[lldb/Test] Disallow using substituted binaries in shell test.

[JDevlieghere]

Summary

Explicitly disallow using lldb instead of %lldb in the shell tests. This is a clever trick that is used by Swift to achieve the same results.

For example, this would've caught the use of lldb in PT_LOAD-overlap-PT_TLS.yaml:

FAIL: lldb-shell :: ObjectFile/ELF/PT_LOAD-overlap-PT_TLS.yaml (50 of 305)
******************** TEST 'lldb-shell :: ObjectFile/ELF/PT_LOAD-overlap-PT_TLS.yaml' FAILED ********************
Script:
--
: 'RUN: at line 3';   /Volumes/Jonas/llvm/build-ra/bin/yaml2obj /Volumes/Jonas/llvm/llvm-project/lldb/test/Shell/ObjectFile/ELF/PT_LOAD-overlap-PT_TLS.yaml > /Volumes/Jonas/llvm/build-ra/tools/lldb/test/ObjectFile/ELF/Output/PT_LOAD-overlap-PT_TLS.yaml.tmp
: 'RUN: at line 4';   /Volumes/Jonas/llvm/build-ra/bin/lldb-test object-file /Volumes/Jonas/llvm/build-ra/tools/lldb/test/ObjectFile/ELF/Output/PT_LOAD-overlap-PT_TLS.yaml.tmp | /Volumes/Jonas/llvm/build-ra/bin/FileCheck /Volumes/Jonas/llvm/llvm-project/lldb/test/Shell/ObjectFile/ELF/PT_LOAD-overlap-PT_TLS.yaml
: 'RUN: at line 5';
    echo '*** Do not use 'lldb' in tests; use '%''lldb'. ***' &&
    exit 1 && echo
  /Volumes/Jonas/llvm/build-ra/tools/lldb/test/ObjectFile/ELF/Output/PT_LOAD-overlap-PT_TLS.yaml.tmp -o "image lookup -a 0x1000" -b | /Volumes/Jonas/llvm/build-ra/bin/FileCheck --check-prefix=LOOKUP /Volumes/Jonas/llvm/llvm-project/lldb/test/Shell/ObjectFile/ELF/PT_LOAD-overlap-PT_TLS.yaml
--
Exit Code: 1

Command Output (stdout):
--
*** Do not use lldb in tests; use %lldb. ***

[compnerd]

lldb/test/Shell/helper/toolchain.py

24

Wow, that took a couple of reads to figure out what was being formatted where. I wish that there was a nicer way to write that.

[JDevlieghere]

lldb/test/Shell/helper/toolchain.py

24

Yeah...

lldb/test/Shell/helper/toolchain.py

 import os
 import itertools
 import platform
 import subprocess
 import sys
 
 import lit.util
 from lit.llvm import llvm_config
 from lit.llvm.subst import FindTool
 from lit.llvm.subst import ToolSubst
 
 
 def _get_lldb_init_path(config):
     return os.path.join(config.test_exec_root, 'Shell', 'lit-lldb-init')
 
 
+def _disallow(config, execName):
+  warning = '''
+    echo '*** Do not use \'{0}\' in tests; use \'%''{0}\'. ***' &&
+    exit 1 && echo
+  '''
+  config.substitutions.append((' {0} '.format(execName),
+                               warning.format(execName)))
+
+
 def use_lldb_substitutions(config):
     # Set up substitutions for primary tools.  These tools must come from config.lldb_tools_dir
     # which is basically the build output directory.  We do not want to find these in path or
     # anywhere else, since they are specifically the programs which are actually being tested.
 
     dsname = 'debugserver' if platform.system() in ['Darwin'] else 'lldb-server'
     dsargs = [] if platform.system() in ['Darwin'] else ['gdbserver']
 
primary_tools = [
                   unresolved='ignore'),
         'lldb-test',
         'lldb-instr',
         ToolSubst('%build',
                   command="'" + sys.executable + "'",
                   extra_args=build_script_args)
         ]
 
+    _disallow(config, 'lldb')
+    _disallow(config, 'debugserver')
+    _disallow(config, 'platformserver')
+
     llvm_config.add_tool_substitutions(primary_tools,
                                        [config.lldb_tools_dir])
 
 def _use_msvc_substitutions(config):
     # If running from a Visual Studio Command prompt (e.g. vcvars), this will
     # detect the include and lib paths, and find cl.exe and link.exe and create
     # substitutions for each of them that explicitly specify /I and /L paths
     cl = lit.util.which('cl')
def use_support_substitutions(config):
 
 
     support_tools = ['yaml2obj', 'obj2yaml', 'llvm-pdbutil',
                      'llvm-mc', 'llvm-readobj', 'llvm-objdump',
                      'llvm-objcopy', 'lli']
     additional_tool_dirs += [config.lldb_tools_dir, config.llvm_tools_dir]
     llvm_config.add_tool_substitutions(support_tools, additional_tool_dirs)
 
+    _disallow(config, 'clang')
 
 def use_lldb_repro_substitutions(config, mode):
     lldb_init = _get_lldb_init_path(config)
     substitutions = [
         ToolSubst(
             '%lldb',
             command=FindTool('lldb-repro'),
             extra_args=[mode, '--no-lldbinit', '-S', lldb_init]),
         ToolSubst(
             '%lldb-init',
             command=FindTool('lldb-repro'),
             extra_args=[mode, '-S', lldb_init]),
     ]
     llvm_config.add_tool_substitutions(substitutions)