From b4b35af91283709689ffca37c4d1eb4f5eee0c30 Mon Sep 17 00:00:00 2001
From: Fabian Meumertzheim <fabian@meumertzhe.im>
Date: Tue, 1 Oct 2024 03:21:32 -0700
Subject: [PATCH] Heuristically path map copts and defines

This allows path mapping to apply to actions that reference execpaths in custom compiler options via location expansion.

Work towards #6526

Closes #23630.

PiperOrigin-RevId: 680941133
Change-Id: Ia10e2df481dcfe4480cbf9dfb1e12ec3b07d8ab2
---
 .../com/google/devtools/build/lib/actions/PathMapper.java  | 5 +++++
 .../build/lib/analysis/actions/StrippingPathMapper.java    | 5 +++++
 .../devtools/build/lib/rules/cpp/CcToolchainVariables.java | 2 +-
 src/test/shell/bazel/path_mapping_test.sh                  | 7 +++++++
 4 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/main/java/com/google/devtools/build/lib/actions/PathMapper.java b/src/main/java/com/google/devtools/build/lib/actions/PathMapper.java
index 7a71c40f1610c6..edbb6f8c6cc3e6 100644
--- a/src/main/java/com/google/devtools/build/lib/actions/PathMapper.java
+++ b/src/main/java/com/google/devtools/build/lib/actions/PathMapper.java
@@ -127,6 +127,11 @@ default ExceptionlessMapFn<Object> getMapFn(@Nullable String previousFlag) {
     return MapFn.DEFAULT;
   }
 
+  /** Heuristically maps all path-like strings in the given argument. */
+  default String mapHeuristically(String arg) {
+    return arg;
+  }
+
   /**
    * Returns a {@link FileRootApi} representing the new root of the given artifact after mapping.
    *
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/actions/StrippingPathMapper.java b/src/main/java/com/google/devtools/build/lib/analysis/actions/StrippingPathMapper.java
index 6466252844073b..4f798292375cb7 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/actions/StrippingPathMapper.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/actions/StrippingPathMapper.java
@@ -189,6 +189,11 @@ public ExceptionlessMapFn<Object> getMapFn(@Nullable String previousFlag) {
     return MapFn.DEFAULT;
   }
 
+  @Override
+  public String mapHeuristically(String arg) {
+    return argStripper.strip(arg);
+  }
+
   @Override
   public FileRootApi mapRoot(Artifact artifact) {
     if (Objects.equals(artifact.getRoot(), outputArtifactRoot)) {
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainVariables.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainVariables.java
index c725d4dcb78f36..ffc07540653d40 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainVariables.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainVariables.java
@@ -1043,7 +1043,7 @@ public ImmutableList<VariableValue> getSequenceValue(
       ImmutableList.Builder<VariableValue> sequences =
           ImmutableList.builderWithExpectedSize(values.size());
       for (String value : values) {
-        sequences.add(new StringValue(value));
+        sequences.add(new StringValue(pathMapper.mapHeuristically(value)));
       }
       return sequences.build();
     }
diff --git a/src/test/shell/bazel/path_mapping_test.sh b/src/test/shell/bazel/path_mapping_test.sh
index 60892c69fb63a0..b5cf054a62f777 100755
--- a/src/test/shell/bazel/path_mapping_test.sh
+++ b/src/test/shell/bazel/path_mapping_test.sh
@@ -542,6 +542,7 @@ cc_library(
     name = "utils",
     srcs = ["dir/utils.cc"],
     hdrs = ["dir/utils.h"],
+    defines = ["MY_FILE=\\\"+$(execpath dir/utils.cc)+\\\""],
     include_prefix = "other_dir",
     strip_include_prefix = "dir",
     visibility = ["//visibility:public"],
@@ -659,7 +660,13 @@ EOF
   cat > "$pkg/common/utils/utils.cc.tpl" <<'EOF'
 #include "utils.h"
 
+#include <cstdlib>
+#include <iostream>
+
 std::string AsGreeting(const std::string& name) {
+  if (std::string(MY_FILE).find("-out/cfg/") == std::string::npos) {
+    std::cerr << "Expected path to contain '-out/cfg/'" << std::endl;
+  }
   return "{GREETING}, " + name + "!";
 }
 EOF