[Dexter] Remove false requirement of lldb for dexter regression tests on Windows

Not quite NFC because a little work was required to configure some tests to run
on Windows at all.

Before this patch on Windows:

    $ llvm-lit cross-project-tests\debuginfo-tests\dexter\feature-tests
       Unsupported: 49
       Passed     : 23

After this patch on Windows:

    $ llvm-lit cross-project-tests\debuginfo-tests\dexter\feature-tests
       Unsupported      : 27
       Passed           : 39
       Expectedly failed:  6

There are 3 main changes here. The first is to add a few more substitutions in
cross-project-tests/lit.cfg.py so that tests need to use specific flags can
still use the dexter regression test defaults for the native platform. These
are:

     %dexter_regression_test_debugger
     %dexter_regression_test_builder
     %dexter_regression_test_cflags
     %dexter_regression_test_ldflags

Tests that now use these options and therefore can be run on Windows too
(though the second is still failing for unknown reasons):

    cross-project-tests/debuginfo-tests/dexte/feature_tests
        /subtools/clang-opt-bisect/clang-opt-bisect.cpp
        /subtools/test/source-root-dir.cpp

The second change is to remove spurious `REQUIRES: system-linux, lldb` and
`UNSUPPORTED: system-windows` directives, and make changes to lit.local.cfg
files that have the same effect. I've also added comments to the genuine
REQUIRES, UNSUPPORTED, and XFAIL directives so it's easier to understand
requirements at a glance. The most common reason for a test to not be supported
on Windows is that it uses DexLimitSteps, DexDeclareAddress, or DexCommandLine,
none of which are supported in the dbgeng driver.

There are two failures on Windows that were previously hidden, which I've
XFAILed:

    cross-project-tests/debuginfo-tests/dexter/feature_tests
        /commands/perfect/dex_finish_test/default_conditional.cpp
        /commands/perfect/dex_finish_test/default_conditional_hit_count.cpp

And two that were easy to fix:

    cross-project-tests/debuginfo-tests/dexter/feature_tests
        /commands/perfect/dex_finish_test/default_simple.cpp
        /commands/perfect/dex_finish_test/default_hit_count.cpp

Lastly, I've set three directories as unsupported.

    cross-project-tests/debuginfo-tests/dexter/feature_tests
        /commands/perfect/limit_steps
        /commands/perfect/dex_declare_address
        /commands/perfect/dex_declare_file

The first two are unsupported on Windows because they contains tests for the
DexLimitSteps and DexDeclareAddress commands which aren't supported in the
dbgeng driver. The third is unsupported on all platforms as the tests involve
invoking clang directly, which isn't currently a supported way of building
tests for dexter in lit (it can cause problems for cross compilers that can
target the host, as the tests use the default triple and linker, which may
be aligned for the default target, not host).

Tested on Windows and Linux.

Reviewed By: jmorse

Differential Revision: https://reviews.llvm.org/D118048

Author: OCHyams

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/penalty/missing_dex_address.cpp

@@ -2,7 +2,8 @@
 //      Test that when a \DexDeclareAddress never resolves to a value, it is
 //      counted as a missing value in any \DexExpectWatchValues.
 //
-// REQUIRES: system-linux
+// The dbgeng driver doesn't support \DexDeclareAddress yet.
+// UNSUPPORTED: system-windows
 //
 // RUN: not %dexter_regression_test -- %s | FileCheck %s
 // CHECK: missing_dex_address.cpp

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/command_line.c

@@ -1,4 +1,5 @@
-// UNSUPPORTED: dbgeng
+// The dbgeng driver doesn't support \DexCommandLine yet.
+// UNSUPPORTED: system-windows
 //
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: command_line.c:

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_declare_address/address_after_ref.cpp

@@ -2,8 +2,6 @@
 //      Test that a \DexDeclareAddress value can have its value defined after
 //      the first reference to that value.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: address_after_ref.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_declare_address/address_hit_count.cpp

@@ -4,8 +4,6 @@
 //      expression after the target line has been stepped on a given number of
 //      times.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: address_hit_count.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_declare_address/expression_address.cpp

@@ -2,8 +2,6 @@
 //      Test that a \DexDeclareAddress value can be used to compare the
 //      addresses of two local variables that refer to the same address.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: expression_address.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_declare_address/identical_address.cpp

@@ -2,8 +2,6 @@
 //      Test that a \DexDeclareAddress value can be used to compare two equal
 //      pointer variables.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: identical_address.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_declare_address/lit.local.cfg

@@ -0,0 +1,3 @@
+# The dbgeng driver doesn't support DexDeclareAddress yet.
+if config.is_msvc:
+    config.unsupported = True

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_declare_address/multiple_address.cpp

@@ -2,8 +2,6 @@
 //      Test that multiple \DexDeclareAddress references that point to different
 //      addresses can be used within a single \DexExpectWatchValue.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: multiple_address.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_declare_address/offset_address.cpp

@@ -2,8 +2,6 @@
 //      Test that a \DexDeclareAddress value can be used to compare two pointer
 //      variables that have a fixed offset between them.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: offset_address.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_declare_address/self_comparison.cpp

@@ -2,8 +2,6 @@
 //      Test that a \DexDeclareAddress value can be used to check the change in
 //      value of a variable over time, relative to its initial value.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: self_comparison.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_declare_file/lit.local.cfg

@@ -0,0 +1,3 @@
+# FIXME: These tests compile code with %clang substitution which needs to run
+# natively but doesn't specify target triple (i.e. default triple is used).
+config.unsupported = True

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_declare_file/precompiled_binary_different_dir/dex_commands/source_root_dir.dex

@@ -2,7 +2,6 @@
 ##    Check that \DexDeclareFile's file declaration can be made relative to the
 ##    --source-root-dir path.
 
-# REQUIRES: lldb
 # UNSUPPORTED: system-darwin
 
 # RUN: %clang %S/../source/test.cpp -O0 -g -o %t

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_finish_test/default_conditional.cpp

@@ -1,11 +1,11 @@
+// FIXME: Feature appears to be broken on Windows with dbgeng.
+// XFAIL: system-windows
 // Purpose:
 //      Test that \DexFinishTest can be used with a condition, so the test exits
 //      when the line referenced by \DexFinishTest is stepped on and the given
 //      condition (x == 5) is satisfied.
 //      Tests using the default controller (no \DexLimitSteps).
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: default_conditional.cpp
 
@@ -15,4 +15,4 @@ int main() {
 }
 
 // DexFinishTest('x', 5, on_line=ref('finish_line'))
-// DexExpectWatchValue('x', 0, 1, 2, 3, 4, 5)
+// DexExpectWatchValue('x', 0, 1, 2, 3, 4, 5, on_line=ref('finish_line'))

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_finish_test/default_conditional_hit_count.cpp

@@ -1,12 +1,12 @@
+// FIXME: Feature appears to be broken on Windows with dbgeng.
+// XFAIL: system-windows
 // Purpose:
 //      Test that \DexFinishTest can be used with a combination of a hit_count
 //      and a condition, so that the test exits after the line referenced
 //      by \DexFinishTest is stepped on while the condition (x == 2) is true a
 //      given number of times.
 //      Tests using the default controller (no \DexLimitSteps).
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: default_conditional_hit_count.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_finish_test/default_hit_count.cpp

@@ -4,8 +4,6 @@
 //      specific number of times.
 //      Tests using the default controller (no \DexLimitSteps).
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: default_hit_count.cpp
 
@@ -15,4 +13,4 @@ int main() {
 }
 
 // DexFinishTest(on_line=ref('finish_line'), hit_count=5)
-// DexExpectWatchValue('x', 0, 1, 2, 3, 4, 5)
+// DexExpectWatchValue('x', 0, 1, 2, 3, 4, 5, on_line=ref('finish_line'))

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_finish_test/default_simple.cpp

@@ -4,16 +4,14 @@
 //      is stepped on.
 //      Tests using the default controller (no \DexLimitSteps).
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: default_simple.cpp
 
 int main() {
-    int x = 0; // DexLabel('start_line')
-    x = 1;
+    int x = 0;
+    x = 1; // DexLabel('start_line')
     x = 2; // DexLabel('finish_line')
 }
 
 // DexFinishTest(on_line=ref('finish_line'))
-// DexExpectWatchValue('x', 0, 1)
+// DexExpectWatchValue('x', 0, 1, from_line=ref('start_line'), to_line=ref('finish_line'))

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_finish_test/limit_steps_conditional.cpp

@@ -4,7 +4,8 @@
 //      condition (x == 5) is satisfied.
 //      Test using the conditional controller (using \DexLimitSteps).
 //
-// REQUIRES: system-linux
+// The dbgeng driver doesn't support \DexLimitSteps yet.
+// UNSUPPORTED: system-windows
 //
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: limit_steps_conditional.cpp

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_finish_test/limit_steps_conditional_hit_count.cpp

@@ -5,7 +5,8 @@
 //      given number of times.
 //      Test using the conditional controller (using \DexLimitSteps).
 //
-// REQUIRES: system-linux
+// The dbgeng driver doesn't support \DexLimitSteps yet.
+// UNSUPPORTED: system-windows
 //
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: limit_steps_conditional_hit_count.cpp

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_finish_test/limit_steps_hit_count.cpp

@@ -4,7 +4,8 @@
 //      specific number of times.
 //      Test using the conditional controller (using \DexLimitSteps).
 //
-// REQUIRES: system-linux
+// The dbgeng driver doesn't support \DexLimitSteps yet.
+// UNSUPPORTED: system-windows
 //
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: limit_steps_hit_count.cpp

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/dex_finish_test/limit_steps_simple.cpp

@@ -4,7 +4,8 @@
 //      is stepped on.
 //      Test using the conditional controller (using \DexLimitSteps).
 //
-// REQUIRES: system-linux
+// The dbgeng driver doesn't support \DexLimitSteps yet.
+// UNSUPPORTED: system-windows
 //
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: limit_steps_simple.cpp

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/hit_count.cpp

@@ -2,8 +2,6 @@
 //      Test that \DexLimitSteps keyword argument hit_count correctly limits
 //      the number of times the command can trigger.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: hit_count.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/limit_steps_check_json_step_count.cpp

@@ -1,8 +1,6 @@
 // Purpose:
 //      Check number of step lines are correctly reported in json output.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test --verbose -- %s | FileCheck %s
 // CHECK: limit_steps_check_json_step_count.cpp
 // CHECK: ## BEGIN ##

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/limit_steps_expect_loop.cpp

@@ -2,8 +2,6 @@
 //      Check the DexLimit steps only gathers step info for 2 iterations of a
 //      for loop.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: limit_steps_expect_loop.cpp:
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/limit_steps_expect_value.cpp

@@ -1,8 +1,6 @@
 // Purpose:
 //      Ensure that limited stepping breaks for all expected values.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: limit_steps_expect_value.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/limit_steps_line_mismatch.cpp

@@ -3,11 +3,6 @@
 //      doesn't exist. This can happen due to optimisations or label is on an
 //      empty line.
 //
-// FIXME: Windows regression tests run with dbgeng. \DexLimitSteps isn't yet
-// supported with dbgeng.
-//
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: limit_steps_line_mismatch.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/limit_steps_overlapping_ranges.cpp

@@ -1,8 +1,6 @@
 // Purpose:
 //      Ensure that multiple overlapping \DexLimitSteps ranges do not interfere.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: limit_steps_overlapping_ranges.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/limit_steps_same_line_conditional.cpp

@@ -1,8 +1,6 @@
 // Purpose:
 //      Test that LimitStep commands can exist on the same from line.
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: limit_steps_same_line_conditional.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/lit.local.cfg

@@ -0,0 +1,4 @@
+# The dbgeng driver doesn't support DexLimitSteps yet.
+if config.is_msvc:
+    config.unsupported = True
+

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/unconditional.cpp

@@ -2,8 +2,6 @@
 //      Test that \DexLimitSteps can be used without a condition (i.e. the
 //      breakpoint range is set any time from_line is stepped on).
 //
-// REQUIRES: system-linux
-//
 // RUN: %dexter_regression_test -- %s | FileCheck %s
 // CHECK: unconditional.cpp
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/lit.local.cfg

@@ -1,12 +1,14 @@
 // Purpose:
 //     Check the `clang-opt-bisect` tool runs with typical input.
 //
-// REQUIRES: system-linux, lldb
-//
 // RUN: true
-// RUN: %dexter_base clang-opt-bisect --debugger 'lldb' --builder 'clang' \
-// RUN:     --cflags "-O0 -g" -- %s \
-// RUN:     | FileCheck %s
+// RUN: %dexter_base clang-opt-bisect \
+// RUN:     --debugger %dexter_regression_test_debugger \
+// RUN:     --builder %dexter_regression_test_builder \
+// RUN:     --cflags "%dexter_regression_test_cflags" \
+// RUN:     --ldflags "%dexter_regression_test_ldflags" \
+// RUN:     -- %s \
+// RUN: | FileCheck %s
 // CHECK: running pass 0
 // CHECK: wrote{{.*}}per_pass_score
 // CHECK: wrote{{.*}}pass-summary

cross-project-tests/debuginfo-tests/dexter/feature_tests/subtools/clang-opt-bisect/clang-opt-bisect.cpp

@@ -8,7 +8,8 @@
 //      display the address properly; if it is implemented, this test should be
 //      updated.
 //
-// REQUIRES: lldb, system-linux
+// The dbgeng driver doesn't support \DexLimitSteps yet.
+// UNSUPPORTED: system-windows
 //
 // RUN: not %dexter_regression_test -v -- %s | FileCheck %s
 

cross-project-tests/debuginfo-tests/dexter/feature_tests/subtools/test/address_printing.cpp

@@ -3,8 +3,7 @@
 //    in a \DexLimitSteps command results in a useful error message.
 //    Use --binary switch to trick dexter into skipping the build step.
 //
-// REQUIRES: system-linux
 // RUN: not %dexter_base test --binary %s --debugger 'lldb' -- %s | FileCheck %s
-// CHECK: parser error:{{.*}}err_limit_steps_no_values.cpp(10): expected 0 or at least 2 positional arguments
+// CHECK: parser error:{{.*}}err_limit_steps_no_values.cpp(9): expected 0 or at least 2 positional arguments
 
 // DexLimitSteps('test')

cross-project-tests/debuginfo-tests/dexter/feature_tests/subtools/test/err_limit_steps_no_values.cpp

@@ -1,6 +1,3 @@
-// REQUIRES: lldb
-// UNSUPPORTED: system-windows
-//
 // Purpose:
 //    Check that the optional keyword argument 'on_line' makes a \DexLabel label
 //    that line instead of the line the command is found on.
@@ -13,5 +10,5 @@ int main() {
   return result;
 }
 
-// DexLabel('test', on_line=13)
+// DexLabel('test', on_line=10)
 // DexExpectWatchValue('result', '0', on_line=ref('test'))

cross-project-tests/debuginfo-tests/dexter/feature_tests/subtools/test/label_another_line.cpp

@@ -1,4 +1,3 @@
-// REQUIRES: lldb
 // Purpose:
 //      Check that we can use label-relative line numbers.
 //

cross-project-tests/debuginfo-tests/dexter/feature_tests/subtools/test/label_offset.cpp

@@ -1,12 +1,10 @@
-// XFAIL:*
 // This test started failing recently for unknown reasons.
-
-// REQUIRES: lldb
-// UNSUPPORTED: system-windows
-//
+// XFAIL:*
 // RUN: %dexter --fail-lt 1.0 -w \
-// RUN:     --builder 'clang' --debugger 'lldb' \
-// RUN:     --cflags "-O0 -glldb -fdebug-prefix-map=%S=/changed" \
+// RUN:     --builder %dexter_regression_test_builder \
+// RUN:     --debugger %dexter_regression_test_debugger \
+// RUN:     --cflags "%dexter_regression_test_cflags -fdebug-prefix-map=%S=/changed" \
+// RUN:     --ldflags "%dexter_regression_test_ldflags" \
 // RUN:     --source-root-dir=%S --debugger-use-relative-paths -- %s
 
 #include <stdio.h>

cross-project-tests/debuginfo-tests/dexter/feature_tests/subtools/test/source-root-dir.cpp

@@ -1,4 +1,3 @@
-// REQUIRES: lldb
 // Purpose:
 //      Check the `view` subtool works with typical inputs.
 //