Fixed several compiler warnings

- Warnings detected thanks to Xcode's compiler settings (more strict by
  default) and clang, warnings mostly but not only related to data sizes
  on 64 bit systems, that were silenced until now by very lax compiler
  settings.
- This also decreases by a great deal the amount of warnings produced by
  MSVC in x64 mode (for the adventurous ones who tried that)
- Also fixed (or silenced in case of false positives) the potential
  issues pointed out by the (awesome) clang static analyzer.
- Patch co-produced with Ind, I'm merging and committing in his place!

Signed-off-by: Haru <haru@dotalux.com>

4 files changed, 46 insertions, 4 deletions

diff --git a/3rdparty/libconfig/extra/gen/Makefile b/3rdparty/libconfig/extra/gen/Makefile
index b4d2db841..0b2e0655e 100644
--- a/3rdparty/libconfig/extra/gen/Makefile
+++ b/3rdparty/libconfig/extra/gen/Makefile
@@ -31,6 +31,7 @@ AM_YFLAGS = -d -p $(PARSER_PREFIX)
 AM_LFLAGS = --nounistd --header-file=scanner.h --prefix=$(PARSER_PREFIX)
 
 all: $(BUILT_SOURCES)
+	@patch -p1 < clangwarnings.patch
 
 .SUFFIXES: .c .l .y
 
diff --git a/3rdparty/libconfig/extra/gen/Makefile.in b/3rdparty/libconfig/extra/gen/Makefile.in
index 5850c2392..0bd4efd62 100644
--- a/3rdparty/libconfig/extra/gen/Makefile.in
+++ b/3rdparty/libconfig/extra/gen/Makefile.in
@@ -31,6 +31,7 @@ AM_YFLAGS = -d -p $(PARSER_PREFIX)
 AM_LFLAGS = --nounistd --header-file=scanner.h --prefix=$(PARSER_PREFIX)
 
 all: $(BUILT_SOURCES)
+	@patch -p1 < clangwarnings.patch
 
 .SUFFIXES: .c .l .y
 
diff --git a/3rdparty/libconfig/extra/gen/clangwarnings.patch b/3rdparty/libconfig/extra/gen/clangwarnings.patch
new file mode 100644
index 000000000..65aef9a08
--- /dev/null
+++ b/3rdparty/libconfig/extra/gen/clangwarnings.patch
@@ -0,0 +1,36 @@
+diff --git a/grammar.c b/grammar.c
+index 3595578..26444f8 100644
+--- a/grammar.c
++++ b/grammar.c
+@@ -1187,9 +1187,7 @@ void libconfig_yyerror(void *scanner, struct parse_context *ctx,
+   YYUSE (ctx);
+   YYUSE (scan_ctx);
+ 
+-  if (!yymsg)
+-    yymsg = "Deleting";
+-  YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);
++  YY_SYMBOL_PRINT (yymsg ? yymsg : "Deleting", yytype, yyvaluep, yylocationp);
+ 
+   switch (yytype)
+     {
+diff --git a/scanner.c b/scanner.c
+index aebd34c..c3a717f 100644
+--- a/scanner.c
++++ b/scanner.c
+@@ -1500,6 +1500,8 @@ static int yy_get_next_buffer (yyscan_t yyscanner)
+ 	else
+ 		ret_val = EOB_ACT_CONTINUE_SCAN;
+ 
++#ifndef __clang_analyzer__
++	// FIXME: Clang's static analyzer complains about leaking the result of libconfig_yyrealloc
+ 	if ((yy_size_t) (yyg->yy_n_chars + number_to_move) > YY_CURRENT_BUFFER_LVALUE->yy_buf_size) {
+ 		/* Extend the array by 50%, plus the number we really need. */
+ 		yy_size_t new_size = yyg->yy_n_chars + number_to_move + (yyg->yy_n_chars >> 1);
+@@ -1507,6 +1509,7 @@ static int yy_get_next_buffer (yyscan_t yyscanner)
+ 		if ( ! YY_CURRENT_BUFFER_LVALUE->yy_ch_buf )
+ 			YY_FATAL_ERROR( "out of dynamic memory in yy_get_next_buffer()" );
+ 	}
++#endif // __clang_analyzer__
+ 
+ 	yyg->yy_n_chars += number_to_move;
+ 	YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[yyg->yy_n_chars] = YY_END_OF_BUFFER_CHAR;
diff --git a/3rdparty/libconfig/extra/gen/scanner.l b/3rdparty/libconfig/extra/gen/scanner.l
index 4b3048fab..66364e019 100644
--- a/3rdparty/libconfig/extra/gen/scanner.l
+++ b/3rdparty/libconfig/extra/gen/scanner.l
@@ -86,6 +86,13 @@ static unsigned long long fromhex(const char *s)
 #endif /* __MINGW32__ */
 }
 
+static int fromihex(const char *s) {
+  unsigned long l = strtoul(s, NULL, 16);
+  if (l > INT32_MAX)
+    l = INT32_MAX;
+  return (int)l;
+}
+
 %}
 
 true              [Tt][Rr][Uu][Ee]
@@ -178,10 +185,7 @@ include_open      ^[ \t]*@include[ \t]+\"
 {float}           { yylval->fval = atof(yytext); return(TOK_FLOAT); }
 {integer}         { yylval->ival = atoi(yytext); return(TOK_INTEGER); }
 {integer64}       { yylval->llval = atoll(yytext); return(TOK_INTEGER64); }
-{hex}             {
-                    yylval->ival = strtoul(yytext, NULL, 16);
-                    return(TOK_HEX);
-                  }
+{hex}             { yylval->ival = fromihex(yytext); return(TOK_HEX); }
 {hex64}           { yylval->llval = fromhex(yytext); return(TOK_HEX64); }
 \[                { return(TOK_ARRAY_START); }
 \]                { return(TOK_ARRAY_END); }