[clang-doc] Avoid deref of invalid std::optional

[ilovepi]

Since our existing guard is insufficient to prevent accessing the
std::optional when in an invalid state, guard the access with
.value_or(). This maintains the desired behavior, without running into
UB.

The new test should prevent regressions.

Fixes #131697

[ilovepi]

• [clang-doc] Correct improper file paths in HTML output #132103
• [clang-doc][NFC] Remove unnecessary directory cleanup #132101
• [clang-doc] Avoid deref of invalid std::optional #131939 👈 (View in Graphite)
• [clang-doc] Enable MD tests in basic-project #131924
• [clang-doc] Add testing without --repository for HTML documentation #131894
• main

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[evelez7]

Fixes the crashes I was experiencing.

[llvmbot]

@llvm/pr-subscribers-clang-tools-extra

Author: Paul Kirth (ilovepi)

Changes

Since our existing guard is insufficient to prevent accessing the
std::optional when in an invalid state, guard the access with
.value_or(). This maintains the desired behavior, without running into
UB.

The new test should prevent regressions.

Fixes #131697

---

Full diff: https://github.com/llvm/llvm-project/pull/131939.diff

2 Files Affected:

• (modified) clang-tools-extra/clang-doc/HTMLGenerator.cpp (+1-1)
• (added) clang-tools-extra/test/clang-doc/DR-131697.cpp (+22)

diff --git a/clang-tools-extra/clang-doc/HTMLGenerator.cpp b/clang-tools-extra/clang-doc/HTMLGenerator.cpp
index 18a0de826630c..a8404479569f9 100644
--- a/clang-tools-extra/clang-doc/HTMLGenerator.cpp
+++ b/clang-tools-extra/clang-doc/HTMLGenerator.cpp
@@ -498,7 +498,7 @@ writeFileDefinition(const Location &L,
     return std::make_unique<TagNode>(
         HTMLTag::TAG_P, "Defined at line " + std::to_string(L.LineNumber) +
                             " of file " + L.Filename);
-  SmallString<128> FileURL(*RepositoryUrl);
+  SmallString<128> FileURL(RepositoryUrl.value_or(""));
   llvm::sys::path::append(
       FileURL, llvm::sys::path::Style::posix,
       // If we're on Windows, the file name will be in the wrong format, and
diff --git a/clang-tools-extra/test/clang-doc/DR-131697.cpp b/clang-tools-extra/test/clang-doc/DR-131697.cpp
new file mode 100644
index 0000000000000..50556ecd2635b
--- /dev/null
+++ b/clang-tools-extra/test/clang-doc/DR-131697.cpp
@@ -0,0 +1,22 @@
+// RUN: rm -rf %t && mkdir -p %t
+// RUN: split-file %s %t
+// RUN: clang-doc -format=html %t/compile-commands.json %t/main.cpp
+
+//--- main.cpp
+
+class Foo {
+  void getFoo();
+};
+
+int main() {
+  return 0;
+}
+
+//--- compile-commands.json
+[
+{
+  "directory": "foo",
+  "file":"main.cpp",
+  "command":"clang main.cpp -c"
+}
+]

[ilovepi]

Merge activity

• Mar 20, 5:02 PM EDT: A user started a stack merge that includes this pull request via Graphite.
• Mar 20, 5:03 PM EDT: Graphite rebased this pull request as part of a merge.
• Mar 20, 5:04 PM EDT: A user merged this pull request with Graphite.