Give files from #line the characteristics of the current file

This allows #line directives to appear in system headers that have code
that clang would normally warn on. This is compatible with GCC, which is
easy to test by running `gcc -E`.

Fixes PR30752

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@303582 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/SourceManager.h b/include/clang/Basic/SourceManager.h
index 6960ea690b91c197fc24506524dd7bbf4b553222..eda8029340065742d508042aa28985ed9e8dd2e6 100644 (file)
--- a/include/clang/Basic/SourceManager.h
+++ b/include/clang/Basic/SourceManager.h
@@ -1399,10 +1399,9 @@ public:
   /// specified by Loc.
   ///
   /// If FilenameID is -1, it is considered to be unspecified.
-  void AddLineNote(SourceLocation Loc, unsigned LineNo, int FilenameID);
   void AddLineNote(SourceLocation Loc, unsigned LineNo, int FilenameID,
                    bool IsFileEntry, bool IsFileExit,
-                   bool IsSystemHeader, bool IsExternCHeader);
+                   SrcMgr::CharacteristicKind FileKind);
 
   /// \brief Determine if the source manager has a line table.
   bool hasLineTable() const { return LineTable != nullptr; }

diff --git a/include/clang/Basic/SourceManagerInternals.h b/include/clang/Basic/SourceManagerInternals.h
index e65c97b0031d6dc593a15c318d7d83dbb4f6d1cf..9403dea8889c25faf61aa0a893b11fd188044692 100644 (file)
--- a/include/clang/Basic/SourceManagerInternals.h
+++ b/include/clang/Basic/SourceManagerInternals.h
@@ -101,8 +101,6 @@ public:
   }
   unsigned getNumFilenames() const { return FilenamesByID.size(); }
 
-  void AddLineNote(FileID FID, unsigned Offset,
-                   unsigned LineNo, int FilenameID);
   void AddLineNote(FileID FID, unsigned Offset,
                    unsigned LineNo, int FilenameID,
                    unsigned EntryExit, SrcMgr::CharacteristicKind FileKind);

diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
index 156aa0b11f7d0571d7bd3a427547499d49cc775b..c5cff74ac97def3079d4af4b4145af6875c84c1b 100644 (file)
--- a/lib/Basic/SourceManager.cpp
+++ b/lib/Basic/SourceManager.cpp
@@ -183,48 +183,22 @@ unsigned LineTableInfo::getLineTableFilenameID(StringRef Name) {
   return IterBool.first->second;
 }
 
-/// AddLineNote - Add a line note to the line table that indicates that there
-/// is a \#line at the specified FID/Offset location which changes the presumed
-/// location to LineNo/FilenameID.
-void LineTableInfo::AddLineNote(FileID FID, unsigned Offset,
-                                unsigned LineNo, int FilenameID) {
-  std::vector<LineEntry> &Entries = LineEntries[FID];
-
-  assert((Entries.empty() || Entries.back().FileOffset < Offset) &&
-         "Adding line entries out of order!");
-
-  SrcMgr::CharacteristicKind Kind = SrcMgr::C_User;
-  unsigned IncludeOffset = 0;
-
-  if (!Entries.empty()) {
-    // If this is a '#line 4' after '#line 42 "foo.h"', make sure to remember
-    // that we are still in "foo.h".
-    if (FilenameID == -1)
-      FilenameID = Entries.back().FilenameID;
-
-    // If we are after a line marker that switched us to system header mode, or
-    // that set #include information, preserve it.
-    Kind = Entries.back().FileKind;
-    IncludeOffset = Entries.back().IncludeOffset;
-  }
-
-  Entries.push_back(LineEntry::get(Offset, LineNo, FilenameID, Kind,
-                                   IncludeOffset));
-}
-
-/// AddLineNote This is the same as the previous version of AddLineNote, but is
-/// used for GNU line markers.  If EntryExit is 0, then this doesn't change the
-/// presumed \#include stack.  If it is 1, this is a file entry, if it is 2 then
-/// this is a file exit.  FileKind specifies whether this is a system header or
-/// extern C system header.
-void LineTableInfo::AddLineNote(FileID FID, unsigned Offset,
-                                unsigned LineNo, int FilenameID,
-                                unsigned EntryExit,
+/// Add a line note to the line table that indicates that there is a \#line or
+/// GNU line marker at the specified FID/Offset location which changes the
+/// presumed location to LineNo/FilenameID. If EntryExit is 0, then this doesn't
+/// change the presumed \#include stack.  If it is 1, this is a file entry, if
+/// it is 2 then this is a file exit. FileKind specifies whether this is a
+/// system header or extern C system header.
+void LineTableInfo::AddLineNote(FileID FID, unsigned Offset, unsigned LineNo,
+                                int FilenameID, unsigned EntryExit,
                                 SrcMgr::CharacteristicKind FileKind) {
-  assert(FilenameID != -1 && "Unspecified filename should use other accessor");
-
   std::vector<LineEntry> &Entries = LineEntries[FID];
 
+  // An unspecified FilenameID means use the last filename if available, or the
+  // main source file otherwise.
+  if (FilenameID == -1 && !Entries.empty())
+    FilenameID = Entries.back().FilenameID;
+
   assert((Entries.empty() || Entries.back().FileOffset < Offset) &&
          "Adding line entries out of order!");
 
@@ -281,47 +255,20 @@ unsigned SourceManager::getLineTableFilenameID(StringRef Name) {
   return getLineTable().getLineTableFilenameID(Name);
 }
 
-
 /// AddLineNote - Add a line note to the line table for the FileID and offset
 /// specified by Loc.  If FilenameID is -1, it is considered to be
 /// unspecified.
-void SourceManager::AddLineNote(SourceLocation Loc, unsigned LineNo,
-                                int FilenameID) {
-  std::pair<FileID, unsigned> LocInfo = getDecomposedExpansionLoc(Loc);
-
-  bool Invalid = false;
-  const SLocEntry &Entry = getSLocEntry(LocInfo.first, &Invalid);
-  if (!Entry.isFile() || Invalid)
-    return;
-  
-  const SrcMgr::FileInfo &FileInfo = Entry.getFile();
-
-  // Remember that this file has #line directives now if it doesn't already.
-  const_cast<SrcMgr::FileInfo&>(FileInfo).setHasLineDirectives();
-
-  getLineTable().AddLineNote(LocInfo.first, LocInfo.second, LineNo, FilenameID);
-}
-
-/// AddLineNote - Add a GNU line marker to the line table.
 void SourceManager::AddLineNote(SourceLocation Loc, unsigned LineNo,
                                 int FilenameID, bool IsFileEntry,
-                                bool IsFileExit, bool IsSystemHeader,
-                                bool IsExternCHeader) {
-  // If there is no filename and no flags, this is treated just like a #line,
-  // which does not change the flags of the previous line marker.
-  if (FilenameID == -1) {
-    assert(!IsFileEntry && !IsFileExit && !IsSystemHeader && !IsExternCHeader &&
-           "Can't set flags without setting the filename!");
-    return AddLineNote(Loc, LineNo, FilenameID);
-  }
-
+                                bool IsFileExit,
+                                SrcMgr::CharacteristicKind FileKind) {
   std::pair<FileID, unsigned> LocInfo = getDecomposedExpansionLoc(Loc);
 
   bool Invalid = false;
   const SLocEntry &Entry = getSLocEntry(LocInfo.first, &Invalid);
   if (!Entry.isFile() || Invalid)
     return;
-  
+
   const SrcMgr::FileInfo &FileInfo = Entry.getFile();
 
   // Remember that this file has #line directives now if it doesn't already.
@@ -329,14 +276,6 @@ void SourceManager::AddLineNote(SourceLocation Loc, unsigned LineNo,
 
   (void) getLineTable();
 
-  SrcMgr::CharacteristicKind FileKind;
-  if (IsExternCHeader)
-    FileKind = SrcMgr::C_ExternCSystem;
-  else if (IsSystemHeader)
-    FileKind = SrcMgr::C_System;
-  else
-    FileKind = SrcMgr::C_User;
-
   unsigned EntryExit = 0;
   if (IsFileEntry)
     EntryExit = 1;

diff --git a/lib/Frontend/FrontendAction.cpp b/lib/Frontend/FrontendAction.cpp
index 1fbb2b054badbfa1df461a298b9fee41de96b616..874c1b6be41ee16d0b51bbe897809eb0aa882379 100644 (file)
--- a/lib/Frontend/FrontendAction.cpp
+++ b/lib/Frontend/FrontendAction.cpp
@@ -252,7 +252,8 @@ static SourceLocation ReadOriginalFileName(CompilerInstance &CI,
 
   if (AddLineNote)
     CI.getSourceManager().AddLineNote(
-        LineNoLoc, LineNo, SourceMgr.getLineTableFilenameID(InputFile));
+        LineNoLoc, LineNo, SourceMgr.getLineTableFilenameID(InputFile), false,
+        false, SrcMgr::C_User);
 
   return T.getLocation();
 }

diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index 0534aeb10ccbca4aa8585ebca60137976fd624e9..030717b8bd5c7d8895531568283d73e0efcbd096 100644 (file)
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -1171,18 +1171,26 @@ void Preprocessor::HandleLineDirective() {
     CheckEndOfDirective("line", true);
   }
 
-  SourceMgr.AddLineNote(DigitTok.getLocation(), LineNo, FilenameID);
+  // Take the file kind of the file containing the #line directive. #line
+  // directives are often used for generated sources from the same codebase, so
+  // the new file should generally be classified the same way as the current
+  // file. This is visible in GCC's pre-processed output, which rewrites #line
+  // to GNU line markers.
+  SrcMgr::CharacteristicKind FileKind =
+      SourceMgr.getFileCharacteristic(DigitTok.getLocation());
+
+  SourceMgr.AddLineNote(DigitTok.getLocation(), LineNo, FilenameID, false,
+                        false, FileKind);
 
   if (Callbacks)
     Callbacks->FileChanged(CurPPLexer->getSourceLocation(),
-                           PPCallbacks::RenameFile,
-                           SrcMgr::C_User);
+                           PPCallbacks::RenameFile, FileKind);
 }
 
 /// ReadLineMarkerFlags - Parse and validate any flags at the end of a GNU line
 /// marker directive.
 static bool ReadLineMarkerFlags(bool &IsFileEntry, bool &IsFileExit,
-                                bool &IsSystemHeader, bool &IsExternCHeader,
+                                SrcMgr::CharacteristicKind &FileKind,
                                 Preprocessor &PP) {
   unsigned FlagVal;
   Token FlagTok;
@@ -1233,7 +1241,7 @@ static bool ReadLineMarkerFlags(bool &IsFileEntry, bool &IsFileExit,
     return true;
   }
 
-  IsSystemHeader = true;
+  FileKind = SrcMgr::C_System;
 
   PP.Lex(FlagTok);
   if (FlagTok.is(tok::eod)) return false;
@@ -1247,7 +1255,7 @@ static bool ReadLineMarkerFlags(bool &IsFileEntry, bool &IsFileExit,
     return true;
   }
 
-  IsExternCHeader = true;
+  FileKind = SrcMgr::C_ExternCSystem;
 
   PP.Lex(FlagTok);
   if (FlagTok.is(tok::eod)) return false;
@@ -1277,14 +1285,15 @@ void Preprocessor::HandleDigitDirective(Token &DigitTok) {
   Lex(StrTok);
 
   bool IsFileEntry = false, IsFileExit = false;
-  bool IsSystemHeader = false, IsExternCHeader = false;
   int FilenameID = -1;
+  SrcMgr::CharacteristicKind FileKind = SrcMgr::C_User;
 
   // If the StrTok is "eod", then it wasn't present.  Otherwise, it must be a
   // string followed by eod.
-  if (StrTok.is(tok::eod))
-    ; // ok
-  else if (StrTok.isNot(tok::string_literal)) {
+  if (StrTok.is(tok::eod)) {
+    // Treat this like "#line NN", which doesn't change file characteristics.
+    FileKind = SourceMgr.getFileCharacteristic(DigitTok.getLocation());
+  } else if (StrTok.isNot(tok::string_literal)) {
     Diag(StrTok, diag::err_pp_linemarker_invalid_filename);
     return DiscardUntilEndOfDirective();
   } else if (StrTok.hasUDSuffix()) {
@@ -1303,15 +1312,13 @@ void Preprocessor::HandleDigitDirective(Token &DigitTok) {
     FilenameID = SourceMgr.getLineTableFilenameID(Literal.GetString());
 
     // If a filename was present, read any flags that are present.
-    if (ReadLineMarkerFlags(IsFileEntry, IsFileExit,
-                            IsSystemHeader, IsExternCHeader, *this))
+    if (ReadLineMarkerFlags(IsFileEntry, IsFileExit, FileKind, *this))
       return;
   }
 
   // Create a line note with this information.
-  SourceMgr.AddLineNote(DigitTok.getLocation(), LineNo, FilenameID,
-                        IsFileEntry, IsFileExit,
-                        IsSystemHeader, IsExternCHeader);
+  SourceMgr.AddLineNote(DigitTok.getLocation(), LineNo, FilenameID, IsFileEntry,
+                        IsFileExit, FileKind);
 
   // If the preprocessor has callbacks installed, notify them of the #line
   // change.  This is used so that the line marker comes out in -E mode for
@@ -1322,11 +1329,6 @@ void Preprocessor::HandleDigitDirective(Token &DigitTok) {
       Reason = PPCallbacks::EnterFile;
     else if (IsFileExit)
       Reason = PPCallbacks::ExitFile;
-    SrcMgr::CharacteristicKind FileKind = SrcMgr::C_User;
-    if (IsExternCHeader)
-      FileKind = SrcMgr::C_ExternCSystem;
-    else if (IsSystemHeader)
-      FileKind = SrcMgr::C_System;
 
     Callbacks->FileChanged(CurPPLexer->getSourceLocation(), Reason, FileKind);
   }

diff --git a/lib/Lex/Pragma.cpp b/lib/Lex/Pragma.cpp
index 99d56182c1bb90f552065ce8d28efe51512d79da..2d078a4e7603eaf6089a5ef62c2b0c65ba60971d 100644 (file)
--- a/lib/Lex/Pragma.cpp
+++ b/lib/Lex/Pragma.cpp
@@ -475,9 +475,9 @@ void Preprocessor::HandlePragmaSystemHeader(Token &SysHeaderTok) {
   // Emit a line marker.  This will change any source locations from this point
   // forward to realize they are in a system header.
   // Create a line note with this information.
-  SourceMgr.AddLineNote(SysHeaderTok.getLocation(), PLoc.getLine()+1,
+  SourceMgr.AddLineNote(SysHeaderTok.getLocation(), PLoc.getLine() + 1,
                         FilenameID, /*IsEntry=*/false, /*IsExit=*/false,
-                        /*IsSystem=*/true, /*IsExternC=*/false);
+                        SrcMgr::C_System);
 }
 
 /// HandlePragmaDependency - Handle \#pragma GCC dependency "foo" blah.

diff --git a/test/Frontend/Inputs/SystemHeaderPrefix/line.h b/test/Frontend/Inputs/SystemHeaderPrefix/line.h
new file mode 100644 (file)
index 0000000..c4c15e5
--- /dev/null
+++ b/test/Frontend/Inputs/SystemHeaderPrefix/line.h
@@ -0,0 +1,2 @@
+#line 1 "foo.h"
+foo();

diff --git a/test/Frontend/Inputs/SystemHeaderPrefix/noline.h b/test/Frontend/Inputs/SystemHeaderPrefix/noline.h
new file mode 100644 (file)
index 0000000..a280f9a
--- /dev/null
+++ b/test/Frontend/Inputs/SystemHeaderPrefix/noline.h
@@ -0,0 +1 @@
+foo();

diff --git a/test/Frontend/system-header-line-directive.c b/test/Frontend/system-header-line-directive.c
new file mode 100644 (file)
index 0000000..16dde64
--- /dev/null
+++ b/test/Frontend/system-header-line-directive.c
@@ -0,0 +1,20 @@
+// RUN: %clang_cc1 -Wall %s -isystem %S/Inputs/SystemHeaderPrefix -verify
+// RUN: %clang_cc1 %s -E -o - -isystem %S/Inputs/SystemHeaderPrefix | FileCheck %s
+#include <noline.h>
+#include <line.h>
+
+// This tests that "#line" directives in system headers preserve system
+// header-ness just like GNU line markers that don't have filenames.  This was
+// PR30752.
+
+// expected-no-diagnostics
+
+// CHECK: # {{[0-9]+}} "{{.*}}system-header-line-directive.c" 2
+// CHECK: # 1 "{{.*}}noline.h" 1 3
+// CHECK: foo();
+// CHECK: # 4 "{{.*}}system-header-line-directive.c" 2
+// CHECK: # 1 "{{.*}}line.h" 1 3
+//      The "3" below indicates that "foo.h" is considered a system header.
+// CHECK: # 1 "foo.h" 3
+// CHECK: foo();
+// CHECK: # {{[0-9]+}} "{{.*}}system-header-line-directive.c" 2