[WebAssembly] Fix CFI index to account for padding nullptr function

The WebAssembly linker now creates a dummy function at index 0 to
prevent miscomparisons with the NULL pointer, see
https://github.com/WebAssembly/binaryen/pull/658. Thanks to pcc for
pointing out this problem!

Patch by Dominic Chen

Differential Revision: https://reviews.llvm.org/D23137

llvm-svn: 278073

diff --git a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
index 1d7ad8b..45fe568 100644 (file)
--- a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
+++ b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
@@ -822,6 +822,7 @@ void LowerTypeTests::buildBitSetsFromFunctionsWASM(
 
   // Build consecutive monotonic integer ranges for each call target set
   DenseMap<GlobalObject *, uint64_t> GlobalLayout;
+
   for (Function *F : Functions) {
     // Skip functions that are not address taken, to avoid bloating the table
     if (!F->hasAddressTaken())
@@ -1049,7 +1050,7 @@ static void init(LowerTypeTests *LTT, Module &M) {
   LTT->Int64Ty = Type::getInt64Ty(M.getContext());
   LTT->IntPtrTy = DL.getIntPtrType(M.getContext(), 0);
   LTT->TypeTestCallSites.clear();
-  LTT->IndirectIndex = 0;
+  LTT->IndirectIndex = 1;
 }
 
 bool LowerTypeTests::runOnModule(Module &M) {

diff --git a/llvm/test/CodeGen/WebAssembly/cfi.ll b/llvm/test/CodeGen/WebAssembly/cfi.ll
index 3cbc65e..e5664ba 100644 (file)
--- a/llvm/test/CodeGen/WebAssembly/cfi.ll
+++ b/llvm/test/CodeGen/WebAssembly/cfi.ll
@@ -14,13 +14,13 @@ define void @h() !type !0 {
 }
 
 ; CHECK-LABEL: f:
-; CHECK: .indidx 0
+; CHECK: .indidx 1
 define void @f() !type !0 {
   ret void
 }
 
 ; CHECK-LABEL: g:
-; CHECK: .indidx 1
+; CHECK: .indidx 2
 define void @g() !type !1 {
   ret void
 }

diff --git a/llvm/test/Transforms/LowerTypeTests/function-disjoint.ll b/llvm/test/Transforms/LowerTypeTests/function-disjoint.ll
index ebf8dcb..a5455a9 100644 (file)
--- a/llvm/test/Transforms/LowerTypeTests/function-disjoint.ll
+++ b/llvm/test/Transforms/LowerTypeTests/function-disjoint.ll
@@ -32,14 +32,14 @@ declare i1 @llvm.type.test(i8* %ptr, metadata %bitset) nounwind readnone
 
 define i1 @foo(i8* %p) {
   ; X64: icmp eq i64 {{.*}}, ptrtoint ([1 x <{ i8, i32, i8, i8, i8 }>]* @[[JT0]] to i64)
-  ; WASM32: icmp eq i64 {{.*}}, 0
+  ; WASM32: icmp eq i64 {{.*}}, 1
   %x = call i1 @llvm.type.test(i8* %p, metadata !"typeid1")
   ; X64: icmp eq i64 {{.*}}, ptrtoint ([1 x <{ i8, i32, i8, i8, i8 }>]* @[[JT1]] to i64)
-  ; WASM32: icmp eq i64 {{.*}}, 1
+  ; WASM32: icmp eq i64 {{.*}}, 2
   %y = call i1 @llvm.type.test(i8* %p, metadata !"typeid2")
   %z = add i1 %x, %y
   ret i1 %z
 }
 
-; WASM32: ![[I0]] = !{i64 0}
-; WASM32: ![[I1]] = !{i64 1}
+; WASM32: ![[I0]] = !{i64 1}
+; WASM32: ![[I1]] = !{i64 2}

diff --git a/llvm/test/Transforms/LowerTypeTests/function-ext.ll b/llvm/test/Transforms/LowerTypeTests/function-ext.ll
index ba4c41f..2e9ab9d 100644 (file)
--- a/llvm/test/Transforms/LowerTypeTests/function-ext.ll
+++ b/llvm/test/Transforms/LowerTypeTests/function-ext.ll
@@ -22,3 +22,4 @@ declare i1 @llvm.type.test(i8* %ptr, metadata %bitset) nounwind readnone
 
 !0 = !{i64 0, !"void"}
 ; WASM-NOT: !{i64 0}
+; WASM-NOT: !{i64 1}

diff --git a/llvm/test/Transforms/LowerTypeTests/function.ll b/llvm/test/Transforms/LowerTypeTests/function.ll
index 120bb9d..a9ef84a 100644 (file)
--- a/llvm/test/Transforms/LowerTypeTests/function.ll
+++ b/llvm/test/Transforms/LowerTypeTests/function.ll
@@ -30,11 +30,11 @@ declare i1 @llvm.type.test(i8* %ptr, metadata %bitset) nounwind readnone
 
 define i1 @foo(i8* %p) {
   ; X64: sub i64 {{.*}}, ptrtoint ([2 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to i64)
-  ; WASM32: sub i64 {{.*}}, 0
+  ; WASM32: sub i64 {{.*}}, 1
   ; WASM32: icmp ult i64 {{.*}}, 2
   %x = call i1 @llvm.type.test(i8* %p, metadata !"typeid1")
   ret i1 %x
 }
 
-; WASM32: ![[I0]] = !{i64 0}
-; WASM32: ![[I1]] = !{i64 1}
+; WASM32: ![[I0]] = !{i64 1}
+; WASM32: ![[I1]] = !{i64 2}