round-robin.sh: Fix shellcheck warnings

* Disable "referenced but not assigned"
  for a bunch of parameters. These are
  set by the wrappers around this script.
* Quote a bunch of expansions
* Use * to get a string from arrays
* When finding files split by null terminator
  so it doesn't break for filenames with spaces.
* Declare and assign separately so we don't
  hide return values.
* Ignore unsafe rm in prepare_abe since we know
  we'll be in the abe folder.
* Add sanity check that pwd isn't / for build_llvm,
  then ignore the warning from the rm.

Change-Id: I0b54e55946d56eef0d48b10c3ccfa30059809d46

1 files changed, 42 insertions, 23 deletions

diff --git a/round-robin.sh b/round-robin.sh
index 242c81b7..6764f348 100644
--- a/round-robin.sh
+++ b/round-robin.sh
@@ -51,10 +51,12 @@ declare -gA rr
 
 # Predicate function to determine whether there is regression between
 # 2 sets of results.
+# shellcheck disable=SC2154
 rr[no_regression_p]=no_regression_p
 
 # Hook to break up updated component (see print_updated_components) into
 # smaller sets: print one set per line.  By default, breakup into singletons.
+# shellcheck disable=SC2154
 rr[breakup_updated_components]=breakup_updated_components
 
 # Print round-robin components that are being updated in this build
@@ -110,6 +112,7 @@ reset_artifacts ()
     # - ${rr[top_artifacts]}/console.log and $run_step_artifacts/console.log, which
     # are being written to by run_step().
     # - ${rr[top_artifacts]}/jenkins/*, which is cleaned by tcwg_kernel.yaml.
+    # shellcheck disable=SC2154
     fresh_dir $run_step_top_artifacts \
 	      $run_step_top_artifacts/console.log \
 	      $run_step_artifacts/console.log \
@@ -122,6 +125,7 @@ reset_artifacts ()
     # base-artifacts repo is big and changes all the time, so we
     # fetch only the $baseline_branch, instead of all branches.
     if [ x"${rr[update_baseline]}" = x"init" ]; then
+  # shellcheck disable=SC2154
 	rr[base-artifacts_rev]=empty
 	single_branch=empty
     else
@@ -210,22 +214,25 @@ prepare_abe ()
     cd abe
 
     # Add ccache wrappers.
-    rm -rf $(pwd)/bin
-    mkdir $(pwd)/bin
+    # shellcheck disable=SC2115
+    rm -rf "$(pwd)/bin"
+    mkdir "$(pwd)/bin"
 
-    cat > $(pwd)/bin/gcc <<EOF
+    cat > "$(pwd)/bin/gcc" <<EOF
 #!/bin/sh
 exec ccache /usr/bin/gcc "\$@"
 EOF
-    chmod +x $(pwd)/bin/gcc
+    chmod +x "$(pwd)/bin/gcc"
 
-    cat > $(pwd)/bin/g++ <<EOF
+    cat > "$(pwd)/bin/g++" <<EOF
 #!/bin/sh
 exec ccache /usr/bin/g++ "\$@"
 EOF
-    chmod +x $(pwd)/bin/g++
+    chmod +x "$(pwd)/bin/g++"
 
-    export PATH=$(pwd)/bin:$PATH
+    local PATH
+    PATH=$(pwd)/bin:$PATH
+    export PATH
 
     ./configure --with-git-reference-dir=/home/tcwg-buildslave/snapshots-ref
     )
@@ -324,7 +331,7 @@ build_abe ()
     done
 
     if [ x"$project" = x"gcc" -a $# != 0 ]; then
-	stage="$stage $@"
+	stage="$stage $*"
     fi
 
     action="--build $project"
@@ -346,8 +353,8 @@ build_abe ()
 	git_dir="$git_dir.git"
 	git_path="abe/snapshots/$git_dir"
 	rm -rf $git_path $git_path~master
-	ln -s $(pwd)/$project $git_path
-	ln -s $(pwd)/$project $git_path~master
+	ln -s "$(pwd)/$project" $git_path
+	ln -s "$(pwd)/$project" $git_path~master
 
 	custom_abe_src_opt="$project=http://git.l.o/$git_dir~master --disable update"
     fi
@@ -363,7 +370,9 @@ build_abe ()
 	set +f; rm -rf builds/*/*/$git_dir*; set -f
     fi
 
-    export PATH=$(pwd)/bin:$PATH
+    local PATH
+    PATH=$(pwd)/bin:$PATH
+    export PATH
 
     if [ x"$component" != x"stage2" ]; then
 	# TODO: Fix install_sysroot logic in ABE.
@@ -391,7 +400,7 @@ build_abe ()
 
     if $check; then
 	mkdir -p ${rr[top_artifacts]}/sumfiles
-	find builds/ -name "*.sum" | xargs -r cp -t ${rr[top_artifacts]}/sumfiles/
+	find builds/ -name "*.sum" -print0 | xargs -0 -r cp -t ${rr[top_artifacts]}/sumfiles/
     fi
     )
 }
@@ -411,32 +420,41 @@ build_llvm ()
     rsync -a --del llvm/clang/ llvm-src/tools/clang/
     rsync -a --del llvm/lld/ llvm-src/tools/lld/
 
+    # Sanity check
+    if [[ $(pwd) == "/" ]]; then
+      echo "pwd is unexpectedly \"/\", exiting"
+      exit 1;
+    fi
+
     # Setup ccache and ninja wrappers.
-    rm -rf $(pwd)/bin
-    mkdir $(pwd)/bin
+    # shellcheck disable=SC2115
+    rm -rf "$(pwd)/bin"
+    mkdir "$(pwd)/bin"
 
-    cat > $(pwd)/bin/cc <<EOF
+    cat > "$(pwd)/bin/cc" <<EOF
 #!/bin/sh
 exec ccache /usr/bin/gcc "\$@"
 EOF
-    chmod +x $(pwd)/bin/cc
+    chmod +x "$(pwd)/bin/cc"
 
-    cat > $(pwd)/bin/c++ <<EOF
+    cat > "$(pwd)/bin/c++" <<EOF
 #!/bin/sh
 exec ccache /usr/bin/g++ "\$@"
 EOF
-    chmod +x $(pwd)/bin/c++
+    chmod +x "$(pwd)/bin/c++"
 
     if [ -f /usr/local/bin/ninja.bin ]; then
 	# Use ninja configuration from llvm buildbots to avoid running out of RAM.
-	cat > $(pwd)/bin/ninja <<EOF
+	cat > "$(pwd)/bin/ninja" <<EOF
 #!/bin/sh
 exec /usr/local/bin/ninja.bin -m 30 -M 50 -D 5000 "\$@"
 EOF
-	chmod +x $(pwd)/bin/ninja
+	chmod +x "$(pwd)/bin/ninja"
     fi
 
-    export PATH=$(pwd)/bin:$PATH
+    local PATH
+    PATH=$(pwd)/bin:$PATH
+    export PATH
 
     local binutils_incdir
     # Freshen up build and install directories.  We rely on ccache for fast rebuilds.
@@ -451,7 +469,7 @@ EOF
     mkdir -p llvm-build
     cd llvm-build
 
-    cmake -G Ninja  ../llvm-src -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_ASSERTIONS=True -DCMAKE_INSTALL_PREFIX=../llvm-install -DLLVM_TARGETS_TO_BUILD=$(print_llvm_target ${rr[target]}) -DLLVM_BINUTILS_INCDIR=$binutils_incdir
+    cmake -G Ninja  ../llvm-src -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_ASSERTIONS=True -DCMAKE_INSTALL_PREFIX=../llvm-install "-DLLVM_TARGETS_TO_BUILD=$(print_llvm_target ${rr[target]})" -DLLVM_BINUTILS_INCDIR=$binutils_incdir
     ccache -z
     ninja
     ninja install
@@ -538,7 +556,8 @@ check_regression ()
 	fi
 
 	# We've got a regression.  Generate trigger-* files.
-	local single_component=$(print_single_updated_component)
+	local single_component
+	single_component=$(print_single_updated_component)
 	local trigger_dest
 
 	if [ x"${rr[update_baseline]}" = x"update" ]; then