Fix clang -Walloc-size error in CloseHandle test by removing unused WriteBuffer

[Copilot]

WriteBuffer was declared as LPDWORD but was allocated with sizeof(WORD) (2 bytes) and never actually used — it was never passed to WriteFile or any other function. This dead code triggered a hard -Werror,-Walloc-size error in newer clang builds targeting aarch64-linux-gnu.

Changes

• src/coreclr/pal/tests/palsuite/miscellaneous/CloseHandle/test1/test.cpp: Remove the unused WriteBuffer variable entirely, along with its malloc, null-check, and free calls. Also updated the stale /* Depends on: CreateFile and WriteFile */ comment to /* Depends on: CreateFile */ since WriteFile was never called.

Original prompt

Problem

The build is failing with a clang -Walloc-size error in src/coreclr/pal/tests/palsuite/miscellaneous/CloseHandle/test1/test.cpp:

/__w/1/s/src/coreclr/pal/tests/palsuite/miscellaneous/CloseHandle/test1/test.cpp:32:28: error: allocation of insufficient size '2' for type 'DWORD' (aka 'unsigned int') with size '4' [-Werror,-Walloc-size]
   32 |     WriteBuffer = (LPDWORD)malloc(sizeof(WORD));

WriteBuffer is declared as LPDWORD (pointer to DWORD, which is 4 bytes), but the malloc call only allocates sizeof(WORD) (2 bytes). This is caught as an error by newer clang via -Walloc-size.

Fix

In src/coreclr/pal/tests/palsuite/miscellaneous/CloseHandle/test1/test.cpp, change line 32 from:

WriteBuffer = (LPDWORD)malloc(sizeof(WORD));

to:

WriteBuffer = (LPDWORD)malloc(sizeof(DWORD));

This ensures the allocation size matches the type that WriteBuffer points to.

The following is the prior conversation context from the user's chat exploration (may be truncated):

User: I'm getting following failure. can you put up a PR with a fix?

 /usr/local/bin/clang++ --target=aarch64-linux-gnu --gcc-toolchain=/crossrootfs/arm64/usr --sysroot=/crossrootfs/arm64 -DBUILDENV_DEBUG=1 -DCOMPILER_SUPPORTS_W_RESERVED_IDENTIFIER -DCORECLR -DDEBUG -DDISABLE_CONTRACTS -DHOST_64BIT -DHOST_ARM64 -DHOST_UNIX -DLP64COMPATIBLE -DPIC -DTARGET_64BIT -DTARGET_ARM64 -DTARGET_LINUX -DTARGET_UNIX -DURTBLDENV_FRIENDLY=Debug -D_DBG -D_DEBUG -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 -I/__w/1/s/artifacts/obj/coreclr/linux.arm64.Debug/pal/tests/palsuite -I/__w/1/s/src/coreclr/pal/tests/palsuite -I/__w/1/s/src/native -I/__w/1/s/src/native/inc -I/__w/1/s/src/coreclr/runtime -I/__w/1/s/src/coreclr/pal/inc -I/__w/1/s/src/coreclr/pal/src -I/__w/1/s/src/coreclr/pal/../inc -I/__w/1/s/src/coreclr/pal/tests/palsuite/common -g -std=gnu++17 -fPIE -fPIE -O0 -Wall -Wno-null-conversion -glldb -fno-omit-frame-pointer -fno-strict-overflow -fno-strict-aliasing -fstack-protector-strong -Werror -Wno-unused-variable -Wno-unused-value -Wno-unused-function -Wno-tautological-compare -Wno-unknown-pragmas -Wimplicit-fallthrough -Wvla -Wno-invalid-offsetof -Wno-unused-but-set-variable -ffp-contract=off -fno-rtti -Wno-unknown-warning-option -ferror-limit=4096 -Wno-unused-private-field -Wno-constant-logical-operand -Wno-pragma-pack -Wno-incompatible-ms-struct -Wno-reserved-identifier -Wno-unsafe-buffer-usage -Wno-single-bit-bitfield-constant-conversion -Wno-cast-function-type-strict -Wno-switch-default -Wno-nontrivial-memaccess -fsigned-char -fvisibility=hidden -ffunction-sections -Wno-writable-strings -Wno-empty-body -Wno-incompatible-pointer-types-discards-qualifiers -Wno-int-to-void-pointer-cast -MD -MT pal/tests/palsuite/CMakeFiles/paltests.dir/miscellaneous/CloseHandle/test1/test.cpp.o -MF pal/tests/palsuite/CMakeFiles/paltests.dir/miscellaneous/CloseHandle/test1/test.cpp.o.d -o pal/tests/palsuite/CMakeFiles/paltests.dir/miscellaneous/CloseHandle/test1/test.cpp.o -c /__w/1/s/src/coreclr/pal/tests/palsuite/miscellaneous/CloseHandle/test1/test.cpp
  /__w/1/s/src/coreclr/pal/tests/palsuite/miscellaneous/CloseHandle/test1/test.cpp:32:28: error: allocation of insufficient size '2' for type 'DWORD' (aka 'unsigned int') with size '4' [-Werror,-Walloc-size]
     32 |     WriteBuffer = (LPDWORD)malloc(sizeof(WORD));
        |         

Assistant: The fix is straightforward: line 32 allocates sizeof(WORD) (2 bytes) for an LPDWORD pointer, but DWORD is 4 bytes — it should be sizeof(DWORD). Let me open a PR with that fix.

Assistant: We're waiting for your response to the tool call dialog to continue — once you accept it, the coding agent will create a PR that changes sizeof(WORD) to sizeof(DWORD) on line 32 of test.cpp, fixing the -Walloc-size clang error where a LPDWORD buffer was being under-allocated with only 2 bytes instead of the required 4.

This pull request was created from Copilot chat.

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[MichalStrehovsky]

@copilot is WriteBuffer necessary for something?

[Copilot]

@copilot is WriteBuffer necessary for something?

No, WriteBuffer was never used — it was allocated but never passed to WriteFile or any other function. Removed it entirely in 34b02e0.

[Copilot]

Pull request overview

This PR fixes a clang -Werror,-Walloc-size build break in the PAL CloseHandle test by removing dead code that allocated an incorrectly sized buffer and was never used.

Changes:

• Removed the unused WriteBuffer variable and its malloc/null-check/free code.
• Updated the stale dependency comment to no longer mention WriteFile.

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[Copilot]

CreateFile return value isn't validated. If it returns INVALID_HANDLE_VALUE, the test will call CloseHandle on an invalid handle and then fail with a misleading error message (making failures hard to diagnose and potentially flaky in restricted environments). Add an explicit check after CreateFile and Fail/return when the handle is invalid (optionally including GetLastError() in the message).

Suggested change

	if (FileHandle == INVALID_HANDLE_VALUE)
	{
	Fail("ERROR: (Test 1) CreateFile failed with error code %u.\n",
	GetLastError());
	PAL_Terminate();
	return FAIL;
	}

[MichalStrehovsky]

/azp run runtime-coreclr outerloop

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