From 9420c01538223dc977060087e5026642cb3fbe2f Mon Sep 17 00:00:00 2001
From: "Wolfgang (Blub) Bumiller" <blub@speed.at>
Date: Sun, 19 Aug 2012 21:26:14 +0200
Subject: [PATCH] added -Wused-uninitialized and warning about variables which
 may be used without being initialized

---
 ir.c      | 31 +++++++++++++++++++++++++++++++
 main.c    |  1 +
 warns.def |  1 +
 3 files changed, 33 insertions(+)

diff --git a/ir.c b/ir.c
index 2079dce..00411a6 100644
--- a/ir.c
+++ b/ir.c
@@ -133,6 +133,24 @@ static void irerror(lex_ctx ctx, const char *msg, ...)
     va_end(ap);
 }
 
+static bool irwarning(lex_ctx ctx, int warntype, const char *fmt, ...)
+{
+	va_list ap;
+	int lvl = LVL_WARNING;
+
+    if (!OPTS_WARN(warntype))
+        return false;
+
+    if (opts_werror)
+	    lvl = LVL_ERROR;
+
+	va_start(ap, fmt);
+    vprintmsg(lvl, ctx.file, ctx.line, "warning", fmt, ap);
+	va_end(ap);
+
+	return opts_werror;
+}
+
 /***********************************************************************
  *IR Builder
  */
@@ -1802,6 +1820,19 @@ bool ir_function_calculate_liferanges(ir_function *self)
             }
         }
     } while (changed);
+    if (self->blocks_count) {
+        ir_block *block = self->blocks[0];
+        for (i = 0; i < block->living_count; ++i) {
+            ir_value *v = block->living[i];
+            if (v->name[0] == '#' || v->name[0] == '%')
+                continue;
+            if (irwarning(v->context, WARN_USED_UNINITIALIZED,
+                          "variable `%s` may be used uninitialized in this function", v->name))
+            {
+                return false;
+            }
+        }
+    }
     return true;
 }
 
diff --git a/main.c b/main.c
index d629373..bccac37 100644
--- a/main.c
+++ b/main.c
@@ -383,6 +383,7 @@ int main(int argc, char **argv) {
     options_set(opts_warn, WARN_FIELD_REDECLARED, true);
     options_set(opts_warn, WARN_TOO_FEW_PARAMETERS, true);
     options_set(opts_warn, WARN_MISSING_RETURN_VALUES, true);
+    options_set(opts_warn, WARN_USED_UNINITIALIZED, true);
 
     if (!options_parse(argc, argv)) {
         return usage();
diff --git a/warns.def b/warns.def
index 6958a99..bda1370 100644
--- a/warns.def
+++ b/warns.def
@@ -4,6 +4,7 @@
 
 GMQCC_DEFINE_FLAG(DEBUG)
 GMQCC_DEFINE_FLAG(UNUSED_VARIABLE)
+GMQCC_DEFINE_FLAG(USED_UNINITIALIZED)
 GMQCC_DEFINE_FLAG(UNKNOWN_CONTROL_SEQUENCE)
 GMQCC_DEFINE_FLAG(EXTENSIONS)
 GMQCC_DEFINE_FLAG(FIELD_REDECLARED)
-- 
2.39.2