Add missing include in ProgramStack.cpp

[Algunenano]

Darwin fails to build with _LIBCPP_REMOVE_TRANSITIVE_INCLUDES=1

[2025-12-19 12:30:48] /home/ubuntu/actions-runner/_work/ClickHouse/ClickHouse/contrib/llvm-project/llvm/lib/Support/ProgramStack.cpp:114:17: error: use of undeclared identifier 'malloc'
[2025-12-19 12:30:48]   114 |   void *Stack = malloc(StackSize);
[2025-12-19 12:30:48]       |                 ^~~~~~
[2025-12-19 12:30:48] /home/ubuntu/actions-runner/_work/ClickHouse/ClickHouse/contrib/llvm-project/llvm/lib/Support/ProgramStack.cpp:119:3: error: use of undeclared identifier 'free'
[2025-12-19 12:30:48]   119 |   free(Stack);
[2025-12-19 12:30:48]       |   ^~~~
[2025-12-19 12:30:48] 2 errors generated.

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[llvmbot]

@llvm/pr-subscribers-llvm-support

Author: Raúl Marín (Algunenano)

Changes

Darwin fails to build with _LIBCPP_REMOVE_TRANSITIVE_INCLUDES=1

[2025-12-19 12:30:48] /home/ubuntu/actions-runner/_work/ClickHouse/ClickHouse/contrib/llvm-project/llvm/lib/Support/ProgramStack.cpp:114:17: error: use of undeclared identifier 'malloc'
[2025-12-19 12:30:48]   114 |   void *Stack = malloc(StackSize);
[2025-12-19 12:30:48]       |                 ^~~~~~
[2025-12-19 12:30:48] /home/ubuntu/actions-runner/_work/ClickHouse/ClickHouse/contrib/llvm-project/llvm/lib/Support/ProgramStack.cpp:119:3: error: use of undeclared identifier 'free'
[2025-12-19 12:30:48]   119 |   free(Stack);
[2025-12-19 12:30:48]       |   ^~~~
[2025-12-19 12:30:48] 2 errors generated.

---

Full diff: https://github.com/llvm/llvm-project/pull/173002.diff

1 Files Affected:

• (modified) llvm/lib/Support/ProgramStack.cpp (+1)

diff --git a/llvm/lib/Support/ProgramStack.cpp b/llvm/lib/Support/ProgramStack.cpp
index 66f74ff660b20..a8c8f00a494a7 100644
--- a/llvm/lib/Support/ProgramStack.cpp
+++ b/llvm/lib/Support/ProgramStack.cpp
@@ -20,6 +20,7 @@
 
 #ifndef LLVM_HAS_SPLIT_STACKS
 # include "llvm/Support/thread.h"
+# include <stdlib.h> // for malloc
 #endif
 
 using namespace llvm;