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diff --git a/share/doc/gccint/Exception-Region-Output.html b/share/doc/gccint/Exception-Region-Output.html new file mode 100644 index 0000000..25b4c5c --- /dev/null +++ b/share/doc/gccint/Exception-Region-Output.html @@ -0,0 +1,251 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1988-2023 Free Software Foundation, Inc. + +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.3 or +any later version published by the Free Software Foundation; with the +Invariant Sections being "Funding Free Software", the Front-Cover +Texts being (a) (see below), and with the Back-Cover Texts being (b) +(see below). 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If not defined, GCC will +provide a default definition if the target supports named sections. +<samp>crtstuff.c</samp> uses this macro to switch to the appropriate section. +</p> +<p>You should define this symbol if your target supports DWARF 2 frame +unwind information and the default definition does not work. +</p></dd></dl> + +<dl> +<dt><a name="index-EH_005fFRAME_005fTHROUGH_005fCOLLECT2"></a>Macro: <strong>EH_FRAME_THROUGH_COLLECT2</strong></dt> +<dd><p>If defined, DWARF 2 frame unwind information will identified by +specially named labels. The collect2 process will locate these +labels and generate code to register the frames. +</p> +<p>This might be necessary, for instance, if the system linker will not +place the eh_frames in-between the sentinals from <samp>crtstuff.c</samp>, +or if the system linker does garbage collection and sections cannot +be marked as not to be collected. +</p></dd></dl> + +<dl> +<dt><a name="index-EH_005fTABLES_005fCAN_005fBE_005fREAD_005fONLY"></a>Macro: <strong>EH_TABLES_CAN_BE_READ_ONLY</strong></dt> +<dd><p>Define this macro to 1 if your target is such that no frame unwind +information encoding used with non-PIC code will ever require a +runtime relocation, but the linker may not support merging read-only +and read-write sections into a single read-write section. +</p></dd></dl> + +<dl> +<dt><a name="index-MASK_005fRETURN_005fADDR"></a>Macro: <strong>MASK_RETURN_ADDR</strong></dt> +<dd><p>An rtx used to mask the return address found via <code>RETURN_ADDR_RTX</code>, so +that it does not contain any extraneous set bits in it. +</p></dd></dl> + +<dl> +<dt><a name="index-DWARF2_005fUNWIND_005fINFO"></a>Macro: <strong>DWARF2_UNWIND_INFO</strong></dt> +<dd><p>Define this macro to 0 if your target supports DWARF 2 frame unwind +information, but it does not yet work with exception handling. +Otherwise, if your target supports this information (if it defines +<code>INCOMING_RETURN_ADDR_RTX</code> and <code>OBJECT_FORMAT_ELF</code>), +GCC will provide a default definition of 1. +</p></dd></dl> + +<dl> +<dt><a name="index-TARGET_005fEXCEPT_005fUNWIND_005fINFO"></a>Common Target Hook: <em>enum unwind_info_type</em> <strong>TARGET_EXCEPT_UNWIND_INFO</strong> <em>(struct gcc_options *<var>opts</var>)</em></dt> +<dd><p>This hook defines the mechanism that will be used for exception handling +by the target. If the target has ABI specified unwind tables, the hook +should return <code>UI_TARGET</code>. If the target is to use the +<code>setjmp</code>/<code>longjmp</code>-based exception handling scheme, the hook +should return <code>UI_SJLJ</code>. If the target supports DWARF 2 frame unwind +information, the hook should return <code>UI_DWARF2</code>. +</p> +<p>A target may, if exceptions are disabled, choose to return <code>UI_NONE</code>. +This may end up simplifying other parts of target-specific code. The +default implementation of this hook never returns <code>UI_NONE</code>. +</p> +<p>Note that the value returned by this hook should be constant. It should +not depend on anything except the command-line switches described by +<var>opts</var>. In particular, the +setting <code>UI_SJLJ</code> must be fixed at compiler start-up as C pre-processor +macros and builtin functions related to exception handling are set up +depending on this setting. +</p> +<p>The default implementation of the hook first honors the +<samp>--enable-sjlj-exceptions</samp> configure option, then +<code>DWARF2_UNWIND_INFO</code>, and finally defaults to <code>UI_SJLJ</code>. If +<code>DWARF2_UNWIND_INFO</code> depends on command-line options, the target +must define this hook so that <var>opts</var> is used correctly. +</p></dd></dl> + +<dl> +<dt><a name="index-TARGET_005fUNWIND_005fTABLES_005fDEFAULT"></a>Common Target Hook: <em>bool</em> <strong>TARGET_UNWIND_TABLES_DEFAULT</strong></dt> +<dd><p>This variable should be set to <code>true</code> if the target ABI requires unwinding +tables even when exceptions are not used. It must not be modified by +command-line option processing. +</p></dd></dl> + +<dl> +<dt><a name="index-DONT_005fUSE_005fBUILTIN_005fSETJMP"></a>Macro: <strong>DONT_USE_BUILTIN_SETJMP</strong></dt> +<dd><p>Define this macro to 1 if the <code>setjmp</code>/<code>longjmp</code>-based scheme +should use the <code>setjmp</code>/<code>longjmp</code> functions from the C library +instead of the <code>__builtin_setjmp</code>/<code>__builtin_longjmp</code> machinery. +</p></dd></dl> + +<dl> +<dt><a name="index-JMP_005fBUF_005fSIZE"></a>Macro: <strong>JMP_BUF_SIZE</strong></dt> +<dd><p>This macro has no effect unless <code>DONT_USE_BUILTIN_SETJMP</code> is also +defined. Define this macro if the default size of <code>jmp_buf</code> buffer +for the <code>setjmp</code>/<code>longjmp</code>-based exception handling mechanism +is not large enough, or if it is much too large. +The default size is <code>FIRST_PSEUDO_REGISTER * sizeof(void *)</code>. +</p></dd></dl> + +<dl> +<dt><a name="index-DWARF_005fCIE_005fDATA_005fALIGNMENT"></a>Macro: <strong>DWARF_CIE_DATA_ALIGNMENT</strong></dt> +<dd><p>This macro need only be defined if the target might save registers in the +function prologue at an offset to the stack pointer that is not aligned to +<code>UNITS_PER_WORD</code>. The definition should be the negative minimum +alignment if <code>STACK_GROWS_DOWNWARD</code> is true, and the positive +minimum alignment otherwise. See <a href="DWARF.html#DWARF">DWARF</a>. Only applicable if +the target supports DWARF 2 frame unwind information. +</p></dd></dl> + +<dl> +<dt><a name="index-TARGET_005fTERMINATE_005fDW2_005fEH_005fFRAME_005fINFO"></a>Target Hook: <em>bool</em> <strong>TARGET_TERMINATE_DW2_EH_FRAME_INFO</strong></dt> +<dd><p>Contains the value true if the target should add a zero word onto the +end of a Dwarf-2 frame info section when used for exception handling. +Default value is false if <code>EH_FRAME_SECTION_NAME</code> is defined, and +true otherwise. +</p></dd></dl> + +<dl> +<dt><a name="index-TARGET_005fDWARF_005fREGISTER_005fSPAN"></a>Target Hook: <em>rtx</em> <strong>TARGET_DWARF_REGISTER_SPAN</strong> <em>(rtx <var>reg</var>)</em></dt> +<dd><p>Given a register, this hook should return a parallel of registers to +represent where to find the register pieces. Define this hook if the +register and its mode are represented in Dwarf in non-contiguous +locations, or if the register should be represented in more than one +register in Dwarf. Otherwise, this hook should return <code>NULL_RTX</code>. +If not defined, the default is to return <code>NULL_RTX</code>. +</p></dd></dl> + +<dl> +<dt><a name="index-TARGET_005fDWARF_005fFRAME_005fREG_005fMODE"></a>Target Hook: <em>machine_mode</em> <strong>TARGET_DWARF_FRAME_REG_MODE</strong> <em>(int <var>regno</var>)</em></dt> +<dd><p>Given a register, this hook should return the mode which the +corresponding Dwarf frame register should have. This is normally +used to return a smaller mode than the raw mode to prevent call +clobbered parts of a register altering the frame register size +</p></dd></dl> + +<dl> +<dt><a name="index-TARGET_005fINIT_005fDWARF_005fREG_005fSIZES_005fEXTRA"></a>Target Hook: <em>void</em> <strong>TARGET_INIT_DWARF_REG_SIZES_EXTRA</strong> <em>(tree <var>address</var>)</em></dt> +<dd><p>If some registers are represented in Dwarf-2 unwind information in +multiple pieces, define this hook to fill in information about the +sizes of those pieces in the table used by the unwinder at runtime. +It will be called by <code>expand_builtin_init_dwarf_reg_sizes</code> after +filling in a single size corresponding to each hard register; +<var>address</var> is the address of the table. +</p></dd></dl> + +<dl> +<dt><a name="index-TARGET_005fASM_005fTTYPE"></a>Target Hook: <em>bool</em> <strong>TARGET_ASM_TTYPE</strong> <em>(rtx <var>sym</var>)</em></dt> +<dd><p>This hook is used to output a reference from a frame unwinding table to +the type_info object identified by <var>sym</var>. It should return <code>true</code> +if the reference was output. Returning <code>false</code> will cause the +reference to be output using the normal Dwarf2 routines. +</p></dd></dl> + +<dl> +<dt><a name="index-TARGET_005fARM_005fEABI_005fUNWINDER"></a>Target Hook: <em>bool</em> <strong>TARGET_ARM_EABI_UNWINDER</strong></dt> +<dd><p>This flag should be set to <code>true</code> on targets that use an ARM EABI +based unwinding library, and <code>false</code> on other targets. This effects +the format of unwinding tables, and how the unwinder in entered after +running a cleanup. The default is <code>false</code>. +</p></dd></dl> + +<hr> +<div class="header"> +<p> +Next: <a href="Alignment-Output.html#Alignment-Output" accesskey="n" rel="next">Alignment Output</a>, Previous: <a href="Dispatch-Tables.html#Dispatch-Tables" accesskey="p" rel="previous">Dispatch Tables</a>, Up: <a href="Assembler-Format.html#Assembler-Format" accesskey="u" rel="up">Assembler Format</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |