[llvm] [Object][WebAssembly] Fix data segment offsets higher than 2^31 (PR #125739)

[Sam Clegg via llvm-commits]

https://github.com/sbc100 updated https://github.com/llvm/llvm-project/pull/125739

>From 82bcfcf1019cfea5b9a7f9cbe7c31436339f0cf4 Mon Sep 17 00:00:00 2001
From: Sam Clegg <sbc at chromium.org>
Date: Tue, 4 Feb 2025 10:34:09 -0800
Subject: [PATCH] [Object][WebAssembly] Fix data segment offsets higher than
 2^31

Fixes: #58555
---
 llvm/include/llvm/BinaryFormat/Wasm.h         |  4 ++--
 llvm/lib/Object/WasmObjectFile.cpp            |  4 ++--
 llvm/test/Object/Wasm/data-offsets.yaml       | 22 +++++++++++++++++++
 llvm/test/ObjectYAML/wasm/global_section.yaml |  4 ++--
 .../wasm/invalidate_data_offset.yaml          | 18 +++++++++++++++
 5 files changed, 46 insertions(+), 6 deletions(-)
 create mode 100644 llvm/test/Object/Wasm/data-offsets.yaml
 create mode 100644 llvm/test/ObjectYAML/wasm/invalidate_data_offset.yaml

diff --git a/llvm/include/llvm/BinaryFormat/Wasm.h b/llvm/include/llvm/BinaryFormat/Wasm.h
index ede2d692a594916..30271be232ca773 100644
--- a/llvm/include/llvm/BinaryFormat/Wasm.h
+++ b/llvm/include/llvm/BinaryFormat/Wasm.h
@@ -333,8 +333,8 @@ struct WasmTable {
 struct WasmInitExprMVP {
   uint8_t Opcode;
   union {
-    int32_t Int32;
-    int64_t Int64;
+    uint32_t Int32;
+    uint64_t Int64;
     uint32_t Float32;
     uint64_t Float64;
     uint32_t Global;
diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
index 0f6fd5612f9d82a..7815c2670223198 100644
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -201,10 +201,10 @@ static Error readInitExpr(wasm::WasmInitExpr &Expr,
   Expr.Inst.Opcode = readOpcode(Ctx);
   switch (Expr.Inst.Opcode) {
   case wasm::WASM_OPCODE_I32_CONST:
-    Expr.Inst.Value.Int32 = readVarint32(Ctx);
+    Expr.Inst.Value.Int32 = readVaruint32(Ctx);
     break;
   case wasm::WASM_OPCODE_I64_CONST:
-    Expr.Inst.Value.Int64 = readVarint64(Ctx);
+    Expr.Inst.Value.Int64 = readVaruint64(Ctx);
     break;
   case wasm::WASM_OPCODE_F32_CONST:
     Expr.Inst.Value.Float32 = readFloat32(Ctx);
diff --git a/llvm/test/Object/Wasm/data-offsets.yaml b/llvm/test/Object/Wasm/data-offsets.yaml
new file mode 100644
index 000000000000000..b2e1d00675233e4
--- /dev/null
+++ b/llvm/test/Object/Wasm/data-offsets.yaml
@@ -0,0 +1,22 @@
+# RUN: yaml2obj %s | llvm-objdump -s -
+
+## Tests data offsets above 2**31 for I32_CONST and offset over 2**32 work for I64_CONST
+
+--- !WASM
+FileHeader:
+  Version:         0x00000001
+Sections:
+  - Type:            DATA
+    Segments:
+      - SectionOffset:   0
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           2147483649
+        Content:         '6401020304'
+      - SectionOffset:   0
+        InitFlags:       0
+        Offset:
+          Opcode:          I64_CONST
+          Value:           4294967297
+        Content:         '6401020304'
diff --git a/llvm/test/ObjectYAML/wasm/global_section.yaml b/llvm/test/ObjectYAML/wasm/global_section.yaml
index e330b072a726eff..20f4d5440990fe0 100644
--- a/llvm/test/ObjectYAML/wasm/global_section.yaml
+++ b/llvm/test/ObjectYAML/wasm/global_section.yaml
@@ -10,7 +10,7 @@ Sections:
         Mutable:     false
         InitExpr:
           Opcode:          I64_CONST
-          Value:           -5
+          Value:           5
 ...
 # CHECK: --- !WASM
 # CHECK: FileHeader:
@@ -23,5 +23,5 @@ Sections:
 # CHECK:        Mutable:     false
 # CHECK:        InitExpr:
 # CHECK:          Opcode:          I64_CONST
-# CHECK:          Value:           -5
+# CHECK:          Value:           5
 # CHECK: ...
diff --git a/llvm/test/ObjectYAML/wasm/invalidate_data_offset.yaml b/llvm/test/ObjectYAML/wasm/invalidate_data_offset.yaml
new file mode 100644
index 000000000000000..ac12026379905ba
--- /dev/null
+++ b/llvm/test/ObjectYAML/wasm/invalidate_data_offset.yaml
@@ -0,0 +1,18 @@
+# RUN: not yaml2obj %s 2>&1 | FileCheck %s
+
+## Tests data offsets above 2**32 are not valid for for I32_CONST
+
+--- !WASM
+FileHeader:
+  Version:         0x00000001
+Sections:
+  - Type:            DATA
+    Segments:
+      - SectionOffset:   0
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4294967297
+        Content:         '6401020304'
+
+# CHECK: error: out of range number