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llvm-project/clang/test/Driver/ropi-rwpi.c

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[ARM] Command-line options for embedded position-independent code This patch (with the corresponding ARM backend patch) adds support for some new relocation models: * Read-only position independence (ROPI): Code and read-only data is accessed PC-relative. The offsets between all code and RO data sections are known at static link time. * Read-write position independence (RWPI): Read-write data is accessed relative to a static base register. The offsets between all writeable data sections are known at static link time. These two modes are independent (they specify how different objects should be addressed), so they can be used individually or together. These modes are intended for bare-metal systems or systems with small real-time operating systems. They are designed to avoid the need for a dynamic linker, the only initialisation required is setting the static base register to an appropriate value for RWPI code. There is one C construct not currently supported by these modes: global variables initialised to the address of another global variable or function, where that address is not known at static-link time. There are a few possible ways to solve this: * Disallow this, and require the user to write their own initialisation function if they need variables like this. * Emit dynamic initialisers for these variables in the compiler, called from the .init_array section (as is currently done for C++ dynamic initialisers). We have a patch to do this, described in my original RFC email (http://lists.llvm.org/pipermail/llvm-dev/2015-December/093022.html), but the feedback from that RFC thread was that this is not something that belongs in clang. * Use a small dynamic loader to fix up these variables, by adding the difference between the load and execution address of the relevant section. This would require linker co-operation to generate a table of addresses that need fixing up. Differential Revision: https://reviews.llvm.org/D23196 llvm-svn: 278016
2016-08-08 23:28:40 +08:00
// RUN: %clang -target arm-none-eabi -### -c %s 2>&1 | FileCheck --check-prefix=STATIC %s
// RUN: %clang -target arm-none-eabi -fropi -### -c %s 2>&1 | FileCheck --check-prefix=ROPI %s
// RUN: %clang -target arm-none-eabi -frwpi -### -c %s 2>&1 | FileCheck --check-prefix=RWPI %s
// RUN: %clang -target arm-none-eabi -fropi -frwpi -### -c %s 2>&1 | FileCheck --check-prefix=ROPI-RWPI %s
// RUN: %clang -target armeb-none-eabi -fropi -### -c %s 2>&1 | FileCheck --check-prefix=ROPI %s
// RUN: %clang -target thumb-none-eabi -fropi -### -c %s 2>&1 | FileCheck --check-prefix=ROPI %s
// RUN: %clang -target thumbeb-none-eabi -fropi -### -c %s 2>&1 | FileCheck --check-prefix=ROPI %s
// RUN: %clang -target x86_64-linux-gnu -fropi -### -c %s 2>&1 | FileCheck --check-prefix=ROPI-NON-ARM %s
// RUN: %clang -target x86_64-linux-gnu -frwpi -### -c %s 2>&1 | FileCheck --check-prefix=RWPI-NON-ARM %s
// RUN: %clang -target x86_64-linux-gnu -fropi -frwpi -### -c %s 2>&1 | FileCheck --check-prefix=ROPI-NON-ARM --check-prefix=RWPI-NON-ARM %s
// RUN: %clang -target arm-none-eabi -fpic -fropi -### -c %s 2>&1 | FileCheck --check-prefix=PIC %s
// RUN: %clang -target arm-none-eabi -fpie -frwpi -### -c %s 2>&1 | FileCheck --check-prefix=PIC %s
// RUN: %clang -target arm-none-eabi -fPIC -fropi -frwpi -### -c %s 2>&1 | FileCheck --check-prefix=PIC %s
// RUN: %clang -target arm-none-eabi -fno-pic -fropi -### -c %s 2>&1 | FileCheck --check-prefix=ROPI %s
// RUN: %clang -target arm-none-eabi -x c++ -fropi -### -c %s 2>&1 | FileCheck --check-prefix=CXX %s
// RUN: %clang -target arm-none-eabi -x c++ -frwpi -### -c %s 2>&1 | FileCheck --check-prefix=RWPI %s
// RUN: %clang -target arm-none-eabi -x c++ -fropi -frwpi -### -c %s 2>&1 | FileCheck --check-prefix=CXX %s
// RUN: %clang -target arm-none-eabi -x c++ -fallow-unsupported -fropi -### -c %s 2>&1 | FileCheck --check-prefix=ROPI %s
// STATIC: "-mrelocation-model" "static"
// ROPI: "-mrelocation-model" "ropi"
// RWPI: "-mrelocation-model" "rwpi"
// ROPI-RWPI: "-mrelocation-model" "ropi-rwpi"
// ROPI-NON-ARM: error: unsupported option '-fropi' for target 'x86_64--linux-gnu'
// RWPI-NON-ARM: error: unsupported option '-frwpi' for target 'x86_64--linux-gnu'
// PIC: error: embedded and GOT-based position independence are incompatible
// CXX: error: ROPI is not compatible with c++