[Clang] Check PP presence when printing stats

[ecnelises]

Front-end option -print-stats can be used to print statistics around the compilation process. But clang with this options will crash when input is IR file. This patch fixes the crash by checking preprocessor presence before invoking it.

[llvmbot]

@llvm/pr-subscribers-clang

Author: Qiu Chaofan (ecnelises)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/131608.diff

2 Files Affected:

• (modified) clang/lib/Frontend/FrontendAction.cpp (+8-4)
• (added) clang/test/Frontend/print-stats.ll (+6)

diff --git a/clang/lib/Frontend/FrontendAction.cpp b/clang/lib/Frontend/FrontendAction.cpp
index 9f789f093f55d..a750953393759 100644
--- a/clang/lib/Frontend/FrontendAction.cpp
+++ b/clang/lib/Frontend/FrontendAction.cpp
@@ -1120,10 +1120,14 @@ void FrontendAction::EndSourceFile() {
 
   if (CI.getFrontendOpts().ShowStats) {
     llvm::errs() << "\nSTATISTICS FOR '" << getCurrentFileOrBufferName() << "':\n";
-    CI.getPreprocessor().PrintStats();
-    CI.getPreprocessor().getIdentifierTable().PrintStats();
-    CI.getPreprocessor().getHeaderSearchInfo().PrintStats();
-    CI.getSourceManager().PrintStats();
+    if (CI.hasPreprocessor()) {
+      CI.getPreprocessor().PrintStats();
+      CI.getPreprocessor().getIdentifierTable().PrintStats();
+      CI.getPreprocessor().getHeaderSearchInfo().PrintStats();
+    }
+    if (CI.hasSourceManager()) {
+      CI.getSourceManager().PrintStats();
+    }
     llvm::errs() << "\n";
   }
 
diff --git a/clang/test/Frontend/print-stats.ll b/clang/test/Frontend/print-stats.ll
new file mode 100644
index 0000000000000..6fd094470ba95
--- /dev/null
+++ b/clang/test/Frontend/print-stats.ll
@@ -0,0 +1,6 @@
+; RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -print-stats \
+; RUN:    -emit-llvm -x ir %s -o - 2>&1 | FileCheck %s
+
+; CHECK: *** Source Manager Stats
+; CHECK: *** File Manager Stats
+; CHECK: *** Virtual File System Stats

[yronglin]

Thanks working on this! Can you add some description for this patch?

[shafik]

Thank you for the fix!

Second, that we need a summary explaining the problem and solution.

Is this linked to a bug report, if it is, then we should mention that bug report as well.

I would also like to see a test showing a case where we successfully print the preprocessor stats as well, if we don't already have one.

[cor3ntin]

This change needs a release note.
Please add an entry to clang/docs/ReleaseNotes.rst in the section the most adapted to the change, and referencing any Github issue this change fixes. Thanks!

[cor3ntin]

LGTM. Will you need me to merge this for you?

[ecnelises]

Done, thanks!

[MaskRay]

LGTM! Thanks for the fix