Backed out changeset fc265b3a728e (bug 1625696) for causing bug 1634877 and bug 1634916

browser/config/mozconfigs/win32/common-win32

@@ -30,7 +30,7 @@ unset VC_PATH
 
 fi
 
-export WINCHECKSEC="${MOZ_FETCHES_DIR}/winchecksec/winchecksec"
+export WINCHECKSEC="${MOZ_FETCHES_DIR}/winchecksec/winchecksec.exe"
 if [ ! -f "${WINCHECKSEC}" ]; then
     unset WINCHECKSEC
 fi

browser/config/mozconfigs/win64-aarch64/common-win64

@@ -31,7 +31,7 @@ unset VC_PATH
 
 fi
 
-export WINCHECKSEC="${MOZ_FETCHES_DIR}/winchecksec/winchecksec"
+export WINCHECKSEC="${MOZ_FETCHES_DIR}/winchecksec/winchecksec.exe"
 if [ ! -f "${WINCHECKSEC}" ]; then
     unset WINCHECKSEC
 fi

browser/config/mozconfigs/win64/common-win64

@@ -30,7 +30,7 @@ unset VC_PATH
 
 fi
 
-export WINCHECKSEC="${MOZ_FETCHES_DIR}/winchecksec/winchecksec"
+export WINCHECKSEC="${MOZ_FETCHES_DIR}/winchecksec/winchecksec.exe"
 if [ ! -f "${WINCHECKSEC}" ]; then
     unset WINCHECKSEC
 fi

build/win32/autowinchecksec.py

@@ -29,7 +29,7 @@ except KeyError:
     sys.exit(1)
 
 wine = buildconfig.substs.get('WINE')
-if wine and winchecksec_path.lower().endswith('.exe'):
+if wine:
     cmd = [wine, winchecksec_path]
 else:
     cmd = [winchecksec_path]

taskcluster/ci/fetch/toolchains.yml

@@ -485,4 +485,4 @@ winchecksec:
     fetch:
         type: git
         repo: https://github.com/trailofbits/winchecksec/
-        revision: 93ffe67dbfc757bf6f440d80b8acf88e652ed60a
+        revision: 8143f621359616f16eaa265e22d10a7962536634

taskcluster/ci/toolchain/misc.yml

@@ -289,6 +289,8 @@ win64-winchecksec:
         symbol: TW64(winchecksec)
     worker:
         docker-image: {in-tree: deb10-toolchain-build}
+        env:
+            TOOLTOOL_MANIFEST: "browser/config/tooltool-manifests/win64/vs2017.manifest"
     run:
         script: build-winchecksec.sh
         toolchain-artifact: public/build/winchecksec.tar.bz2
@@ -296,3 +298,6 @@ win64-winchecksec:
     fetches:
         fetch:
             - winchecksec
+        toolchain:
+            - linux64-clang-win-cross
+            - linux64-liblowercase

taskcluster/scripts/misc/build-winchecksec.sh

@@ -1,17 +1,45 @@
 #!/bin/bash
 set -e -v -x
 
-mkdir -p $UPLOAD_DIR
-
 cd $MOZ_FETCHES_DIR/winchecksec
 
+export PATH="$MOZ_FETCHES_DIR/clang/bin:$PATH"
+
+export LD_PRELOAD=$MOZ_FETCHES_DIR/liblowercase/liblowercase.so
+export LOWERCASE_DIRS=$MOZ_FETCHES_DIR/vs2017_15.8.4
+
+. $GECKO_PATH/taskcluster/scripts/misc/vs-setup.sh
+. $GECKO_PATH/taskcluster/scripts/misc/tooltool-download.sh
+
+# Patch pe-parse because clang-cl doesn't support /analyze.
+patch -p1 <<'EOF'
+--- a/pe-parse/cmake/compilation_flags.cmake
++++ b/pe-parse/cmake/compilation_flags.cmake
+@@ -1,5 +1,5 @@
+ if (MSVC)
+-  list(APPEND DEFAULT_CXX_FLAGS /W4 /analyze)
++  list(APPEND DEFAULT_CXX_FLAGS /W4)
+
+   if (CMAKE_BUILD_TYPE STREQUAL "Debug" OR CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
+     list(APPEND DEFAULT_CXX_FLAGS /Zi)
+EOF
+
 cmake \
   -GNinja \
+  -DCMAKE_CXX_COMPILER=clang-cl \
+  -DCMAKE_C_COMPILER=clang-cl \
+  -DCMAKE_LINKER=lld-link \
+  -DCMAKE_C_FLAGS=-fuse-ld=lld \
+  -DCMAKE_CXX_FLAGS="-fuse-ld=lld \
+  -EHsc" \
+  -DCMAKE_RC_COMPILER=llvm-rc \
+  -DCMAKE_MT=llvm-mt \
+  -DCMAKE_SYSTEM_NAME=Windows \
   -DCMAKE_BUILD_TYPE=Release \
-  -DBUILD_SHARED_LIBS=Off
+  -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded
 
 ninja -v
 
 cd ..
-tar -caf winchecksec.tar.bz2 winchecksec/winchecksec
+tar -caf winchecksec.tar.bz2 winchecksec/winchecksec.{dll,exe}
 cp winchecksec.tar.bz2 $UPLOAD_DIR/

toolkit/moz.configure

@@ -2019,7 +2019,7 @@ def allow_missing_winchecksec(automation, c_compiler):
     if c_compiler and c_compiler.type != 'clang-cl':
         return True
 
-check_prog('WINCHECKSEC', ['winchecksec.exe', 'winchecksec'], paths=toolchain_search_path,
+check_prog('WINCHECKSEC', ['winchecksec.exe'], paths=toolchain_search_path,
            allow_missing=allow_missing_winchecksec,
            when=compile_environment & target_is_windows)