Document supported compiler versions in building.md (#7512)

* Document supported compiler versions in building.md

Closes https://github.com/shader-slang/slang/issues/7376

* multiple checked versions

1 files changed, 141 insertions, 0 deletions

diff --git a/extras/verify-documented-compiler-version.sh b/extras/verify-documented-compiler-version.sh
new file mode 100755
index 000000000..b98a29dc4
--- /dev/null
+++ b/extras/verify-documented-compiler-version.sh
@@ -0,0 +1,141 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+# File paths
+DOCS_FILE="docs/building.md"
+CMAKE_CACHE="build/CMakeCache.txt"
+
+# Check if required files exist
+if [[ ! -f "$DOCS_FILE" ]]; then
+  echo "::warning::Documentation file $DOCS_FILE not found"
+  exit 0
+fi
+
+if [[ ! -f "$CMAKE_CACHE" ]]; then
+  echo "::warning::CMakeCache.txt not found at $CMAKE_CACHE"
+  exit 0
+fi
+
+# Extract compiler path from CMakeCache.txt
+COMPILER_PATH=$(grep "^CMAKE_CXX_COMPILER:FILEPATH=" "$CMAKE_CACHE" | cut -d'=' -f2)
+
+if [[ -z "$COMPILER_PATH" ]]; then
+  echo "::warning::Could not find CMAKE_CXX_COMPILER in CMakeCache.txt"
+  exit 0
+fi
+
+# Determine compiler type and get version
+COMPILER_NAME=$(basename "$COMPILER_PATH")
+COMPILER_VERSION=""
+COMPILER_TYPE=""
+
+if [[ "$COMPILER_NAME" =~ ^g\+\+|^gcc ]]; then
+  COMPILER_TYPE="GCC"
+  # Get GCC version (e.g., "gcc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0")
+  COMPILER_VERSION=$("$COMPILER_PATH" --version | head -1 | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | head -1)
+elif [[ "$COMPILER_NAME" =~ ^clang\+\+|^clang ]]; then
+  COMPILER_TYPE="Clang"
+  # Get Clang version (e.g., "Ubuntu clang version 15.0.7")
+  COMPILER_VERSION=$("$COMPILER_PATH" --version | head -1 | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | head -1)
+elif [[ "$COMPILER_NAME" =~ ^cl\.exe|^cl$ ]]; then
+  COMPILER_TYPE="MSVC"
+  # MSVC version is more complex, extract major version
+  # MSVC outputs version like "19.29.30133" where 19 is the major version
+  COMPILER_VERSION=$("$COMPILER_PATH" 2>&1 | grep -oE 'Version [0-9]+\.[0-9]+' | grep -oE '[0-9]+\.[0-9]+' | head -1)
+else
+  echo "::warning::Unknown compiler type: $COMPILER_NAME"
+  exit 0
+fi
+
+if [[ -z "$COMPILER_VERSION" ]]; then
+  echo "::warning::Could not determine version for compiler: $COMPILER_PATH"
+  exit 0
+fi
+
+# Extract major.minor version only
+COMPILER_MAJOR_MINOR=$(echo "$COMPILER_VERSION" | cut -d'.' -f1,2)
+
+# Function to extract versions from a line
+extract_versions() {
+  local line="$1"
+  local is_msvc="$2"
+
+  # Extract the part between compiler name and "are/is tested in CI"
+  local version_part
+  version_part=$(echo "$line" | sed -E 's/^_[^_]+_ //; s/ (are|is) tested in CI.*//')
+
+  # Split by "and" and extract version numbers
+  local versions=()
+  if [[ "$is_msvc" == "true" ]]; then
+    # For MSVC, just extract numbers
+    while IFS= read -r version; do
+      version=$(echo "$version" | grep -oE '[0-9]+' | head -1)
+      [[ -n "$version" ]] && versions+=("$version")
+    done < <(echo "$version_part" | tr ',' '\n' | sed 's/ and /\n/g')
+  else
+    # For GCC/Clang, extract major.minor versions
+    while IFS= read -r version; do
+      version=$(echo "$version" | grep -oE '[0-9]+\.[0-9]+' | head -1)
+      [[ -n "$version" ]] && versions+=("$version")
+    done < <(echo "$version_part" | tr ',' '\n' | sed 's/ and /\n/g')
+  fi
+
+  echo "${versions[@]}"
+}
+
+# Parse the documentation for the expected versions
+EXPECTED_VERSIONS=()
+VERSION_FOUND=false
+
+case "$COMPILER_TYPE" in
+"GCC")
+  DOC_LINE=$(grep -E "^_GCC_ .+ (are|is) tested in CI" "$DOCS_FILE" | head -1)
+  if [[ -n "$DOC_LINE" ]]; then
+    # shellcheck disable=SC2207
+    EXPECTED_VERSIONS=($(extract_versions "$DOC_LINE" "false"))
+  fi
+  ;;
+"Clang")
+  DOC_LINE=$(grep -E "^_Clang_ .+ (are|is) tested in CI" "$DOCS_FILE" | head -1)
+  if [[ -n "$DOC_LINE" ]]; then
+    # shellcheck disable=SC2207
+    EXPECTED_VERSIONS=($(extract_versions "$DOC_LINE" "false"))
+  fi
+  ;;
+"MSVC")
+  # For MSVC, we only compare major version
+  DOC_LINE=$(grep -E "^_MSVC_ .+ (are|is) tested in CI" "$DOCS_FILE" | head -1)
+  if [[ -n "$DOC_LINE" ]]; then
+    # shellcheck disable=SC2207
+    EXPECTED_VERSIONS=($(extract_versions "$DOC_LINE" "true"))
+  fi
+  COMPILER_MAJOR_MINOR=$(echo "$COMPILER_VERSION" | cut -d'.' -f1)
+  ;;
+esac
+
+if [[ ${#EXPECTED_VERSIONS[@]} -eq 0 ]]; then
+  echo "::warning::Could not find expected version for $COMPILER_TYPE in $DOCS_FILE"
+  exit 0
+fi
+
+# Check if current version matches any expected version
+for expected in "${EXPECTED_VERSIONS[@]}"; do
+  if [[ "$COMPILER_MAJOR_MINOR" == "$expected" ]]; then
+    VERSION_FOUND=true
+    break
+  fi
+done
+
+# Report results
+if [[ "$VERSION_FOUND" == "false" ]]; then
+  EXPECTED_LIST=$(
+    IFS=', '
+    echo "${EXPECTED_VERSIONS[*]}"
+  )
+  echo "::warning::Compiler version mismatch for $COMPILER_TYPE: Documentation says $EXPECTED_LIST but found $COMPILER_MAJOR_MINOR (full version: $COMPILER_VERSION)"
+else
+  echo "✓ Compiler version matches: $COMPILER_TYPE $COMPILER_MAJOR_MINOR"
+fi
+
+exit 0