[libclang] Allow to put a reproducer into a custom location. (#10577)

Tools using the reproducers can specify a custom location to support
scenarios similar to those covered by `-fcrash-diagnostics-dir` and
`CLANG_CRASH_DIAGNOSTICS_DIR`.

Author: vsapsai

clang/include/clang-c/Dependencies.h

@@ -336,6 +336,10 @@ CINDEX_LINKAGE void
  * \param argc the number of compiler invocation arguments (including argv[0]).
  * \param argv the compiler driver invocation arguments (including argv[0]).
  * \param WorkingDirectory the directory in which the invocation runs.
+ * \param ReproducerLocation the directory where to store the reproducer files.
+ *                           If NULL, use a temporary location.
+ * \param UseUniqueReproducerName if reproducer files should have unique names
+ *                                to avoid collisions with existing files.
  * \param [out] MessageOut A pointer to store the human-readable message
  *                         describing the result of the operation. If non-NULL,
  *                         owned and should be disposed by the caller.
@@ -347,6 +351,7 @@ CINDEX_LINKAGE void
 CINDEX_LINKAGE enum CXErrorCode
 clang_experimental_DependencyScanner_generateReproducer(
     int argc, const char *const *argv, const char *WorkingDirectory,
+    const char *ReproducerLocation, bool UseUniqueReproducerName,
     CXString *MessageOut);
 
 /**

clang/test/Modules/reproducer-with-module-dependencies.c

@@ -13,6 +13,12 @@
 // RUN:   -- clang-executable -c %t/failed-reproducer.c -o %t/reproducer.o \
 // RUN:      -fmodules -fmodules-cache-path=%t 2>&1 | FileCheck %t/failed-reproducer.c
 
+// Test the content of a reproducer script.
+// RUN: c-index-test core -gen-deps-reproducer -working-dir %t -o %t/repro-content \
+// RUN:   -- clang-executable -c %t/reproducer.c -o %t/reproducer.o \
+// RUN:      -fmodules -fmodules-cache-path=%t
+// RUN: FileCheck %t/script-expectations.txt --input-file %t/repro-content/reproducer.sh
+
 //--- modular-header.h
 void fn_in_modular_header(void);
 
@@ -30,3 +36,7 @@ void test(void) {
 //--- failed-reproducer.c
 // CHECK: fatal error: 'non-existing-header.h' file not found
 #include "non-existing-header.h"
+
+//--- script-expectations.txt
+CHECK: clang-executable
+CHECK: -fmodule-file=Test=reproducer.cache/explicitly-built-modules/Test-{{.*}}.pcm

clang/tools/c-index-test/core_main.cpp

@@ -925,14 +925,17 @@ static int scanDeps(ArrayRef<const char *> Args, std::string WorkingDirectory,
 }
 
 static int generateDepsReproducer(ArrayRef<const char *> Args,
-                                  std::string WorkingDirectory) {
+                                  std::string WorkingDirectory,
+                                  std::string ReproLocation) {
   CXString MessageString;
   auto DisposeMessageString = llvm::make_scope_exit([&]() {
     clang_disposeString(MessageString);
   });
   CXErrorCode ExitCode =
       clang_experimental_DependencyScanner_generateReproducer(
-          Args.size(), Args.data(), WorkingDirectory.c_str(), &MessageString);
+          Args.size(), Args.data(), WorkingDirectory.c_str(),
+          ReproLocation.empty() ? nullptr : ReproLocation.c_str(),
+          /*UseUniqueReproducerName=*/ReproLocation.empty(), &MessageString);
   if (ExitCode == CXError_Success) {
     llvm::outs() << clang_getCString(MessageString) << "\n";
   } else {
@@ -1571,7 +1574,8 @@ int indextest_core_main(int argc, const char **argv) {
       errs() << "error: missing -working-dir\n";
       return 1;
     }
-    return generateDepsReproducer(CompArgs, options::WorkingDir);
+    return generateDepsReproducer(CompArgs, options::WorkingDir,
+                                  options::OutputFile);
   }
 
   if (options::Action == ActionType::UploadCachedJob) {

clang/tools/libclang/CDependencies.cpp

@@ -345,6 +345,7 @@ class MessageEmitter {
 
 enum CXErrorCode clang_experimental_DependencyScanner_generateReproducer(
     int argc, const char *const *argv, const char *WorkingDirectory,
+    const char *ReproducerLocation, bool UseUniqueReproducerName,
     CXString *MessageOut) {
   auto Report = [MessageOut](CXErrorCode ErrorCode) -> MessageEmitter {
     return MessageEmitter(ErrorCode, MessageOut);
@@ -357,6 +358,9 @@ enum CXErrorCode clang_experimental_DependencyScanner_generateReproducer(
     return Report(CXError_InvalidArguments) << "missing compilation command";
   if (!WorkingDirectory)
     return Report(CXError_InvalidArguments) << "missing working directory";
+  if (!UseUniqueReproducerName && !ReproducerLocation)
+    return Report(CXError_InvalidArguments)
+           << "non-unique reproducer is allowed only in a custom location";
 
   CASOptions CASOpts;
   IntrusiveRefCntPtr<llvm::cas::CachingOnDiskFileSystem> FS;
@@ -367,9 +371,26 @@ enum CXErrorCode clang_experimental_DependencyScanner_generateReproducer(
 
   llvm::SmallString<128> ReproScriptPath;
   int ScriptFD;
-  if (auto EC = llvm::sys::fs::createTemporaryFile("reproducer", "sh", ScriptFD,
-                                                   ReproScriptPath)) {
-    return ReportFailure() << "failed to create a reproducer script file";
+  if (ReproducerLocation) {
+    if (!llvm::sys::fs::exists(ReproducerLocation)) {
+      if (auto EC = llvm::sys::fs::create_directories(ReproducerLocation))
+        return ReportFailure() << "failed to create a reproducer location '"
+                               << ReproducerLocation << "'\n"
+                               << EC.message();
+    }
+    SmallString<128> Path(ReproducerLocation);
+    llvm::sys::path::append(Path, "reproducer");
+    const char *UniqueSuffix = UseUniqueReproducerName ? "-%%%%%%" : "";
+    if (auto EC = llvm::sys::fs::createUniqueFile(Path + UniqueSuffix + ".sh",
+                                                  ScriptFD, ReproScriptPath))
+      return ReportFailure() << "failed to create a reproducer script file\n"
+                             << EC.message();
+  } else {
+    if (auto EC = llvm::sys::fs::createTemporaryFile(
+            "reproducer", "sh", ScriptFD, ReproScriptPath)) {
+      return ReportFailure() << "failed to create a reproducer script file\n"
+                             << EC.message();
+    }
   }
   SmallString<128> FileCachePath = ReproScriptPath;
   llvm::sys::path::replace_extension(FileCachePath, ".cache");