[6.3.0] Add additional_compiler_inputs attribute for cc_library. (#18882)

* Add additional_compiler_inputs attribute for cc_library.

Also, ensure that location function expansion works with these inputs as
expected.

RELNOTES: Additional source inputs can now be specified for compilation in cc_library targets using the additional_compiler_inputs attribute, and these inputs can be used in the $(location) function.

Fixes #18766.

PiperOrigin-RevId: 545766084
Change-Id: I2d9f195d81a1358c696601873e60d3cad810a150
(cherry picked from commit ade32e6)
Signed-off-by: Brentley Jones <[email protected]>

* Add `_expand(targets)`

From ff92499.

Signed-off-by: Brentley Jones <[email protected]>

---------

Signed-off-by: Brentley Jones <[email protected]>

Author: brentleyjones

src/main/java/com/google/devtools/build/lib/bazel/rules/cpp/BazelCcLibraryRule.java

@@ -63,6 +63,12 @@ public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment env)
             attr("implementation_deps", LABEL_LIST)
                 .allowedFileTypes(FileTypeSet.NO_FILE)
                 .mandatoryProviders(CcInfo.PROVIDER.id()))
+        /*<!-- #BLAZE_RULE(cc_library).ATTRIBUTE(additional_compiler_inputs) -->
+        Any additional files you might want to pass to the compiler command line, such as sanitizer
+        ignorelists, for example. Files specified here can then be used in copts with the
+        $(location) function.
+        <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/
+        .add(attr("additional_compiler_inputs", LABEL_LIST).allowedFileTypes(FileTypeSet.ANY_FILE))
         .advertiseStarlarkProvider(CcInfo.PROVIDER.id())
         .build();
   }

src/main/starlark/builtins_bzl/common/cc/cc_helper.bzl

@@ -706,16 +706,15 @@ def _get_cc_flags_make_variable(ctx, common, cc_toolchain):
     cc_flags.extend(feature_config_cc_flags)
     return {"CC_FLAGS": " ".join(cc_flags)}
 
-def _expand_nested_variable(ctx, additional_vars, exp, execpath = True):
+def _expand_nested_variable(ctx, additional_vars, exp, execpath = True, targets = []):
     # If make variable is predefined path variable(like $(location ...))
     # we will expand it first.
     if exp.find(" ") != -1:
         if not execpath:
             if exp.startswith("location"):
                 exp = exp.replace("location", "rootpath", 1)
-        targets = []
         if ctx.attr.data != None:
-            targets = ctx.attr.data
+            targets.extend(ctx.attr.data)
         return ctx.expand_location("$({})".format(exp), targets = targets)
 
     # Recursively expand nested make variables, but since there is no recursion
@@ -739,7 +738,7 @@ def _expand_nested_variable(ctx, additional_vars, exp, execpath = True):
         fail("potentially unbounded recursion during expansion of {}".format(exp))
     return exp
 
-def _expand(ctx, expression, additional_make_variable_substitutions, execpath = True):
+def _expand(ctx, expression, additional_make_variable_substitutions, execpath = True, targets = []):
     idx = 0
     last_make_var_end = 0
     result = []
@@ -781,7 +780,7 @@ def _expand(ctx, expression, additional_make_variable_substitutions, execpath =
                 #   last_make_var_end  make_var_start make_var_end
                 result.append(expression[last_make_var_end:make_var_start - 1])
                 make_var = expression[make_var_start + 1:make_var_end]
-                exp = _expand_nested_variable(ctx, additional_make_variable_substitutions, make_var, execpath)
+                exp = _expand_nested_variable(ctx, additional_make_variable_substitutions, make_var, execpath, targets)
                 result.append(exp)
 
                 # Update indexes.
@@ -868,16 +867,19 @@ def _expand_single_make_variable(ctx, token, additional_make_variable_substituti
 
 def _expand_make_variables_for_copts(ctx, tokenization, unexpanded_tokens, additional_make_variable_substitutions):
     tokens = []
+    targets = []
+    for additional_compiler_input in getattr(ctx.attr, "additional_compiler_inputs", []):
+        targets.append(additional_compiler_input)
     for token in unexpanded_tokens:
         if tokenization:
-            expanded_token = _expand(ctx, token, additional_make_variable_substitutions)
+            expanded_token = _expand(ctx, token, additional_make_variable_substitutions, targets = targets)
             _tokenize(tokens, expanded_token)
         else:
             exp = _expand_single_make_variable(ctx, token, additional_make_variable_substitutions)
             if exp != None:
                 _tokenize(tokens, exp)
             else:
-                tokens.append(_expand(ctx, token, additional_make_variable_substitutions))
+                tokens.append(_expand(ctx, token, additional_make_variable_substitutions, targets = targets))
     return tokens
 
 def _get_copts(ctx, common, feature_configuration, additional_make_variable_substitutions):

src/main/starlark/builtins_bzl/common/cc/cc_library.bzl

@@ -72,6 +72,7 @@ def _cc_library_impl(ctx):
         textual_hdrs = ctx.files.textual_hdrs,
         include_prefix = ctx.attr.include_prefix,
         strip_include_prefix = ctx.attr.strip_include_prefix,
+        additional_inputs = ctx.files.additional_compiler_inputs,
     )
 
     precompiled_objects = cc_common.create_compilation_outputs(
@@ -600,6 +601,10 @@ attrs = {
     ),
     "win_def_file": attr.label(allow_single_file = [".def"]),
     "licenses": attr.license() if hasattr(attr, "license") else attr.string_list(),
+    "additional_compiler_inputs": attr.label_list(
+        allow_files = True,
+        flags = ["ORDER_INDEPENDENT", "DIRECT_COMPILE_TIME_INPUT"],
+    ),
     "_stl": semantics.get_stl(),
     "_grep_includes": attr.label(
         allow_files = True,