Merge pull request #6511 from MaskRay/master

fix SIGFPE caused by integer division overflow `sinteger_t.min / (-1)` in constant folding
dlang · Feb 11, 2017 · 4f1425c · 4f1425c
2 parents 307a7b9 + a4cedfa
commit 4f1425c
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Showing 2 changed files with 37 additions and 2 deletions.
diff --git a/src/constfold.d b/src/constfold.d
@@ -433,6 +433,20 @@ extern (C++) UnionExp Div(Loc loc, Type type, Expression e1, Expression e2)
             e2.error("divide by 0");
             n2 = 1;
         }
+        if (n2 == -1 && !type.isunsigned())
+        {
+            // Check for int.min / -1
+            if (n1 == 0xFFFFFFFF80000000UL && type.toBasetype().ty != Tint64)
+            {
+                e2.error("integer overflow: int.min / -1");
+                n2 = 1;
+            }
+            else if (n1 == 0x8000000000000000L) // long.min / -1
+            {
+                e2.error("integer overflow: long.min / -1");
+                n2 = 1;
+            }
+        }
         if (e1.type.isunsigned() || e2.type.isunsigned())
             n = (cast(dinteger_t)n1) / (cast(dinteger_t)n2);
         else
@@ -486,12 +500,12 @@ extern (C++) UnionExp Mod(Loc loc, Type type, Expression e1, Expression e2)
             // Check for int.min % -1
             if (n1 == 0xFFFFFFFF80000000UL && type.toBasetype().ty != Tint64)
             {
-                e2.error("integer overflow: int.min % -1");
+                e2.error("integer overflow: int.min %% -1");
                 n2 = 1;
             }
             else if (n1 == 0x8000000000000000L) // long.min % -1
             {
-                e2.error("integer overflow: long.min % -1");
+                e2.error("integer overflow: long.min %% -1");
                 n2 = 1;
             }
         }

diff --git a/test/fail_compilation/test4682.d b/test/fail_compilation/test4682.d
@@ -0,0 +1,21 @@
+/*
+TEST_OUTPUT:
+----
+fail_compilation/test4682.d(18): Error: integer overflow: int.min / -1
+fail_compilation/test4682.d(18): Error: integer overflow: int.min / -1
+fail_compilation/test4682.d(18): Error: integer overflow: int.min / -1
+fail_compilation/test4682.d(19): Error: integer overflow: long.min / -1
+fail_compilation/test4682.d(19): Error: integer overflow: long.min / -1
+fail_compilation/test4682.d(19): Error: integer overflow: long.min / -1
+fail_compilation/test4682.d(20): Error: integer overflow: int.min % -1
+fail_compilation/test4682.d(20): Error: integer overflow: int.min % -1
+fail_compilation/test4682.d(20): Error: integer overflow: int.min % -1
+fail_compilation/test4682.d(21): Error: integer overflow: long.min % -1
+fail_compilation/test4682.d(21): Error: integer overflow: long.min % -1
+fail_compilation/test4682.d(21): Error: integer overflow: long.min % -1
+----
+*/
+auto a = int.min / -1;
+auto b = long.min / -1;
+auto c = int.min % -1;
+auto d = long.min % -1;