From 421ed1b46ff018f33a497df913a11d20f8dd1acc Mon Sep 17 00:00:00 2001
From: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Date: Mon, 2 Sep 2024 21:41:03 +0100
Subject: [PATCH] cmake: Introduce `SECP256K1_APPEND_LDFLAGS` variable

Downstream projects may include libsecp test executables in their test
suites. In such cases, if a `-fsanitize=...` flag is passed via the
`SECP256K1_APPEND_CFLAGS` variable, the same flag must also be passed to
the linker.
---
 CMakeLists.txt | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4ca8cbe8e3..d5a7a2de39 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -276,6 +276,14 @@ if(SECP256K1_APPEND_CFLAGS)
   string(APPEND CMAKE_C_COMPILE_OBJECT " ${SECP256K1_APPEND_CFLAGS}")
 endif()
 
+set(SECP256K1_APPEND_LDFLAGS "" CACHE STRING "Linker flags that are appended to the command line after all other flags added by the build system. This variable is intended for debugging and special builds.")
+if(SECP256K1_APPEND_LDFLAGS)
+  # Appending to this low-level rule variable is the only way to
+  # guarantee that the flags appear at the end of the command line.
+  string(APPEND CMAKE_C_CREATE_SHARED_LIBRARY " ${SECP256K1_APPEND_LDFLAGS}")
+  string(APPEND CMAKE_C_LINK_EXECUTABLE " ${SECP256K1_APPEND_LDFLAGS}")
+endif()
+
 add_subdirectory(src)
 if(SECP256K1_BUILD_EXAMPLES)
   add_subdirectory(examples)
@@ -355,6 +363,9 @@ endif()
 if(SECP256K1_APPEND_CFLAGS)
   message("SECP256K1_APPEND_CFLAGS ............... ${SECP256K1_APPEND_CFLAGS}")
 endif()
+if(SECP256K1_APPEND_LDFLAGS)
+  message("SECP256K1_APPEND_LDFLAGS .............. ${SECP256K1_APPEND_LDFLAGS}")
+endif()
 message("")
 if(print_msan_notice)
   message(