cmake: Read RUSTFLAGS from environment and propagate correctly

Author: NickeZ

.github/workflows/ci-common.yml

@@ -10,6 +10,9 @@ on:
       container-version:
         required: true
         type: string
+env:
+  RUSTFLAGS: "-Dwarnings"
+  CFLAGS: "-Werror"
 
 jobs:
   check-sigs:
@@ -54,8 +57,6 @@ jobs:
     runs-on: ubuntu-22.04
     container:
       image: ${{ inputs.container-repo }}:${{ inputs.container-version }}
-      env:
-        RUSTFLAGS: "-Dwarnings"
     steps:
       - name: Clone the repo
         uses: actions/checkout@v4
@@ -81,8 +82,6 @@ jobs:
     runs-on: ubuntu-22.04
     container:
       image: ${{ inputs.container-repo }}:${{ inputs.container-version }}
-      env:
-        RUSTFLAGS: "-Dwarnings"
     steps:
       - name: Clone the repo
         uses: actions/checkout@v4
@@ -170,8 +169,6 @@ jobs:
     runs-on: ubuntu-22.04
     container:
       image: ${{ inputs.container-repo }}:${{ inputs.container-version }}
-      env:
-        RUSTFLAGS: "-Dwarnings"
     steps:
       - name: Clone the repo
         uses: actions/checkout@v4

CMakeLists.txt

@@ -243,6 +243,10 @@ set(CMAKE_C_FLAGS_RELEASE "-Os -DNDEBUG")
 set(CMAKE_C_FLAGS_DEBUG "-Os -ggdb")
 set(CMAKE_C_FLAGS_RELWITHDEBINFO "-Os -ggdb -DNDEBUG")
 
+if(DEFINED ENV{RUSTFLAGS})
+    set(RUSTFLAGS $ENV{RUSTFLAGS})
+endif()
+
 #-----------------------------------------------------------------------------
 # Print system information and build options
 
@@ -270,6 +274,7 @@ message(STATUS "Compiler cache:         ${CMAKE_C_COMPILER_LAUNCHER}")
 message(STATUS "Linker:                 ${CMAKE_LINKER}")
 message(STATUS "Archiver:               ${CMAKE_AR}")
 message(STATUS "Default CFLAGS:         ${CMAKE_C_FLAGS} ${CMAKE_C_FLAGS_${CMAKE_BUILD_TYPE}}")
+message(STATUS "Default RUSTFLAGS:      ${RUSTFLAGS}")
 message(STATUS "Default EXE LDFLAGS:    ${CMAKE_EXE_LINKER_FLAGS}")
 message(STATUS "            - Options -")
 message(STATUS "Build type:             ${CMAKE_BUILD_TYPE}")

src/CMakeLists.txt

@@ -230,12 +230,12 @@ else()
   set(RUST_PROFILE "release")
   set(RUST_CARGO_FLAGS "--release")
   # For binary reproducibility, strip path prefixes that can be different depending on environment (e.g. /home/<user>, etc.).
-  set(RUSTFLAGS "--remap-path-prefix=${CMAKE_CURRENT_SOURCE_DIR}/rust=src --remap-path-prefix=$ENV{HOME}=")
+  string(APPEND RUSTFLAGS " --remap-path-prefix=${CMAKE_CURRENT_SOURCE_DIR}/rust=src --remap-path-prefix=$ENV{HOME}=")
 endif()
 
 # Use libsecp256k1 that we link ourselves.
 # See https://github.com/rust-bitcoin/rust-secp256k1/tree/7c8270a8506e31731e540fab7ee1abde1f48314e/secp256k1-sys#linking-to-external-symbols
-set(RUSTFLAGS "${RUSTFLAGS} --cfg=rust_secp_no_symbol_renaming")
+string(APPEND RUSTFLAGS " --cfg=rust_secp_no_symbol_renaming")
 
 if(CMAKE_CROSSCOMPILING)
   set(RUST_TARGET_ARCH thumbv7em-none-eabi)