[clang] 0f9cf42 - Allow /D flags absent during PCH creation under msvc-compat
Reid Kleckner via cfe-commits
cfe-commits at lists.llvm.org
Tue Jan 14 17:26:07 PST 2020
Author: Zachary Henkel
Date: 2020-01-14T17:26:01-08:00
New Revision: 0f9cf42facaf9eff47dc0b9eb7e6ed8803d3bc3b
URL: https://github.com/llvm/llvm-project/commit/0f9cf42facaf9eff47dc0b9eb7e6ed8803d3bc3b
DIFF: https://github.com/llvm/llvm-project/commit/0f9cf42facaf9eff47dc0b9eb7e6ed8803d3bc3b.diff
LOG: Allow /D flags absent during PCH creation under msvc-compat
Summary:
Before this patch adding a new /D flag when compiling a source file that consumed a PCH with clang-cl would issue a diagnostic and then fail. With the patch, the diagnostic is still issued but the definition is accepted. This matches the msvc behavior. The fuzzy-pch-msvc.c is a clone of the existing fuzzy-pch.c tests with some msvc specific rework.
msvc diagnostic:
warning C4605: '/DBAR=int' specified on current command line, but was not specified when precompiled header was built
Output of the CHECK-BAR test prior to the code change:
<built-in>(1,9): warning: definition of macro 'BAR' does not match definition in precompiled header [-Wclang-cl-pch]
#define BAR int
^
D:\repos\llvm\llvm-project\clang\test\PCH\fuzzy-pch-msvc.c(12,1): error: unknown type name 'BAR'
BAR bar = 17;
^
D:\repos\llvm\llvm-project\clang\test\PCH\fuzzy-pch-msvc.c(23,4): error: BAR was not defined
# error BAR was not defined
^
1 warning and 2 errors generated.
Reviewers: rnk, thakis, hans, zturner
Subscribers: mikerice, aganea, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72405
Added:
clang/test/PCH/ms-pch-macro.c
Modified:
clang/lib/Lex/PPDirectives.cpp
Removed:
################################################################################
diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 3b7eaee3c914..e433b2cf1b95 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -2727,7 +2727,9 @@ void Preprocessor::HandleDefineDirective(
/*Syntactic=*/LangOpts.MicrosoftExt))
Diag(MI->getDefinitionLoc(), diag::warn_pp_macro_def_mismatch_with_pch)
<< MacroNameTok.getIdentifierInfo();
- return;
+ // Issue the diagnostic but allow the change if msvc extensions are enabled
+ if (!LangOpts.MicrosoftExt)
+ return;
}
// Finally, if this identifier already had a macro defined for it, verify that
diff --git a/clang/test/PCH/ms-pch-macro.c b/clang/test/PCH/ms-pch-macro.c
new file mode 100644
index 000000000000..eb45be1b6b73
--- /dev/null
+++ b/clang/test/PCH/ms-pch-macro.c
@@ -0,0 +1,39 @@
+// Test -D and -U interaction with a PCH when -fms-extensions is enabled.
+
+// RUN: %clang_cc1 -DFOO %S/variables.h -emit-pch -o %t1.pch
+
+// RUN: not %clang_cc1 -DFOO=blah -DBAR=int -include-pch %t1.pch -pch-through-header=%S/variables.h %s 2> %t.err
+// RUN: FileCheck -check-prefix=CHECK-FOO %s < %t.err
+
+// RUN: not %clang_cc1 -UFOO -DBAR=int -include-pch %t1.pch %s -pch-through-header=%S/variables.h 2> %t.err
+// RUN: FileCheck -check-prefix=CHECK-NOFOO %s < %t.err
+
+// RUN: %clang_cc1 -include-pch %t1.pch -DBAR=int -pch-through-header=%S/variables.h -verify %s 2> %t.err
+
+// Enabling MS extensions should allow us to add BAR definitions.
+// RUN: %clang_cc1 -fms-extensions -DFOO %S/variables.h -emit-pch -o %t1.pch
+// RUN: %clang_cc1 -fms-extensions -include-pch %t1.pch -DBAR=int -pch-through-header=%S/variables.h -verify %s 2> %t.err
+
+#include "variables.h"
+
+BAR bar = 17;
+#ifndef _MSC_EXTENSIONS
+// expected-error at -2 {{unknown type name 'BAR'}}
+#endif
+
+#ifndef FOO
+# error FOO was not defined
+#endif
+
+#if FOO != 1
+# error FOO has the wrong definition
+#endif
+
+#if defined(_MSC_EXTENSIONS) && !defined(BAR)
+# error BAR was not defined
+#endif
+
+// CHECK-FOO: definition of macro 'FOO'
diff ers between the precompiled header ('1') and the command line ('blah')
+// CHECK-NOFOO: macro 'FOO' was defined in the precompiled header but undef'd on the command line
+
+// expected-warning at 1 {{definition of macro 'BAR' does not match definition in precompiled header}}
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