BreakpointResolverFileLine: Restrict move-to-nearest-code from moving across function boundaries

Summary:
This fixes the case where a user tries to set a breakpoint on a source
line outside of any function (e.g. because that code is #ifdefed out, or
the compiler did not emit code for the function, etc.) and we would
silently move the breakpoint to the next function.

Now we check whether the line range of the resolved symbol context
function matches the original line number. We reject any breakpoint
locations that appear to move the breakpoint into a new function. This
filtering only happens if we have full debug info available (e.g. in
case of -gline-tables-only compilation, we still set the breakpoint on
the nearest source line).

Reviewers: jingham

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D30817

llvm-svn: 297817

9 files changed, 116 insertions, 34 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_options/TestBreakpointOptions.py b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_options/TestBreakpointOptions.py
index c0c2267a836..871363b7aed 100644
--- a/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_options/TestBreakpointOptions.py
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_options/TestBreakpointOptions.py
@@ -45,14 +45,6 @@ class BreakpointOptionsTestCase(TestBase):
             extra_options="-K 0",
             num_expected_locations=1)
 
-        # This should create a breakpoint 0 locations.
-        lldbutil.run_break_set_by_file_and_line(
-            self,
-            "main.cpp",
-            self.line,
-            extra_options="-m 0",
-            num_expected_locations=0)
-
         # Run the program.
         self.runCmd("run", RUN_SUCCEEDED)
 
@@ -68,8 +60,6 @@ class BreakpointOptionsTestCase(TestBase):
                 "1: file = 'main.cpp', line = %d, exact_match = 0, locations = 1" %
                 self.line,
                 "2: file = 'main.cpp', line = %d, exact_match = 0, locations = 1" %
-                self.line,
-                "3: file = 'main.cpp', line = %d, exact_match = 1, locations = 0" %
                 self.line])
 
         # Continue the program, there should be another stop.
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_options/main.cpp b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_options/main.cpp
index 363b90003d7..b2e8f523c84 100644
--- a/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_options/main.cpp
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_options/main.cpp
@@ -1,8 +1,4 @@
-// Set break point at this line.
-
 extern "C" int foo(void);
-int
-main (int argc, char **argv)
-{ 
+int main (int argc, char **argv) { // Set break point at this line.
   return foo();
 }
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/Makefile b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/Makefile
new file mode 100644
index 00000000000..e7a1cab7e19
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/Makefile
@@ -0,0 +1,8 @@
+LEVEL = ../../../make
+
+DYLIB_NAME := foo
+DYLIB_CXX_SOURCES := foo.cpp
+CXX_SOURCES := main.cpp
+CFLAGS_EXTRAS += -fPIC
+
+include $(LEVEL)/Makefile.rules
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/TestMoveNearest.py b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/TestMoveNearest.py
new file mode 100644
index 00000000000..ae58ad9960d
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/TestMoveNearest.py
@@ -0,0 +1,58 @@
+from __future__ import print_function
+
+
+import unittest2
+import lldb
+from lldbsuite.test.lldbtest import *
+import lldbsuite.test.lldbutil as lldbutil
+
+
+class TestMoveNearest(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+    NO_DEBUG_INFO_TESTCASE = True
+
+    def setUp(self):
+        # Call super's setUp().
+        TestBase.setUp(self)
+        # Find the line number to break inside main().
+        self.line1 = line_number('foo.h', '// !BR1')
+        self.line2 = line_number('foo.h', '// !BR2')
+        self.line_main = line_number('main.cpp', '// !BR_main')
+
+    def test(self):
+        """Test target.move-to-nearest logic"""
+
+        self.build()
+        target = self.dbg.CreateTarget("a.out")
+        self.assertTrue(target, VALID_TARGET)
+
+        # Regardless of the -m value the breakpoint should have exactly one
+        # location on the foo functions
+        self.runCmd("settings set target.move-to-nearest-code true")
+        lldbutil.run_break_set_by_file_and_line(self, 'foo.h', self.line1,
+                loc_exact=True, extra_options="-m 1")
+        lldbutil.run_break_set_by_file_and_line(self, 'foo.h', self.line2,
+                loc_exact=True, extra_options="-m 1")
+
+        self.runCmd("settings set target.move-to-nearest-code false")
+        lldbutil.run_break_set_by_file_and_line(self, 'foo.h', self.line1,
+                loc_exact=True, extra_options="-m 0")
+        lldbutil.run_break_set_by_file_and_line(self, 'foo.h', self.line2,
+                loc_exact=True, extra_options="-m 0")
+
+
+        # Make sure we set a breakpoint in main with -m 1 for various lines in
+        # the function declaration
+        # "int"
+        lldbutil.run_break_set_by_file_and_line(self, 'main.cpp',
+                self.line_main-1, extra_options="-m 1")
+        # "main()"
+        lldbutil.run_break_set_by_file_and_line(self, 'main.cpp',
+                self.line_main, extra_options="-m 1")
+        # "{"
+        lldbutil.run_break_set_by_file_and_line(self, 'main.cpp',
+                self.line_main+1, extra_options="-m 1")
+        # "return .."
+        lldbutil.run_break_set_by_file_and_line(self, 'main.cpp',
+                self.line_main+2, extra_options="-m 1")
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/foo.cpp b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/foo.cpp
new file mode 100644
index 00000000000..8dad0a23f36
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/foo.cpp
@@ -0,0 +1,3 @@
+#include "foo.h"
+
+int call_foo1() { return foo1(); }
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/foo.h b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/foo.h
new file mode 100644
index 00000000000..060b91f5a5e
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/foo.h
@@ -0,0 +1,6 @@
+LLDB_TEST_API inline int foo1() { return 1; } // !BR1
+
+LLDB_TEST_API inline int foo2() { return 2; } // !BR2
+
+LLDB_TEST_API extern int call_foo1();
+LLDB_TEST_API extern int call_foo2();
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/main.cpp b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/main.cpp
new file mode 100644
index 00000000000..c9295a5c7d3
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/move_nearest/main.cpp
@@ -0,0 +1,9 @@
+#include "foo.h"
+
+int call_foo2() { return foo2(); }
+
+int
+main() // !BR_main
+{
+  return call_foo1() + call_foo2();
+}
diff --git a/lldb/packages/Python/lldbsuite/test/tools/lldb-mi/breakpoint/TestMiBreak.py b/lldb/packages/Python/lldbsuite/test/tools/lldb-mi/breakpoint/TestMiBreak.py
index 99cec7492cb..16f71fe8130 100644
--- a/lldb/packages/Python/lldbsuite/test/tools/lldb-mi/breakpoint/TestMiBreak.py
+++ b/lldb/packages/Python/lldbsuite/test/tools/lldb-mi/breakpoint/TestMiBreak.py
@@ -226,38 +226,47 @@ class MiBreakTestCase(lldbmi_testcase.MiTestCaseBase):
         self.runCmd(
             "-interpreter-exec console \"settings set target.move-to-nearest-code off\"")
         self.expect("\^done")
-        line = line_number('main.cpp', '// BP_before_main')
-        self.runCmd("-break-insert -f main.cpp:%d" % line)
+        line_decl = line_number('main.cpp', '// BP_main_decl')
+        line_in = line_number('main.cpp', '// BP_in_main')
+        self.runCmd("-break-insert -f main.cpp:%d" % line_in)
         self.expect("\^done,bkpt={number=\"1\"")
 
         # Test that non-pending BP will not be set on non-existing line if target.move-to-nearest-code=off
         # Note: this increases the BP number by 1 even though BP #2 is invalid.
-        self.runCmd("-break-insert main.cpp:%d" % line)
+        self.runCmd("-break-insert main.cpp:%d" % line_in)
         self.expect(
             "\^error,msg=\"Command 'break-insert'. Breakpoint location 'main.cpp:%d' not found\"" %
-            line)
+            line_in)
 
         # Set target.move-to-nearest-code=on and target.skip-prologue=on and
-        # set BP #3
+        # set BP #3 & #4
         self.runCmd(
             "-interpreter-exec console \"settings set target.move-to-nearest-code on\"")
         self.runCmd(
             "-interpreter-exec console \"settings set target.skip-prologue on\"")
         self.expect("\^done")
-        self.runCmd("-break-insert main.cpp:%d" % line)
+        self.runCmd("-break-insert main.cpp:%d" % line_in)
         self.expect("\^done,bkpt={number=\"3\"")
+        self.runCmd("-break-insert main.cpp:%d" % line_decl)
+        self.expect("\^done,bkpt={number=\"4\"")
 
-        # Set target.skip-prologue=off and set BP #4
+        # Set target.skip-prologue=off and set BP #5
         self.runCmd(
             "-interpreter-exec console \"settings set target.skip-prologue off\"")
         self.expect("\^done")
-        self.runCmd("-break-insert main.cpp:%d" % line)
-        self.expect("\^done,bkpt={number=\"4\"")
+        self.runCmd("-break-insert main.cpp:%d" % line_decl)
+        self.expect("\^done,bkpt={number=\"5\"")
 
-        # Test that BP #4 is located before BP #3
+        # Test that BP #5 is located before BP #4
         self.runCmd("-exec-run")
         self.expect("\^running")
         self.expect(
+            "\*stopped,reason=\"breakpoint-hit\",disp=\"del\",bkptno=\"5\"")
+
+        # Test that BP #4 is hit
+        self.runCmd("-exec-continue")
+        self.expect("\^running")
+        self.expect(
             "\*stopped,reason=\"breakpoint-hit\",disp=\"del\",bkptno=\"4\"")
 
         # Test that BP #3 is hit
@@ -266,7 +275,7 @@ class MiBreakTestCase(lldbmi_testcase.MiTestCaseBase):
         self.expect(
             "\*stopped,reason=\"breakpoint-hit\",disp=\"del\",bkptno=\"3\"")
 
-        # Test that the target.language=pascal setting works and that BP #5 is
+        # Test that the target.language=pascal setting works and that BP #6 is
         # NOT set
         self.runCmd(
             "-interpreter-exec console \"settings set target.language c\"")
@@ -274,16 +283,16 @@ class MiBreakTestCase(lldbmi_testcase.MiTestCaseBase):
         self.runCmd("-break-insert ns.foo1")
         self.expect("\^error")
 
-        # Test that the target.language=c++ setting works and that BP #6 is hit
+        # Test that the target.language=c++ setting works and that BP #7 is hit
         self.runCmd(
             "-interpreter-exec console \"settings set target.language c++\"")
         self.expect("\^done")
         self.runCmd("-break-insert ns::foo1")
-        self.expect("\^done,bkpt={number=\"6\"")
+        self.expect("\^done,bkpt={number=\"7\"")
         self.runCmd("-exec-continue")
         self.expect("\^running")
         self.expect(
-            "\*stopped,reason=\"breakpoint-hit\",disp=\"del\",bkptno=\"6\"")
+            "\*stopped,reason=\"breakpoint-hit\",disp=\"del\",bkptno=\"7\"")
 
         # Test that BP #1 and #2 weren't set by running to program exit
         self.runCmd("-exec-continue")
diff --git a/lldb/packages/Python/lldbsuite/test/tools/lldb-mi/breakpoint/main.cpp b/lldb/packages/Python/lldbsuite/test/tools/lldb-mi/breakpoint/main.cpp
index 9416a0d01c7..366c53c3143 100644
--- a/lldb/packages/Python/lldbsuite/test/tools/lldb-mi/breakpoint/main.cpp
+++ b/lldb/packages/Python/lldbsuite/test/tools/lldb-mi/breakpoint/main.cpp
@@ -15,13 +15,16 @@ namespace ns
     int foo2(void) { printf("In foo2\n"); return 2; }
 }
 
-// BP_before_main
-
 int x;
-int
-main(int argc, char const *argv[])
-{
+int main(int argc, char const *argv[]) { // BP_main_decl
     printf("Print a formatted string so that GCC does not optimize this printf call: %s\n", argv[0]);
+  // This is a long comment with no code inside
+  // This is a long comment with no code inside
+  // This is a long comment with no code inside
+  // BP_in_main
+  // This is a long comment with no code inside
+  // This is a long comment with no code inside
+  // This is a long comment with no code inside
     x = ns::foo1() + ns::foo2();
     return 0; // BP_return
 }