diff --git a/clang/include/clang/Basic/CodeGenOptions.def b/clang/include/clang/Basic/CodeGenOptions.def --- a/clang/include/clang/Basic/CodeGenOptions.def +++ b/clang/include/clang/Basic/CodeGenOptions.def @@ -366,8 +366,8 @@ /// Whether to report the hotness of the code region for optimization remarks. CODEGENOPT(DiagnosticsWithHotness, 1, 0) -/// Whether copy relocations support is available when building as PIE. -CODEGENOPT(PIECopyRelocations, 1, 0) +/// Whether to use direct access relocations (instead of GOT) to reference external data symbols. +CODEGENOPT(DirectAccessExternalData, 1, 0) /// Whether we should use the undefined behaviour optimization for control flow /// paths that reach the end of a function without executing a required return. diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -1863,6 +1863,10 @@ def fno_pic : Flag<["-"], "fno-pic">, Group; def fpie : Flag<["-"], "fpie">, Group; def fno_pie : Flag<["-"], "fno-pie">, Group; +def fdirect_access_external_data : Flag<["-"], "fdirect-access-external-data">, Group, Flags<[CC1Option]>, + HelpText<"Don't use GOT indirection to reference external data symbols">; +def fno_direct_access_external_data : Flag<["-"], "fno-direct-access-external-data">, Group, Flags<[CC1Option]>, + HelpText<"Use GOT indirection to reference external data symbols">; defm plt : OptOutFFlag<"plt", "", "Use GOT indirection instead of PLT to make external function calls (x86 only)">; defm ropi : OptInFFlag<"ropi", "Generate read-only position independent code (ARM only)">; @@ -2719,10 +2723,10 @@ HelpText<"Use the given offset for addressing the stack-protector guard">; def mstack_protector_guard_reg_EQ : Joined<["-"], "mstack-protector-guard-reg=">, Group, Flags<[CC1Option]>, HelpText<"Use the given reg for addressing the stack-protector guard">; -def mpie_copy_relocations : Flag<["-"], "mpie-copy-relocations">, Group, - Flags<[CC1Option]>, - HelpText<"Use copy relocations support for PIE builds">; -def mno_pie_copy_relocations : Flag<["-"], "mno-pie-copy-relocations">, Group; +def mpie_copy_relocations : Flag<["-"], "mpie-copy-relocations">, + Alias, Group; +def mno_pie_copy_relocations : Flag<["-"], "mno-pie-copy-relocations">, + Alias, Group; def mfentry : Flag<["-"], "mfentry">, HelpText<"Insert calls to fentry at function entry (x86/SystemZ only)">, Flags<[CC1Option]>, Group; def mnop_mcount : Flag<["-"], "mnop-mcount">, HelpText<"Generate mcount/__fentry__ calls as nops. To activate they need to be patched in.">, diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -976,7 +976,7 @@ // If we can use copy relocations we can assume it is local. if (auto *Var = dyn_cast(GV)) if (!Var->isThreadLocal() && - (RM == llvm::Reloc::Static || CGOpts.PIECopyRelocations)) + (RM == llvm::Reloc::Static || CGOpts.DirectAccessExternalData)) return true; // If we can use a plt entry as the symbol address we can assume it diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -4811,11 +4811,14 @@ CmdArgs.push_back("-mms-bitfields"); } - if (Args.hasFlag(options::OPT_mpie_copy_relocations, - options::OPT_mno_pie_copy_relocations, - false)) { - CmdArgs.push_back("-mpie-copy-relocations"); - } + // Non-PIC code defaults to -fdirect-access-external-data while PIC code + // defaults to -fno-direct-access-external-data. Pass the option if different + // from the default. + if (Arg *A = Args.getLastArg(options::OPT_fdirect_access_external_data, + options::OPT_fno_direct_access_external_data)) + if (A->getOption().matches(options::OPT_fdirect_access_external_data) != + (PICLevel == 0)) + A->render(Args, CmdArgs); if (Args.hasFlag(options::OPT_fno_plt, options::OPT_fplt, false)) { CmdArgs.push_back("-fno-plt"); diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp --- a/clang/lib/Frontend/CompilerInvocation.cpp +++ b/clang/lib/Frontend/CompilerInvocation.cpp @@ -1073,8 +1073,10 @@ Opts.RelaxAll = Args.hasArg(OPT_mrelax_all); Opts.IncrementalLinkerCompatible = Args.hasArg(OPT_mincremental_linker_compatible); - Opts.PIECopyRelocations = - Args.hasArg(OPT_mpie_copy_relocations); + Opts.DirectAccessExternalData = + Args.hasArg(OPT_fdirect_access_external_data) || + (!Args.hasArg(OPT_fno_direct_access_external_data) && + getLastArgIntValue(Args, OPT_pic_level, 0, Diags) == 0); Opts.NoPLT = Args.hasArg(OPT_fno_plt); Opts.SaveTempLabels = Args.hasArg(OPT_msave_temp_labels); Opts.NoDwarfDirectoryAsm = Args.hasArg(OPT_fno_dwarf_directory_asm); diff --git a/clang/test/CodeGen/dso-local-executable.c b/clang/test/CodeGen/dso-local-executable.c --- a/clang/test/CodeGen/dso-local-executable.c +++ b/clang/test/CodeGen/dso-local-executable.c @@ -42,7 +42,7 @@ // PIE-DAG: define dso_local i32* @zed() // PIE-DAG: declare void @import_func() -// RUN: %clang_cc1 -triple x86_64 -emit-llvm -pic-level 1 -pic-is-pie -mpie-copy-relocations %s -o - | FileCheck --check-prefix=PIE-DIRECT %s +// RUN: %clang_cc1 -triple x86_64 -emit-llvm -pic-level 1 -pic-is-pie -fdirect-access-external-data %s -o - | FileCheck --check-prefix=PIE-DIRECT %s // PIE-DIRECT: @baz = dso_local global i32 42 // PIE-DIRECT-NEXT: @import_var = external dso_local global i32 // PIE-DIRECT-NEXT: @weak_bar = extern_weak global i32 @@ -64,7 +64,7 @@ // NOPLT-DAG: define dso_local i32* @zed() // NOPLT-DAG: declare void @import_func() -// RUN: %clang_cc1 -triple x86_64 -emit-llvm -fno-plt -pic-level 1 -pic-is-pie -mpie-copy-relocations %s -o - | FileCheck --check-prefix=PIE-DIRECT-NOPLT %s +// RUN: %clang_cc1 -triple x86_64 -emit-llvm -fno-plt -pic-level 1 -pic-is-pie -fdirect-access-external-data %s -o - | FileCheck --check-prefix=PIE-DIRECT-NOPLT %s // PIE-DIRECT-NOPLT: @baz = dso_local global i32 42 // PIE-DIRECT-NOPLT-NEXT: @import_var = external dso_local global i32 // PIE-DIRECT-NOPLT-NEXT: @weak_bar = extern_weak global i32 @@ -75,7 +75,7 @@ // PIE-DIRECT-NOPLT-DAG: define dso_local i32* @zed() // PIE-DIRECT-NOPLT-DAG: declare void @import_func() -// RUN: %clang_cc1 -triple x86_64 -emit-llvm -pic-is-pie -fno-plt %s -o - | FileCheck --check-prefix=PIE-NO-PLT %s +// RUN: %clang_cc1 -triple x86_64 -emit-llvm -pic-level 1 -pic-is-pie -fno-plt %s -o - | FileCheck --check-prefix=PIE-NO-PLT %s // RUN: %clang_cc1 -triple powerpc64le -emit-llvm -mrelocation-model static %s -o - | FileCheck --check-prefix=PIE-NO-PLT %s // PIE-NO-PLT: @baz = dso_local global i32 42 // PIE-NO-PLT-NEXT: @import_var = external global i32 diff --git a/clang/test/Driver/fdirect-access-external-data.c b/clang/test/Driver/fdirect-access-external-data.c new file mode 100644 --- /dev/null +++ b/clang/test/Driver/fdirect-access-external-data.c @@ -0,0 +1,18 @@ +/// -fno-pic code defaults to -fdirect-access-external-data. +// RUN: %clang -### -c -target x86_64 %s 2>&1 | FileCheck %s --check-prefix=DEFAULT +// RUN: %clang -### -c -target x86_64 %s -fdirect-access-external-data 2>&1 | FileCheck %s --check-prefix=DEFAULT +// RUN: %clang -### -c -target x86_64 %s -fdirect-access-external-data -fno-direct-access-external-data 2>&1 | FileCheck %s --check-prefix=INDIRECT + +/// -fpie/-fpic code defaults to -fdirect-access-external-data. +// RUN: %clang -### -c -target x86_64 %s -fpie 2>&1 | FileCheck %s --check-prefix=DEFAULT +// RUN: %clang -### -c -target x86_64 %s -fpie -fno-direct-access-external-data -fdirect-access-external-data 2>&1 | FileCheck %s --check-prefix=DIRECT +// RUN: %clang -### -c -target aarch64 %s -fpic 2>&1 | FileCheck %s --check-prefix=DEFAULT +// RUN: %clang -### -c -target aarch64 %s -fpic -fdirect-access-external-data 2>&1 | FileCheck %s --check-prefix=DIRECT + +/// -m[no-]pie-copy-relocations are aliases for compatibility. +// RUN: %clang -### -c -target riscv64 %s -mno-pie-copy-relocations 2>&1 | FileCheck %s --check-prefix=INDIRECT +// RUN: %clang -### -c -target riscv64 %s -fpic -mpie-copy-relocations 2>&1 | FileCheck %s --check-prefix=DIRECT + +// DEFAULT-NOT: direct-access-external-data" +// DIRECT: "-fdirect-access-external-data" +// INDIRECT: "-fno-direct-access-external-data"