[llvm] 91d0618 - [llvm-objcopy] Reland "Fix --add-section when section contain empty bytes"

[Derek Schuff via llvm-commits]

Author: Guilhem
Date: 2022-12-05T18:05:22-08:00
New Revision: 91d0618368c0248e200d90b367322f9c1f74e387

URL: https://github.com/llvm/llvm-project/commit/91d0618368c0248e200d90b367322f9c1f74e387
DIFF: https://github.com/llvm/llvm-project/commit/91d0618368c0248e200d90b367322f9c1f74e387.diff

LOG: [llvm-objcopy] Reland "Fix --add-section when section contain empty bytes"

Implicit cast between char* and StringRef when writing sections.

Reproduce:
```
$> llvm-objcopy --dump-section=name=name.data out.wasm
$> llvm-objcopy --remove-section=name out.wasm out_no_name.wasm
$> llvm-objcopy --add-section=name=name.data out_no_name.wasm out_new_name.wasm

```

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D139210

Added: 
    

Modified: 
    llvm/lib/ObjCopy/wasm/WasmObjcopy.cpp
    llvm/test/tools/llvm-objcopy/wasm/add-section.test

Removed: 
    


################################################################################
diff  --git a/llvm/lib/ObjCopy/wasm/WasmObjcopy.cpp b/llvm/lib/ObjCopy/wasm/WasmObjcopy.cpp
index 6877cd68bee47..19f10bf4c8180 100644
--- a/llvm/lib/ObjCopy/wasm/WasmObjcopy.cpp
+++ b/llvm/lib/ObjCopy/wasm/WasmObjcopy.cpp
@@ -126,9 +126,11 @@ static Error handleArgs(const CommonConfig &Config, Object &Obj) {
     Sec.SectionType = llvm::wasm::WASM_SEC_CUSTOM;
     Sec.Name = NewSection.SectionName;
 
+    llvm::StringRef InputData =
+        llvm::StringRef(NewSection.SectionData->getBufferStart(),
+                        NewSection.SectionData->getBufferSize());
     std::unique_ptr<MemoryBuffer> BufferCopy = MemoryBuffer::getMemBufferCopy(
-        NewSection.SectionData->getBufferStart(),
-        NewSection.SectionData->getBufferIdentifier());
+        InputData, NewSection.SectionData->getBufferIdentifier());
     Sec.Contents = makeArrayRef<uint8_t>(
         reinterpret_cast<const uint8_t *>(BufferCopy->getBufferStart()),
         BufferCopy->getBufferSize());

diff  --git a/llvm/test/tools/llvm-objcopy/wasm/add-section.test b/llvm/test/tools/llvm-objcopy/wasm/add-section.test
index 2f32eaca0ac46..1a0df092dc7c4 100644
--- a/llvm/test/tools/llvm-objcopy/wasm/add-section.test
+++ b/llvm/test/tools/llvm-objcopy/wasm/add-section.test
@@ -20,6 +20,17 @@
 # REPLACE:   Name:    foo
 # REPLACE:   Payload: 3132330A
 
+## Check that raw data bytes can be imported and exported unchanged especially the ones containing empty bytes.
+# RUN: echo -e -n "\x02\x01\x00\x01\x02" > %t6
+# RUN: llvm-objcopy --add-section=bar=%t6 %t %t7
+# RUN: llvm-objcopy --dump-section=bar=%t8 %t7
+# RUN: 
diff  %t8 %t6
+# RUN: obj2yaml %t7 | FileCheck %s --check-prefix=RAW-DATA
+
+## Check that raw data is well formated in the file as well.
+# RAW-DATA:      Name: bar
+# RAW-DATA-NEXT: Payload: '0201000102'
+
 --- !WASM
 FileHeader:
   Version: 0x00000001