[ARM/FDPIC,v4,01/20,ARM] FDPIC: Add -mfdpic option support

Message ID 20181116154808.25154-2-christophe.lyon@st.com
State New
Headers show
Series
  • FDPIC ABI for ARM
Related show

Commit Message

Christophe Lyon Nov. 16, 2018, 3:47 p.m.
2018-XX-XX  Christophe Lyon  <christophe.lyon@st.com>
	Mickaël Guêné  <mickael.guene@st.com>

	gcc/
	* config/arm/arm.opt: Add -mfdpic option.
	* doc/invoke.texi: Add documentation for -mfdpic.

-- 
2.6.3

Patch

diff --git a/gcc/config/arm/arm.opt b/gcc/config/arm/arm.opt
index a1286a4..231c1cb 100644
--- a/gcc/config/arm/arm.opt
+++ b/gcc/config/arm/arm.opt
@@ -302,3 +302,7 @@  When linking for big-endian targets, generate a legacy BE32 format image.
 mbranch-cost=
 Target RejectNegative Joined UInteger Var(arm_branch_cost) Init(-1)
 Cost to assume for a branch insn.
+
+mfdpic
+Target Report Mask(FDPIC)
+Enable Function Descriptor PIC mode.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 535b258..6b08b09 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -691,7 +691,8 @@  Objective-C and Objective-C++ Dialects}.
 -mrestrict-it @gol
 -mverbose-cost-dump @gol
 -mpure-code @gol
--mcmse}
+-mcmse @gol
+-mfdpic}
 
 @emph{AVR Options}
 @gccoptlist{-mmcu=@var{mcu}  -mabsdata  -maccumulate-args @gol
@@ -17538,6 +17539,23 @@  MOVT instruction.
 Generate secure code as per the "ARMv8-M Security Extensions: Requirements on
 Development Tools Engineering Specification", which can be found on
 @url{http://infocenter.arm.com/help/topic/com.arm.doc.ecm0359818/ECM0359818_armv8m_security_extensions_reqs_on_dev_tools_1_0.pdf}.
+
+@item -mfdpic
+@itemx -mno-fdpic
+@opindex mfdpic
+@opindex mno-fdpic
+Select the FDPIC ABI, which uses function descriptors to represent
+pointers to functions.  When the compiler is configured for
+@code{arm-*-uclinuxfdpiceabi} targets, this option is on by default
+and implies @option{-fPIE} if none of the PIC/PIE-related options is
+provided.  On other targets, it only enables the FDPIC-specific code
+generation features, and the user should explicitly provide the
+PIC/PIE-related options as needed.
+
+The opposite @option{-mno-fdpic} option is useful (and required) to
+build the Linux kernel using the same (@code{arm-*-uclinuxfdpiceabi})
+toolchain as the one used to build the userland programs.
+
 @end table
 
 @node AVR Options