Get sha1 commit from tree-sitter-cpp crate for mozcpp

Instead of hard-coding the sha1 of the commit associated to
the tree-sitter-cpp grammar used to generate the mozcpp grammar,
retrieve automatically it from the tree-sitter-cpp crate version
present in Cargo.toml

generate-grammars/generate-mozcpp.sh

@@ -4,22 +4,47 @@
 #
 # Usage: ./generate-grammars/generate-mozcpp.sh
 
-# Set tree-sitter-cpp version
-TS_CPP_VERSION="05cf2030e5415e9e931f620f0924107f73976796"
+# Name of the tree-sitter-cpp crate
+TS_CPP_CRATE="tree-sitter-cpp"
+
+# Filename of the JSON file containing the sha1 of the commit associated to
+# the current tree-sitter-cpp crate version
+JSON_CRATE_FILENAME=".cargo_vcs_info.json"
+
+# Get the current tree-sitter-cpp crate version from the tree-sitter-mozcpp grammar
+TS_CPP_VERSION=`grep tree-sitter-mozcpp Cargo.toml | cut -f2 -d "," | cut -f2 -d "=" | tr -d ' ' | tr -d } | tr -d \"`
+
+# Name assigned to the compressed binary crate downloaded from crates.io
+CRATE_OUTPUT="$TS_CPP_CRATE-download.gz"
+
+# Link of the current tree-sitter-cpp crate on crates.io
+CRATES_IO_LINK="https://crates.io/api/v1/crates/$TS_CPP_CRATE/$TS_CPP_VERSION/download"
+
+# Download the crate from crates.io and uncompress it
+wget -O $CRATE_OUTPUT $CRATES_IO_LINK && tar -xf $CRATE_OUTPUT
+
+# Uncompressed directory name
+CRATE_DIR="$TS_CPP_CRATE-$TS_CPP_VERSION"
+
+# Get the sha1 of the commit associated to the current tree-sitter-cpp crate version
+TS_CPP_SHA1=`grep "sha1" $CRATE_DIR/$JSON_CRATE_FILENAME | cut -f2 -d ":" | tr -d ' ' | tr -d \"`
+
+# Remove compressed binary file and the relative uncompressed directory
+rm -rf $CRATE_OUTPUT $CRATE_DIR
 
 # Enter the mozcpp directory
 pushd tree-sitter-mozcpp
 
 # Create tree-sitter-cpp directory
-mkdir -p tree-sitter-cpp
+mkdir -p $TS_CPP_CRATE
 
 # Enter tree-sitter-cpp directory
-pushd tree-sitter-cpp
+pushd $TS_CPP_CRATE
 
 # Shallow clone tree-sitter-cpp to a specific revision
 git init
 git remote add origin https://github.com/tree-sitter/tree-sitter-cpp.git
-git fetch --depth 1 origin $TS_CPP_VERSION
+git fetch --depth 1 origin $TS_CPP_SHA1
 git checkout FETCH_HEAD
 
 # Install tree-sitter-cpp dependencies
@@ -29,7 +54,7 @@ npm install -y
 popd
 
 # Copy tree-sitter-cpp `scanner.cc` functions into the `src` directory
-cp --verbose tree-sitter-cpp/src/scanner.cc ./src/scanner.cc
+cp --verbose $TS_CPP_CRATE/src/scanner.cc ./src/scanner.cc
 
 # Exit tree-sitter-mozcpp directory
 popd
@@ -38,4 +63,4 @@ popd
 ./generate-grammars/generate-grammar.sh tree-sitter-mozcpp
 
 # Delete tree-sitter-mozcpp/tree-sitter-cpp directory
-rm -rf ./tree-sitter-mozcpp/tree-sitter-cpp
+rm -rf ./tree-sitter-mozcpp/$TS_CPP_CRATE