Author: Jordan Rupprecht Date: 2021-04-07T10:48:47-07:00 New Revision: f49a4440d38a4123b01ded6493a02b4cbf038928
URL: https://github.com/llvm/llvm-project/commit/f49a4440d38a4123b01ded6493a02b4cbf038928 DIFF: https://github.com/llvm/llvm-project/commit/f49a4440d38a4123b01ded6493a02b4cbf038928.diff LOG: [lldb][Editline] Fix crash when navigating through empty command history. An empty history entry can happen by entering the expression evaluator an immediately hitting enter: ``` $ lldb (lldb) e Enter expressions, then terminate with an empty line to evaluate: 1: <hit enter> ``` The next time the user enters the expression evaluator, if they hit the up arrow to load the previous expression, lldb crashes. This patch treats empty history sessions as a single expression of zero length, instead of an empty list of expressions. Fixes http://llvm.org/PR49845. Differential Revision: https://reviews.llvm.org/D100048 Added: Modified: lldb/source/Host/common/Editline.cpp lldb/test/API/commands/expression/multiline-navigation/TestMultilineNavigation.py Removed: ################################################################################ diff --git a/lldb/source/Host/common/Editline.cpp b/lldb/source/Host/common/Editline.cpp index fa06bfb265833..85c62b4288a97 100644 --- a/lldb/source/Host/common/Editline.cpp +++ b/lldb/source/Host/common/Editline.cpp @@ -153,6 +153,11 @@ std::vector<EditLineStringType> SplitLines(const EditLineStringType &input) { result.push_back(input.substr(start, end - start)); start = end + 1; } + // Treat an empty history session as a single command of zero-length instead + // of returning an empty vector. + if (result.empty()) { + result.emplace_back(); + } return result; } diff --git a/lldb/test/API/commands/expression/multiline-navigation/TestMultilineNavigation.py b/lldb/test/API/commands/expression/multiline-navigation/TestMultilineNavigation.py index d95e69fc8aa5d..95ad2c8857088 100644 --- a/lldb/test/API/commands/expression/multiline-navigation/TestMultilineNavigation.py +++ b/lldb/test/API/commands/expression/multiline-navigation/TestMultilineNavigation.py @@ -69,3 +69,26 @@ def test_nav_arrow_down(self): self.child.expect_exact("(int) $0 = 334") self.quit() + + @skipIfAsan + @skipIfEditlineSupportMissing + @expectedFailureAll(oslist=['freebsd'], bugnumber='llvm.org/pr48316') + def test_nav_arrow_up_empty_pr49845(self): + """Tests that navigating with the up arrow doesn't crash.""" + self.launch() + + # Create an empty history session by only entering a newline. + self.child.sendline("expr") + self.child.expect_exact("terminate with an empty line to evaluate") + self.child.send("\n") + self.expect_prompt() + + # Send just the up arrow in the expression evaluator. This should bring up the previous empty expression. + self.child.sendline("expr") + self.child.expect_exact("terminate with an empty line to evaluate") + self.child.send(self.arrow_up) + self.child.expect_exact("1: ") + self.child.send("\n") + self.expect_prompt() + + self.quit() _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
