Pointer: raise on negative count in copy/move methods

crystal-lang · Jun 13, 2016 · ce2f6e2 · ce2f6e2
1 parent c3cd3a7
commit ce2f6e2
Showing 2 changed files with 36 additions and 0 deletions.
diff --git a/spec/std/pointer_spec.cr b/spec/std/pointer_spec.cr
@@ -35,6 +35,13 @@ describe "Pointer" do
         p2[0].should eq(p1[0])
       end
     end
+
+    it "raises on negative count" do
+      p1 = Pointer.malloc(4, 0)
+      expect_raises(ArgumentError, "negative count") do
+        p1.copy_from(p1, -1)
+      end
+    end
   end
 
   describe "copy_to" do
@@ -46,6 +53,13 @@ describe "Pointer" do
         p2[0].should eq(p1[0])
       end
     end
+
+    it "raises on negative count" do
+      p1 = Pointer.malloc(4, 0)
+      expect_raises(ArgumentError, "negative count") do
+        p1.copy_to(p1, -1)
+      end
+    end
   end
 
   describe "move_from" do
@@ -66,6 +80,13 @@ describe "Pointer" do
       p1[2].should eq(1)
       p1[3].should eq(2)
     end
+
+    it "raises on negative count" do
+      p1 = Pointer.malloc(4, 0)
+      expect_raises(ArgumentError, "negative count") do
+        p1.move_from(p1, -1)
+      end
+    end
   end
 
   describe "move_to" do
@@ -86,6 +107,13 @@ describe "Pointer" do
       p1[2].should eq(1)
       p1[3].should eq(2)
     end
+
+    it "raises on negative count" do
+      p1 = Pointer.malloc(4, 0)
+      expect_raises(ArgumentError, "negative count") do
+        p1.move_to(p1, -1)
+      end
+    end
   end
 
   describe "memcmp" do

diff --git a/src/pointer.cr b/src/pointer.cr
@@ -146,6 +146,8 @@ struct Pointer(T)
   # ptr1[3] # => 4
   # ```
   def copy_from(source : Pointer(T), count : Int)
+    raise ArgumentError.new("negative count") if count < 0
+
     if self.class == source.class
       Intrinsics.memcpy(self.as(Void*), source.as(Void*), (count * sizeof(T)).to_u32, 0_u32, false)
     else
@@ -158,6 +160,8 @@ struct Pointer(T)
 
   # :nodoc:
   def copy_from(source : Pointer(NoReturn), count : Int)
+    raise ArgumentError.new("negative count") if count < 0
+
     # We need this overload for cases when we have a pointer to unreachable
     # data, like when doing Tuple.new.to_a
     self
@@ -203,6 +207,8 @@ struct Pointer(T)
   # ptr1[3] # => 3
   # ```
   def move_from(source : Pointer(T), count : Int)
+    raise ArgumentError.new("negative count") if count < 0
+
     if self.class == source.class
       Intrinsics.memmove(self.as(Void*), source.as(Void*), (count * sizeof(T)).to_u32, 0_u32, false)
     else
@@ -219,6 +225,8 @@ struct Pointer(T)
 
   # :nodoc:
   def move_from(source : Pointer(NoReturn), count : Int)
+    raise ArgumentError.new("negative count") if count < 0
+
     # We need this overload for cases when we have a pointer to unreachable
     # data, like when doing Tuple.new.to_a
     self