Adding a pass - RewritePNaClLibraryCalls, that replaces known library calls with stable bitcode int…

test/Transforms/NaCl/rewrite-setlongjmp-calls.ll

Index: test/Transforms/NaCl/rewrite-setlongjmp-calls.ll
diff --git a/test/Transforms/NaCl/rewrite-setlongjmp-calls.ll b/test/Transforms/NaCl/rewrite-setlongjmp-calls.ll
new file mode 100644
index 0000000000000000000000000000000000000000..afb40bf9726b500aee5f0a04dda83e8b40ba7554
--- /dev/null
+++ b/test/Transforms/NaCl/rewrite-setlongjmp-calls.ll
@@ -0,0 +1,52 @@
+; RUN: opt < %s -rewrite-pnacl-library-calls -S | FileCheck %s
+; Test the RewritePNaClLibraryCalls pass
+
+declare i32 @setjmp(i64*)

[jvoung (off chromium), 2013/05/10 16:42:49]

CHECK that it now declares the llvm.nacl.setjmp and longjmp, as well?

[eliben, 2013/05/10 23:39:52]

Done.

[eliben, 2013/05/10 23:39:52]

Done.

+declare void @longjmp(i64*, i32)
+
+define i32 @call_setjmp(i64* %arg) {
+; CHECK-NOT: call i32 @setjmp
+; CHECK: %jmp_buf_i8 = bitcast i64* %arg to i8*
+; CHECK-NEXT: call i32 @llvm.nacl.setjmp(i8* %jmp_buf_i8)

[Mark Seaborn, 2013/05/10 16:34:36]

Make this: "%val = call"

[eliben, 2013/05/10 23:39:52]

Done.

+  %val = call i32 @setjmp(i64* %arg)
+  ret i32 %val
+}
+
+define void @call_longjmp(i64* %arg, i32 %num) {
+; CHECK-NOT: call void @longjmp
+; CHECK: %jmp_buf_i8 = bitcast i64* %arg to i8*
+; CHECK-NEXT: call void @llvm.nacl.longjmp(i8* %jmp_buf_i8, i32 %num)
+  call void @longjmp(i64* %arg, i32 %num)
+  ret void
+}
+
+; A more complex example with a number of calls in several BBs
+define void @multiple_calls(i64* %arg, i32 %num) {
+entryblock:
+; CHECK: entryblock
+; CHECK: bitcast
+; CHECK-NEXT: call void @llvm.nacl.longjmp
+  call void @longjmp(i64* %arg, i32 %num)

[jvoung (off chromium), 2013/05/10 16:42:49]

This function doesn't quite have the "normal" usage of longjmp and setjmp.

longjmp doesn't return to the point right after it (almost like there's an
"unreachable" inst right after), so it's a bit weird to be doing a bunch of
stuff after.

What are the important parts of this test case?  That the rewrite traverses all
blocks of the function?  That you properly replace all uses of the setjmp return
value?

[eliben, 2013/05/10 23:39:52]

Yes, these tests (and the pass, really) have nothing to do with the actual
semantics of setjmp/longjmp. But since it does a bunch of replacements I figured
it would make sense to test it on a non-trivial "single BB with just the right
function appearing once" case. It helps code coverage ;-)

+  br label %block1
+block1:
+; CHECK: block1
+; CHECK: bitcast 
+; CHECK-NEXT: call void @llvm.nacl.longjmp
+  call void @longjmp(i64* %arg, i32 %num)
+; CHECK: call i32 @llvm.nacl.setjmp
+  %val = call i32 @setjmp(i64* %arg)
+  %num2 = add i32 %val, %num
+; CHECK: bitcast
+; CHECK-NEXT: call void @llvm.nacl.longjmp
+  call void @longjmp(i64* %arg, i32 %num2)
+  br label %exitblock
+exitblock:
+  %num3 = add i32 %num, %num
+  call void @longjmp(i64* %arg, i32 %num3)
+  %num4 = add i32 %num, %num3
+; CHECK: bitcast
+; CHECK-NEXT: call void @llvm.nacl.longjmp
+  call void @longjmp(i64* %arg, i32 %num4)
+  ret void
+}
+