Ignore breakpoint for a specified number of iterations. (#19157)

* Implement new debugger command `:ignore` to set an `ignore count`
  for a specified breakpoint.
* Allow new optional parameter on `:continue` command to set an
  `ignore count` for the current breakpoint.

* In the Interpreter replace the current `Word8` BreakArray with
  an `Int` array.
* Change semantics of values in `BreakArray` to:
   n < 0  : Breakpoint is disabled.
   n == 0 : Breakpoint is enabled.
   n > 0  : Breakpoint is enabled, but ignore next `n` iterations.
* Rewrite `:enable`/`:disable` processing as a special case of `:ignore`.
* Remove references to `BreakArray` from `ghc/UI.hs`.

4 files changed, 70 insertions, 0 deletions

diff --git a/testsuite/tests/ghci.debugger/scripts/T19157.hs b/testsuite/tests/ghci.debugger/scripts/T19157.hs
new file mode 100644
index 0000000000..d844a31e7e
--- /dev/null
+++ b/testsuite/tests/ghci.debugger/scripts/T19157.hs
@@ -0,0 +1,8 @@
+module T19157 where
+
+mySum :: [Int] -> Int
+mySum lst = go 0 lst
+  where
+    go :: Int -> [Int] -> Int
+    go sum [] = sum
+    go sum (s : ss) = go (sum + s) ss
diff --git a/testsuite/tests/ghci.debugger/scripts/T19157.script b/testsuite/tests/ghci.debugger/scripts/T19157.script
new file mode 100644
index 0000000000..edcad557d5
--- /dev/null
+++ b/testsuite/tests/ghci.debugger/scripts/T19157.script
@@ -0,0 +1,20 @@
+:l T19157
+:break mySum.go
+putStrLn "---------------------- Test 1"
+mySum [1,2,3,4,5,6]
+:cont 2
+:cont 1
+:cont
+:cont
+putStrLn "---------------------- Test 2"
+:ig 1 1000
+mySum [1..2000]
+putStrLn "---------------------- Test 3"
+:continue q
+:continue -1
+:cont 3 4
+:ig a 5
+:ignore 5 a
+:ignore 0
+:ignore 1 2 3 4
+:ignore 0 -1
diff --git a/testsuite/tests/ghci.debugger/scripts/T19157.stdout b/testsuite/tests/ghci.debugger/scripts/T19157.stdout
new file mode 100644
index 0000000000..f0ac09d7f4
--- /dev/null
+++ b/testsuite/tests/ghci.debugger/scripts/T19157.stdout
@@ -0,0 +1,41 @@
+Breakpoint 0 activated at T19157.hs:7:17-19
+Breakpoint 1 activated at T19157.hs:8:23-37
+---------------------- Test 1
+Stopped in T19157.mySum.go, T19157.hs:8:23-37
+_result :: Int = _
+go :: Int -> [Int] -> Int = _
+s :: Int = 1
+ss :: [Int] = [2,3,4,5,6]
+sum :: Int = 0
+Stopped in T19157.mySum.go, T19157.hs:8:23-37
+_result :: Int = _
+go :: Int -> [Int] -> Int = _
+s :: Int = 4
+ss :: [Int] = [5,6]
+sum :: Int = _
+Stopped in T19157.mySum.go, T19157.hs:8:23-37
+_result :: Int = _
+go :: Int -> [Int] -> Int = _
+s :: Int = 6
+ss :: [Int] = []
+sum :: Int = _
+Stopped in T19157.mySum.go, T19157.hs:7:17-19
+_result :: Int = _
+sum :: Int = _
+21
+---------------------- Test 2
+Stopped in T19157.mySum.go, T19157.hs:8:23-37
+_result :: Int = _
+go :: Int -> [Int] -> Int = _
+s :: Int = 1001
+ss :: [Int] = _
+sum :: Int = _
+---------------------- Test 3
+Ignore count ‘q’ is not numeric
+Ignore count ‘-1’ must be >= 0
+After ':continue' only one ignore count is allowed
+Breakpoint a not found
+Breakpoint 5 not found
+Syntax:  :ignore <breaknum> <count>
+Syntax:  :ignore <breaknum> <count>
+Ignore count ‘-1’ must be >= 0
diff --git a/testsuite/tests/ghci.debugger/scripts/all.T b/testsuite/tests/ghci.debugger/scripts/all.T
index 30e5c4312c..489fa89d36 100644
--- a/testsuite/tests/ghci.debugger/scripts/all.T
+++ b/testsuite/tests/ghci.debugger/scripts/all.T
@@ -125,3 +125,4 @@ test('T16700', normal, ghci_script, ['T16700.script'])
 test('break029', extra_files(['break029.hs']), ghci_script, ['break029.script'])
 test('T2215', normal, ghci_script, ['T2215.script'])
 test('T17989', normal, ghci_script, ['T17989.script'])
+test('T19157', normal, ghci_script, ['T19157.script'])