[FileCheck] Fix numeric variable redefinition

Summary:
Commit r365249 changed usage of FileCheckNumericVariable to have one
instance of that class per variable as opposed to one instance per
definition of a given variable as was done before. However, it retained
the safety check in setValue that it should only be called with the
variable unset, even after r365625.

However this causes assert failure when a non-pseudo variable is being
redefined. And while redefinition of @line at each CHECK line work in
the general case, it caused problem when a substitution failed (fixed in
r365624) and still causes problem when a CHECK line does not match since
@line's value is cleared after substitutions in match() happened but
printSubstitutions also attempts a substitution.

This commit solves the root of the problem by changing setValue to set a
new value regardless of whether a value was set or not, thus fixing all
the aforementioned issues.

Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk

Subscribers: hiraditya, llvm-commits, probinson, dblaikie, grimar, arichardson, tra, rnk, kristina, hfinkel, rogfer01, JonChesterfield

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64882

llvm-svn: 366434

Author: Thomas Preud'homme

llvm/include/llvm/Support/FileCheck.h

@@ -115,13 +115,12 @@ class FileCheckNumericVariable {
   /// \returns this variable's value.
   Optional<uint64_t> getValue() const { return Value; }
 
-  /// Sets value of this numeric variable, if undefined. Triggers an assertion
-  /// failure if the variable is actually defined.
-  void setValue(uint64_t Value);
+  /// Sets value of this numeric variable to \p NewValue.
+  void setValue(uint64_t NewValue) { Value = NewValue; }
 
   /// Clears value of this numeric variable, regardless of whether it is
   /// currently defined or not.
-  void clearValue();
+  void clearValue() { Value = None; }
 
   /// \returns the line number where this variable is defined, if any, or None
   /// if defined before input is parsed.

llvm/lib/Support/FileCheck.cpp

@@ -24,17 +24,6 @@
 
 using namespace llvm;
 
-void FileCheckNumericVariable::setValue(uint64_t NewValue) {
-  assert(!Value && "Overwriting numeric variable's value is not allowed");
-  Value = NewValue;
-}
-
-void FileCheckNumericVariable::clearValue() {
-  if (!Value)
-    return;
-  Value = None;
-}
-
 Expected<uint64_t> FileCheckNumericVariableUse::eval() const {
   Optional<uint64_t> Value = NumericVariable->getValue();
   if (Value)
@@ -631,10 +620,8 @@ Expected<size_t> FileCheckPattern::match(StringRef Buffer, size_t &MatchLen,
     for (const auto &Substitution : Substitutions) {
       // Substitute and check for failure (e.g. use of undefined variable).
       Expected<std::string> Value = Substitution->getResult();
-      if (!Value) {
-        Context->LineVariable->clearValue();
+      if (!Value)
         return Value.takeError();
-      }
 
       // Plop it into the regex at the adjusted offset.
       TmpStr.insert(TmpStr.begin() + Substitution->getIndex() + InsertOffset,
@@ -644,7 +631,6 @@ Expected<size_t> FileCheckPattern::match(StringRef Buffer, size_t &MatchLen,
 
     // Match the newly constructed regex.
     RegExToMatch = TmpStr;
-    Context->LineVariable->clearValue();
   }
 
   SmallVector<StringRef, 4> MatchInfo;

llvm/test/FileCheck/line-count.txt

@@ -55,12 +55,18 @@
 55 BAD11: [[@LINE-1x]]
 56 ERR11: line-count.txt:[[#@LINE-1]]:20: error: unexpected characters at end of expression 'x'
 57
-58 CHECK: [[#@LINE]] CHECK
-59 CHECK: [[# @LINE]] CHECK
-60 CHECK: [[# @LINE ]] CHECK
-61
-62 CHECK: [[#@LINE-1]]
-63 CHECK: [[# @LINE-1]] CHECK
-64 CHECK: [[# @LINE -1]] CHECK
-65 CHECK: [[# @LINE - 1]] CHECK
-66 CHECK: [[# @LINE - 1 ]] CHECK
+; RUN: not FileCheck -check-prefix BAD12 -input-file %s %s 2>&1 \
+; RUN:   | FileCheck -check-prefix ERR12 %s
+60
+61 BAD12: [[#@LINE-1]] NOT HERE
+62 ERR12: note: with "@LINE-1" equal to "60"
+63
+64 CHECK: [[#@LINE]] CHECK
+65 CHECK: [[# @LINE]] CHECK
+66 CHECK: [[# @LINE ]] CHECK
+67
+68 CHECK: [[#@LINE-1]]
+69 CHECK: [[# @LINE-1]] CHECK
+70 CHECK: [[# @LINE -1]] CHECK
+71 CHECK: [[# @LINE - 1]] CHECK
+72 CHECK: [[# @LINE - 1 ]] CHECK

llvm/test/FileCheck/numeric-expression.txt

@@ -4,7 +4,7 @@ RUN: FileCheck --input-file %s %s
 
 ; Numeric variable definition without spaces.
 DEF NO SPC
-11
+10
 CHECK-LABEL: DEF NO SPC
 CHECK-NEXT: [[#VAR1:]]
 
@@ -18,6 +18,12 @@ CHECK-NEXT: [[# VAR1a:]]
 CHECK-NEXT: [[# VAR1b :]]
 CHECK-NEXT: [[# VAR1c : ]]
 
+; Numeric variable redefinition.
+REDEF NO SPC
+11
+CHECK-LABEL: REDEF
+CHECK-NEXT: [[#VAR1:]]
+
 ; Numeric expressions using variables defined on other lines without spaces.
 USE NO SPC
 11

llvm/unittests/Support/FileCheckTest.cpp

@@ -55,7 +55,7 @@ static void expectUndefError(const Twine &ExpectedUndefVarName, Error Err) {
 
 TEST_F(FileCheckTest, NumericVariable) {
   // Undefined variable: getValue and eval fail, error returned by eval holds
-  // the name of the undefined variable and setValue does not trigger assert.
+  // the name of the undefined variable.
   FileCheckNumericVariable FooVar = FileCheckNumericVariable("FOO", 1);
   EXPECT_EQ("FOO", FooVar.getName());
   FileCheckNumericVariableUse FooVarUse =
@@ -64,6 +64,7 @@ TEST_F(FileCheckTest, NumericVariable) {
   Expected<uint64_t> EvalResult = FooVarUse.eval();
   EXPECT_FALSE(EvalResult);
   expectUndefError("FOO", EvalResult.takeError());
+
   FooVar.setValue(42);
 
   // Defined variable: getValue and eval return value set.