[libcxx-commits] [libcxx] 94c6dfb - [clang] Implement setting crash_diagnostics_dir through env variable

[Matheus Izvekov via libcxx-commits]

Author: Matheus Izvekov
Date: 2022-09-06T19:27:37+02:00
New Revision: 94c6dfbaebbd5b9474794b2437757dfb6aedefc3

URL: https://github.com/llvm/llvm-project/commit/94c6dfbaebbd5b9474794b2437757dfb6aedefc3
DIFF: https://github.com/llvm/llvm-project/commit/94c6dfbaebbd5b9474794b2437757dfb6aedefc3.diff

LOG: [clang] Implement setting crash_diagnostics_dir through env variable

This implements setting the equivalent of `-fcrash-diagnostics-dir`
through the environment variable `CLANG_CRASH_DIAGNOSTICS_DIR`.
If present, the flag still takes precedence.

This helps integration with test frameworks and pipelines.

With this feature, we change the libcxx bootstrapping build
pipeline to produce clang crash reproducers as artifacts.

Signed-off-by: Matheus Izvekov <mizvekov at gmail.com>

Differential Revision: https://reviews.llvm.org/D133082

Added: 
    clang/test/Driver/crash-diagnostics-dir-3.c

Modified: 
    clang/docs/ReleaseNotes.rst
    clang/docs/UsersManual.rst
    clang/lib/Driver/Driver.cpp
    libcxx/utils/ci/buildkite-pipeline.yml

Removed: 
    


################################################################################
diff  --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 146b2149f9d7e..1d381649b6bb4 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -135,6 +135,9 @@ Improvements to Clang's diagnostics
 
 Non-comprehensive list of changes in this release
 -------------------------------------------------
+- It's now possible to set the crash diagnostics directory through
+  the environment variable ``CLANG_CRASH_DIAGNOSTICS_DIR``.
+  The ``-fcrash-diagnostics-dir`` flag takes precedence.
 
 New Compiler Flags
 ------------------

diff  --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst
index bf17677274e0c..8afe5cab64cb5 100644
--- a/clang/docs/UsersManual.rst
+++ b/clang/docs/UsersManual.rst
@@ -687,6 +687,11 @@ of generating a delta reduced test case.
   Specify where to write the crash diagnostics files; defaults to the
   usual location for temporary files.
 
+.. envvar:: CLANG_CRASH_DIAGNOSTICS_DIR=<dir>
+
+   Like :option:`-fcrash-diagnostics-dir=<dir>`, specifies where to write the
+   crash diagnostics files, but with lower precedence than the option.
+
 Clang is also capable of generating preprocessed source file(s) and associated
 run script(s) even without a crash. This is specially useful when trying to
 generate a reproducer for warnings or errors while using modules.

diff  --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 0a61b5e2d62d4..3743515d3d43f 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -5413,15 +5413,18 @@ const char *Driver::CreateTempFile(Compilation &C, StringRef Prefix,
                                    StringRef BoundArch) const {
   SmallString<128> TmpName;
   Arg *A = C.getArgs().getLastArg(options::OPT_fcrash_diagnostics_dir);
-  if (CCGenDiagnostics && A) {
-    SmallString<128> CrashDirectory(A->getValue());
-    if (!getVFS().exists(CrashDirectory))
-      llvm::sys::fs::create_directories(CrashDirectory);
-    llvm::sys::path::append(CrashDirectory, Prefix);
+  Optional<std::string> CrashDirectory =
+      CCGenDiagnostics && A
+          ? std::string(A->getValue())
+          : llvm::sys::Process::GetEnv("CLANG_CRASH_DIAGNOSTICS_DIR");
+  if (CrashDirectory) {
+    if (!getVFS().exists(*CrashDirectory))
+      llvm::sys::fs::create_directories(*CrashDirectory);
+    SmallString<128> Path(*CrashDirectory);
+    llvm::sys::path::append(Path, Prefix);
     const char *Middle = !Suffix.empty() ? "-%%%%%%." : "-%%%%%%";
-    std::error_code EC = llvm::sys::fs::createUniqueFile(
-        CrashDirectory + Middle + Suffix, TmpName);
-    if (EC) {
+    if (std::error_code EC =
+            llvm::sys::fs::createUniqueFile(Path + Middle + Suffix, TmpName)) {
       Diag(clang::diag::err_unable_to_make_temp) << EC.message();
       return "";
     }

diff  --git a/clang/test/Driver/crash-diagnostics-dir-3.c b/clang/test/Driver/crash-diagnostics-dir-3.c
new file mode 100644
index 0000000000000..9529e30021045
--- /dev/null
+++ b/clang/test/Driver/crash-diagnostics-dir-3.c
@@ -0,0 +1,5 @@
+// RUN: rm -rf %t
+// RUN: not env CLANG_CRASH_DIAGNOSTICS_DIR=%t %clang -c %s -o - 2>&1 | FileCheck %s
+#pragma clang __debug parser_crash
+// CHECK: Preprocessed source(s) and associated run script(s) are located at:
+// CHECK: diagnostic msg: {{.*}}{{/|\\}}crash-diagnostics-dir-3.c.tmp{{(/|\\).*}}.c

diff  --git a/libcxx/utils/ci/buildkite-pipeline.yml b/libcxx/utils/ci/buildkite-pipeline.yml
index d15172980e612..61951720ef650 100644
--- a/libcxx/utils/ci/buildkite-pipeline.yml
+++ b/libcxx/utils/ci/buildkite-pipeline.yml
@@ -369,10 +369,12 @@ steps:
     artifact_paths:
       - "**/test-results.xml"
       - "**/*.abilist"
+      - "**/crash_diagnostics/*"
     env:
         CC: "clang-${LLVM_HEAD_VERSION}"
         CXX: "clang++-${LLVM_HEAD_VERSION}"
         LLVM_SYMBOLIZER_PATH: "/usr/bin/llvm-symbolizer-${LLVM_HEAD_VERSION}"
+        CLANG_CRASH_DIAGNOSTICS_DIR: "crash_diagnostics"
     agents:
       queue: "libcxx-builders"
       os: "linux"