Merge pull request #7976 from WalterBright/fix5212

fix Issue 5212 - no escape analysis for typesafe variadic function ar…
dlang · Mar 3, 2018 · de44987 · de44987
2 parents 65bc408 + be4ad4b
commit de44987
Show file tree

Hide file tree

Showing 6 changed files with 38 additions and 7 deletions.
diff --git a/src/dmd/dtemplate.d b/src/dmd/dtemplate.d
@@ -739,7 +739,12 @@ extern (C++) final class TemplateDeclaration : ScopeDsymbol
                 fparam.storageClass &= (STC.in_ | STC.out_ | STC.ref_ | STC.lazy_ | STC.final_ | STC.TYPECTOR | STC.nodtor);
                 fparam.storageClass |= STC.parameter;
                 if (fvarargs == 2 && i + 1 == nfparams)
+                {
                     fparam.storageClass |= STC.variadic;
+                    /* Don't need to set STC.scope_ because this will only
+                     * be evaluated at compile time
+                     */
+                }
             }
             for (size_t i = 0; i < fparameters.dim; i++)
             {

diff --git a/src/dmd/expressionsem.d b/src/dmd/expressionsem.d
@@ -604,7 +604,7 @@ private bool functionParameters(Loc loc, Scope* sc, TypeFunction tf, Type tthis,
                 nargs++;
             }
 
-            if (tf.varargs == 2 && i + 1 == nparams)
+            if (tf.varargs == 2 && i + 1 == nparams) // https://dlang.org/spec/function.html#variadic
             {
                 //printf("\t\tvarargs == 2, p.type = '%s'\n", p.type.toChars());
                 {

diff --git a/src/dmd/semantic3.d b/src/dmd/semantic3.d
@@ -442,7 +442,17 @@ private extern(C++) final class Semantic3Visitor : Visitor
                     //printf("declaring parameter %s of type %s\n", v.toChars(), v.type.toChars());
                     stc |= STC.parameter;
                     if (f.varargs == 2 && i + 1 == nparams)
+                    {
                         stc |= STC.variadic;
+                        auto vtypeb = vtype.toBasetype();
+                        if (vtypeb.ty == Tarray)
+                        {
+                            /* Since it'll be pointing into the stack for the array
+                             * contents, it needs to be `scope`
+                             */
+                            stc |= STC.scope_;
+                        }
+                    }
                     if (funcdecl.flags & FUNCFLAG.inferScope && !(fparam.storageClass & STC.scope_))
                         stc |= STC.maybescope;
                     stc |= fparam.storageClass & (STC.in_ | STC.out_ | STC.ref_ | STC.return_ | STC.scope_ | STC.lazy_ | STC.final_ | STC.TYPECTOR | STC.nodtor);

diff --git a/test/fail_compilation/fail13902.d b/test/fail_compilation/fail13902.d
@@ -323,19 +323,18 @@ int[] testSlice2() { int[3] sa; int n; return sa[n..2][1..2]; }
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/fail13902.d(324): Error: returning `vda[0]` escapes a reference to parameter `vda`, perhaps annotate with `return`
-fail_compilation/fail13902.d(325): Error: returning `vda[]` escapes a reference to variadic parameter `vda`
+fail_compilation/fail13902.d(323): Error: returning `vda[0]` escapes a reference to parameter `vda`, perhaps annotate with `return`
 ---
 */
 ref int testDynamicArrayVariadic1(int[] vda...) { return vda[0]; }
-int[]   testDynamicArrayVariadic2(int[] vda...) { return vda[]; }
+@safe int[]   testDynamicArrayVariadic2(int[] vda...) { return vda[]; }
 int[3]  testDynamicArrayVariadic3(int[] vda...) { return vda[0..3]; }   // no error
 
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/fail13902.d(335): Error: returning `vsa[0]` escapes a reference to parameter `vsa`, perhaps annotate with `return`
-fail_compilation/fail13902.d(336): Error: returning `vsa[]` escapes a reference to variadic parameter `vsa`
+fail_compilation/fail13902.d(334): Error: returning `vsa[0]` escapes a reference to parameter `vsa`, perhaps annotate with `return`
+fail_compilation/fail13902.d(335): Error: returning `vsa[]` escapes a reference to variadic parameter `vsa`
 ---
 */
 ref int testStaticArrayVariadic1(int[3] vsa...) { return vsa[0]; }

diff --git a/test/fail_compilation/fix5212.d b/test/fail_compilation/fix5212.d
@@ -0,0 +1,17 @@
+/* REQUIRED_ARGS: -dip1000
+TEST_OUTPUT:
+---
+fail_compilation/fix5212.d(14): Error: scope variable `args_` assigned to `this` with longer lifetime
+---
+*/
+
+
+// https://issues.dlang.org/show_bug.cgi?id=5212
+
+class Foo {
+    int[] args;
+    @safe this(int[] args_...) {
+        args = args_;
+    }
+}
+
diff --git a/test/fail_compilation/retscope.d b/test/fail_compilation/retscope.d
@@ -7,7 +7,7 @@ fail_compilation/retscope.d(23): Error: scope variable `p` may not be returned
 fail_compilation/retscope.d(33): Error: returning `b ? nested1(& i) : nested2(& j)` escapes a reference to local variable `j`
 fail_compilation/retscope.d(46): Error: scope variable `p` assigned to non-scope `q`
 fail_compilation/retscope.d(48): Error: address of variable `i` assigned to `q` with longer lifetime
-fail_compilation/retscope.d(49): Error: variadic variable `a` assigned to non-scope `b`
+fail_compilation/retscope.d(49): Error: scope variable `a` assigned to non-scope `b`
 fail_compilation/retscope.d(50): Error: reference to stack allocated value returned by `(*fp2)()` assigned to non-scope `q`
 ---
 */