From ea03d0d3c32b22aeddfeb139a4a515f7e5961347 Mon Sep 17 00:00:00 2001 From: Yao Qi Date: Wed, 26 Jul 2017 14:39:54 +0100 Subject: [PATCH] Lazily and dynamically create i386-linux target descriptions Instead of using pre-generated target descriptions, this patch changes GDB to lazily and dynamically create target descriptions according to the target hardware capability (xcr0 in i386). This support any combination of target features. Some reg in target description has "regnum" attribute, so its register number is got from the attribute value instead from sequential allocation. when target description is created, it should match the regnum, so this patch adds a new field m_next_regnum to track it, if attribute number is greater than the m_next_regnum, print the code to set register number explicitly. gdb: 2017-07-26 Yao Qi * i386-linux-tdep.c: Don't include features/i386/i386-*linux.c. Include features/i386/32bit-*.c. (i386_linux_read_description): Generate target description if it doesn't exist. (_initialize_i386_linux_tdep): Don't call _initialize_tdesc_i386 functions. * features/i386/32bit-linux.c: Re-generated. * features/i386/32bit-sse.c: Likewise. * target-descriptions.c (print_c_feature::visit): Print code to set register number if needed. (print_c_feature) : New field. --- gdb/ChangeLog | 14 ++++++ gdb/features/i386/32bit-linux.c | 1 + gdb/features/i386/32bit-sse.c | 1 + gdb/i386-linux-tdep.c | 83 +++++++++++++++++++-------------- gdb/target-descriptions.c | 47 +++++++++++++++++++ 5 files changed, 112 insertions(+), 34 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 0f4ec469594..77c74f20f8b 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,17 @@ +2017-07-26 Yao Qi + + * i386-linux-tdep.c: Don't include features/i386/i386-*linux.c. + Include features/i386/32bit-*.c. + (i386_linux_read_description): Generate target description if it + doesn't exist. + (_initialize_i386_linux_tdep): Don't call _initialize_tdesc_i386 + functions. + * features/i386/32bit-linux.c: Re-generated. + * features/i386/32bit-sse.c: Likewise. + * target-descriptions.c (print_c_feature::visit): Print code to + set register number if needed. + (print_c_feature) : New field. + 2017-07-26 Yao Qi * features/Makefile (CFILES): Rename with TDESC_CFILES. diff --git a/gdb/features/i386/32bit-linux.c b/gdb/features/i386/32bit-linux.c index 686a2f114a0..1b50882c6c8 100644 --- a/gdb/features/i386/32bit-linux.c +++ b/gdb/features/i386/32bit-linux.c @@ -9,6 +9,7 @@ create_feature_i386_32bit_linux (struct target_desc *result, long regnum) struct tdesc_feature *feature; feature = tdesc_create_feature (result, "org.gnu.gdb.i386.linux"); + regnum = 41; tdesc_create_reg (feature, "orig_eax", regnum++, 1, NULL, 32, "int"); return regnum; } diff --git a/gdb/features/i386/32bit-sse.c b/gdb/features/i386/32bit-sse.c index 032623e2431..c0684fbdcce 100644 --- a/gdb/features/i386/32bit-sse.c +++ b/gdb/features/i386/32bit-sse.c @@ -61,6 +61,7 @@ create_feature_i386_32bit_sse (struct target_desc *result, long regnum) tdesc_add_flag (type, 12, "PM"); tdesc_add_flag (type, 15, "FZ"); + regnum = 32; tdesc_create_reg (feature, "xmm0", regnum++, 1, NULL, 128, "vec128"); tdesc_create_reg (feature, "xmm1", regnum++, 1, NULL, 128, "vec128"); tdesc_create_reg (feature, "xmm2", regnum++, 1, NULL, 128, "vec128"); diff --git a/gdb/i386-linux-tdep.c b/gdb/i386-linux-tdep.c index e986d6feaa6..4c0f597a689 100644 --- a/gdb/i386-linux-tdep.c +++ b/gdb/i386-linux-tdep.c @@ -45,13 +45,14 @@ #include "record-full.h" #include "linux-record.h" -#include "features/i386/i386-linux.c" -#include "features/i386/i386-mmx-linux.c" -#include "features/i386/i386-mpx-linux.c" -#include "features/i386/i386-avx-mpx-linux.c" -#include "features/i386/i386-avx-linux.c" -#include "features/i386/i386-avx-avx512-linux.c" -#include "features/i386/i386-avx-mpx-avx512-pku-linux.c" + +#include "features/i386/32bit-core.c" +#include "features/i386/32bit-sse.c" +#include "features/i386/32bit-linux.c" +#include "features/i386/32bit-avx.c" +#include "features/i386/32bit-mpx.c" +#include "features/i386/32bit-avx512.c" +#include "features/i386/32bit-pkeys.c" /* Return non-zero, when the register is in the corresponding register group. Put the LINUX_ORIG_EAX register in the system group. */ @@ -683,27 +684,50 @@ i386_linux_core_read_xcr0 (bfd *abfd) const struct target_desc * i386_linux_read_description (uint64_t xcr0) { - switch ((xcr0 & X86_XSTATE_ALL_MASK)) + if (xcr0 == 0) + return NULL; + + static struct target_desc *i386_linux_tdescs \ + [2/*X87*/][2/*SSE*/][2/*AVX*/][2/*MPX*/][2/*AVX512*/][2/*PKRU*/] = {}; + struct target_desc **tdesc; + + tdesc = &i386_linux_tdescs[(xcr0 & X86_XSTATE_X87) ? 1 : 0] + [(xcr0 & X86_XSTATE_SSE) ? 1 : 0] + [(xcr0 & X86_XSTATE_AVX) ? 1 : 0] + [(xcr0 & X86_XSTATE_MPX) ? 1 : 0] + [(xcr0 & X86_XSTATE_AVX512) ? 1 : 0] + [(xcr0 & X86_XSTATE_PKRU) ? 1 : 0]; + + if (*tdesc == NULL) { - case X86_XSTATE_AVX_MPX_AVX512_PKU_MASK: - return tdesc_i386_avx_mpx_avx512_pku_linux; - case X86_XSTATE_AVX_AVX512_MASK: - return tdesc_i386_avx_avx512_linux; - case X86_XSTATE_MPX_MASK: - return tdesc_i386_mpx_linux; - case X86_XSTATE_AVX_MPX_MASK: - return tdesc_i386_avx_mpx_linux; - case X86_XSTATE_AVX_MASK: - return tdesc_i386_avx_linux; - case X86_XSTATE_SSE_MASK: - return tdesc_i386_linux; - case X86_XSTATE_X87_MASK: - return tdesc_i386_mmx_linux; - default: - break; + *tdesc = allocate_target_description (); + set_tdesc_architecture (*tdesc, bfd_scan_arch ("i386")); + set_tdesc_osabi (*tdesc, osabi_from_tdesc_string ("GNU/Linux")); + + long regnum = 0; + + if (xcr0 & X86_XSTATE_X87) + regnum = create_feature_i386_32bit_core (*tdesc, regnum); + + if (xcr0 & X86_XSTATE_SSE) + regnum = create_feature_i386_32bit_sse (*tdesc, regnum); + + regnum = create_feature_i386_32bit_linux (*tdesc, regnum); + + if (xcr0 & X86_XSTATE_AVX) + regnum = create_feature_i386_32bit_avx (*tdesc, regnum); + + if (xcr0 & X86_XSTATE_MPX) + regnum = create_feature_i386_32bit_mpx (*tdesc, regnum); + + if (xcr0 & X86_XSTATE_AVX512) + regnum = create_feature_i386_32bit_avx512 (*tdesc, regnum); + + if (xcr0 & X86_XSTATE_PKRU) + regnum = create_feature_i386_32bit_pkeys (*tdesc, regnum); } - return NULL; + return *tdesc; } /* Get Linux/x86 target description from core dump. */ @@ -1092,13 +1116,4 @@ _initialize_i386_linux_tdep (void) { gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_LINUX, i386_linux_init_abi); - - /* Initialize the Linux target description. */ - initialize_tdesc_i386_linux (); - initialize_tdesc_i386_mmx_linux (); - initialize_tdesc_i386_avx_linux (); - initialize_tdesc_i386_mpx_linux (); - initialize_tdesc_i386_avx_mpx_linux (); - initialize_tdesc_i386_avx_avx512_linux (); - initialize_tdesc_i386_avx_mpx_avx512_pku_linux (); } diff --git a/gdb/target-descriptions.c b/gdb/target-descriptions.c index 5fd07ef0451..333cbd89ab7 100644 --- a/gdb/target-descriptions.c +++ b/gdb/target-descriptions.c @@ -2104,6 +2104,48 @@ public: void visit (const tdesc_reg *reg) override { + /* Most "reg" in XML target descriptions don't have "regnum" + attribute, so the register number is allocated sequentially. + In case that reg has "regnum" attribute, register number + should be set by that explicitly. */ + + if (reg->target_regnum < m_next_regnum) + { + /* The integrity check, it can catch some errors on register + number collision, like this, + + + + + + + + but it also has false negatives. The target description + below is correct, + + + + + + + but it is not a good practice, so still error on this, + and also print the message so that it can be saved in the + generated c file. */ + + printf_unfiltered ("ERROR: \"regnum\" attribute %ld ", + reg->target_regnum); + printf_unfiltered ("is not the largest number (%d).\n", + m_next_regnum); + error (_("\"regnum\" attribute %ld is not the largest number (%d)."), + reg->target_regnum, m_next_regnum); + } + + if (reg->target_regnum > m_next_regnum) + { + printf_unfiltered (" regnum = %ld;\n", reg->target_regnum); + m_next_regnum = reg->target_regnum; + } + printf_unfiltered (" tdesc_create_reg (feature, \"%s\", regnum++, %d, ", reg->name, reg->save_restore); if (reg->group) @@ -2111,8 +2153,13 @@ public: else printf_unfiltered ("NULL, "); printf_unfiltered ("%d, \"%s\");\n", reg->bitsize, reg->type); + + m_next_regnum++; } +private: + /* The register number to use for the next register we see. */ + int m_next_regnum = 0; }; static void -- 2.30.2