[llvm] 144ec1c - [WebAssembly] Encode numbers in ULEB128 in event section

[Heejin Ahn via llvm-commits]

Author: Heejin Ahn
Date: 2021-03-30T16:21:58-07:00
New Revision: 144ec1c38ef1d3a6d37dadf7240ef5f04c10daae

URL: https://github.com/llvm/llvm-project/commit/144ec1c38ef1d3a6d37dadf7240ef5f04c10daae
DIFF: https://github.com/llvm/llvm-project/commit/144ec1c38ef1d3a6d37dadf7240ef5f04c10daae.diff

LOG: [WebAssembly] Encode numbers in ULEB128 in event section

The number of events and the type index should be encoded in ULEB128,
but they were incorrctly encoded in LEB128. The smallest number with
which its LEB128 and ULEB128 encodings are different is 64.
There's no way we can generate 64 events in the C++ toolchain
implementation so we can't test that, but the attached test tests when
the type index is 64.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D99627

Added: 
    llvm/test/MC/WebAssembly/event-section-encoding.ll

Modified: 
    llvm/lib/Object/WasmObjectFile.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
index f759a61161987..b7bf7705e4930 100644
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -1134,13 +1134,13 @@ Error WasmObjectFile::parseMemorySection(ReadContext &Ctx) {
 
 Error WasmObjectFile::parseEventSection(ReadContext &Ctx) {
   EventSection = Sections.size();
-  uint32_t Count = readVarint32(Ctx);
+  uint32_t Count = readVaruint32(Ctx);
   Events.reserve(Count);
   while (Count--) {
     wasm::WasmEvent Event;
     Event.Index = NumImportedEvents + Events.size();
     Event.Type.Attribute = readVaruint32(Ctx);
-    Event.Type.SigIndex = readVarint32(Ctx);
+    Event.Type.SigIndex = readVaruint32(Ctx);
     Events.push_back(Event);
   }
 

diff  --git a/llvm/test/MC/WebAssembly/event-section-encoding.ll b/llvm/test/MC/WebAssembly/event-section-encoding.ll
new file mode 100644
index 0000000000000..54b6f6a417289
--- /dev/null
+++ b/llvm/test/MC/WebAssembly/event-section-encoding.ll
@@ -0,0 +1,345 @@
+; RUN: llc -filetype=obj -exception-model=wasm -mattr=+exception-handling %s -o - | obj2yaml | FileCheck %s
+
+; This is a regression test for an encoding bug that happens when an event's
+; sigindex is greater than 63, so we put 63 dummy functions with 
diff erent
+; signatures before the function that contains the 'throw' instruction to make
+; the event's sigindex 64.
+
+target triple = "wasm32-unknown-unknown"
+
+declare void @llvm.wasm.throw(i32, i8*)
+
+define i32 @dummy0() {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy1(i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy2(i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy3(i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy4(i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy5(i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy6(i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy7(i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy8(i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy9(i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy10(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy11(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy12(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy13(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy14(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy15(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy16(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy17(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy18(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy19(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy20(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy21(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy22(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy23(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy24(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy25(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy26(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy27(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy28(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy29(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy30(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy31(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy32(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy33(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy34(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy35(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy36(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy37(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy38(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy39(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy40(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy41(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy42(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy43(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy44(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy45(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy46(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy47(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy48(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy49(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy50(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy51(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy52(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy53(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy54(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy55(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy56(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy57(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy58(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy59(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy60(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy61(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy62(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @dummy63(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) {
+entry:
+  ret i32 0
+}
+
+define i32 @test_throw(i8* %p) {
+  call void @llvm.wasm.throw(i32 0, i8* %p)
+  ret i32 0
+}
+
+; Checks to see if the event index is correctly encoded in ULEB128. If it is
+; encoded with LEB128, 64 will not be correctly decoded. 64 is the smallest
+; number with which its LEB128 and ULEB128 encodings are 
diff erent, because its
+; 7th least significant bit is not 0.
+; CHECK:      - Type:            EVENT
+; CHECK-NEXT:   Events:
+; CHECK-NEXT:     - Index:           0
+; CHECK-NEXT:       Attribute:       0
+; CHECK-NEXT:       SigIndex:        64