.h

@@ -39,11 +39,11 @@
 ** Computes the minimum between 'n' and 'MAX_SIZET/sizeof(t)', so that
 ** the result is not larger than 'n' and cannot overflow a 'size_t'
 ** when multiplied by the size of type 't'. (Assumes that 'n' is an
-** 'int' or 'unsigned int' and that 'int' is not larger than 'size_t'.)
+** 'int' and that 'int' is not larger than 'size_t'.)
 */
 #define luaM_limitN(n,t)  \
   ((cast_sizet(n) <= MAX_SIZET/sizeof(t)) ? (n) :  \
-     cast_uint((MAX_SIZET/sizeof(t))))
+     cast_int((MAX_SIZET/sizeof(t))))
 
 
 /*

lobject.c

@@ -194,6 +194,7 @@ void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
 
 
 lu_byte luaO_hexavalue (int c) {
+  lua_assert(lisxdigit(c));
   if (lisdigit(c)) return cast_byte(c - '0');
   else return cast_byte((ltolower(c) - 'a') + 10);
 }

lparser.c

@@ -405,7 +405,7 @@ static int searchvar (FuncState *fs, TString *n, expdesc *var) {
         init_exp(var, VCONST, fs->firstlocal + i);
       else  /* real variable */
         init_var(fs, var, i);
-      return var->k;
+      return cast_int(var->k);
     }
   }
   return -1;  /* not found */

ltable.c

@@ -96,7 +96,7 @@ typedef union {
 ** between 2^MAXHBITS and the maximum size such that, measured in bytes,
 ** it fits in a 'size_t'.
 */
-#define MAXHSIZE	luaM_limitN(1u << MAXHBITS, Node)
+#define MAXHSIZE	luaM_limitN(1 << MAXHBITS, Node)
 
 
 /*
@@ -598,7 +598,7 @@ static void setnodevector (lua_State *L, Table *t, unsigned size) {
   else {
     int i;
     int lsize = luaO_ceillog2(size);
-    if (lsize > MAXHBITS || (1u << lsize) > MAXHSIZE)
+    if (lsize > MAXHBITS || (1 << lsize) > MAXHSIZE)
       luaG_runerror(L, "table overflow");
     size = twoto(lsize);
     if (lsize < LIMFORLAST)  /* no 'lastfree' field? */

makefile

@@ -15,7 +15,6 @@ CWARNSCPP= \
 	-Wdouble-promotion \
 	-Wmissing-declarations \
 	-Wconversion \
-	-Wuninitialized \
 	-Wstrict-overflow=2 \
         # the next warnings might be useful sometimes,
 	# but usually they generate too much noise

manual/manual.of

@@ -3848,7 +3848,6 @@ or zero if the value at @id{idx} is not a number.
 
 Calls a function (or a callable object) in protected mode.
 
-
 Both @id{nargs} and @id{nresults} have the same meaning as
 in @Lid{lua_call}.
 If there are no errors during the call,
@@ -3998,9 +3997,9 @@ Lua will call @id{falloc} before raising the error.
 Pushes onto the stack a formatted string
 and returns a pointer to this string @see{constchar}.
 The result is a copy of @id{fmt} with
-each @emph{conversion specifier} replaced by its respective
+each @emph{conversion specifier} replaced by a string representation
-extra argument.
+of its respective extra argument.
-A conversion specifier can be
+A conversion specifier (and its corresponding extra argument) can be
 @Char{%%} (inserts the character @Char{%}),
 @Char{%s} (inserts a zero-terminated string, with no size restrictions),
 @Char{%f} (inserts a @Lid{lua_Number}),

testes/libs/makefile

@@ -5,7 +5,7 @@ LUA_DIR = ../../
 CC = gcc
 
 # compilation should generate Dynamic-Link Libraries
-CFLAGS = -Wall -std=gnu99 -O2 -I$(LUA_DIR) -fPIC -shared
+CFLAGS = -Wall -std=c99 -O2 -I$(LUA_DIR) -fPIC -shared
 
 # libraries used by the tests
 all: lib1.so lib11.so lib2.so lib21.so lib2-v2.so