[clang] [LifetimeSafety] Overhaul CFG and analysis to also work with trivially destructed temporary objects (PR #177985)

[Utkarsh Saxena via cfe-commits]

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@@ -298,19 +298,19 @@ std::string_view danglingRefToOptionalFromTemp4() {
 void danglingReferenceFromTempOwner() {
   int &&r = *std::optional<int>();          // expected-warning {{object backing the pointer will be destroyed at the end of the full-expression}} \
                                             // cfg-warning {{object whose reference is captured does not live long enough}} cfg-note {{destroyed here}}
-  // FIXME: Detect this using the CFG-based lifetime analysis.
   //        https://github.com/llvm/llvm-project/issues/175893
-  int &&r2 = *std::optional<int>(5);        // expected-warning {{object backing the pointer will be destroyed at the end of the full-expression}}
+  int &&r2 = *std::optional<int>(5);        // expected-warning {{object backing the pointer will be destroyed at the end of the full-expression}} \
+                                              // cfg-warning {{object whose reference is captured does not live long enough}} cfg-note {{destroyed here}}
 
-  // FIXME: Detect this using the CFG-based lifetime analysis.
   //        https://github.com/llvm/llvm-project/issues/175893
-  int &&r3 = std::optional<int>(5).value(); // expected-warning {{object backing the pointer will be destroyed at the end of the full-expression}}
+  int &&r3 = std::optional<int>(5).value(); // expected-warning {{object backing the pointer will be destroyed at the end of the full-expression}} \
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usx95 wrote:

Could you please add a fixes link to the end of the description for all the bugs that this will fix. Example

Fixes https://github.com/llvm/llvm-project/issues/175893

https://github.com/llvm/llvm-project/pull/177985