Add command line argument parsing to the Windows packaging script.

[CarlosAlbertoEnciso]

Summary

As discussed here:
https://discourse.llvm.org/t/build-llvm-release-bat-script-options

Add a function to parse command line arguments: parse_args.

The format for the arguments is:
Boolean: --option
Value: --option<separator>value
with <separator> being: space, colon, semicolon or equal sign

Command line usage example:
my-batch-file.bat --build --type=release --version 123
It will create 3 variables:
build with the value true
type with the value release
version with the value 123

Usage:

set "build="
set "type="
set "version="

REM Parse arguments.
call :parse_args %*

if defined build (
  ...
)
if %type%=='release' (
  ...
)
if %version%=='123' (
  ...
)

[CarlosAlbertoEnciso]

After this patch, we can introduce the options presented in https://reviews.llvm.org/D127938 on incremental patches.

[hans]

Can you change the description from "Update Windows packaging script" which is pretty generic to something like "Add command line argument parsing to the Windows packaging script"?

llvm/utils/release/build_llvm_release.bat

295

I'm probably missing something, but for --type=release it seems like this would set arg_name to type=release? Or does it get split into the name and value in some way?

Or, it looks like the code would maybe work for --type release, but in that case the example above would need updating.

[CarlosAlbertoEnciso]

Update title, example and how to use the function.

[CarlosAlbertoEnciso]

llvm/utils/release/build_llvm_release.bat

295

I'm probably missing something, but for --type=release it seems like this would set arg_name to type=release? Or does it get split into the name and value in some way?

The = sign in the command line is interpreted as argument separator. The same for space, comma and semicolon.

--type=release and type release are splitted in 2 arguments --type and release.

[hans]

lgtm

llvm/utils/release/build_llvm_release.bat

295

Interesting, I did not know Windows did that.

[CarlosAlbertoEnciso]

@hans Thanks.

llvm/utils/release/build_llvm_release.bat

 ninja check-sanitizer || ninja check-sanitizer || ninja check-sanitizer || exit /b 1
 ninja check-clang-tools || ninja check-clang-tools || ninja check-clang-tools || exit /b 1
 ninja check-clangd || ninja check-clangd || ninja check-clangd || exit /b 1
 ninja package || exit /b 1
 cd ..
 
 exit /b 0
 ::==============================================================================
+
+::=============================================================================
+:: Parse command line arguments.
+:: The format for the arguments is:
+::   Boolean: --option
+::   Value:   --option<separator>value
+::     with <separator> being: space, colon, semicolon or equal sign
+::
+:: Command line usage example:
+::   my-batch-file.bat --build --type=release --version 123
+:: It will create 3 variables:
+::   'build' with the value 'true'
+::   'type' with the value 'release'
+::   'version' with the value '123'
+::
+:: Usage:
+::   set "build="
+::   set "type="
+::   set "version="
+::
+::   REM Parse arguments.
+::   call :parse_args %*
+::
+::   if defined build (
+::     ...
+::   )
+::   if %type%=='release' (
+::     ...
+::   )
+::   if %version%=='123' (
+::     ...
+::   )
+::=============================================================================
+:parse_args
+  set "arg_name="
+  :parse_args_start
+  if "%1" == "" (
+    :: Set a seen boolean argument.
+    if "%arg_name%" neq "" (
+      set "%arg_name%=true"
+    )
+    goto :parse_args_done
+  )
+  set aux=%1
+  if "%aux:~0,2%" == "--" (
+    :: Set a seen boolean argument.
+    if "%arg_name%" neq "" (
+      set "%arg_name%=true"
+    )
+    set "arg_name=%aux:~2,250%"
+  ) else (
+    set "%arg_name%=%1"
+    set "arg_name="
+  )
+  shift
+  goto :parse_args_start
+
+:parse_args_done
+exit /b 0
+::==============================================================================