Make all PCH-incompatibility warnings into errors, and abort

compilation if the user requested a PCH file but no such PCH file
exists.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@70332 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 41 insertions, 48 deletions

diff --git a/include/clang/Basic/DiagnosticFrontendKinds.td b/include/clang/Basic/DiagnosticFrontendKinds.td
index 678cd3a2aa..94ec2a5a16 100644
--- a/include/clang/Basic/DiagnosticFrontendKinds.td
+++ b/include/clang/Basic/DiagnosticFrontendKinds.td
@@ -24,97 +24,95 @@ def warn_fixit_no_changes : Note<
     "FIX-IT detected errors it could not fix; no output will be generated">;
 
 // PCH reader
-def warn_pch_target_triple : Warning<
+def warn_pch_target_triple : Error<
     "PCH file was compiled for the target '%0' but the current translation "
     "unit is being compiled for target '%1'">;
-def note_ignoring_pch : Note<
-    "ignoring precompiled header '%0'">;
-def warn_pch_c99 : Warning<
+def warn_pch_c99 : Error<
     "C99 support was %select{disabled|enabled}0 in PCH file but is "
     "currently %select{disabled|enabled}1">;
-def warn_pch_cplusplus : Warning<
+def warn_pch_cplusplus : Error<
     "C++ support was %select{disabled|enabled}0 in PCH file but is "
     "currently %select{disabled|enabled}1">;
-def warn_pch_cplusplus0x : Warning<
+def warn_pch_cplusplus0x : Error<
     "C++0x support was %select{disabled|enabled}0 in PCH file but is "
     "currently %select{disabled|enabled}1">;
-def warn_pch_objective_c : Warning<
+def warn_pch_objective_c : Error<
     "Objective-C support was %select{disabled|enabled}0 in PCH file but is "
     "currently %select{disabled|enabled}1">;
-def warn_pch_objective_c2 : Warning<
+def warn_pch_objective_c2 : Error<
     "Objective-C 2.0 support was %select{disabled|enabled}0 in PCH file but "
     "is currently %select{disabled|enabled}1">;
-def warn_pch_nonfragile_abi : Warning<
+def warn_pch_nonfragile_abi : Error<
     "PCH file was compiled with the %select{32-bit|non-fragile}0 Objective-C "
     "ABI but the %select{32-bit|non-fragile}1 Objective-C ABI is selected">;
-def warn_pch_extensions : Warning<
+def warn_pch_extensions : Error<
     "extensions were %select{enabled|disabled}0 in PCH file but are "
     "currently %select{enabled|disabled}1">;
-def warn_pch_gnu_extensions : Warning<
+def warn_pch_gnu_extensions : Error<
     "GNU extensions were %select{disabled|enabled}0 in PCH file but are "
     "currently %select{disabled|enabled}1">;
-def warn_pch_microsoft_extensions : Warning<
+def warn_pch_microsoft_extensions : Error<
     "Microsoft extensions were %select{disabled|enabled}0 in PCH file but are "
     "currently %select{disabled|enabled}1">;
-def warn_pch_heinous_extensions : Warning<
+def warn_pch_heinous_extensions : Error<
     "heinous extensions were %select{disabled|enabled}0 in PCH file but are "
     "currently %select{disabled|enabled}1">;
-def warn_pch_lax_vector_conversions : Warning<
+def warn_pch_lax_vector_conversions : Error<
     "lax vector conversions were %select{disabled|enabled}0 in PCH file but "
     "are currently %select{disabled|enabled}1">;
-def warn_pch_exceptions : Warning<
+def warn_pch_exceptions : Error<
     "exceptions were %select{disabled|enabled}0 in PCH file but "
     "are currently %select{disabled|enabled}1">;
-def warn_pch_objc_runtime : Warning<
+def warn_pch_objc_runtime : Error<
     "PCH file was compiled with the %select{NeXT|GNU}0 runtime but the "
     "%select{NeXT|GNU}1 runtime is selected">;
-def warn_pch_freestanding : Warning<
+def warn_pch_freestanding : Error<
     "PCH file was compiled with a %select{hosted|freestanding}0  "
     "implementation but a %select{hosted|freestanding}1 implementation "
     "is selected">;
-def warn_pch_builtins : Warning<
+def warn_pch_builtins : Error<
     "PCH file was compiled with builtins %select{enabled|disabled}0 but "
     "builtins are currently %select{enabled|disabled}1">;
-def warn_pch_thread_safe_statics : Warning<
+def warn_pch_thread_safe_statics : Error<
     "PCH file was compiled %select{without|with}0 thread-safe statics but"
     "thread-safe statics are currently %select{disabled|enabled}1">;
-def warn_pch_blocks : Warning<
+def warn_pch_blocks : Error<
     "blocks were %select{disabled|enabled}0 in PCH file but "
     "are currently %select{disabled|enabled}1">;
-def warn_pch_math_errno : Warning<
+def warn_pch_math_errno : Error<
     "math functions %select{do not respect|respect}0 'errno' in PCH "
     "file but they are currently set to %select{not respect|respect}1 "
     "'errno'">;
-def warn_pch_overflow_checking : Warning<
+def warn_pch_overflow_checking : Error<
     "signed integer overflow checking was %select{disabled|enabled}0 in PCH "
     "file but is currently %select{disabled|enabled}1">;
-def warn_pch_optimize : Warning<
+def warn_pch_optimize : Error<
     "the macro '__OPTIMIZE__' was %select{not defined|defined}0 in "
     "the PCH file but is currently %select{undefined|defined}1">;
-def warn_pch_optimize_size : Warning<
+def warn_pch_optimize_size : Error<
     "the macro '__OPTIMIZE_SIZE__' was %select{not defined|defined}0 in "
     "the PCH file but is currently %select{undefined|defined}1">;
-def warn_pch_static : Warning<
+def warn_pch_static : Error<
     "the PCH file was compiled %select{dynamic|static}0 but the "
     "current translation unit is being compiled as %select{dynamic|static}1">;
-def warn_pch_pic_level : Warning<
+def warn_pch_pic_level : Error<
     "PCH file was compiled with PIC level %0, but the current translation "
     "unit will be compiled with PIC level %1">;
-def warn_pch_gnu_inline : Warning<
+def warn_pch_gnu_inline : Error<
     "PCH file was compiled with %select{C99|GNU|}0 inline semantics but "
     "%select{C99|GNU}1 inline semantics are currently selected">;
-def warn_pch_no_inline : Warning<
+def warn_pch_no_inline : Error<
     "the macro '__NO_INLINE__' was %select{not defined|defined}0 in "
     "the PCH file but is currently %select{undefined|defined}1">;
-def warn_pch_gc_mode : Warning<
+def warn_pch_gc_mode : Error<
     "the PCH file was built with %select{no||hybrid}0 garbage collection but "
     "the current translation unit will compiled with %select{no||hybrid}1 "
     "garbage collection">;
-def warn_pch_version_too_old : Warning<
+def warn_pch_version_too_old : Error<
     "PCH file uses an older PCH format that is no longer supported">;
-def warn_pch_version_too_new : Warning<
+def warn_pch_version_too_new : Error<
     "PCH file uses a newer PCH format that cannot be read">;
-def warn_cmdline_conflicting_macro_def : Warning<
+def warn_cmdline_conflicting_macro_def : Error<
     "definition of the macro '%0' conflicts with the definition used to "
     "build the precompiled header">;
 def note_pch_macro_defined_as : Note<
@@ -123,10 +121,10 @@ def warn_cmdline_missing_macro_defs : Warning<
     "macro definitions used to build the precompiled header are missing">;
 def note_using_macro_def_from_pch : Note<
     "using this macro definition from precompiled header">;
-def warn_macro_name_used_in_pch : Warning<
+def warn_macro_name_used_in_pch : Error<
     "definition of macro %0 conflicts with an identifier used in the "
     "precompiled header">;
-def warn_pch_compiler_options_mismatch : Warning<
+def warn_pch_compiler_options_mismatch : Error<
     "compiler options used when building the precompiled header differ from "
     "the options used when using the precompiled header">;
 def err_not_a_pch_file : Error<
diff --git a/lib/Frontend/PCHReader.cpp b/lib/Frontend/PCHReader.cpp
index 99b5fb9685..ead6dcc101 100644
--- a/lib/Frontend/PCHReader.cpp
+++ b/lib/Frontend/PCHReader.cpp
@@ -414,7 +414,6 @@ bool PCHReader::CheckPredefinesBuffer(const char *PCHPredef,
     const std::string &Missing = MissingPredefines[I];
     if (!startsWith(Missing, "#define ") != 0) {
       Diag(diag::warn_pch_compiler_options_mismatch);
-      Diag(diag::note_ignoring_pch) << FileName;
       return true;
     }
     
@@ -489,10 +488,8 @@ bool PCHReader::CheckPredefinesBuffer(const char *PCHPredef,
     Diag(PCHMissingLoc, diag::note_using_macro_def_from_pch);
   }
   
-  if (ConflictingDefines) {
-    Diag(diag::note_ignoring_pch) << FileName;
+  if (ConflictingDefines)
     return true;
-  }
   
   // Determine what predefines were introduced based on command-line
   // parameters that were not present when building the PCH
@@ -506,7 +503,6 @@ bool PCHReader::CheckPredefinesBuffer(const char *PCHPredef,
     const std::string &Extra = ExtraPredefines[I];
     if (!startsWith(Extra, "#define ") != 0) {
       Diag(diag::warn_pch_compiler_options_mismatch);
-      Diag(diag::note_ignoring_pch) << FileName;
       return true;
     }
 
@@ -527,8 +523,6 @@ bool PCHReader::CheckPredefinesBuffer(const char *PCHPredef,
                                  MacroName.c_str() + MacroName.size())) {
       Diag(diag::warn_macro_name_used_in_pch)
         << II;
-      Diag(diag::note_ignoring_pch)
-        << FileName;
       return true;
     }
 
@@ -1102,7 +1096,6 @@ PCHReader::ReadPCHBlock() {
       if (TargetTriple != PP.getTargetInfo().getTargetTriple()) {
         Diag(diag::warn_pch_target_triple)
           << TargetTriple << PP.getTargetInfo().getTargetTriple();
-        Diag(diag::note_ignoring_pch) << FileName;
         return IgnorePCH;
       }
       break;
@@ -1392,7 +1385,6 @@ bool PCHReader::ParseLanguageOptions(
 #define PARSE_LANGOPT_IMPORTANT(Option, DiagID)                 \
   if (Record[Idx] != LangOpts.Option) {                         \
     Diag(DiagID) << (unsigned)Record[Idx] << LangOpts.Option;   \
-    Diag(diag::note_ignoring_pch) << FileName;                  \
     return true;                                                \
   }                                                             \
   ++Idx
@@ -1446,7 +1438,6 @@ bool PCHReader::ParseLanguageOptions(
   if ((LangOpts.getGCMode() != 0) != (Record[Idx] != 0)) {
     Diag(diag::warn_pch_gc_mode) 
       << (unsigned)Record[Idx] << LangOpts.getGCMode();
-    Diag(diag::note_ignoring_pch) << FileName;
     return true;
   }
   ++Idx;
diff --git a/tools/clang-cc/clang-cc.cpp b/tools/clang-cc/clang-cc.cpp
index ad00664af5..1fa49c141c 100644
--- a/tools/clang-cc/clang-cc.cpp
+++ b/tools/clang-cc/clang-cc.cpp
@@ -1775,15 +1775,19 @@ static void ProcessInputFile(Preprocessor &PP, PreprocessorFactory &PPF,
       return;
 
     case PCHReader::IgnorePCH:
-      // No suitable PCH file could be found. Just ignore the
-      // -include-pch option entirely.
-      
+      // No suitable PCH file could be found. Return an error.
+      return;
+
+#if 0
+      // FIXME: We can recover from failed attempts to load PCH
+      // files. This code will do so, if we ever want to enable it.
+
       // We delayed the initialization of builtins in the hope of
       // loading the PCH file. Since the PCH file could not be
       // loaded, initialize builtins now.
       if (ContextOwner)
         ContextOwner->InitializeBuiltins(PP.getIdentifierTable());
-      break;
+#endif
     }
 
     // Finish preprocessor initialization. We do this now (rather