Fix inlining to not produce duplicate landingpad clauses
Before this change, inlining one "invoke" into an outer "invoke" call
site can lead to the outer landingpad's catch/filter clauses being
copied multiple times into the resulting landingpad. This happens:
* when the inlined function contains multiple "resume" instructions,
because forwardResume() copies the clauses but is called multiple
times;
* when the inlined function contains a "resume" and a "call", because
HandleCallsInBlockInlinedThroughInvoke() copies the clauses but is
redundant with forwardResume().
Fix this by deduplicating the code.
This problem doesn't lead to any incorrect execution; it's only
untidy.
This change will make fixing PR17872 a little easier.
llvm-svn: 196710
diff --git a/llvm/test/Transforms/Inline/invoke-combine-clauses.ll b/llvm/test/Transforms/Inline/invoke-combine-clauses.ll
new file mode 100644
index 0000000..5f06039
--- /dev/null
+++ b/llvm/test/Transforms/Inline/invoke-combine-clauses.ll
@@ -0,0 +1,117 @@
+; RUN: opt %s -inline -S | FileCheck %s
+
+declare void @external_func()
+declare void @abort()
+
+@exception_inner = external global i8
+@exception_outer = external global i8
+@condition = external global i1
+
+
+; Check for a bug in which multiple "resume" instructions in the
+; inlined function caused "catch i8* @exception_outer" to appear
+; multiple times in the resulting landingpad.
+
+define internal void @inner_multiple_resume() {
+ invoke void @external_func()
+ to label %cont unwind label %lpad
+cont:
+ ret void
+lpad:
+ %lp = landingpad i32 personality i8* null
+ catch i8* @exception_inner
+ %cond = load i1* @condition
+ br i1 %cond, label %resume1, label %resume2
+resume1:
+ resume i32 1
+resume2:
+ resume i32 2
+}
+
+define void @outer_multiple_resume() {
+ invoke void @inner_multiple_resume()
+ to label %cont unwind label %lpad
+cont:
+ ret void
+lpad:
+ %lp = landingpad i32 personality i8* null
+ catch i8* @exception_outer
+ resume i32 %lp
+}
+; CHECK: define void @outer_multiple_resume()
+; CHECK: %lp.i = landingpad
+; CHECK-NEXT: catch i8* @exception_inner
+; CHECK-NEXT: catch i8* @exception_outer
+; Check that there isn't another "catch" clause:
+; CHECK-NEXT: load
+
+
+; Check for a bug in which having a "resume" and a "call" in the
+; inlined function caused "catch i8* @exception_outer" to appear
+; multiple times in the resulting landingpad.
+
+define internal void @inner_resume_and_call() {
+ call void @external_func()
+ invoke void @external_func()
+ to label %cont unwind label %lpad
+cont:
+ ret void
+lpad:
+ %lp = landingpad i32 personality i8* null
+ catch i8* @exception_inner
+ resume i32 %lp
+}
+
+define void @outer_resume_and_call() {
+ invoke void @inner_resume_and_call()
+ to label %cont unwind label %lpad
+cont:
+ ret void
+lpad:
+ %lp = landingpad i32 personality i8* null
+ catch i8* @exception_outer
+ resume i32 %lp
+}
+; CHECK: define void @outer_resume_and_call()
+; CHECK: %lp.i = landingpad
+; CHECK-NEXT: catch i8* @exception_inner
+; CHECK-NEXT: catch i8* @exception_outer
+; Check that there isn't another "catch" clause:
+; CHECK-NEXT: br
+
+
+; Check what happens if the inlined function contains an "invoke" but
+; no "resume". In this case, the inlined landingpad does not need to
+; include the "catch i8* @exception_outer" clause from the outer
+; function (since the outer function's landingpad will not be
+; reachable), but it's OK to include this clause.
+
+define internal void @inner_no_resume_or_call() {
+ invoke void @external_func()
+ to label %cont unwind label %lpad
+cont:
+ ret void
+lpad:
+ %lp = landingpad i32 personality i8* null
+ catch i8* @exception_inner
+ ; A landingpad might have no "resume" if a C++ destructor aborts.
+ call void @abort() noreturn nounwind
+ unreachable
+}
+
+define void @outer_no_resume_or_call() {
+ invoke void @inner_no_resume_or_call()
+ to label %cont unwind label %lpad
+cont:
+ ret void
+lpad:
+ %lp = landingpad i32 personality i8* null
+ catch i8* @exception_outer
+ resume i32 %lp
+}
+; CHECK: define void @outer_no_resume_or_call()
+; CHECK: %lp.i = landingpad
+; CHECK-NEXT: catch i8* @exception_inner
+; CHECK-NEXT: catch i8* @exception_outer
+; Check that there isn't another "catch" clause:
+; CHECK-NEXT: call void @abort()