[PATCH] D116329: [clang-check] Adjust argument adjusters for clang-check to strip options blocking the static analyzer

[Ella Ma via Phabricator via cfe-commits]

OikawaKirie created this revision.
OikawaKirie added reviewers: kbobyrev, sammccall, labath.
OikawaKirie added a project: clang.
Herald added subscribers: manas, ASDenysPetrov, dkrupp, donat.nagy, Szelethus, a.sidorin, baloghadamsoftware.
OikawaKirie requested review of this revision.
Herald added a subscriber: cfe-commits.

Output generation options (like `-save-temps`) will make the analyzer not executed even `--analyze` option is provided in the driver arguments.
Besides, the original approach of adding `--analyze` option will not work when (more than one) `-fsyntax-only` options are provided in the driver arguments.

This patch fixes these two problems by using the syntax-only adjuster to remove output generation options and manually filter out redundant `-fsyntax-only` options.

In the new implementation, the adjusters added by `ClangTool` will not be removed but used as dependencies for clang-check adjusters for analyzer options.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D116329

Files:
  clang/test/Tooling/clang-check-analyze-save-temps.cpp
  clang/tools/clang-check/ClangCheck.cpp


Index: clang/tools/clang-check/ClangCheck.cpp
===================================================================
--- clang/tools/clang-check/ClangCheck.cpp
+++ clang/tools/clang-check/ClangCheck.cpp
@@ -208,27 +208,39 @@
   ClangTool Tool(OptionsParser.getCompilations(),
                  OptionsParser.getSourcePathList());
 
-  // Clear adjusters because -fsyntax-only is inserted by the default chain.
-  Tool.clearArgumentsAdjusters();
-
-  // Reset output path if is provided by user.
-  Tool.appendArgumentsAdjuster(
-      Analyze ? [&](const CommandLineArguments &Args, StringRef File) {
-                  auto Ret = getClangStripOutputAdjuster()(Args, File);
-                  if (!AnalyzerOutput.empty()) {
-                    Ret.emplace_back("-o");
-                    Ret.emplace_back(AnalyzerOutput);
-                  }
-                  return Ret;
-                }
-              : getClangStripOutputAdjuster());
-
-  Tool.appendArgumentsAdjuster(getClangStripDependencyFileAdjuster());
-
-  // Running the analyzer requires --analyze. Other modes can work with the
-  // -fsyntax-only option.
-  Tool.appendArgumentsAdjuster(getInsertArgumentAdjuster(
-      Analyze ? "--analyze" : "-fsyntax-only", ArgumentInsertPosition::BEGIN));
+  if (Analyze) {
+    // Set output path if is provided by user.
+    //
+    // As the original -o options have been removed by strip-output adjuster, we
+    // only need to add the analyzer -o options here.
+    if (!AnalyzerOutput.empty()) {
+      Tool.appendArgumentsAdjuster(getInsertArgumentAdjuster("-o"));
+      Tool.appendArgumentsAdjuster(
+          getInsertArgumentAdjuster(AnalyzerOutput.c_str()));
+    }
+
+    // Running the analyzer requires --analyze. Other modes can work with the
+    // -fsyntax-only option.
+    //
+    // The syntax-only adjuster can also help us to remove other options that
+    // trigger output generation, e.g. -save-temps. Besides, to enable the
+    // analyzer, we also need to replace the first -fsyntax-only option with
+    // option --analyze, and remove redundant ones.
+    Tool.appendArgumentsAdjuster(
+        [&](const CommandLineArguments &Args, StringRef /*unused*/) {
+          CommandLineArguments AdjustedArgs;
+          bool HasAnalyze = false;
+          for (const StringRef Arg : Args) {
+            if (Arg != "-fsyntax-only") {
+              AdjustedArgs.emplace_back(Arg);
+            } else if (!HasAnalyze) {
+              AdjustedArgs.emplace_back("--analyze");
+              HasAnalyze = true;
+            }
+          }
+          return AdjustedArgs;
+        });
+  }
 
   ClangCheckActionFactory CheckFactory;
   std::unique_ptr<FrontendActionFactory> FrontendFactory;
Index: clang/test/Tooling/clang-check-analyze-save-temps.cpp
===================================================================
--- /dev/null
+++ clang/test/Tooling/clang-check-analyze-save-temps.cpp
@@ -0,0 +1,19 @@
+// Check whether output generation options (like -save-temps) will not affect
+// the execution of the analyzer.
+
+// RUN: clang-check -analyze %s -- -save-temps -c -Xclang -verify
+
+
+// Check whether redundant -fsyntax-only options will affect the execution of
+// the analyzer.
+
+// RUN: clang-check -analyze %s -- \
+// RUN:   -fsyntax-only -c -fsyntax-only -Xclang -verify 2>&1 | \
+// RUN:   FileCheck %s --allow-empty
+
+// CHECK-NOT: argument unused during compilation: '--analyze'
+
+void a(int *x) {
+  if (x) { }
+  *x = 47; // expected-warning {{Dereference of null pointer}}
+}


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