Add Valgrind testing infrastructure for memory bug detection

Makefile

@@ -1,4 +1,4 @@
-.PHONY: duckdb install-duckdb clean-duckdb clean-all lintcheck check-regression-duckdb clean-regression
+.PHONY: duckdb install-duckdb clean-duckdb clean-all lintcheck check-regression-duckdb clean-regression valgrind-check
 
 MODULE_big = pg_duckdb
 EXTENSION = pg_duckdb
@@ -109,6 +109,13 @@ check: installcheck pycheck schedulecheck
 schedulecheck:
 	./scripts/schedule-check.sh
 
+valgrind-check:
+	@if [ -z "$(PG_SRC)" ]; then \
+		echo "Usage: make valgrind-check PG_SRC=/path/to/postgres"; \
+		exit 1; \
+	fi
+	./scripts/valgrind_pgduckdb.sh PG_SRC=$(PG_SRC)
+
 duckdb: $(FULL_DUCKDB_LIB)
 
 .git/modules/third_party/duckdb/HEAD:

scripts/valgrind_pgduckdb.sh

@@ -0,0 +1,93 @@
+#!/bin/bash
+
+set -euo pipefail
+
+# Check arguments
+if [ $# -ne 1 ] || [[ "$1" != PG_SRC=* ]]; then
+    echo "Usage: $0 PG_SRC=/path/to/postgres"
+    exit 1
+fi
+
+PG_SRC="${1#PG_SRC=}"
+
+if [ ! -d "$PG_SRC" ]; then
+    echo "Error: PostgreSQL source directory '$PG_SRC' does not exist"
+    exit 1
+fi
+
+echo "Building PostgreSQL with Valgrind support..."
+
+# Setup temp directories
+TEMP_DIR=$(mktemp -d)
+PG_INSTALL="$TEMP_DIR/postgres_install"
+PG_DATA="$TEMP_DIR/postgres_data"
+PG_LOG="$TEMP_DIR/postgres_log"
+
+# Cleanup function
+cleanup() {
+    if [ -n "${PG_PID:-}" ]; then
+        kill $PG_PID 2>/dev/null || true
+    fi
+    rm -rf "$TEMP_DIR"
+}
+
+trap cleanup EXIT
+
+# Build PostgreSQL
+cd "$PG_SRC"
+./configure --prefix="$PG_INSTALL" --enable-debug \
+    CFLAGS="-O0 -g -DUSE_VALGRIND" \
+    CXXFLAGS="-O0 -g -DUSE_VALGRIND"
+make -j$(nproc)
+make install
+cd - > /dev/null
+
+# Build pg_duckdb
+echo "Building pg_duckdb..."
+make clean
+make PG_CONFIG="$PG_INSTALL/bin/pg_config"
+
+# Setup and start PostgreSQL
+echo "Starting PostgreSQL..."
+"$PG_INSTALL/bin/initdb" -D "$PG_DATA" --no-locale
+"$PG_INSTALL/bin/pg_ctl" -D "$PG_DATA" -l "$PG_LOG/postgres.log" start
+sleep 3
+
+if ! "$PG_INSTALL/bin/pg_ctl" -D "$PG_DATA" status > /dev/null 2>&1; then
+    echo "PostgreSQL failed to start"
+    cat "$PG_LOG/postgres.log"
+    exit 1
+fi
+
+PG_PID=$(cat "$PG_DATA/postmaster.pid" 2>/dev/null || echo "")
+
+# Run Valgrind test
+echo "Running Valgrind test..."
+TEST_SQL="test/regression/sql/valgrind_basic.sql"
+
+if [ ! -f "$TEST_SQL" ]; then
+    echo "Test file '$TEST_SQL' not found"
+    exit 1
+fi
+
+valgrind \
+    --tool=memcheck \
+    --leak-check=full \
+    --show-leak-kinds=all \
+    --track-origins=yes \
+    --num-callers=50 \
+    --error-exitcode=99 \
+    --suppressions="$PG_SRC/src/tools/valgrind.supp" \
+    "$PG_INSTALL/bin/psql" \
+    -h localhost -p 5432 -U "$(whoami)" -d postgres \
+    -f "$TEST_SQL"
+
+EXIT_CODE=$?
+
+if [ $EXIT_CODE -eq 0 ]; then
+    echo "Valgrind test passed"
+else
+    echo "Valgrind test failed"
+fi
+
+exit $EXIT_CODE

test/regression/expected/valgrind_basic.out

@@ -0,0 +1,27 @@
+CREATE EXTENSION pg_duckdb;
+SELECT * FROM duckdb.query('SELECT 42 as answer');
+ answer
+--------
+     42
+(1 row)
+
+SELECT * FROM duckdb.query('SELECT generate_series(1, 10) as num');
+ num
+-----
+   1
+   2
+   3
+   4
+   5
+   6
+   7
+   8
+   9
+  10
+(10 rows)
+
+SELECT * FROM duckdb.query('SELECT ''Hello, Valgrind!'' as message');
+     message
+------------------
+ Hello, Valgrind!
+(1 row)

test/regression/sql/valgrind_basic.sql

@@ -0,0 +1,7 @@
+CREATE EXTENSION pg_duckdb;
+
+SELECT * FROM duckdb.query('SELECT 42 as answer');
+
+SELECT * FROM duckdb.query('SELECT generate_series(1, 10) as num');
+
+SELECT * FROM duckdb.query('SELECT ''Hello, Valgrind!'' as message');