zahiraam created this revision.
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When float_t and double_t types are used inside a scope with potential ABI
breakage. See https://godbolt.org/z/56zG4Wo91
This patch prevents this.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D146148
Files:
clang/include/clang/Basic/DiagnosticParseKinds.td
clang/lib/Parse/ParseStmt.cpp
clang/test/CodeGen/Inputs/math.h
clang/test/CodeGen/abi-check-1.c
clang/test/CodeGen/abi-check-2.c
clang/test/CodeGen/abi-check-3.c
Index: clang/test/CodeGen/abi-check-3.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/abi-check-3.c
@@ -0,0 +1,34 @@
+// RUN: %clang_cc1 -isystem %S/Inputs -triple x86_64-linux-gnu \
+// RUN: -emit-llvm -o - %s | FileCheck %s
+
+// RUN: not %clang_cc1 -isystem %S/Inputs -triple x86_64-linux-gnu \
+// RUN: -ffp-eval-method=source -emit-obj -o %t %s 2>&1 \
+// RUN: | FileCheck -check-prefix=ERROR-1 %s
+
+// RUN: not %clang_cc1 -isystem %S/Inputs -triple x86_64-linux-gnu \
+// RUN: -ffp-eval-method=double -emit-obj -o %t %s 2>&1 \
+// RUN: | FileCheck -check-prefix=ERROR-2 %s
+
+// RUN: %clang_cc1 -isystem %S/Inputs -triple x86_64-linux-gnu \
+// RUN: -ffp-eval-method=extended -emit-llvm -o - %s \
+// RUN: | FileCheck -check-prefix=CHECK-EXT %s
+
+#include <math.h>
+
+float foo1() {
+#pragma clang fp eval_method(extended)
+
+ float_t a;
+ double_t b;
+ // CHECK: alloca float
+ // CHECK: alloca double
+ // CHECK-EXT: alloca x86_fp80
+ // CHECK-EXT: alloca x86_fp80
+ // ERROR-1: error: float_t type definition cannot be modified inside a scope containing '#pragma clang fp eval_method(extended)' when a command line option 'ffp-eval-method=source' is used
+ // ERROR-1: error: double_t type definition cannot be modified inside a scope containing '#pragma clang fp eval_method(extended)' when a command line option 'ffp-eval-method=source' is used
+ // ERROR-2: error: float_t type definition cannot be modified inside a scope containing '#pragma clang fp eval_method(extended)' when a command line option 'ffp-eval-method=double' is used
+ // ERROR-2: error: double_t type definition cannot be modified inside a scope containing '#pragma clang fp eval_method(extended)' when a command line option 'ffp-eval-method=double' is used
+
+ return a - b;
+}
+
Index: clang/test/CodeGen/abi-check-2.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/abi-check-2.c
@@ -0,0 +1,33 @@
+// RUN: %clang_cc1 -isystem %S/Inputs -triple x86_64-linux-gnu \
+// RUN: -emit-llvm -o - %s | FileCheck %s
+
+// RUN: not %clang_cc1 -isystem %S/Inputs -triple x86_64-linux-gnu \
+// RUN: -ffp-eval-method=source -emit-obj -o %t %s 2>&1 \
+// RUN: | FileCheck -check-prefix=ERROR-1 %s
+
+// RUN: %clang_cc1 -isystem %S/Inputs -triple x86_64-linux-gnu \
+// RUN: -ffp-eval-method=double -emit-llvm -o - %s \
+// RUN: | FileCheck -check-prefix=CHECK-DBL %s
+
+// RUN: not %clang_cc1 -isystem %S/Inputs -triple x86_64-linux-gnu \
+// RUN: -ffp-eval-method=extended -emit-obj -o %t %s 2>&1 \
+// RUN: | FileCheck -check-prefix=ERROR-2 %s
+
+#include <math.h>
+
+float foo1() {
+#pragma clang fp eval_method(double)
+
+ float_t a;
+ double_t b;
+ // CHECK: alloca float
+ // CHECK: alloca double
+ // CHECK-DBL: alloca double
+ // CHECK-DBL: alloca double
+ // ERROR-1: error: float_t type definition cannot be modified inside a scope containing '#pragma clang fp eval_method(double)' when a command line option 'ffp-eval-method=source' is used
+ // ERROR-1: error: double_t type definition cannot be modified inside a scope containing '#pragma clang fp eval_method(double)' when a command line option 'ffp-eval-method=source' is used
+ // ERROR-2: error: float_t type definition cannot be modified inside a scope containing '#pragma clang fp eval_method(double)' when a command line option 'ffp-eval-method=extended' is used
+ // ERROR-2: error: double_t type definition cannot be modified inside a scope containing '#pragma clang fp eval_method(double)' when a command line option 'ffp-eval-method=extended' is used
+ return a - b;
+}
+
Index: clang/test/CodeGen/abi-check-1.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/abi-check-1.c
@@ -0,0 +1,30 @@
+// RUN: %clang_cc1 -isystem %S/Inputs -triple x86_64-linux-gnu \
+// RUN: -emit-llvm -o - %s | FileCheck %s
+
+// RUN: %clang_cc1 -isystem %S/Inputs -ffp-eval-method=source \
+// RUN: -triple x86_64-linux-gnu -emit-llvm -o - %s | FileCheck %s
+
+// RUN: not %clang_cc1 -isystem %S/Inputs -triple x86_64-linux-gnu \
+// RUN: -ffp-eval-method=double -emit-obj -o %t %s 2>&1 \
+// RUN: | FileCheck -check-prefix=ERROR-1 %s
+
+// RUN: not %clang_cc1 -isystem %S/Inputs -triple x86_64-linux-gnu \
+// RUN: -ffp-eval-method=extended -emit-obj -o %t %s 2>&1 \
+// RUN: | FileCheck -check-prefix=ERROR-2 %s
+
+#include <math.h>
+
+float foo1() {
+#pragma clang fp eval_method(source)
+
+ float_t a;
+ double_t b;
+ // CHECK: alloca float
+ // CHECK: alloca double
+ // ERROR-1: error: float_t type definition cannot be modified inside a scope containing '#pragma clang fp eval_method(source)' when a command line option 'ffp-eval-method=double' is used
+ // ERROR-1: error: double_t type definition cannot be modified inside a scope containing '#pragma clang fp eval_method(source)' when a command line option 'ffp-eval-method=double' is used
+ // ERROR-2: error: float_t type definition cannot be modified inside a scope containing '#pragma clang fp eval_method(source)' when a command line option 'ffp-eval-method=extended' is used
+ // ERROR-2: error: double_t type definition cannot be modified inside a scope containing '#pragma clang fp eval_method(source)' when a command line option 'ffp-eval-method=extended' is used
+ return a - b;
+}
+
Index: clang/test/CodeGen/Inputs/math.h
===================================================================
--- /dev/null
+++ clang/test/CodeGen/Inputs/math.h
@@ -0,0 +1,43 @@
+#ifdef __FLT_EVAL_METHOD__
+#if __FLT_EVAL_METHOD__ == -1
+#define __GLIBC_FLT_EVAL_METHOD 2
+#else
+#define __GLIBC_FLT_EVAL_METHOD __FLT_EVAL_METHOD__
+#endif
+#elif defined __x86_64__
+#define __GLIBC_FLT_EVAL_METHOD 0
+#else
+#define __GLIBC_FLT_EVAL_METHOD 2
+#endif
+
+# if __GLIBC_FLT_EVAL_METHOD == 0 || __GLIBC_FLT_EVAL_METHOD == 16
+typedef float float_t;
+typedef double double_t;
+# elif __GLIBC_FLT_EVAL_METHOD == 1
+typedef double float_t;
+typedef double double_t;
+# elif __GLIBC_FLT_EVAL_METHOD == 2
+typedef long double float_t;
+typedef long double double_t;
+# elif __GLIBC_FLT_EVAL_METHOD == 32
+typedef _Float32 float_t;
+typedef double double_t;
+# elif __GLIBC_FLT_EVAL_METHOD == 33
+typedef _Float32x float_t;
+typedef _Float32x double_t;
+# elif __GLIBC_FLT_EVAL_METHOD == 64
+typedef _Float64 float_t;
+typedef _Float64 double_t;
+# elif __GLIBC_FLT_EVAL_METHOD == 65
+typedef _Float64x float_t;
+typedef _Float64x double_t;
+# elif __GLIBC_FLT_EVAL_METHOD == 128
+typedef _Float128 float_t;
+typedef _Float128 double_t;
+# elif __GLIBC_FLT_EVAL_METHOD == 129
+typedef _Float128x float_t;
+typedef _Float128x double_t;
+# else
+# error "Unknown __GLIBC_FLT_EVAL_METHOD"
+# endif
+
Index: clang/lib/Parse/ParseStmt.cpp
===================================================================
--- clang/lib/Parse/ParseStmt.cpp
+++ clang/lib/Parse/ParseStmt.cpp
@@ -1111,6 +1111,19 @@
return Actions.ActOnExprStmt(E, /*DiscardedValue=*/!IsStmtExprResult);
}
+StringRef EvalMethodValToStr(LangOptions::FPEvalMethodKind Kind) {
+ switch (Kind) {
+ case LangOptions::FPEvalMethodKind::FEM_Double:
+ return "double";
+ case LangOptions::FPEvalMethodKind::FEM_Extended:
+ return "extended";
+ case LangOptions::FPEvalMethodKind::FEM_Source:
+ return "source";
+ default:
+ llvm_unreachable("unexpected eval method value");
+ }
+}
+
/// ParseCompoundStatementBody - Parse a sequence of statements optionally
/// followed by a label and invoke the ActOnCompoundStmt action. This expects
/// the '{' to be the current token, and consume the '}' at the end of the
@@ -1182,6 +1195,19 @@
continue;
StmtResult R;
+ if (Tok.is(tok::identifier)) {
+ if (Tok.getIdentifierInfo()->getName().str() == "float_t" ||
+ Tok.getIdentifierInfo()->getName().str() == "double_t") {
+ if (getLangOpts().getFPEvalMethod() !=
+ LangOptions::FPEvalMethodKind::FEM_UnsetOnCommandLine &&
+ PP.getLastFPEvalPragmaLocation().isValid() &&
+ PP.getCurrentFPEvalMethod() != getLangOpts().getFPEvalMethod())
+ Diag(Tok.getLocation(), diag::err_type_definition_cannot_be_modified)
+ << Tok.getIdentifierInfo()->getName().str()
+ << EvalMethodValToStr(PP.getCurrentFPEvalMethod())
+ << EvalMethodValToStr(getLangOpts().getFPEvalMethod());
+ }
+ }
if (Tok.isNot(tok::kw___extension__)) {
R = ParseStatementOrDeclaration(Stmts, SubStmtCtx);
} else {
Index: clang/include/clang/Basic/DiagnosticParseKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticParseKinds.td
+++ clang/include/clang/Basic/DiagnosticParseKinds.td
@@ -659,6 +659,10 @@
def warn_cxx20_compat_consteval_if : Warning<
"consteval if is incompatible with C++ standards before C++2b">,
InGroup<CXXPre2bCompat>, DefaultIgnore;
+def err_type_definition_cannot_be_modified : Error<
+ "%0 type definition cannot be modified inside a scope containing "
+ "'#pragma clang fp eval_method(%1)' when a command line "
+ "option 'ffp-eval-method=%2' is used">;
def ext_init_statement : ExtWarn<
"'%select{if|switch}0' initialization statements are a C++17 extension">,
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