Merge pull request #164 from 9rnsr/fix4539

Retry to fix issue 4539 - Refuse assignment to string literal
dlang · Jan 29, 2012 · 7f33ed7 · 7f33ed7
2 parents 425a97c + 05089ef
commit 7f33ed7
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Showing 5 changed files with 63 additions and 8 deletions.
diff --git a/src/expression.c b/src/expression.c
@@ -3379,7 +3379,10 @@ int StringExp::isBool(int result)
 #if DMDV2
 int StringExp::isLvalue()
 {
-    return 1;
+    /* string literal is rvalue in default, but
+     * conversion to reference of static array is only allowed.
+     */
+    return 0;
 }
 #endif
 
@@ -3389,6 +3392,12 @@ Expression *StringExp::toLvalue(Scope *sc, Expression *e)
     return this;
 }
 
+Expression *StringExp::modifiableLvalue(Scope *sc, Expression *e)
+{
+    error("Cannot modify '%s'", toChars());
+    return this;
+}
+
 unsigned StringExp::charAt(size_t i)
 {   unsigned value;
 

diff --git a/src/expression.h b/src/expression.h
@@ -385,6 +385,7 @@ struct StringExp : Expression
     int isBool(int result);
     int isLvalue();
     Expression *toLvalue(Scope *sc, Expression *e);
+    Expression *modifiableLvalue(Scope *sc, Expression *e);
     unsigned charAt(size_t i);
     void toCBuffer(OutBuffer *buf, HdrGenState *hgs);
     void toMangleBuffer(OutBuffer *buf);

diff --git a/src/mtype.c b/src/mtype.c
@@ -5673,13 +5673,18 @@ int TypeFunction::callMatch(Expression *ethis, Expressions *args, int flag)
         Type *tprm = wildmatch ? p->type->substWildTo(wildmatch) : p->type;
 
         // Non-lvalues do not match ref or out parameters
-        if (p->storageClass & (STCref | STCout))
+        if (p->storageClass & STCref)
         {   if (!arg->isLvalue())
-                goto Nomatch;
-        }
+            {   if (arg->op == TOKstring && tprm->ty == Tsarray)
+                {   if (targ->ty != Tsarray)
+                        targ = new TypeSArray(targ->nextOf(),
+                                new IntegerExp(0, ((StringExp *)arg)->len,
+                                Type::tindex));
+                }
+                else
+                    goto Nomatch;
+            }
 
-        if (p->storageClass & STCref)
-        {
             /* Don't allow static arrays to be passed to mutable references
              * to static arrays if the argument cannot be modified.
              */
@@ -5692,7 +5697,11 @@ int TypeFunction::callMatch(Expression *ethis, Expressions *args, int flag)
                 goto Nomatch;
 
             // ref variable behaves like head-const reference
-            if (arg->op != TOKstring && !targb->constConv(tprmb))
+            if (!targb->constConv(tprmb))
+                goto Nomatch;
+        }
+        else if (p->storageClass & STCout)
+        {   if (!arg->isLvalue())
                 goto Nomatch;
         }
 

diff --git a/test/runnable/test42.d b/test/runnable/test42.d
@@ -3995,7 +3995,8 @@ float parse(ref string p)
 void test230()
 {
     float f;
-    f = parse( "123e+2" );
+    string s = "123e+2";
+    f = parse( s );
     //printf("f = %g\n", f);
     assert( f == 123e+2f );
 }

diff --git a/test/runnable/xtest46.d b/test/runnable/xtest46.d
@@ -3317,6 +3317,40 @@ static assert(!is(typeof(Bar4258.init + 1)));
 static assert(!is(typeof(Bar4258.init += 1)));
 static assert(!is(typeof(1 + Baz4258.init)));
 
+/***************************************************/
+// 4539
+
+void test4539()
+{
+    static assert(!__traits(compiles, "hello" = "red"));
+
+    void foo1(ref string s){}
+    void foo2(ref const char[10] s){}
+    void foo3(ref char[5] s){}
+
+    void foo4(ref const char[5] s)
+    {
+        assert(s[0] == 'h');
+        assert(s[4] == 'o');
+    }
+    void foo5(ref const ubyte[5] s)
+    {
+        assert(s[0] == 0xc3);
+        assert(s[4] == 0x61);
+    }
+
+    static assert(!__traits(compiles, foo1("hello")));
+    static assert(!__traits(compiles, foo2("hello")));
+    static assert(!__traits(compiles, foo3("hello")));
+
+    // same as test68, 69, 70
+    foo4("hello");
+    foo5(cast(ubyte[5])x"c3fcd3d761");
+
+    //import std.conv;
+    //static assert(!__traits(compiles, parse!int("10") == 10));
+}
+
 /***************************************************/
 // 1471
 
@@ -4594,6 +4628,7 @@ int main()
     test155();
     test156();
     test4258();
+    test4539();
     test4963();
     test4031();
     test6230();