Revert "Revert "[analyzer] Prevent misuses of -analyze-function""

This reverts commit 620d99b7edc64ee87b1ce209f179305e6a919006.

Let's see if removing the two offending RUN lines makes this patch pass.
Not ideal to drop tests but, it's just a debugging feature, probably not
that important.

1 files changed, 30 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp b/clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
index 323c002..9e96e00 100644
--- a/clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
+++ b/clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
@@ -499,6 +499,28 @@ static bool fileContainsString(StringRef Substring, ASTContext &C) {
   return Buffer.contains(Substring);
 }
 
+static void reportAnalyzerFunctionMisuse(const AnalyzerOptions &Opts,
+                                         const ASTContext &Ctx) {
+  llvm::errs() << "Every top-level function was skipped.\n";
+
+  if (!Opts.AnalyzerDisplayProgress)
+    llvm::errs() << "Pass the -analyzer-display-progress for tracking which "
+                    "functions are analyzed.\n";
+
+  bool HasBrackets =
+      Opts.AnalyzeSpecificFunction.find("(") != std::string::npos;
+
+  if (Ctx.getLangOpts().CPlusPlus && !HasBrackets) {
+    llvm::errs()
+        << "For analyzing C++ code you need to pass the function parameter "
+           "list: -analyze-function=\"foobar(int, _Bool)\"\n";
+  } else if (!Ctx.getLangOpts().CPlusPlus && HasBrackets) {
+    llvm::errs() << "For analyzing C code you shouldn't pass the function "
+                    "parameter list, only the name of the function: "
+                    "-analyze-function=foobar\n";
+  }
+}
+
 void AnalysisConsumer::runAnalysisOnTranslationUnit(ASTContext &C) {
   BugReporter BR(*Mgr);
   TranslationUnitDecl *TU = C.getTranslationUnitDecl();
@@ -535,6 +557,14 @@ void AnalysisConsumer::runAnalysisOnTranslationUnit(ASTContext &C) {
 
   BR.FlushReports();
   RecVisitorBR = nullptr;
+
+  // If the user wanted to analyze a specific function and the number of basic
+  // blocks analyzed is zero, than the user might not specified the function
+  // name correctly.
+  // FIXME: The user might have analyzed the requested function in Syntax mode,
+  // but we are unaware of that.
+  if (!Opts->AnalyzeSpecificFunction.empty() && NumFunctionsAnalyzed == 0)
+    reportAnalyzerFunctionMisuse(*Opts, *Ctx);
 }
 
 void AnalysisConsumer::reportAnalyzerProgress(StringRef S) {