Commit Graph

8 Commits

Author SHA1 Message Date
Zachary Turner ba968c0d1d [lit] Add a generic build script with a lit substitution.
This adds a script called build.py as well as a lit substitution
called %build that we can use to invoke it.  The idea is that
this allows a lit test to build test inferiors without having
to worry about architecture / platform specific differences,
command line syntax, finding / configurationg a proper toolchain,
and other issues.  They can simply write something like:

%build --arch=32 -o %t.exe %p/Inputs/foo.cpp

and it will just work.  This paves the way for being able to
run lit tests with multiple configurations, platforms, and
compilers with a single test.

Differential Revision: https://reviews.llvm.org/D54914

llvm-svn: 348058
2018-12-01 00:22:21 +00:00
Zachary Turner 58db03a116 Fix some issues with LLDB's lit configuration files.
Recently I tried to port LLDB's lit configuration files over to use a
on the surface, but broke some cases that weren't broken before and also
exposed some additional problems with the old approach that we were just
getting lucky with.

When we set up a lit environment, the goal is to make it as hermetic as
possible. We should not be relying on PATH and enabling the use of
arbitrary shell commands. Instead, only whitelisted commands should be
allowed. These are, generally speaking, the lit builtins such as echo,
cd, etc, as well as anything for which substitutions have been
explicitly set up for. These substitutions should map to the build
output directory, but in some cases it's useful to be able to override
this (for example to point to an installed tools directory).

This is, of course, how it's supposed to work. What was actually
happening is that we were bringing in PATH and LD_LIBRARY_PATH and then
just running the given run line as a shell command. This led to problems
such as finding the wrong version of clang-cl on PATH since it wasn't
even a substitution, and flakiness / non-determinism since the
environment the tests were running in would change per-machine. On the
other hand, it also made other things possible. For example, we had some
tests that were explicitly running cl.exe and link.exe instead of
clang-cl and lld-link and the only reason it worked at all is because it
was finding them on PATH. Unfortunately we can't entirely get rid of
these tests, because they support a few things in debug info that
clang-cl and lld-link don't (notably, the LF_UDT_MOD_SRC_LINE record
which makes some of the tests fail.

The high level changes introduced in this patch are:

1. Removal of functionality - The lit test suite no longer respects
   LLDB_TEST_C_COMPILER and LLDB_TEST_CXX_COMPILER. This means there is no
   more support for gcc, but nobody was using this anyway (note: The
   functionality is still there for the dotest suite, just not the lit test
   suite). There is no longer a single substitution %cxx and %cc which maps
   to <arbitrary-compiler>, you now explicitly specify the compiler with a
   substitution like %clang or %clangxx or %clang_cl. We can revisit this
   in the future when someone needs gcc.

2. Introduction of the LLDB_LIT_TOOLS_DIR directory. This does in spirit
   what LLDB_TEST_C_COMPILER and LLDB_TEST_CXX_COMPILER used to do, but now
   more friendly. If this is not specified, all tools are expected to be
   the just-built tools. If it is specified, the tools which are not
   themselves being tested but are being used to construct and run checks
   (e.g. clang, FileCheck, llvm-mc, etc) will be searched for in this
   directory first, then the build output directory.

3. Changes to core llvm lit files. The use_lld() and use_clang()
   functions were introduced long ago in anticipation of using them in
   lldb, but since they were never actually used anywhere but their
   respective problems, there were some issues to be resolved regarding
   generality and ability to use them outside their project.

4. Changes to .test files - These are all just replacing things like
   clang-cl with %clang_cl and %cxx with %clangxx, etc.

5. Changes to lit.cfg.py - Previously we would load up some system
   environment variables and then add some new things to them. Then do a
   bunch of work building out our own substitutions. First, we delete the
   system environment variable code, making the environment hermetic. Then,
   we refactor the substitution logic into two separate helper functions,
   one which sets up substitutions for the tools we want to test (which
   must come from the build output directory), and another which sets up
   substitutions for support tools (like compilers, etc).

6. New substitutions for MSVC -- Previously we relied on location of
   MSVC by bringing in the entire parent's PATH and letting
   subprocess.Popen just run the command line. Now we set up real
   substitutions that should have the same effect. We use PATH to find
   them, and then look for INCLUDE and LIB to construct a substitution
   command line with appropriate /I and /LIBPATH: arguments. The nice thing
   about this is that it opens the door to having separate %msvc-cl32 and
   %msvc-cl64 substitutions, rather than only requiring the user to run
   vcvars first. Because we can deduce the path to 32-bit libraries from
   64-bit library directories, and vice versa. Without these substitutions
   this would have been impossible.

Differential Revision: https://reviews.llvm.org/D54567

llvm-svn: 347216
2018-11-19 15:12:34 +00:00
Zachary Turner 71f484c967 Add REQUIRES: lld to SymbolFileNativePDB tests.
llvm-svn: 344431
2018-10-12 23:07:32 +00:00
Zachary Turner 8040eea9cb Try to fix some failures on MacOSX with the NativePDB patch.
This adds -- before any filenames, so that /U doesn't get interpreted
as a command line.

It also adds better error checking, so that we don't get assertions
on the failure path when a file fails to parse as a PDB.

llvm-svn: 344429
2018-10-12 22:57:40 +00:00
Zachary Turner 307f5ae898 Resubmit "Add SymbolFileNativePDB plugin."
This was originally reverted due to some test failures on
Linux.  Those problems turned out to require several additional
patches to lld and clang in order to fix, which have since been
submitted.  This patch is resubmitted unchanged.  All tests now
pass on both Linux and Windows.

llvm-svn: 344409
2018-10-12 19:47:13 +00:00
Zachary Turner e8a6c3eb96 Revert SymbolFileNativePDB plugin.
This was originally causing some test failures on non-Windows
platforms, which required fixes in the compiler and linker.  After
those fixes, however, other tests started failing.  Reverting
temporarily until I can address everything.

llvm-svn: 344279
2018-10-11 18:45:44 +00:00
Zachary Turner e502f8b315 Better support for POSIX paths in PDBs.
While it doesn't make a *ton* of sense for POSIX paths to be
in PDBs, it's possible to occur in real scenarios involving
cross compilation.

The tools need to be able to handle this, because certain types
of debugging scenarios are possible without a running process
and so don't necessarily require you to be on a Windows system.
These include post-mortem debugging and binary forensics (e.g.
using a debugger to disassemble functions and examine symbols
without running the process).

There's changes in clang, LLD, and lldb in this patch.  After
this the cross-platform disassembly and source-list tests pass
on Linux.

Furthermore, the behavior of LLD can now be summarized by a much
simpler rule than before: Unless you specify /pdbsourcepath and
/pdbaltpath, the PDB ends up with paths that are valid within
the context of the machine that the link is performed on.

Differential Revision: https://reviews.llvm.org/D53149

llvm-svn: 344269
2018-10-11 18:01:55 +00:00
Zachary Turner 72148edc36 Create a SymbolFile plugin for cross-platform PDB access.
The existing SymbolFilePDB only works on Windows, as it is written
against a closed-source Microsoft SDK that ships with their debugging
tools.

There are several reasons we want to bypass this and go straight to the
bits of the PDB, but just to list a few:

More room for optimization. We can't see inside the implementation of
the Microsoft SDK, so we don't always know if we're doing things in the
most efficient way possible. For example, setting a breakpoint on main
of a big program currently takes several seconds. With the
implementation here, the time is unnoticeable.
We want to be able to symbolize Windows minidumps even if not on
Windows. Someone should be able to debug Windows minidumps as if they
were on Windows, given that no running process is necessary.
This patch is a very crude first attempt at filling out some of the
basic pieces.

I've implemented FindFunctions, ParseCompileUnitLineTable, and
ResolveSymbolContext for a limited subset of possible parameter values,
which is just enough to get it to display something nice for the
breakpoint location.

I've added several tests exercising this functionality which are limited
enough to work on all platforms but still exercise this functionality.
I'll try to add as many tests of this nature as I can, but at some
point we'll need a live process.

For now, this plugin is enabled always on non-Windows, and by setting
the environment variable LLDB_USE_NATIVE_PDB_READER=1 on Windows.
Eventually, once it's at parity with the Windows implementation, we'll
delete the Windows DIA-based implementation.

Differential Revision: https://reviews.llvm.org/D53002

llvm-svn: 344154
2018-10-10 16:39:07 +00:00