clang-cl: accept -f[no-]data-sections and -f[no-]function-sections

[inglorion]

Summary

This adds -fdata-sections, -ffunction-sections, and their negations to
the list of -f options accepted by clang-cl. As a result, these
options can be used with the same spelling for both clang and
clang-cl.

[thakis]

The clang-cl spelling of this is /Gy and /Gw. If you want to use the gcc spelling, you can do that through the /clang: flag.

[thakis]

In other words: The point of clang-cl is to use cl.exe flag spellings where they exist. So unless there's some good reason for adding this, I don't think we should add it.

[inglorion]

Ok, thanks for clarifying.

The benefit this would get us is not having to spell the flags differently depending on whether the frontend is clang or clang-cl. I figured this would fit in with all the -f options we already take and not really increase the risk of conflicting with future cl.exe options. But as you said, there are clang-cl options that will enable the exact same functionality, so I'll abandon this.

clang/include/clang/Driver/Options.td

def fno_virtual_function_elimination : Flag<["-"], "fno-virtual-function_elimination">, Group<f_Group>,
   Flags<[CoreOption]>;
 
 def fwrapv : Flag<["-"], "fwrapv">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Treat signed integer overflow as two's complement">;
 def fwritable_strings : Flag<["-"], "fwritable-strings">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Store string literals as writable data">;
 def fzero_initialized_in_bss : Flag<["-"], "fzero-initialized-in-bss">, Group<f_Group>;
 def ffunction_sections : Flag<["-"], "ffunction-sections">, Group<f_Group>,
-  Flags<[CC1Option]>,
+  Flags<[CoreOption, CC1Option]>,
   HelpText<"Place each function in its own section">;
-def fno_function_sections : Flag<["-"], "fno-function-sections">, Group<f_Group>;
+def fno_function_sections : Flag<["-"], "fno-function-sections">, Group<f_Group>, Flags<[CoreOption, CC1Option]>;
 def fbasic_block_sections_EQ : Joined<["-"], "fbasic-block-sections=">, Group<f_Group>,
   Flags<[CC1Option, CC1AsOption]>,
   HelpText<"Place each function's basic blocks in unique sections (ELF Only) : all | labels | none | list=<file>">,
   DocBrief<[{Generate labels for each basic block or place each basic block or a subset of basic blocks in its own section.}]>,
   Values<"all,labels,none,list=">;
 def fdata_sections : Flag <["-"], "fdata-sections">, Group<f_Group>,
- Flags<[CC1Option]>, HelpText<"Place each data in its own section">;
-def fno_data_sections : Flag <["-"], "fno-data-sections">, Group<f_Group>;
+ Flags<[CoreOption, CC1Option]>, HelpText<"Place each data in its own section">;
+def fno_data_sections : Flag <["-"], "fno-data-sections">, Group<f_Group>, Flags<[CoreOption, CC1Option]>;
 def fstack_size_section : Flag<["-"], "fstack-size-section">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Emit section containing metadata on function stack sizes">;
 def fno_stack_size_section : Flag<["-"], "fno-stack-size-section">, Group<f_Group>,
   HelpText<"Don't emit section containing metadata on function stack sizes">;
 
 def funique_section_names : Flag <["-"], "funique-section-names">,
   Group<f_Group>,
   HelpText<"Use unique names for text and data sections">;

clang/test/Driver/cl-options.c

 
 // RUN: %clang_cl /GS -### -- %s 2>&1 | FileCheck -check-prefix=GS %s
 // GS: "-stack-protector" "2"
 
 // RUN: %clang_cl /GS- -### -- %s 2>&1 | FileCheck -check-prefix=GS_ %s
 // GS_-NOT: -stack-protector
 
 // RUN: %clang_cl /Gy -### -- %s 2>&1 | FileCheck -check-prefix=Gy %s
+// RUN: %clang_cl -ffunction-sections -### -- %s 2>&1 | FileCheck -check-prefix=Gy %s
 // Gy: -ffunction-sections
 
 // RUN: %clang_cl /Gy /Gy- -### -- %s 2>&1 | FileCheck -check-prefix=Gy_ %s
+// RUN: %clang_cl -fno-function-sections -### -- %s 2>&1 | FileCheck -check-prefix=Gy_ %s
 // Gy_-NOT: -ffunction-sections
 
 // RUN: %clang_cl /Gs -### -- %s 2>&1 | FileCheck -check-prefix=Gs %s
 // Gs: "-mstack-probe-size=4096"
 // RUN: %clang_cl /Gs0 -### -- %s 2>&1 | FileCheck -check-prefix=Gs0 %s
 // Gs0: "-mstack-probe-size=0"
 // RUN: %clang_cl /Gs4096 -### -- %s 2>&1 | FileCheck -check-prefix=Gs4096 %s
 // Gs4096: "-mstack-probe-size=4096"
 
 // RUN: %clang_cl /Gw -### -- %s 2>&1 | FileCheck -check-prefix=Gw %s
+// RUN: %clang_cl -fdata-sections -### -- %s 2>&1 | FileCheck -check-prefix=Gw %s
 // Gw: -fdata-sections
 
 // RUN: %clang_cl /Gw /Gw- -### -- %s 2>&1 | FileCheck -check-prefix=Gw_ %s
+// RUN: %clang_cl -fno-data-sections -### -- %s 2>&1 | FileCheck -check-prefix=Gw_ %s
 // Gw_-NOT: -fdata-sections
 
 // RUN: %clang_cl /Imyincludedir -### -- %s 2>&1 | FileCheck -check-prefix=SLASH_I %s
 // RUN: %clang_cl /I myincludedir -### -- %s 2>&1 | FileCheck -check-prefix=SLASH_I %s
 // SLASH_I: "-I" "myincludedir"
 
 // RUN: %clang_cl /imsvcmyincludedir -### -- %s 2>&1 | FileCheck -check-prefix=SLASH_imsvc %s
 // RUN: %clang_cl /imsvc myincludedir -### -- %s 2>&1 | FileCheck -check-prefix=SLASH_imsvc %s

 // RUN:     -fno-builtin \
 // RUN:     -fno-builtin-strcpy \
 // RUN:     -fcolor-diagnostics \
 // RUN:     -fno-color-diagnostics \
 // RUN:     -fcoverage-mapping \
 // RUN:     -fno-coverage-mapping \
 // RUN:     -fdiagnostics-color \
 // RUN:     -fno-diagnostics-color \
+// RUN:     -fdata-sections \
+// RUN:     -fno-data-sections \
 // RUN:     -fdebug-compilation-dir . \
 // RUN:     -fdebug-compilation-dir=. \
 // RUN:     -fdiagnostics-parseable-fixits \
 // RUN:     -fdiagnostics-absolute-paths \
 // RUN:     -ferror-limit=10 \
+// RUN:     -ffunction-sections \
+// RUN:     -fno-function-sections \
 // RUN:     -fmsc-version=1800 \
 // RUN:     -fno-strict-aliasing \
 // RUN:     -fstrict-aliasing \
 // RUN:     -fsyntax-only \
 // RUN:     -fms-compatibility \
 // RUN:     -fno-ms-compatibility \
 // RUN:     -fms-extensions \
 // RUN:     -fno-ms-extensions \