[Preprocessor] Don't avoid entering included files after hitting a fatal error.

Change in r337953 violated the contract for `CXTranslationUnit_KeepGoing`:

> Do not stop processing when fatal errors are encountered.

Use different approach to fix long processing times with multiple inclusion
cycles. Instead of stopping preprocessing for fatal errors, do this after
reaching the max allowed include depth and only for the files that were
processed already. It is likely but not guaranteed those files cause a cycle.

rdar://problem/46108547

Reviewers: erik.pilkington, arphaman

Reviewed By: erik.pilkington

Subscribers: jkorous, dexonsmith, ilya-biryukov, Dmitry.Kozhevnikov

Differential Revision: https://reviews.llvm.org/D55095

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@348641 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index 792f8af7dae02b6215ee5951023aa133304ed362..64ddb5307fb0e8dcb4b401471564823bf16530bf 100644 (file)
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -319,6 +319,10 @@ class Preprocessor {
   /// This is used when loading a precompiled preamble.
   std::pair<int, bool> SkipMainFilePreamble;
 
+  /// Whether we hit an error due to reaching max allowed include depth. Allows
+  /// to avoid hitting the same error over and over again.
+  bool HasReachedMaxIncludeDepth = false;
+
 public:
   struct PreambleSkipInfo {
     SourceLocation HashTokenLoc;

diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index 541dfecd65766344a43a3b4d9258e6892dad0777..a61ba736250362ada0d12a5727ef6de71a6dda36 100644 (file)
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -1707,6 +1707,7 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
   // Check that we don't have infinite #include recursion.
   if (IncludeMacroStack.size() == MaxAllowedIncludeStackDepth-1) {
     Diag(FilenameTok, diag::err_pp_include_too_deep);
+    HasReachedMaxIncludeDepth = true;
     return;
   }
 
@@ -1855,10 +1856,11 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
   if (PPOpts->SingleFileParseMode)
     ShouldEnter = false;
 
-  // Any diagnostics after the fatal error will not be visible. As the
-  // compilation failed already and errors in subsequently included files won't
-  // be visible, avoid preprocessing those files.
-  if (ShouldEnter && Diags->hasFatalErrorOccurred())
+  // If we've reached the max allowed include depth, it is usually due to an
+  // include cycle. Don't enter already processed files again as it can lead to
+  // reaching the max allowed include depth again.
+  if (ShouldEnter && HasReachedMaxIncludeDepth && File &&
+      HeaderInfo.getFileInfo(File).NumIncludes)
     ShouldEnter = false;
 
   // Determine whether we should try to import the module for this #include, if

diff --git a/test/Index/Inputs/cycle.h b/test/Index/Inputs/cycle.h
new file mode 100644 (file)
index 0000000..5dc8890
--- /dev/null
+++ b/test/Index/Inputs/cycle.h
@@ -0,0 +1 @@
+#include "cycle.h"

diff --git a/test/Index/keep-going-include-cycle.c b/test/Index/keep-going-include-cycle.c
new file mode 100644 (file)
index 0000000..b0fe24f
--- /dev/null
+++ b/test/Index/keep-going-include-cycle.c
@@ -0,0 +1,10 @@
+#include "cycle.h"
+#include "foo.h"
+
+// RUN: env CINDEXTEST_KEEP_GOING=1 c-index-test -test-print-type -I%S/Inputs %s 2> %t.stderr.txt | FileCheck %s
+// RUN: FileCheck -check-prefix CHECK-DIAG %s < %t.stderr.txt
+
+// Verify that we don't stop preprocessing after an include cycle.
+// CHECK: VarDecl=global_var:1:12 [type=int] [typekind=Int] [isPOD=1]
+
+// CHECK-DIAG: cycle.h:1:10: error: #include nested too deeply

diff --git a/test/Index/keep-going.cpp b/test/Index/keep-going.cpp
index dbfcad32d3d28fb12e77895af8a926faf246041a..b3f29c5d3dae0b539f2c42b1240bb47f6046d214 100644 (file)
--- a/test/Index/keep-going.cpp
+++ b/test/Index/keep-going.cpp
@@ -9,11 +9,18 @@ class B : public A<int> { };
 
 class C : public A<float> { };
 
-// RUN: env CINDEXTEST_EDITING=1 CINDEXTEST_KEEP_GOING=1 c-index-test -test-print-type %s -std=c++03 2> %t.stderr.txt  | FileCheck %s
+// Not found includes shouldn't affect subsequent correct includes.
+#include "foo.h"
+
+// RUN: env CINDEXTEST_EDITING=1 CINDEXTEST_KEEP_GOING=1 c-index-test -test-print-type -I%S/Inputs %s -std=c++03 2> %t.stderr.txt  | FileCheck %s
 // RUN: FileCheck -check-prefix CHECK-DIAG %s < %t.stderr.txt
 
+// Verify that even without CINDEXTEST_EDITING we don't stop processing after a fatal error.
+// RUN: env CINDEXTEST_KEEP_GOING=1 c-index-test -test-print-type -I%S/Inputs %s -std=c++03 2> %t.stderr.txt  | FileCheck -check-prefix CHECK-KEEP-GOING-ONLY %s
+
 // CHECK: inclusion directive=missing1.h ((null)) [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: inclusion directive=missing2.h ((null)) [type=] [typekind=Invalid] [isPOD=0]
+// CHECK: inclusion directive=foo.h ({{.*[/\\]}}test{{[/\\]}}Index{{[/\\]}}Inputs{{[/\\]}}foo.h) [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: ClassTemplate=A:4:7 (Definition) [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: TemplateTypeParameter=T:3:16 (Definition) [type=T] [typekind=Unexposed] [canonicaltype=type-parameter-0-0] [canonicaltypekind=Unexposed] [isPOD=0]
 // CHECK: FieldDecl=a:4:13 (Definition) [type=T] [typekind=Unexposed] [canonicaltype=type-parameter-0-0] [canonicaltypekind=Unexposed] [isPOD=0]
@@ -25,5 +32,7 @@ class C : public A<float> { };
 // CHECK: C++ base class specifier=A<float>:4:7 [access=public isVirtual=false] [type=A<float>] [typekind=Unexposed] [templateargs/1= [type=float] [typekind=Float]] [canonicaltype=A<float>] [canonicaltypekind=Record] [canonicaltemplateargs/1= [type=float] [typekind=Float]] [isPOD=0] [nbFields=1]
 // CHECK: TemplateRef=A:4:7 [type=] [typekind=Invalid] [isPOD=0]
 
+// CHECK-KEEP-GOING-ONLY: VarDecl=global_var:1:12 [type=int] [typekind=Int] [isPOD=1]
+
 // CHECK-DIAG: keep-going.cpp:1:10: fatal error: 'missing1.h' file not found
 // CHECK-DIAG: keep-going.cpp:8:10: fatal error: 'missing2.h' file not found