Use GITHUB_TOKEN for fetching prebuilt (#6712)

* Use GITHUB_TOKEN for fetching prebuilt

This PR extends Commit c6b702c to use GITHUB_TOKEN if set for fetching
prebuilt binaries.
This allows webgpu-dawn and slang-tint to be downloaded for certain IPs
where the github API rate is limited.

Fixes #6689

* Don't ignore download failure if github token is provided

* Update readme for getting github access token

* format code

* combine cmake_parse_arguments calls

* format code

---------

Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>
Co-authored-by: Jay Kwak <82421531+jkwak-work@users.noreply.github.com>
Co-authored-by: Ellie Hermaszewska <ellieh@nvidia.com>

3 files changed, 32 insertions, 13 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6c6b5eb93..081a40fb4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -375,6 +375,7 @@ if(SLANG_WEBGPU_DAWN_BINARY_URL)
         "webgpu_dawn"
         "${SLANG_WEBGPU_DAWN_BINARY_URL}"
         IGNORE_FAILURE
+        SLANG_GITHUB_TOKEN ${SLANG_GITHUB_TOKEN}
     )
 endif()
 
@@ -387,6 +388,7 @@ if(SLANG_SLANG_TINT_BINARY_URL)
         "slang-tint"
         "${SLANG_SLANG_TINT_BINARY_URL}"
         IGNORE_FAILURE
+        SLANG_GITHUB_TOKEN ${SLANG_GITHUB_TOKEN}
     )
 endif()
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 822d44f08..36d297214 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -170,15 +170,11 @@ Call Stack (most recent call first):
   CMakeLists.txt:141 (get_best_slang_binary_release_url)
 ```
 
-The limit is higher when you use your personal account with a "Passkey".
+The limit is higher when you use your personal account with a "personal access token".
 
-To generate a "Passkey" on GitHub:
- 1. Go to GitHub "Settings" for your account.
- 2. Go to "Password and Authentication".
- 3. Click "Add a passkey" button.
- 4. GitHub will generate a "Passkey".
+To generate a "personal access token" on GitHub, follow steps in [Creating a personal access token (classic)](https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/managing-your-personal-access-tokens#creating-a-personal-access-token-classic)
 
-Use the generated "Passkey" with a cmake option "-DSLANG_GITHUB_TOKEN=your-pass-key-here".
+Use the generated "token" with a cmake option "-DSLANG_GITHUB_TOKEN=your-token-here".
 
 ### Making Changes
 Make your changes and ensure to follow our [Design Decisions](docs/design/README.md).
diff --git a/cmake/FetchedSharedLibrary.cmake b/cmake/FetchedSharedLibrary.cmake
index e2bd29b93..08a346da6 100644
--- a/cmake/FetchedSharedLibrary.cmake
+++ b/cmake/FetchedSharedLibrary.cmake
@@ -6,6 +6,7 @@ endif()
 
 # Helper function to download and extract an archive
 function(download_and_extract archive_name url)
+    cmake_parse_arguments(ARG "" "SLANG_GITHUB_TOKEN" "" ${ARGN})
     cmake_path(GET url FILENAME filename_with_ext)
     cmake_path(GET url STEM LAST_ONLY file_stem)
     set(archive_path "${CMAKE_CURRENT_BINARY_DIR}/${filename_with_ext}")
@@ -26,15 +27,28 @@ function(download_and_extract archive_name url)
                 "Using existing archive for ${archive_name}: ${archive_path}"
             )
         else()
-            message(STATUS "Fetching ${archive_name} from ${url}")
-            file(DOWNLOAD ${url} ${archive_path} STATUS status)
+            set(download_args ${url} ${archive_path} STATUS status)
+            if(ARG_SLANG_GITHUB_TOKEN)
+                list(
+                    APPEND
+                    download_args
+                    HTTPHEADER
+                    "Authorization: token ${ARG_SLANG_GITHUB_TOKEN}"
+                )
+            endif()
+
+            file(DOWNLOAD ${download_args})
 
             list(GET status 0 status_code)
             list(GET status 1 status_string)
             if(NOT status_code EQUAL 0)
                 message(
                     WARNING
-                    "Failed to download ${archive_name} from ${url}: ${status_string}"
+                    "Failed to download ${archive_name} from ${url}: ${status_string} with status code ${status_code}"
+                )
+                message(
+                    WARNING
+                    "If API rate limit is exceeded, Github allows a higher limit when you use token. Try a cmake option -DSLANG_GITHUB_TOKEN=your_token_here"
                 )
                 return()
             endif()
@@ -55,8 +69,11 @@ endfunction()
 # Otherwise, the 'url' is interpreted as an URL, and the content of the URL will be fetched, extracted and searched
 # for the shared library to produce the install rule.
 function(copy_fetched_shared_library library_name url)
-    cmake_parse_arguments(ARG "IGNORE_FAILURE" "" "" ${ARGN})
-    if(ARG_IGNORE_FAILURE)
+    cmake_parse_arguments(ARG "IGNORE_FAILURE" "SLANG_GITHUB_TOKEN" "" ${ARGN})
+
+    # Don't ignore failure if a Github token is provided;
+    # as we assume that the token will fix the rate limit issue.
+    if(ARG_IGNORE_FAILURE AND NOT ARG_SLANG_GITHUB_TOKEN)
         set(error_type STATUS)
     else()
         set(error_type SEND_ERROR)
@@ -95,7 +112,11 @@ function(copy_fetched_shared_library library_name url)
         set(source_object "${url}")
     else()
         # Otherwise, download and extract from whatever URL we have
-        download_and_extract("${library_name}" "${url}")
+        download_and_extract(
+            "${library_name}"
+            "${url}"
+            SLANG_GITHUB_TOKEN ${ARG_SLANG_GITHUB_TOKEN}
+        )
         if(DEFINED ${library_name}_SOURCE_DIR)
             from_glob(${${library_name}_SOURCE_DIR})
         elseif(ARG_IGNORE_FAILURE)