From 966f88e3da50157ea410182775e67417b6cbbfaa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin@martin.st>
Date: Tue, 7 Jun 2022 00:53:03 +0300
Subject: [PATCH] build-llvm: Improve code for checking for preexisting native
 tools when cross compiling

Check for the prescence of the llvm-tblgen binary in addition to just
checking whether the llvm/build or llvm/build-asserts directories
exist.

In cases where having multiple build directories around, where some
are older than others, it's now possible to clarify which one to use
for tools by just removing the llvm-tblgen binary from the other ones.

Also check for the prescenece of each individual tool before setting
it; this fixes builds where the native build might not have all
components enable as as enabled in the cross build.
---
 build-llvm.sh | 48 +++++++++++++++++++++++++++++++-----------------
 1 file changed, 31 insertions(+), 17 deletions(-)

diff --git a/build-llvm.sh b/build-llvm.sh
index ef40d3b..f8b2da7 100755
--- a/build-llvm.sh
+++ b/build-llvm.sh
@@ -145,16 +145,6 @@ else
 fi
 
 if [ -n "$HOST" ]; then
-    find_native_tools() {
-        if [ -d llvm-project/llvm/build/bin ]; then
-            echo $(pwd)/llvm-project/llvm/build/bin
-        elif [ -d llvm-project/llvm/build-asserts/bin ]; then
-            echo $(pwd)/llvm-project/llvm/build-asserts/bin
-        elif [ -n "$(which llvm-tblgen)" ]; then
-            echo $(dirname $(which llvm-tblgen))
-        fi
-    }
-
     CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_SYSTEM_NAME=Windows"
     CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_CROSSCOMPILING=TRUE"
     CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_C_COMPILER=$HOST-gcc"
@@ -162,16 +152,40 @@ if [ -n "$HOST" ]; then
     CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_RC_COMPILER=$HOST-windres"
     CMAKEFLAGS="$CMAKEFLAGS -DCROSS_TOOLCHAIN_FLAGS_NATIVE="
 
-    native=$(find_native_tools)
-    if [ -n "$native" ]; then
+    native=""
+    for dir in llvm-project/llvm/build/bin llvm-project/llvm/build-asserts/bin; do
+        if [ -x "$dir/llvm-tblgen.exe" ]; then
+            native="$(pwd)/$dir"
+            suffix=".exe"
+            break
+        elif [ -x "$dir/llvm-tblgen" ]; then
+            native="$(pwd)/$dir"
+            suffix=""
+            break
+        fi
+    done
+    if [ -z "$native" ] && [ -n "$(which llvm-tblgen)" ]; then
+        native="$(dirname $(which llvm-tblgen))"
         suffix=""
-        if [ -f $native/llvm-tblgen.exe ]; then
+        if [ -x "$native/llvm-tblgen.exe" ]; then
             suffix=".exe"
         fi
-        CMAKEFLAGS="$CMAKEFLAGS -DLLVM_TABLEGEN=$native/llvm-tblgen$suffix"
-        CMAKEFLAGS="$CMAKEFLAGS -DCLANG_TABLEGEN=$native/clang-tblgen$suffix"
-        CMAKEFLAGS="$CMAKEFLAGS -DLLDB_TABLEGEN=$native/lldb-tblgen$suffix"
-        CMAKEFLAGS="$CMAKEFLAGS -DLLVM_CONFIG_PATH=$native/llvm-config$suffix"
+    fi
+
+
+    if [ -n "$native" ]; then
+        if [ -x "$native/llvm-tblgen$suffix" ]; then
+            CMAKEFLAGS="$CMAKEFLAGS -DLLVM_TABLEGEN=$native/llvm-tblgen$suffix"
+        fi
+        if [ -x "$native/clang-tblgen$suffix" ]; then
+            CMAKEFLAGS="$CMAKEFLAGS -DCLANG_TABLEGEN=$native/clang-tblgen$suffix"
+        fi
+        if [ -x "$native/lldb-tblgen$suffix" ]; then
+            CMAKEFLAGS="$CMAKEFLAGS -DLLDB_TABLEGEN=$native/lldb-tblgen$suffix"
+        fi
+        if [ -x "$native/llvm-config$suffix" ]; then
+            CMAKEFLAGS="$CMAKEFLAGS -DLLVM_CONFIG_PATH=$native/llvm-config$suffix"
+        fi
     fi
     CROSS_ROOT=$(cd $(dirname $(which $HOST-gcc))/../$HOST && pwd)
     CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_FIND_ROOT_PATH=$CROSS_ROOT"