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11.20.3 Output of Uninitialized Variables

Each of the macros in this section is used to do the whole job of outputting a single uninitialized variable.

— Macro: ASM_OUTPUT_COMMON (stream, name, size, rounded)

A C statement (sans semicolon) to output to the stdio stream stream the assembler definition of a common-label named name whose size is size bytes. The variable rounded is the size rounded up to whatever alignment the caller wants.

Use the expression assemble_name (stream, name) to output the name itself; before and after that, output the additional assembler syntax for defining the name, and a newline.

This macro controls how the assembler definitions of uninitialized common global variables are output.

— Macro: ASM_OUTPUT_ALIGNED_COMMON (stream, name, size, alignment)

Like ASM_OUTPUT_COMMON except takes the required alignment as a separate, explicit argument. If you define this macro, it is used in place of ASM_OUTPUT_COMMON, and gives you more flexibility in handling the required alignment of the variable. The alignment is specified as the number of bits.

— Macro: ASM_OUTPUT_ALIGNED_DECL_COMMON (stream, decl, name, size, alignment)

Like ASM_OUTPUT_ALIGNED_COMMON except that decl of the variable to be output, if there is one, or NULL_TREE if there is no corresponding variable. If you define this macro, GCC will use it in place of both ASM_OUTPUT_COMMON and ASM_OUTPUT_ALIGNED_COMMON. Define this macro when you need to see the variable's decl in order to chose what to output.

— Macro: ASM_OUTPUT_SHARED_COMMON (stream, name, size, rounded)

If defined, it is similar to ASM_OUTPUT_COMMON, except that it is used when name is shared. If not defined, ASM_OUTPUT_COMMON will be used.

— Macro: ASM_OUTPUT_BSS (stream, decl, name, size, rounded)

A C statement (sans semicolon) to output to the stdio stream stream the assembler definition of uninitialized global decl named name whose size is size bytes. The variable rounded is the size rounded up to whatever alignment the caller wants.

Try to use function asm_output_bss defined in varasm.c when defining this macro. If unable, use the expression assemble_name (stream, name) to output the name itself; before and after that, output the additional assembler syntax for defining the name, and a newline.

This macro controls how the assembler definitions of uninitialized global variables are output. This macro exists to properly support languages like C++ which do not have common data. However, this macro currently is not defined for all targets. If this macro and ASM_OUTPUT_ALIGNED_BSS are not defined then ASM_OUTPUT_COMMON or ASM_OUTPUT_ALIGNED_COMMON or ASM_OUTPUT_ALIGNED_DECL_COMMON is used.

— Macro: ASM_OUTPUT_ALIGNED_BSS (stream, decl, name, size, alignment)

Like ASM_OUTPUT_BSS except takes the required alignment as a separate, explicit argument. If you define this macro, it is used in place of ASM_OUTPUT_BSS, and gives you more flexibility in handling the required alignment of the variable. The alignment is specified as the number of bits.

Try to use function asm_output_aligned_bss defined in file varasm.c when defining this macro.

— Macro: ASM_OUTPUT_SHARED_BSS (stream, decl, name, size, rounded)

If defined, it is similar to ASM_OUTPUT_BSS, except that it is used when name is shared. If not defined, ASM_OUTPUT_BSS will be used.

— Macro: ASM_OUTPUT_LOCAL (stream, name, size, rounded)

A C statement (sans semicolon) to output to the stdio stream stream the assembler definition of a local-common-label named name whose size is size bytes. The variable rounded is the size rounded up to whatever alignment the caller wants.

Use the expression assemble_name (stream, name) to output the name itself; before and after that, output the additional assembler syntax for defining the name, and a newline.

This macro controls how the assembler definitions of uninitialized static variables are output.

— Macro: ASM_OUTPUT_ALIGNED_LOCAL (stream, name, size, alignment)

Like ASM_OUTPUT_LOCAL except takes the required alignment as a separate, explicit argument. If you define this macro, it is used in place of ASM_OUTPUT_LOCAL, and gives you more flexibility in handling the required alignment of the variable. The alignment is specified as the number of bits.

— Macro: ASM_OUTPUT_ALIGNED_DECL_LOCAL (stream, decl, name, size, alignment)

Like ASM_OUTPUT_ALIGNED_DECL except that decl of the variable to be output, if there is one, or NULL_TREE if there is no corresponding variable. If you define this macro, GCC will use it in place of both ASM_OUTPUT_DECL and ASM_OUTPUT_ALIGNED_DECL. Define this macro when you need to see the variable's decl in order to chose what to output.

— Macro: ASM_OUTPUT_SHARED_LOCAL (stream, name, size, rounded)

If defined, it is similar to ASM_OUTPUT_LOCAL, except that it is used when name is shared. If not defined, ASM_OUTPUT_LOCAL will be used.