[Modules] Fix using va_list with modules and a precompiled header.
#100837
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Fix the false warning
> incompatible pointer types passing 'va_list' (aka '__builtin_va_list') to parameter of type 'struct __va_list_tag *' [-Wincompatible-pointer-types]
The warning is wrong because both in the function declaration and at the call
site we are using `va_list`.
When we call `ASTContext::getBuiltinVaListDecl` at a specific moment, we
end up re-entering this function which causes creating 2 instances of
`BuiltinVaListDecl` and 2 instances of `VaListTagDecl` but the stored
instances are unrelated to each other because of the call sequence like
getBuiltinVaListDecl
CreateX86_64ABIBuiltinVaListDecl
VaListTagDecl = TagA
indirectly call getBuiltinVaListDecl
CreateX86_64ABIBuiltinVaListDecl
VaListTagDecl = TagB
BuiltinVaListDecl = ListB
BuiltinVaListDecl = ListA
Now we have `BuiltinVaListDecl == ListA` and `VaListTagDecl == TagB`.
For x86_64 '__builtin_va_list' and 'struct __va_list_tag *' are compatible
because '__builtin_va_list' == '__va_list_tag[1]'. But because we have
unrelated decls for VaListDecl and VaListTagDecl the types are considered
incompatible as we are comparing type pointers.
Fix the error by creating `BuiltinVaListDecl` before
`ASTReader::InitializeSema`, so that during `ASTContext::getBuiltinVaListDecl`
ASTReader doesn't try to de-serialize '__builtin_va_list' and to call
`ASTContext::getBuiltinVaListDecl` again.
rdar://130947515
llvmbot
added
clang
|
@llvm/pr-subscribers-clang-modules @llvm/pr-subscribers-clang Author: Volodymyr Sapsai (vsapsai) ChangesFix the false warning The warning is wrong because both in the function declaration and at the call site we are using When we call Now we have For x86_64 '__builtin_va_list' and 'struct __va_list_tag *' are compatible because '__builtin_va_list' == '__va_list_tag[1]'. But because we have unrelated decls for VaListDecl and VaListTagDecl the types are considered incompatible as we are comparing type pointers. Fix the error by creating rdar://130947515 Full diff: https://github.com/llvm/llvm-project/pull/100837.diff 2 Files Affected:
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 2e989f0ba6fe4..19d8692ee6484 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -310,6 +310,13 @@ void Sema::addImplicitTypedef(StringRef Name, QualType T) {
}
void Sema::Initialize() {
+ // Create BuiltinVaListDecl *before* ExternalSemaSource::InitializeSema(this)
+ // because during initialization ASTReader can emit globals that require
+ // name mangling. And the name mangling uses BuiltinVaListDecl.
+ if (Context.getTargetInfo().hasBuiltinMSVaList())
+ (void)Context.getBuiltinMSVaListDecl();
+ (void)Context.getBuiltinVaListDecl();
+
if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer))
SC->InitializeSema(*this);
diff --git a/clang/test/Modules/builtin-vararg.c b/clang/test/Modules/builtin-vararg.c
new file mode 100644
index 0000000000000..ed6e6aeb6e50f
--- /dev/null
+++ b/clang/test/Modules/builtin-vararg.c
@@ -0,0 +1,83 @@
+// Check how builtins using varargs behave with the modules.
+
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+
+// RUN: %clang_cc1 -triple x86_64-apple-darwin \
+// RUN: -fmodules -fno-implicit-modules -fbuiltin-headers-in-system-modules \
+// RUN: -emit-module -fmodule-name=DeclareVarargs \
+// RUN: -x c %t/include/module.modulemap -o %t/DeclareVarargs.pcm \
+// RUN: -fmodule-map-file=%t/resource_dir/module.modulemap -isystem %t/resource_dir
+// RUN: %clang_cc1 -triple x86_64-apple-darwin \
+// RUN: -fmodules -fno-implicit-modules -fbuiltin-headers-in-system-modules \
+// RUN: -emit-pch -fmodule-name=Prefix \
+// RUN: -x c-header %t/prefix.pch -o %t/prefix.pch.gch \
+// RUN: -fmodule-map-file=%t/include/module.modulemap -fmodule-file=DeclareVarargs=%t/DeclareVarargs.pcm \
+// RUN: -I %t/include
+// RUN: %clang_cc1 -triple x86_64-apple-darwin \
+// RUN: -fmodules -fno-implicit-modules -fbuiltin-headers-in-system-modules \
+// RUN: -emit-obj -fmodule-name=test \
+// RUN: -x c %t/test.c -o %t/test.o \
+// RUN: -Werror=incompatible-pointer-types \
+// RUN: -fmodule-file=%t/DeclareVarargs.pcm -include-pch %t/prefix.pch.gch \
+// RUN: -I %t/include
+
+//--- include/declare-varargs.h
+#ifndef DECLARE_VARARGS_H
+#define DECLARE_VARARGS_H
+
+#include <stdarg.h>
+
+int vprintf(const char *format, va_list args);
+
+// 1. initializeBuiltins 'acos' causes its deserialization and deserialization
+// of 'implementation_of_builtin'. Because this is done before Sema initialization,
+// 'implementation_of_builtin' DeclID is added to PreloadedDeclIDs.
+#undef acos
+#define acos(__x) implementation_of_builtin(__x)
+
+// 2. Because of 'static' the function isn't added to EagerlyDeserializedDecls
+// and not deserialized in `ASTReader::StartTranslationUnit` before `ASTReader::InitializeSema`.
+// 3. Because of '__overloadable__' attribute the function requires name mangling during deserialization.
+// And the name mangling requires '__builtin_va_list' decl.
+// Because the function is added to PreloadedDeclIDs, the deserialization happens in `ASTReader::InitializeSema`.
+static int __attribute__((__overloadable__)) implementation_of_builtin(int x) {
+ return x;
+}
+
+#endif // DECLARE_VARARGS_H
+
+//--- include/module.modulemap
+module DeclareVarargs {
+ header "declare-varargs.h"
+ export *
+}
+
+//--- resource_dir/stdarg.h
+#ifndef STDARG_H
+#define STDARG_H
+
+typedef __builtin_va_list va_list;
+#define va_start(ap, param) __builtin_va_start(ap, param)
+#define va_end(ap) __builtin_va_end(ap)
+
+#endif // STDARG_H
+
+//--- resource_dir/module.modulemap
+module _Builtin_stdarg {
+ header "stdarg.h"
+ export *
+}
+
+//--- prefix.pch
+#include <declare-varargs.h>
+
+//--- test.c
+#include <declare-varargs.h>
+
+void test(const char *format, ...) {
+ va_list argParams;
+ va_start(argParams, format);
+ vprintf(format, argParams);
+ va_end(argParams);
+}
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Thanks for the review! |
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/3117 Here is the relevant piece of the build log for the reference: |
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/65/builds/2302 Here is the relevant piece of the build log for the reference: |
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/154/builds/2288 Here is the relevant piece of the build log for the reference: |
dyung
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Aug 2, 2024
…header." (#101752) Reverts #100837 The test Modules/builtin-vararg.c is failing on AArch64 build bots: - https://lab.llvm.org/buildbot/#/builders/190/builds/3117 - https://lab.llvm.org/buildbot/#/builders/65/builds/2302 - https://lab.llvm.org/buildbot/#/builders/154/builds/2288 Revert to get the bots back to green.
|
Looks like need something like |
vsapsai
added a commit
that referenced
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Aug 2, 2024
…header. (#100837)" Fix the false warning > incompatible pointer types passing 'va_list' (aka '__builtin_va_list') to parameter of type 'struct __va_list_tag *' [-Wincompatible-pointer-types] The warning is wrong because both in the function declaration and at the call site we are using `va_list`. When we call `ASTContext::getBuiltinVaListDecl` at a specific moment, we end up re-entering this function which causes creating 2 instances of `BuiltinVaListDecl` and 2 instances of `VaListTagDecl` but the stored instances are unrelated to each other because of the call sequence like getBuiltinVaListDecl CreateX86_64ABIBuiltinVaListDecl VaListTagDecl = TagA indirectly call getBuiltinVaListDecl CreateX86_64ABIBuiltinVaListDecl VaListTagDecl = TagB BuiltinVaListDecl = ListB BuiltinVaListDecl = ListA Now we have `BuiltinVaListDecl == ListA` and `VaListTagDecl == TagB`. For x86_64 '__builtin_va_list' and 'struct __va_list_tag *' are compatible because '__builtin_va_list' == '__va_list_tag[1]'. But because we have unrelated decls for VaListDecl and VaListTagDecl the types are considered incompatible as we are comparing type pointers. Fix the error by creating `BuiltinVaListDecl` before `ASTReader::InitializeSema`, so that during `ASTContext::getBuiltinVaListDecl` ASTReader doesn't try to de-serialize '__builtin_va_list' and to call `ASTContext::getBuiltinVaListDecl` again. Reland with the requirement to have x86 target to avoid errors like > error: unable to create target: 'No available targets are compatible with triple "x86_64-apple-darwin"' rdar://130947515
banach-space
pushed a commit
to banach-space/llvm-project
that referenced
this pull request
Aug 7, 2024
…lvm#100837) Fix the false warning > incompatible pointer types passing 'va_list' (aka '__builtin_va_list') to parameter of type 'struct __va_list_tag *' [-Wincompatible-pointer-types] The warning is wrong because both in the function declaration and at the call site we are using `va_list`. When we call `ASTContext::getBuiltinVaListDecl` at a specific moment, we end up re-entering this function which causes creating 2 instances of `BuiltinVaListDecl` and 2 instances of `VaListTagDecl` but the stored instances are unrelated to each other because of the call sequence like getBuiltinVaListDecl CreateX86_64ABIBuiltinVaListDecl VaListTagDecl = TagA indirectly call getBuiltinVaListDecl CreateX86_64ABIBuiltinVaListDecl VaListTagDecl = TagB BuiltinVaListDecl = ListB BuiltinVaListDecl = ListA Now we have `BuiltinVaListDecl == ListA` and `VaListTagDecl == TagB`. For x86_64 '__builtin_va_list' and 'struct __va_list_tag *' are compatible because '__builtin_va_list' == '__va_list_tag[1]'. But because we have unrelated decls for VaListDecl and VaListTagDecl the types are considered incompatible as we are comparing type pointers. Fix the error by creating `BuiltinVaListDecl` before `ASTReader::InitializeSema`, so that during `ASTContext::getBuiltinVaListDecl` ASTReader doesn't try to de-serialize '__builtin_va_list' and to call `ASTContext::getBuiltinVaListDecl` again. rdar://130947515
banach-space
pushed a commit
to banach-space/llvm-project
that referenced
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Aug 7, 2024
…header." (llvm#101752) Reverts llvm#100837 The test Modules/builtin-vararg.c is failing on AArch64 build bots: - https://lab.llvm.org/buildbot/#/builders/190/builds/3117 - https://lab.llvm.org/buildbot/#/builders/65/builds/2302 - https://lab.llvm.org/buildbot/#/builders/154/builds/2288 Revert to get the bots back to green.
banach-space
pushed a commit
to banach-space/llvm-project
that referenced
this pull request
Aug 7, 2024
…header. (llvm#100837)" Fix the false warning > incompatible pointer types passing 'va_list' (aka '__builtin_va_list') to parameter of type 'struct __va_list_tag *' [-Wincompatible-pointer-types] The warning is wrong because both in the function declaration and at the call site we are using `va_list`. When we call `ASTContext::getBuiltinVaListDecl` at a specific moment, we end up re-entering this function which causes creating 2 instances of `BuiltinVaListDecl` and 2 instances of `VaListTagDecl` but the stored instances are unrelated to each other because of the call sequence like getBuiltinVaListDecl CreateX86_64ABIBuiltinVaListDecl VaListTagDecl = TagA indirectly call getBuiltinVaListDecl CreateX86_64ABIBuiltinVaListDecl VaListTagDecl = TagB BuiltinVaListDecl = ListB BuiltinVaListDecl = ListA Now we have `BuiltinVaListDecl == ListA` and `VaListTagDecl == TagB`. For x86_64 '__builtin_va_list' and 'struct __va_list_tag *' are compatible because '__builtin_va_list' == '__va_list_tag[1]'. But because we have unrelated decls for VaListDecl and VaListTagDecl the types are considered incompatible as we are comparing type pointers. Fix the error by creating `BuiltinVaListDecl` before `ASTReader::InitializeSema`, so that during `ASTContext::getBuiltinVaListDecl` ASTReader doesn't try to de-serialize '__builtin_va_list' and to call `ASTContext::getBuiltinVaListDecl` again. Reland with the requirement to have x86 target to avoid errors like > error: unable to create target: 'No available targets are compatible with triple "x86_64-apple-darwin"' rdar://130947515
kstoimenov
pushed a commit
to kstoimenov/llvm-project
that referenced
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Aug 15, 2024
…header." (llvm#101752) Reverts llvm#100837 The test Modules/builtin-vararg.c is failing on AArch64 build bots: - https://lab.llvm.org/buildbot/#/builders/190/builds/3117 - https://lab.llvm.org/buildbot/#/builders/65/builds/2302 - https://lab.llvm.org/buildbot/#/builders/154/builds/2288 Revert to get the bots back to green.
kstoimenov
pushed a commit
to kstoimenov/llvm-project
that referenced
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Aug 15, 2024
…header. (llvm#100837)" Fix the false warning > incompatible pointer types passing 'va_list' (aka '__builtin_va_list') to parameter of type 'struct __va_list_tag *' [-Wincompatible-pointer-types] The warning is wrong because both in the function declaration and at the call site we are using `va_list`. When we call `ASTContext::getBuiltinVaListDecl` at a specific moment, we end up re-entering this function which causes creating 2 instances of `BuiltinVaListDecl` and 2 instances of `VaListTagDecl` but the stored instances are unrelated to each other because of the call sequence like getBuiltinVaListDecl CreateX86_64ABIBuiltinVaListDecl VaListTagDecl = TagA indirectly call getBuiltinVaListDecl CreateX86_64ABIBuiltinVaListDecl VaListTagDecl = TagB BuiltinVaListDecl = ListB BuiltinVaListDecl = ListA Now we have `BuiltinVaListDecl == ListA` and `VaListTagDecl == TagB`. For x86_64 '__builtin_va_list' and 'struct __va_list_tag *' are compatible because '__builtin_va_list' == '__va_list_tag[1]'. But because we have unrelated decls for VaListDecl and VaListTagDecl the types are considered incompatible as we are comparing type pointers. Fix the error by creating `BuiltinVaListDecl` before `ASTReader::InitializeSema`, so that during `ASTContext::getBuiltinVaListDecl` ASTReader doesn't try to de-serialize '__builtin_va_list' and to call `ASTContext::getBuiltinVaListDecl` again. Reland with the requirement to have x86 target to avoid errors like > error: unable to create target: 'No available targets are compatible with triple "x86_64-apple-darwin"' rdar://130947515
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Fix the false warning
The warning is wrong because both in the function declaration and at the call site we are using
va_list.When we call
ASTContext::getBuiltinVaListDeclat a specific moment, we end up re-entering this function which causes creating 2 instances ofBuiltinVaListDecland 2 instances ofVaListTagDeclbut the stored instances are unrelated to each other because of the call sequence likeNow we have
BuiltinVaListDecl == ListAandVaListTagDecl == TagB.For x86_64 '__builtin_va_list' and 'struct __va_list_tag *' are compatible because '__builtin_va_list' == '__va_list_tag[1]'. But because we have unrelated decls for VaListDecl and VaListTagDecl the types are considered incompatible as we are comparing type pointers.
Fix the error by creating
BuiltinVaListDeclbeforeASTReader::InitializeSema, so that duringASTContext::getBuiltinVaListDeclASTReader doesn't try to de-serialize '__builtin_va_list' and to callASTContext::getBuiltinVaListDeclagain.rdar://130947515