Commit b47b35ff authored by Tyker's avatar Tyker
Browse files

[Diagnostic] Add ftabstop to -Wmisleading-indentation 

Summary:
this allow much better support of codebases like the linux kernel that mix tabs and spaces.

-ftabstop=//Width// allow specifying how large tabs are considered to be.

Reviewers: xbolva00, aaron.ballman, rsmith

Reviewed By: aaron.ballman

Subscribers: jyknight, riccibruno, rsmith, nathanchance

Differential Revision: https://reviews.llvm.org/D71037
parent 65661908

clang/lib/Parse/ParseStmt.cpp

+38 −3
Original line number Diff line number Diff line
@@ -1214,6 +1214,41 @@ struct MisleadingIndentationChecker { 
    if (Kind == MSK_else && !ShouldSkip)

      P.MisleadingIndentationElseLoc = SL;

  }



  /// Compute the column number will aligning tabs on TabStop (-ftabstop), this

  /// gives the visual indentation of the SourceLocation.

  static unsigned getVisualIndentation(SourceManager &SM, SourceLocation Loc) {

    unsigned TabStop = SM.getDiagnostics().getDiagnosticOptions().TabStop;



    unsigned ColNo = SM.getSpellingColumnNumber(Loc);

    if (ColNo == 0 || TabStop == 1)

      return ColNo;



    std::pair<FileID, unsigned> FIDAndOffset = SM.getDecomposedLoc(Loc);



    bool Invalid;

    StringRef BufData = SM.getBufferData(FIDAndOffset.first, &Invalid);

    if (Invalid)

      return 0;



    const char *EndPos = BufData.data() + FIDAndOffset.second;

    assert(FIDAndOffset.second > ColNo &&

           "Column number smaller than file offset?");



    unsigned VisualColumn = 0; // Stored as 0-based column, here.

    // Loop from beginning of line up to Loc's file position, counting columns,

    // expanding tabs.

    for (const char *CurPos = EndPos - (ColNo - 1); CurPos != EndPos;

         ++CurPos) {

      if (*CurPos == '\t')

        // Advance visual column to next tabstop.

        VisualColumn += (TabStop - VisualColumn % TabStop);

      else

        VisualColumn++;

    }

    return VisualColumn + 1;

  }



  void Check() {

    Token Tok = P.getCurToken();

    if (P.getActions().getDiagnostics().isIgnored(
@@ -1230,9 +1265,9 @@ struct MisleadingIndentationChecker { 
      P.MisleadingIndentationElseLoc = SourceLocation();



    SourceManager &SM = P.getPreprocessor().getSourceManager();

    unsigned PrevColNum = SM.getSpellingColumnNumber(PrevLoc);

    unsigned CurColNum = SM.getSpellingColumnNumber(Tok.getLocation());

    unsigned StmtColNum = SM.getSpellingColumnNumber(StmtLoc);

    unsigned PrevColNum = getVisualIndentation(SM, PrevLoc);

    unsigned CurColNum = getVisualIndentation(SM, Tok.getLocation());

    unsigned StmtColNum = getVisualIndentation(SM, StmtLoc);



    if (PrevColNum != 0 && CurColNum != 0 && StmtColNum != 0 &&

        ((PrevColNum > StmtColNum && PrevColNum == CurColNum) ||

clang/test/Parser/warn-misleading-indentation.cpp

+81 −2
Original line number Diff line number Diff line 
// RUN: %clang_cc1 -x c -fsyntax-only -verify %s

// RUN: %clang_cc1 -x c -fsyntax-only -verify -Wmisleading-indentation -DWITH_WARN %s

// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify -Wall -Wno-unused -DWITH_WARN -DCXX17 %s

// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify -Wall -Wno-unused -Wno-misleading-indentation -DCXX17 %s

// RUN: %clang_cc1 -x c -fsyntax-only -verify -Wmisleading-indentation -DWITH_WARN -ftabstop 8 -DTAB_SIZE=8 %s

// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify -Wall -Wno-unused -DWITH_WARN  -ftabstop 4 -DTAB_SIZE=4 -DCXX17 %s

// RUN: %clang_cc1 -x c -fsyntax-only -verify -Wall -Wno-unused -DWITH_WARN -ftabstop 1 -DTAB_SIZE=1 %s

// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify -Wall -Wno-unused -Wmisleading-indentation -DCXX17 -DWITH_WARN -ftabstop 2 -DTAB_SIZE=2 %s



#ifndef WITH_WARN

// expected-no-diagnostics
@@ -225,3 +227,80 @@ void s(int num) { 
// expected-warning@-2 {{misleading indentation; statement is not part of the previous 'if'}}

#endif

}

int a4()

{

	if (0)

		return 1;

 	return 0;

#if (TAB_SIZE == 1)

// expected-warning@-2 {{misleading indentation; statement is not part of the previous 'if'}}

// expected-note@-5 {{here}}

#endif 

}



int a5()

{

	if (0)

		return 1;

		return 0;

#if WITH_WARN

// expected-warning@-2 {{misleading indentation; statement is not part of the previous 'if'}}

// expected-note@-5 {{here}}

#endif

}



int a6()

{

	if (0)

		return 1;

      		return 0;

#if (TAB_SIZE == 8)

// expected-warning@-2 {{misleading indentation; statement is not part of the previous 'if'}}

// expected-note@-5 {{here}}

#endif

}



#define FOO \

 goto fail



int main(int argc, char* argv[]) {

  if (5 != 0)

    goto fail;

  else

    goto fail;



  if (1) {

    if (1)

      goto fail;

    else if (1)

      goto fail;

    else if (1)

      goto fail;

    else

      goto fail;

  } else if (1) {

    if (1)

      goto fail;

  }



  if (1) {

    if (1)

      goto fail;

  } else if (1)

    goto fail;





  if (1) goto fail; goto fail;



    if (0)

        goto fail;



    goto fail;



    if (0)

        FOO;



    goto fail;



fail:;

}