Do not make -pass-remarks additive.

Summary:
When I initially introduced -pass-remarks, I thought it would be a
neat idea to make it additive. So, if one used it as:

$ llc -pass-remarks=inliner --pass-remarks=loop.*

the compiler would build the regular expression '(inliner)|(loop.*)'.

The more I think about it, the more I regret it. This is not how
other flags work. The standard semantics are right-to-left overrides.

This is how clang interprets -Rpass. And I think the two should be
compatible in this respect.

Reviewers: qcolombet

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D3614

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208122 91177308-0d34-0410-b5e6-96231b3b80d8

lib/IR/LLVMContextImpl.cpp

@@ -73,22 +73,12 @@ namespace {
 /// LLVMContext::emitOptimizationRemark.
 static Regex *OptimizationRemarkPattern = nullptr;
 
-/// \brief String to hold all the values passed via -pass-remarks. Every
-/// instance of -pass-remarks on the command line will be concatenated
-/// to this string. Values are stored inside braces and concatenated with
-/// the '|' operator. This implements the expected semantics that multiple
-/// -pass-remarks are additive.
-static std::string OptimizationRemarkExpr;
-
 struct PassRemarksOpt {
   void operator=(const std::string &Val) const {
     // Create a regexp object to match pass names for emitOptimizationRemark.
     if (!Val.empty()) {
-      if (!OptimizationRemarkExpr.empty())
-        OptimizationRemarkExpr += "|";
-      OptimizationRemarkExpr += "(" + Val + ")";
       delete OptimizationRemarkPattern;
-      OptimizationRemarkPattern = new Regex(OptimizationRemarkExpr);
+      OptimizationRemarkPattern = new Regex(Val);
       std::string RegexError;
       if (!OptimizationRemarkPattern->isValid(RegexError))
         report_fatal_error("Invalid regular expression '" + Val +

test/Other/optimization-remarks-inline.ll

@@ -1,7 +1,14 @@
 ; RUN: opt < %s -inline -pass-remarks='inline' -S 2>&1 | FileCheck %s
 ; RUN: opt < %s -inline -pass-remarks='inl.*' -S 2>&1 | FileCheck %s
 ; RUN: opt < %s -inline -pass-remarks='vector' -pass-remarks='inl' -S 2>&1 | FileCheck %s
+
+; These two should not yield an inline remark for the same reason.
+; In the first command, we only ask for vectorizer remarks, in the
+; second one we ask for the inliner, but we then ask for the vectorizer
+; (thus overriding the first flag).
 ; RUN: opt < %s -inline -pass-remarks='vector' -S 2>&1 | FileCheck --check-prefix=REMARKS %s
+; RUN: opt < %s -inline -pass-remarks='inl' -pass-remarks='vector' -S 2>&1 | FileCheck --check-prefix=REMARKS %s
+
 ; RUN: opt < %s -inline -S 2>&1 | FileCheck --check-prefix=REMARKS %s
 ; RUN: not opt < %s -pass-remarks='(' 2>&1 | FileCheck --check-prefix=BAD-REGEXP %s